Customer Interface for the 3512B Well Fracturing Engine (ADEM II){1408} Caterpillar

Engine:

3512B (S/N: 2AF1-462)

Introduction

This document describes the available functions for the ADEM II Electronic Control Module (ECM) and for the interface with the customer's control. All of the components that are shown in this document are shown in the unpowered state.

A section of reference information is included. This will help the customer identify associated Caterpillar hardware. This will help the customer better understand Caterpillar wiring diagrams. A list of the service literature that is available for this application is also included.

Do not perform any procedure that is outlined in this Special Instruction until the entire Special Instruction has been read and understood.

General Wiring

Illustration 1	g01024452
Basic connections for the power and the controls

Table 1

Customer Connector (40 Pin)
Pin Number	Function	Engine Harness Wire (Identification)
1	Positive Battery Power	150-OR-14
2	Positive Battery Power	150-OR-14
3	Shutdown Notify Relay (Power)	E798-PK
4	Air Shutoff Solenoid (Power)	G971-BR
5	Start Enable Relay (Power)	F701-BR
6	Local Cat Data Link (Negative Power)	892-BR
7	Local Cat Data Link (Positive Power)	893-GN
8	General Alarm Relay (Power)	F700-BU
9	Digital Sensor Return	998-BR
10	Engine Speed Input (Throttle)	F702-GN
11	Oil Temperature Sensor (Signal)	D839-YL
12	Global Cat Data Link (Negative Power)	J982-OR
13	Global Cat Data Link (Positive Power)	J981-WH
14	Load Feedback	J782-GN
15	Oil Temperature Sensor (Return)	200-BK
16	Engine Shutdown (Signal "D")	F719-BR
17	Engine Shutdown (Signal "C")	F715-PU
18	N/A	G721-GY
19	Air Temperature Sensor (Signal)	B472-YL
20	Air Temperature Sensor (Return)	200-BK
21	Torque Limit (Signal) (Fuel Position Multiplier)	G746-WH
22	Ether Relay (Return)	F710-GN
23	start/run/stop Switch "1"	F716-WH
24	start/run/stop Switch "2"	F717-YL
25	Diagnostic Lamp (Power)	F404-RD
26	Prelube Pressure Switch	F718-BU
27	ECM (Key Switch Input)	113-OR
28	Magnetic Speed pickup (Signal)	SPD1-BK
29	Magnetic Speed pickup (Return)	SPD2-CL
30	Magnetic Speed pickup (Shield)	SPDS-SH
31	CAN Data Link (Positive Power)	F711-GN
32	CAN Data Link (Negative Power)	F712-GY
33	CAN Data Link (Shield Ground)	A249-BK
34	Negative Battery Power	229-BK-14
35	Negative Battery Power	229-BK-14
36	Prelube Pump Relay (Power)	F705-PK
37	Prelube Pump Relay (Return)	A268-BK
38	Ether Switch (Manual Override)	F720-PU
39	Engine Protection Switch (Override)	N917-RD
40	Torque Limit (Overspeed Verify Switch)	F706-PU

Illustration 2	g01026018

Illustration 2 shows the details of the power supply for the Electronic Control Module (ECM) and of connections to other components and systems on the vehicle. The connections for the power supply and for the engine throttle control must be made in order to have a engine system that functions.

Empty contact cavities in the customer's harness connector must be plugged in order to keep moisture out.

Refer to the Electrical Schematic from the engine Service Manual for specific wire identifications and functions.

Power Requirements and Grounding Considerations (Pins 1, 2, 27, 34, and 35)

Grounding Considerations

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NOTICE
Improper grounding can cause uncontrolled or unreliable electrical circuit paths and electrical noise. This can also result in damage to the engine bearings or other engine components.

Proper grounding for the vehicle and for the engine electrical systems is necessary for proper performance and for reliability. Improper grounding results in unreliable electrical circuit paths and electrical noise. Uncontrolled electrical currents can damage the following components: main bearings, crankshaft bearing journal surface and aluminum components. Electrical noise that is generated by uncontrolled electrical currents can degrade the control and system performance. The diagnoses and the repair of this type of electrical problem is very difficult.

Power supply

Battery connections to the engine electrical system must not use the chassis (frame) as the return to the battery. All of the DC electrical equipment must have a positive wire and a negative wire that is run directly back to the DC power source. This will ensure a reliable electrical circuit and a continuous electrical circuit.

The power supply to the Caterpillar engine control system is nominally 24 VDC. The power supply can have a range that is between 24 to 30 VDC. Damage to the ECM will result if the voltage exceeds 32 VDC (maximum value). If the voltage is less than 24 VDC, the resulting increased current draw may cause damage to the ECM due to overheating.

Table 2

Engine model	Amp/Watts at Volts	Inrush Current/Duration
3516B	10 A / 250 W	80 A / 3 milli-sec
3512B	10 A / 250 W	80 A / 3 milli-sec
3508B	10 A / 250 W	80 A / 3 milli-sec

-Battery

The engine control system has been designed to operate with the 24 Volt power supply negative connected to the engine block. A large voltage potential between the 24 Volt power supply and the engine block can damage the system's hardware. Electrical noise between the 24 Volt power supply's negative connection and the engine block can adversely affect control system operation.

Capacitance that is uncontrolled will always be present between the following components: main battery system, vehicle control module, engine block, chassis (frame) and engine control system. The impedance of this capacitance that is uncontrolled could be relatively low at the frequencies that are present in these high power electrical transients. If the engine control system's negative power supply is not solidly connected to the engine block these high power electrical transients could impose a high voltage between the engine control system and the engine block. This high voltage could cause damage to the electrical equipment that is mounted on the engine. The sensors are at the greatest risk.

The engine control system's negative connection must be solidly connected to the engine block. This connection confines the electrical current to the area that has been designed to handle it. The wiring harness connections to the 24 Volt engine control system must have a high degree of integrity. The connections must not be susceptible to shorts to the chassis. Grounding circuits through chassis (frame) must be avoided.

The 3500B engine wiring harness does not provide a common power -Battery connection point. The customer is responsible for providing a single connection directly to the engine block. This connection may be a stud that is threaded into an available hole in the engine block. The customer must provide an 8 AWG wire from this single point on the engine block to the -Battery bus bar that connects to the battery. No more than three terminals must be connected to the power -Battery common stud in order to ensure connection's integrity. The use of more than three terminals may cause the retaining nut to loosen as the terminals are deformed under the load that is imposed by the nut. Use a oversize washer that is hardened under the nut in order to minimize deformation of the terminals. Ensure that all paint and all other loose material is removed before installing the terminals. The wire strap that is between the ECM and the engine block must be intact.

Note: Connect a flexible wire strap between the engine and the vehicle(frame) in order to provide a secure electrical path. This is especially important with rubber isolation of the ECM.

Note: The performance of the electrical equipment and of the electronic equipment may be governed by national standards and by international standards. Equipment that is powered directly from the batteries must function properly with a range of input voltages. The equipment must withstand the voltage drops and the overvoltage that occurs during the start-up of the engine. Direct high voltage transients may require incorporation of a transient voltage suppressor across the power input.

Welding on a Vehicle that is Equipped with an Electronic Engine

Before welding on a vehicle that is equipped with an electronically controlled engine, the following precautions should be observed:

• Turn off all power to the engine. Totally disconnect the two multipin connectors on the ECM.

• Disconnect the NEGATIVE battery cable at the battery. If a battery disconnect switch is provided, open the switch.

• Connect the welder's ground cable directly to the engine component that will be welded. Place the clamp as close as possible to the weld in order to reduce the possibility of welding current damage to engine bearings, to the electrical components and to the other engine components. Do not use electrical components, the ECM, or the engine mounted -Battery stud for grounding the welder.

• Protect the wiring from welding debris and from welding spatter.

Switched Power And Unswitched Power +Battery

Illustration 3	g01026432

Powering the electronic control system through dedicated and protected circuits reduces the possibility of degraded electronic control system performance and this minimizes the chance of an engine shutdown due to a short in the electrical system. Additional loads must not be connected between the ECM and circuit protection that is for the ECM.

Power connections to the ECM are made at the customer connector (40 pin) mounted on the engine. Refer to Illustration 3 for the correct pin numbers. The customer must provide 14 AWG wires from the customer connector to the +Battery connection on the bus bar for the battery. Each of the power supply's contacts must have an individual wire back to the +Battery bus bar.

The switched +Battery circuit has a low current switch. This switch is used to shut down the ECM. This feature increases the battery life.

Note: Do not use in-line fuses for circuit protection. Caterpillar recommends using circuit breakers for circuit protection. Install the circuit breakers with other protection devices in a centrally located, dedicated panel. If circuit breakers that reset automatically are used, consideration of the location of the breaker and the breaker's effect on the trip point is critical.

Note: The trip point of some circuit breakers can be significantly reduced below the rated trip point if the breakers are exposed to high temperatures. This can cause intermittent shutdowns that will result in incorrectly replaced electronic components.

Shutdown Notify Relay (Pin 3)

Illustration 4	g01026487

The shut down notify relay must have a set of dry Form-C contacts. The contacts are used by the ECM to notify the load control that the ECM is shutting down the engine, regardless of the reason. The load control can then disengage the equipment or the load control can unload the equipment. The load control can then notify the operator that the engine is shutting down. The shutdown notify relay will be energized after programmed crank terminate speed has been attained. The relay will be de-energized if any of the following occurs:

• The engine is shutdown by the Programmable Monitoring System.

• In the Emergency Stop position, the contacts for the Engine Shutdown are both open.

• The Overspeed Verify Feature has been activated and the Overspeed Verify Feature has caused a shutdown.

• The contacts for the start/run/stop switch are both open in the engine Stop position.

• A normal shutdown has been initiated by an optional Customer Communication Module (CCM).

• An emergency shutdown has been initiated by an optional CCM.

• The speed of the engine drops below programmed Crank Terminate speed.

• A Personality Module Interlock occurs. This condition will prevent the engine from running due to incorrect software that was loaded into ECM.

A control for the prealarm de-energizes the shutdown notify relay by one second prior to the cutoff of the fuel, if the shutdown was caused by the programmable monitoring system. This prealarm will allow the control system to remove the load from the engine before the fuel injection is disabled by minimizing any potentially large inertial loads that may be applied to the coupling and the drive shaft.

The shutdowns for the programmable monitoring system are the following:

• Low oil pressure

• High coolant temperature

• Engine overspeed (no prealarm)

• High crankcase pressure (no prealarm)

• High aftercooler water temperature

The only shutdowns that do not have the one second prealarm are engine overspeed and high crankcase pressure.

Choose a relay with similar electrical properties to the suggested Caterpillar part number. It is important to limit the inductive voltage spike when the relay is de-energized, in order to avoid damage to the ECM. A flyback diode or a resistor that is properly sized should be installed across the relay coil in order to provide maximum protection.

Table 3

Caterpillar Part Number	Description	Quantity
9Y-2921	Relay (24 Volt)	1
7E-8866	Terminal	5

Air Shutoff Solenoid (Pin 4)

Illustration 5	g01026987

This circuit can be arranged in two very different configurations.

• If the load control or the operator determines that there is an engine overspeed or an other emergency event, the circuit for the air shutoff solenoid is activated. The ECM cannot detect this emergency event and the ECM will continue to fuel the engine. Power to this circuit must be interlocked with the engine's emergency shutdown signals in order to ensure that the fuel is cutoff.

• Emergency shutdowns that are initiated by the ECM directly provide 24 Volt power to the air shutoff solenoid. If the load control is monitoring this circuit, the specific event could be annunciated and the appropriate action could be taken. This annunciator would be in addition to the shutdown notify relay.

Start Enable Relay (Pin 5)

The ECM via the start enable relay controls engine cranking. The start enable relay has a set of dry contacts that can be used to directly control the starter motor solenoid or interface with the load control and power.

Electric Starters

The starting sequence will be disabled until engine speed equals 0 rpm and both of the start/run/stop switch contacts go from "Stop" to "Start". After these prerequisites are met and any programmed prelube is completed, the start enable relay is cycled. The cycle of cranking will continue until the engine starts or the maximum number of crank cycles has been reached. The cycle crank time and the maximum number of crank cycles define this cycle. The cycle crank time is the equal amount of time for the on/off cycle of the electric starting motor. The maximum number of crank cycles is the maximum number of times for the on/off cycle of the electric starting motor. If the engine does not start after the maximum number of crank cycles, an overcrank will be logged. The overcrank will remain active until the start/run/stop switch contacts go from "Start" to "Stop". This will also re-enable the cranking sequence. During the crank cycle, if engine speed reaches programmed crank terminate speed, the start enable relay will be de-energized.

Illustration 6	g01027015

Table 4

Crank Duration (seconds)
Setting	Minimum	Default	Maximum
Default Value	0	0	60

Table 5

Maximum Number of Crank Cycles
Setting	Minimum	Default	Maximum
Default Value	0	0	10

Table 6

Crank Terminate Speed (rpm)
Setting	Minimum	Default	Maximum
Value	100	400	500

The start enable relay will be turned off and the crank cycle will be terminated when any of these conditions exist:

• In the emergency stop position, the contacts for the engine shutdown are both open.

• ECM (key switch input) is turned to the "Stop" position.

• Engine speed is greater than crank terminate speed.

• Starter butt engagement or failure to crank

If the engine is running and if both the start/run/stop switch contacts go from "Start" to "Stop" position, the engine will go into the programmed cooldown mode.

Note: The ECM can determine if the starter pinion fails to engage with flywheel ring gear. This condition is known as a starter butt engagement. The ECM forces the cycle to go directly to the next off cycle. The cycle crank time is shortened during a starter butt engagement. The ECM assumes that the entire crank cycle has occurred. A butt engagement is determined when the starter is engaged for three seconds but the ECM senses no engine speed. The ECM will also interpret simultaneous failure of both speed-timing sensors as a butt engagement.

Use a Caterpillar 9X-8124 Magnetic Switch for the start enable relay. It is important to limit the inductive voltage spike when the relay is de-energized in order to avoid damage to the ECM. A flyback diode or a resistor that is properly sized must be installed across the relay coil in order to provide maximum protection. It is important to provide a relay or a combination of a relay and a load resistor that draws a minimum of 0.8 Amp. Failure to follow this requirement will cause the ECM to generate a diagnostic code.

When dual electric starter motors are used, a separate relay for each solenoid is required. Wire the relays in parallel. Refer to Illustration 7.

Illustration 7	g01030242

Air Starters

When an air starter is used the same logic for starting will apply. When an air starter is used there is not a concern about overheating the starting motor due to extended crank cycle times. The crank duration and the maximum number of crank cycles can be set at the maximum values. The value of the crank terminate does not change.

Manual Crank Switch

Illustration 8	g01027021

A crank enable switch can be incorporated into the load control in order to power the start enable relay. The crank enable switch can be operated remotely or the crank enable switch can be operated manually. The use of this feature requires use of other ECM inputs to ensure that the engine is capable of being started. This feature is used when a problem exists with the ECM inputs from the start/run/stop switch or from functions of the engine shutdown. Each of these functions provides dual switch inputs to the ECM. The ECM will detect an incorrect input if the switch inputs become complementary. The ECM will bypass the remaining logic of the start/stop sequencing. When this occurs, the engine must be cranked manually.

Table 7

Caterpillar Part Number	Description	Quantity
8N-0694	Toggle Switch	1
2L-8074	Terminal	2
9X-8124	Magnetic Switch	1
2L-8067	Terminal	2
7E-8866	Terminal	2

Cat Data Link (Pins 6, 7, 12, and 13)

Illustration 9	g01027056

The ECM communicates with the Caterpillar Electronic Technician (Cat ET) and other control modules that use the CAT Data Link. The Cat Data Link also communicates with remote displays such as the engine monitoring system in order to reduce system wiring. The Cat Data Link provides the notification to the operator of engine status and the Cat Data Link allows on board display of diagnostics. Communication with the service tool provides off-board capabilities for service that are beyond the capabilities of the onboard displays. The Cat data link is a proprietary high speed data link that is used on a new engine and vehicle systems for the transfer of data from module to module.

The ECM supports two Cat Data Links that are defined as "LOCAL or PRIMARY" and "GLOBAL or SECONDARY". Each data link serves a different function and care must be taken in order to connect the correct data link.

The local Cat Data Link is used primarily for communication with the Cat ET and the remote displays such as the engine monitoring system and the programmable relay control module.

The Global Cat data link is used with the CCM in order to communicate with two to eight engines. Use Cat ET to verify that only one engine is on the data link. Further information can be found in publication Operation and Maintenance Manual, SEBU6874.

Table 8

Identifier for the Global Cat Data Link
Setting	Minimum	Default	Maximum
Value for Adjustment	Control 1	Control 1	Control 8

To ensure reliable communications of data, use the 123-2376 Electrical Cable in order to connect the Cat Data Link. This cable consists of a twisted pair of 16 AWG wires without shield. Locate any terminal connections in order to minimize the overall cable length. The maximum allowable total length of data link cable is 30 m (100 ft).

General Alarm Relay (Pin 8)

Illustration 10	g01027059

The General Alarm Relay (GAR) must have a set of dry Form-C contacts. The contacts can be used in the logic of the vehicle and of engine control. The ECM will energize the GAR for any event or for an active/logged diagnostic. This will provide an additional output signal for any of the following conditions: warning, derate, shutdown and active/logged diagnostic code. These conditions do not necessarily indicate that the engine is shutting down. The GAR will not be activated for an altitude derate.

Choose a relay with similar electrical properties to the suggested Caterpillar part number. It is important to limit the inductive voltage spike when the relay is de-energized in order to avoid damage to the ECM. A flyback diode or a resistor that is properly sized must be installed across the relay coil in order to provide maximum protection.

Table 9

Caterpillar Part Number	Description	Quantity
9Y-2921	Relay	1
7E-8866	Terminal	5

Digital Sensor Return (Pin 9)

Illustration 11	g01027148

The digital sensor return provides an external negative power return to the ECM that is used in a number of functions that are related to controls. This return must not be used for any other purpose. This return must never be used to provide a negative power path for other equipment of any description.

Due to the variety of possible connections to the single pin for the customer connector, it is necessary to provide a suitable connection point for all the functions. This connector is referred to as the "Digital Reference Common Terminal" in this document.

Engine Speed Input (Pin 10)

Illustration 12	g01027225

A signal for the desired engine speed (throttle position) is required by the engine speed governor. The signal can be provided in a number of ways. Use a module that has inputs 0 to 5 Volt or 4 to 20 mA. A throttle position sensor can be used to provide the electronic signal. Vehicles that use a microprocessor for vehicle controls may elect to provide the required electronic signal directly. Refer to ""Requirements for the Throttle Signal" ".

Illustration 13	g01027150

Using an electronic signal eliminates the mechanical throttle linkage and manual adjustments. This signal is pulse width modulated. After the signal is read and the signal is filtered the signal is then made available to the software. The software uses the signal to compute the desired engine speed. The frequency of this signal is nominally 500 Hz. Illustration 13 shows that a pulse width of 5 to 10 percent will be low idle. A pulse width of 90 to 95 percent will be high idle.

A duty cycle that is less than 5 percent or a duty cycle that is greater than 95 percent will cause the ECM to generate a diagnostic code. This will cause desired speed to be low idle. Cat ET will display "Desired Engine Speed" with no ramp rate for acceleration or for deceleration.

Oil Temperature Sensor (Pins 11 and 15)

The oil temperature sensor is installed in an engine oil gallery after the oil cooler and wired to the customer connector (40 pin). This sensor is not used by the ECM but the sensor is available for the customer. Refer to ""Temperature Sensors for the Engine Oil and the Air Inlet Manifold" " for additional information.

Load Feedback Signal (Pin 14)

Illustration 14	g01027254

A load feedback signal can be used for installations that use the load control to monitor the available engine power in order to take advantage of the engine's full operating range. The load feedback signal that is produced by the ECM is the ratio of the amount of engine power output versus the total actual capability of the engine. The load feedback signal is a comparison of the current setting of the fuel rack versus the maximum setting of the fuel rack under the current operating conditions of the engine. Both of values of the fuel rack are instantaneous and the load feedback signal is also instantaneous. This signal varies between 0 and 200 milliamperes:

Load feedback (in milliamps) = [Actual Rack / Maximum Rack] x 200

Illustration 15	g01027255

There are three major benefits from using the load feedback signal.

• In the event of an engine derate, the maximum fuel rack is used in order to compute the load feedback signal. This includes all of the active derates. This means that a derate event is completely invisible to the load control system. The load control does not need to take any special action in order to accommodate any derate event.

• Control of an engine with a different power setting is simplified because the load feedback signal is standardized by using the maximum fuel rack of the engine. This value may vary slightly from an engine to an engine, but the load control system is transparent to any difference in the engines. The load feedback signal is a ratio and the load feedback signal does not relate to a specific power level. The load control does not need to take any special action in order to accommodate different ratings. The use of the load feedback signal for the load control system's strategy for managing the engine's load will be different from traditional strategies.

• Correctly managing the load that is applied to the engine will avoid damage to the engine. This will also increase performance of the engine. The main functions of a strategy for the load management helps to avoid lugging of the engine during changes of load and of speed. The strategy also helps operate the engine under steady state conditions that are compatible with the required performance.

Illustration 16	g01027257

Illustration 16 shows two performance curves:

• Steady state fuel consumption

• Transient performance

In both cases, if the load control system follows these maps the engine will be operated under steady state conditions at a load feedback signal less than 100 percent. This will avoid a lug condition. The engine will have a margin of fuel in order to accelerate whenever the throttle is increased. This margin will be greater for the transient performance because the engine will accelerate at a higher rate. This margin is reduced to zero as the engine speed approaches the rated engine speed.

Start/Stop Control (Pins 16, 17, 23, 24, and 27)

Illustration 17	g01027276

There are three sets of input signals to the ECM that are used for the start/stop control of the engine.

• Emergency stop switch

• Start/Run/Stop switch

• Key switch

The signal for the engine shutdown uses input "C" and input "D" that are connected to the emergency stop switch. The emergency stop switch has one contact and two control circuits into the ECM. These two inputs must be at the same level of logic. When the switch is closed the control circuits are connected to negative control power. This circuit contains two switches that are wired in series. The switches indicate if the flaps for the air shutoff have closed. When the two air shutoffs are in the normally open position each of the flaps cause a switch to remain closed. This maintains the integrity of the circuit. If one or both of the flaps close the control circuit will be opened and this will cause a complete emergency shutdown. The redundant signals indicate to the ECM if there is a problem in the wiring. The opening of the emergency stop switch causes the ECM to energize the air shutoff solenoid and the ECM sets the fuel injection delivery to zero. This sequence of events will occur if the engine is running or the engine is not running. Once the air shutoff solenoid is activated, the ECM will de-energize the solenoid after five seconds. This will prevent the solenoid from being overheated. The air shutoff solenoid or the air shutoff relay will also be de-energized whenever the emergency stop switch is closed. The logic for the emergency stop will be latched until power is disconnected from the ECM by using the key switch (pin 27) or by disconnecting the main power supply on pins 1 and 2.

The different combinations of these two inputs are listed below:

• If both inputs are open, the emergency stop switch is activated or an air shutoff switch is activated.

• If both inputs are connected to negative control power, the emergency stop switch is not activated and the air shutoff switch is not activated.

• The ECM will detect an incorrect input if the switch inputs become complementary. The ECM will bypass the remaining logic of the start/stop sequencing. When this occurs, the engine must be cranked manually. The engine must be shutdown by opening the emergency stop switch or by disconnecting the main power supply to the ECM on pins 1 and 2. A diagnostic code of this problem will be logged. The problem will also be active until the ECM is powered down by disconnecting the main power supply on pins 1 and 2. The ECM monitors both of the inputs. If both inputs go open an emergency stop sequence will be initiated.

Note: If the inputs from the emergency stop switch are complementary, The ECM will allow 0.25 seconds for the switches to return to the same state. The switches may not connect to both of the contacts at the same time. After 0.25 seconds, the complementary inputs are activated. Any number of additional switches or switch pairs can be installed on the vehicle in order to meet operating requirements. Each additional set of contacts must be arranged in series in order to maintain the integrity of the circuit and the function of the circuit.

The Start/Run/Stop switch (signal) for the engine is part of an integrated system for engine operation. This switch (signal) will provide an input for the following functions: prelubing the engine, cranking the engine, running the engine in normal operation, running the engine in cooldown mode and stopping the engine under normal situations The ECM controls engine cranking via the start enable relay.

The Start/Run/Stop switch (signal) has two contacts (inputs 1 and 2), and two control circuits into the ECM. The contacts are normally closed. The control circuits are wired in parallel. These two inputs must be at the same level of logic. When the switch is closed the control circuits are connected to negative control power. The redundant signals indicate to the ECM if there is a problem in the wiring.

The different combinations of these two inputs are listed below:

• If both of the inputs are open the start/run/stop switch is in the Stop position.

• If both inputs are connected to the negative control power the start/run/stop switch is in the Run position.

• The ECM will detect an incorrect input if the switch inputs become complementary. The ECM will bypass the remaining logic of the start/stop sequencing. When this occurs, the engine must be cranked manually. The engine must be shutdown by opening the emergency stop switch or by disconnecting the main power supply to the ECM on pins 1 and 2. A diagnostic annunciating of this problem will be logged. The problem will also be active until the ECM is powered down by disconnecting the main power supply on pins 1 and 2.

• When the engine is running and the switch inputs become complementary, the engine will continue to run. A diagnostic code will be generated and the code will be logged. The problem will be active until the ECM is powered down. The engine can be shutdown by using the start/run/stop switch so long as the broken circuit is not shorted to ground. The engine can be shutdown by removing power from the ECM by disconnecting the main power supply on pins 1 and 2.

Note: If the inputs from the start/run/stop switch are complementary, The ECM will allow 0.25 seconds for the switches to return to the same state. The switches may not connect to both of the contacts at the same time. After 0.25 seconds, the complementary inputs are activated. Any number of additional switches or switch pairs can be installed on the vehicle in order to meet operating requirements. Each additional set of contacts must be arranged in series in order to maintain the integrity of the circuit and the function of the circuit.

The key switch allows the ECM to be shut down via a low current switch that will increase the life of the battery. The key switch allows an engine shutdown without entering the cooldown mode. When the key switch is opened and both start/run/stop switch's contacts are also open, the ECM will immediately disable the fuel injection and the ECM will shut down the engine without going through any previously programmed cooldown mode. If the key switch is opened with engine speed less than 200 rpm, the ECM will cause the engine to shutdown. If the key switch is opened with the engine speed that is greater than 200 rpm and the contacts for the Start/Run/Stop switch are closed, the ECM will take no action.

Air Temperature Sensor (Pins 19 and 20)

The air temperature sensor is installed in the engine inlet manifold after the aftercooler and wired to the customer connector. This sensor is not used by the ECM. This sensor is available for use by the customer. Refer to ""Temperature Sensors for the Engine Oil and the Air Inlet Manifold" " for additional information.

Torque Limit for the Fuel Position Multiplier (Pin 21)

Illustration 18	g01027287

Some applications may benefit from this feature by allowing the load control system to adjust the fuel injector rack in order to compensate for an overload condition. When the output torque of the engine is reduced, the engine speed remains constant. This feature can be enabled or disabled through a configuration parameter that is programmed with the Cat ET.

Illustration 19	g01027288

The input from the fuel position multiplier is read by the ECM. The input signal is Pulse Width Modulated (PWM). After the signal is read and the signal is filtered, the signal is then made available to the software. The software uses the signal in order to compute a value between 0 and 1 for the fuel position multiplier. The frequency of this signal is 500 Hertz. Illustration 19 shows that a pulse width of 5 to 10 percent will cause the multiplier to be 1. A pulse width of 90 to 95 percent will cause the multiplier to be 0.

A pulse width that is less than 5 percent will cause the ECM to generate a diagnostic code. This will cause the multiplier to be 1. A pulse width that is greater than 95 percent is considered to be a fault. This will cause the multiplier to be 1.

Table 10

Fuel Position Multiplier
Setting	Minimum	Default	Maximum
Value for Adjustment	Disabled	Enabled	Enabled

In addition to the parameter for the "Fuel Position Multiplier", there is a parameter for the Cat Data Link for the "Fuel Position Multiplier Duty Cycle" for the service tool's calibration screen. This is used in the calibration of the input signal. The diagnostic range is between 0 to 5 percent and 95 to 100 percent duty cycle.

When this feature is disabled, all diagnostics and all functionality will be disabled and the ECM will not respond to the parameter for the "Fuel Position Multiplier" and the parameter for "Fuel Position Multiplier Duty Cycle".

Ether Injection Control (Pins 22 and 38)

Illustration 20	g01027395

An optional system can be used to inject ether into the air intake manifold of the engine. This will improve engine starting. this will also reduce peak cylinder pressures, and white smoke. The ether injection control is designed for continuous injection of ether. The ECM controls ether injection automatically when engine speed is present and jacket water coolant temperature is below the trip point. An additional switch input (momentary contact) is provided to the ECM in order to allow the operator to manually inject additional ether whenever the jacket water coolant temperature is below the trip point. Programming the parameter for the ether control to "Disabled" will disable the ether injection, the diagnostics, the manual override, and any parameters for the ether control.

Table 11

Ether Control
Setting	Minimum	Default	Maximum
Value for Adjustment	Disabled	Disabled	Enabled

The ECM performs automatic ether injection when the engine speed is between the minimum and maximum points and the temperature of the jacket water is below the set point. Manual injection occurs whenever the ether switch is depressed and temperature of the jacket water is below the set point. The duration of ether injection varies with temperature of the jacket water and between points of the two temperatures that are shown in Illustration 21.

Illustration 21	g01027396

The ECM uses a single 300 mA driver to control ether injection. This driver controls a relay, which provides a signal to a control unit that provides one shot of ether. The activation of this control will provide the needed pull-in current for two seconds. When the control turns off and the relay remains energized, the current will be reduced to a hold-in current by placing a 20 Ohm resistor in series with the ether solenoid(s). This will result in a 1 Amp hold-in current (24 VDC system). One or two of the ether solenoids can be driven in parallel depending on the engine's ether needs.

During system troubleshooting, an override is available to actuate the ether injection system. By using Cat ET, ether injection can be started and stopped. Once ether injection is initiated, the ECM activates the 300 mA driver in order to provide pull-in and hold-in current. The ether solenoid will remain energized until either engine speed is detected or Cat ET is used to terminate injection.

Choose a relay with similar electrical properties to the suggested Caterpillar part number. It is important to limit the inductive voltage spike when the relay is de-energized in order to avoid damage to the ECM. A flyback diode or a resistor that is properly sized must be installed across the relay coil in order to provide maximum protection.

Table 12

Caterpillar Part Number	Description	Quantity
PA-3777	Ether aid	1
2L-8074	Terminal	2
7N-9738	Receptacle Housing	1
7N-7779	Connector Socket	1
7N-7780	Connector Pin	1
7E-8866	Terminal	4

Diagnostic Lamp Output (Pin 25)

Illustration 22	g01027423

The installation of a diagnostic lamp is recommended in order to alert the operator of an active diagnostic code or of an event code that is detected by the ECM. A sequence of flashes from the lamp represents the system diagnostic message (flash code). The timing for the sequence of the lamp flash.

The first sequence of flashes ... "ON" for 0.5 seconds "OFF" for 0.3 seconds (first digit of the flash code)

Pause between the first digit and the second digit ... "OFF" for 1 second

The second sequence of flashes ... "ON" for 0.5 second "OFF" for 0.3 second (second digit of the flash code)

Pause between multiple codes ... "OFF" for 3 seconds

Pause after displaying all codes ... OFF for 4 seconds

The entire sequence of flash codes will be repeated until the codes are cleared or the condition is corrected. The flash codes are used only to indicate the nature of a diagnostic condition. Do not use flash codes to perform detailed troubleshooting. Refer to Troubleshooting, SENR5079 for additional information.

The ECM provides a high side driver for the lamp circuit that is sized for a maximum current load of 300 mA. The ECM does not provide diagnostic codes for this circuit, for a burnt out bulb or for an open circuit. The driver provides an electrical path to positive power in order to activate the lamp. While circuit protection is recommended for the driver for the lamp, Caterpillar does not require dedicated circuit protection.

Table 13

Caterpillar Part Number	Description	Quantity
9D-3127	Indicator Light Base	1
7N-5876	Lamp	1
9D-9161	Green Lens (1)	1
9D-2867	Amber Lens (1)	1
9D-2868	Red Lens (1)	1
7E-8866	Terminal	2

( 1 )

OEM or customer option

Prelube System (Pins 26, 36, and 37)

Illustration 23	g01027445

The ECM provides the ability to automatically prelube the engine before cranking is initiated. Prelubing the engine will increase the life of certain engine components such as the crankshaft bearings and the valve train components. This benefit is especially critical after an oil change because a film of oil is not present in order to support the loads that are associated with the start-up of the engine. This is also true if the engine has not been operated for long periods of time. When a prelube system is installed on the engine, the ECM will automatically start the prelube cycle and the ECM will crank the engine. This option can be configured to operate an electric pump or an air driven pump.

The contacts of the Start/Run/Stop circuit (inputs 1 and 2) and the contacts of the engine shutdown signal (inputs C and D) are closed when the control circuits are connected to negative power. This will occur when the key switch is closed in order to connect positive power to the ECM and the engine control will initiate the prelube cycle for the engine. Engine speed must equal zero, before the prelube will begin. The duration of the operating time for the pump is programmable by the customer.

The following states of the prelube are possible:

OFF - This condition is valid when an engine shutdown is active.

ON - This condition is valid when an engine shutdown is not active and the control circuits are correctly configured.

DISABLED - This condition is valid when the engine prelube duration is programmed to 0.

COMPLETED - This condition is valid when the engine prelube duration is reached or when the prelube pressure switch closes.

Table 14

Engine Prelube Duration (seconds)
Setting	Minimum	Default	Maximum
Value for Adjustment	0	0	210

The prelube cycle can be bypassed in special circumstances. When the engine must be cranked immediately without waiting for the prelube cycle to be completed, a normally open momentary switch can be connected in parallel with the prelube pressure switch. When the switch is closed the completed circuit will indicate to the ECM that there is oil pressure. Cranking of the engine can begin.

The prelube function will be terminated when one of the following conditions occur:

• The prelube pressure switch closes.

• Engine prelube duration reaches the programmed time.

• The manual prelube override switch is closed.

The ECM is not capable of driving the pump motor directly. The circuit for the pump motor must be designed to include a slave relay with suitable contact rating that are connected directly to the battery. Choose a master relay with similar electrical properties to Caterpillar part number 9Y-2921 Relay . It is important to limit the inductive voltage spike when the relay is de-energized in order to avoid damage to the ECM. A flyback diode or a resistor that is properly sized must be installed across the relay coil in order to provide maximum protection.

Table 15

Caterpillar Part Number	Description	Quantity
3E-6477	Relay As	1
9X-8124	Magnetic Switch	1
2L-8067	Terminal	2
4D-1836	Toggle Switch	1
2L-8074	Terminal	1
7E-8866	Terminal	6
150-1240	Pressure Switch	1
155-2270	Connecting Plug Kit	1
8T-8730	Connector Socket	2

Magnetic Speed Sensor (Pins 28, 29, and 30)

Illustration 24	g01027466

The engine is equipped with a speed sensor for the purpose of customer's control. The speed sensor assembly is commonly referred to as a passive magnetic speed sensor or as a magnetic pickup. The output voltage of the sensor is inversely proportional to the square of the clearance between the speed sensor and the flywheel ring gear's teeth with a value of 29 ± 6 Volts. The vehicle control's input impedance must be maximized in order to avoid a reduction in sensor output and the impedance must not be less than 18 kOhm. The sensor is mounted in the engine flywheel housing. The signal from the sensor is generated by rotation of the flywheel ring gear. The standard flywheel is a SAE "0" or 18 inch size, which has 151 teeth.

The pair of wires for the sensor is shielded with the shield that comes through the customer connection on a dedicated terminal. The shield must be grounded at the control end of the wiring.

SAE J1939 CAN Data Link (Pins 31, 32, and 33)

Illustration 25	g01027476

The ECM also has the ability to communicate via a broadcast only SAE J1935 CAN data link. In addition to monitoring a variety of engine parameters, the CAN data link allows communication with compatible aftermarket remote controls and the CAN data link displays using a industry standard architecture. Using a data link reduces system wiring, but careful attention to wiring details is required.

The following table shows parameters that are broadcast and transmission rates.

Table 16

Parameter	PGN	Bytes	Resolution (Offset)	Byte Order In Message	Transmission Rate
% Load	61443	1	1 %/bit (0%)	3	50 ms
Oil Pressure	65263	1	4 kPa/bit, (0 kPa)	4	500 ms
Battery Voltage	65271	2	0.05 V/bit (0 V)	5, 6, 7, 8	1 s
Boost Pressure	65270	1	2 kPa/bit (0 kPa)	2	500 ms
Coolant Temperature	65262	1	1 degC/bit (-40 deg C)	1	1 s
Fuel Pressure	65263	1	4 kPa/bit (0 kPa)	1	500 ms
Fuel Temperature	65262	1	1 degC/bit (-40 degC)	1	1 s
Fuel Rate	65266	2	0.05 L/h/bit (0 L/h)	1, 2	100 ms
Engine Speed	61444	2	0.125 rpm/bit (0 rpm)	4, 5	15 ms
Engine Hours	65253	4	0.05 h/bit (0 h)	1, 2, 3, 4	50 ms
Throttle Position	61443	1	0.4 %/bit (0%)	2	50 ms
Atmospheric Pressure	65269	1	0.5 kPa/bit (0 kPa)	1	1 s

SAE standard J1939 includes a description of the physical network that includes specific details on requirements for the system wiring. The cable shield is terminated at the ECM through a capacitor that is in series and a resistor to ground. Per the SAE standard, each node on the bus for data must provide a ground that is shielded. The connection must be made by a capacitor in series and a resistor to the best ground connection within the node. Additionally, the shield must be terminated by a conductor and directly grounded at only one point. The engine wiring harness does not provide this single point of grounding. Refer to the SAE standard for additional details. Refer to ""Configuration of the circuit for the SAE J1935 CAN Data Link" "for a typical circuit for the data link and for available options for the hardware.

Override Switch (Pin 39)

Illustration 26	g01027493

The override switch provides a mechanism in order to override derates and engine shutdown events that are caused by the programmable monitoring system. The switch is used for emergency situations when a loss of engine power would be hazardous. This switch will override the ECM. If a derate is overridden, a "Derate Overridden" event will be logged. If a shutdown is overridden, a "Shutdown Overridden" event will be logged.

Usually when a shutdown occurs there will not be a specific enough warning after the event. After an engine shutdown has occurred using this switch will allow the engine to restart. This will allow the engine to operate without shutdown protection.

Table 17

Caterpillar Part Number	Description	Quantity
4D-1836	Toggle Switch	1
2L-8074	Terminal	2

Torque Limit Control and Overspeed Verify Switch (Pin 40)

This input has a dual function to the ECM. When the switch is closed the ECM uses the input in order to satisfy a torque limit that was programmed by the customer. The second function of this input to the ECM is during the testing of the shutdown system. The input functions as an overspeed verify feature. The specific feature is selected and activated by using Cat ET.

Torque Limit Control

It is possible to program the maximum delivered engine torque to a lower value. The maximum torque value of the engine occurs at peak torque speed, which is approximately 60 to 70 percent of rated speed. The minimum value for the torque limit that can be programmed will be dependent on the engine's map for the torque limit. The control software for engines that are compliant for emissions will limit the value for the minimum torque to the torque that is produced at rated speed. For engines that do not require a certification for emissions, the value can be set to zero for the minimum torque.

By using Cat ET, the maximum torque value can be input with a resolution of 1 N·m. Programmed values that are greater than the maximum value for the torque limit will default to the maximum value for the torque limit and this value will be displayed on Cat ET. Programmed values which are less than the minimum torque value will default to the minimum torque value and this value will be displayed on Cat ET.

Table 18

Torque Limit (N·m)
Setting	Minimum	Default	Maximum
Value for Adjustment	Map	Map	Map

Overspeed Verify Switch

Illustration 27	g01027511

During periodic testing of the engine's controls for the overspeed shutdown, actual operation of the engine and of driven equipment at the overspeed condition is highly undesirable. When this input is activated this input provides the ability to test the strategy for the engine overspeed. This eliminates the need to operate the equipment in an overspeed condition. The value for engine overspeed is set to 75 percent of the programmed set point.Cat ET is used in order to select the "engine overspeed verify" feature.

During the test, when the engine speed reaches the modified set point, the normal strategy for engine overspeed is initiated there by testing the entire shutoff system. This test simulates an actual overspeed event. The fuel will be disabled and the air shutoff solenoid will be energized. The power to the ECM must be shut off for three seconds in order to clear the condition and the flaps for the air shutoff must be manually opened.

Note: This strategy is disabled if the engine monitoring system's function for overspeed shutdown is programmed to "OFF".

Table 19

Caterpillar Part Number	Description	Quantity
4D-1836	Toggle Switch	1
2L-8074	Terminal	2

Additional Information

Requirements for the Throttle Signal

Caterpillar engines with electronic controls require an electrical throttle signal to the ECM. The throttle signal must be PWM with a square wave signal. In order to control the engine speed, the ECM processes the throttle signal and the engine speed/timing signal. The engine speed is controlled by the ECM, based on the percent duty cycle of the PWM signal. When an existing throttle position sensor (TPS) that is available from Caterpillar cannot be used then an alternative source of this signal must be found. The following information describes the requirements for the throttle signal.

• Open collector with a sinking PWM output with pull up resistor

• Low sensor stop 7.5 ± 2.5 percent

• High sensor stop 92.5 ± 2.5 percent

• Output frequency of 300 Hz minimum, 500 Hz nominal, 700 Hz maximum

• Output voltage (DC) high of 5.5 VDC minimum, 5.7 VDC nominal, 5.9 VDC maximum

• With output voltage high, must sustain 4.0 V minimum with a source current no less than 0.2 mA

• With output voltage low, must sustain 0.25 V maximum with 1.0 mA sink current, and 0.70 V maximum with 10.0 mA sink current

• Output linearity ± 2.5 percent duty versus throttle position

Illustration 28	g01030282

Illustration 29	g01030285

To ensure that the engine speed will reach both the minimum and the maximum values, an area of deadband must be included at each end of the curve for the duty cycle.

Illustration 30	g01030286

There is a deadband of five percent at both ends of the duty cycle range. A value between 5 percent and 10 percent ensures low idle and a value between 90 percent and 95 percent ensures high idle.

There is also an area at both ends of the duty cycle range, between 0 and 5 percent and between 95 percent and 100 percent that will cause a drop in the engine speed to low idle and the ECM will generate a diagnostic code.

Testing the Throttle Control

Note: This section concerns requirements for throttle controls that are not supplied by Caterpillar.

Show/hide table

NOTICE
Caterpillar is not liable for problems and/or for equipment damage that results from installation of a PWM converter that is not supplied by Caterpillar. Compatibility of the signal, transient operation, noise, and protection from faults is the responsibility of the customer or of the supplier.

The ECM must be tested in order to verify proper PWM input for a customer supplied throttle control. Caterpillar must be notified prior to the use of a customer supplied PWM converter. The ECM software must match the PWM duty cycle.

Assembly of the test equipment, performance of the test, and evaluation of the results must be performed by technicians that are experienced. The following items are required for the testing:

• Cat ET

• Digital oscilloscope that has been calibrated for accuracy which can display the duty cycle and frequency

• Electrical circuit that is shown in Illustration 31

• Voltage supply that is capable of sinking or of sourcing up to 5 mA of current

Conduct the test in the actual configuration of the intended installation. Use data from Cat ET to verify the correct operation of the ECM. Verify that the ECM does not find a fault with the range of the PWM duty cycle. Verify that the throttle command that is displayed on Cat ET can vary between 0 and 100 percent.

If any problems occur with the use of a customer supplied PWM converter, check the problem with Cat ET first. This will help avoid unnecessary charges for Caterpillar service when problems are isolated to customer supplied components.

Optional Configurations for the PWM converter

There are two options for the PWM converter circuit:

• An active output for sourcing and for sinking of the current

• An output that only has a pull-down capability

The option of sourcing and sinking current is commonly used in throttle position sensors that are supplied by Caterpillar. This is the more difficult configuration, but this option can provide improvements in rise time and in fall time. This is especially the case for long runs of cable between the PWM converter and the ECM.

The pull-down option is easier to use. This option uses optical isolators with either a metal oxide semiconductor field effect transistor or a bipolar transistor. In this configuration, two wires are connected to the -Battery of the ECM. The throttle input signal is connected to the two output terminals of the optical isolator. In this configuration, the ECM provides appropriate pull-up voltage and resistance.

For installations with multiple electronic control modules, a separate drive circuit is recommended for each ECM. This will minimize the ground loop and AC/DC differences between the electronic control modules. This also limits the effects of sneak paths when one or more electronic control modules are powered OFF.

In all cases, appropriate measures must be taken in order to protect the output of the PWM converter from the following effects: improper connections, electrostatic discharge, electromagnetic discharge, electromagnetic coupling and load dump.

Specifications for the PWM converter

The PWM converter must meet the following specifications:

The PWM converter must be able to withstand the following maximum continuous voltage. ... 32 V

Minimum frequency ... 300 Hz

Nominal frequency ... 500 Hz

Maximum frequency ... 700 Hz

Minimum rise time at terminals with no loads and at voltage of 10 to 90 percent ... 15 microseconds

Minimum fall time at terminals with no loads and at voltage of 10 to 90 percent ... 15 microseconds

The maximum low output voltage with a current flow of 5 mA from each ECM ... 0.7V

For the option of sourcing and sinking current, the PWM converter must have the following characteristics in order to drive each throttle input of each ECM:

Range of high output voltage with unloaded terminals ... 4.5 to 32 V

For unloaded PWM output voltage that is greater than 13 V, the following voltage is the range of high output voltage with sourcing of 2.0 mA. ... 4.5 to 26 V

For unloaded PWM output voltage that is less than 13 V, the following voltage is the range of high output voltage with sinking of 1.5 mA. ... 4.5 to 26 V

For the optical isolator, the following specifications are needed to drive each ECM throttle input. The specifications must be valid throughout the range of operating temperatures for the device.

Maximum current leakage with an input of 13 VDC and the isolator in an OFF state ... 0.2 mA

Minimum continuous pull-down capability ... 5 mA

Requirements for the Wiring

The gauge of the wire limits the distance between the PWM converter and the ECM. The selection of wire will also affect the amount of noise that can distort the throttle signal. This includes the wire gauge, the shielding, the length, the capacitive loading, and the coupling between wires.

For all testing of a PWM converter, select wiring in order to represent the intended installation. To obtain valid results, conduct the test under conditions that simulate the intended installation.

Install the wiring according to the schematic in Illustration 31. Connect the output from the PWM converter to the positive lead and negative lead of the "Input for Test". Measure the characteristics of the signal at the positive lead and negative lead of the "Output Check Level".

Illustration 31	g01030307

For configurations that use more than one ECM, provide multiple loads of the circuit that is shown in Illustration 31 in order to simulate the intended installation.

If the use of multiple engines are planned for the throttle control, verify the operation of the electronic control modules. Verify the throttle control when any one module is not operating or when several modules are not operating. For testing, reduce the positive power supply for an ECM to 0 volts while you verify proper operation of the remaining signal outputs. Perform this test with different combinations of electronic control modules.

Duty Cycle and Jitter

Duty cycle is computed by the ratio of the time between 4.5 V on a rise and the next 0.8 V on a fall and on time between consecutive 4.5 V rises or 0.8 V falls. Refer to Illustration 32.

Using different voltages for timing calculations is not necessary when the rise time or the fall time is 1 microsecond or less than 1 microsecond.

The calculation in Table 20 and the waveform in Illustration 32 define the duty cycle.

Table 20

Calculation for the Duty Cycle

Duty Cycle=(Time B-Time A)/(Time C-Time A)

Illustration 32	g01030304

Jitter is determined by the greater value of two calculations.

The first calculation is the absolute value of the difference between the following two waveforms that are observed in 20 consecutive cycles that are measured at intervals of 2.0 V:

• The average period of the waveform

• The period of the waveform that has the most variation from the average period of the waveform

The second calculation is the absolute value of the difference between the following two duty cycles that are observed in 20 consecutive cycles. The result is then multiplied by the average period of the waveform over the 20 consecutive cycles.

• The average duty cycle

• The duty cycle that has the most variation from the average duty cycle

Settings for the PWM converter

For low idle, set the nominal PWM duty cycle near 7.5 percent.

For high idle, set the nominal PWM duty cycle near 92.5 percent.

In order to prevent the ECM from sensing faults, the PWM converter must not generate a duty cycle less than 5 percent or more than 95 percent. The ECM will not use the signal from the converter when the duty cycle is less than 5 percent or the duty cycle greater than 95 percent.

The ECM will use the full range of the throttle's operation when the PWM converter produces duty cycles that are between 10 percent and 90 percent.

The nominal frequency of the PWM converter is between 300 and 700 Hz.

The ECM will not use the signal from the converter when the frequency is less than 150 Hz or the frequency greater than 1000 Hz.

Specifications for the Test Results

The following specifications are the characteristics of the PWM signal that are required for simulating the operation of the ECM:

Minimum frequency ... 300 Hz

Nominal frequency ... 500 Hz

Maximum frequency ... 700 Hz

Range of high level output voltage ... 4.5 to 32 V

Maximum low level output voltage ... 0.8 V

Maximum output jitter ... 3 microseconds

Maximum time between 0.8 V and 4.5 V (rise) ... 5 microseconds

Maximum time between 4.5 V and 0.8 V (fall) ... 5 microseconds

Duty cycle at the minimum throttle setting ... 5.5 to 9.5 percent

Duty cycle at the maximum throttle setting ... 90.5 to 94.5 percent

Temperature Sensors for the Engine Oil and the Air Inlet Manifold

Illustration 33	g01030316

This temperature probe consists of a thermistor that is located at the probe tip. The sensor output is an analog voltage signal that decreases with increasing temperature from -40° to 150°C (-40° to 270°F). Refer to Table 21 for the output versus the temperature. The sensor must not be connected to battery voltage. The sensor is not protected against dump and overvoltage. The sensor has a low voltage signal and the sensor is a passive sensor. The effects of losses in the harness must be considered.

Operating supply voltage through a resistor in control ... 4.75 VDC to 5.25 VDC

Output voltage (SIG) for VS = 5 Volts ... 0.3 VDC to 4.9 VDC

Maximum output current ... 10 mA

Maximum capacitance of control input ... 4700 pF

The connector that mates to the sensor is 155-2270 Connecting Plug Kit .

Table 21

Output Voltage Versus Temperature
Temp	Output Voltage	Temp	Output Voltage	Temp	Output Voltage
-40 °C	0.97392	25 °C	0.66712	90 °C	0.21122
-35 °C	0.96612	30 °C	0.6257	95 °C	0.19062
-30 °C	0.95646	35 °C	0.5836	100 °C	0.17204
-25 °C	0.94462	40 °C	0.54142	105 °C	0.15532
-20 °C	0.93032	45 °C	0.49984	110 °C	0.14028
-15 °C	0.91328	50 °C	0.45936	115 °C	0.12682
-10 °C	0.89324	55 °C	0.42046	120 °C	0.11474
-5 °C	0.87004	60 °C	0.38354	125 °C	0.10392
0 °C	0.84358	65 °C	0.3488	130 °C	0.09422
5 °C	0.81386	70 °C	0.31644	135 °C	0.08554
10 °C	0.781	75 °C	0.28654	140 °C	0.07778
15 °C	0.74532	80 °C	0.25908	145 °C	0.07214
20 °C	0.70718	85 °C	0.234	150 °C	0.06454

Illustration 34	g01030324
Basic control circuit

Configuration of the circuit for the SAE J1935 CAN Data Link

Illustration 35	g01030325

Table 22

Available Hardware
Part Number	Description	Quantity
5P-6011	Tube	As required
125-7876	Heat Shrink Tube	As required
153-2707	Electrical Cable	As required
174-0503	Plug Kit	As required
9X-3402	Connector Socket	2 per plug
133-0969	Socket Connector	1 per plug
176-9299	Receptacle Kit	As required
9X-3401	Connector Pin	2 per receptacle
133-0967	Pin	1 per receptacle
140-7684	Receptacle As	As required
134-2540	Receptacle As	As required

Programming Parameters

Cat ET can be used to view certain parameters that can affect the operation of the engine. The Cat ET can also be used to change certain parameters. The parameters are stored in the ECM. The parameters are not stored in the personality module. Some of the parameters are protected from unauthorized changes by passwords. Parameters that can be changed have a tattletale number. The tattletale number shows if a parameter has been changed.

Always document the parameters and the settings that are programmed into the engine control. A permanent record is essential when customer programmable parameters must be recovered back to the original following inadvertent change or following replacement of the engine control.

Passwords

Passwords are part of a security system that helps to prevent unauthorized reprogramming of certain parameters. Passwords prevent unauthorized erasing of logged events. Passwords allow the factory to control access to engine calibration parameters. Passwords allow the customer to control access to certain programmable engine parameters.

Factory Passwords

Factory passwords are required to clear any event code. Factory passwords are required to change certain parameters such as full load setting. The factory passwords restrict changes to authorized personnel. When the correct factory passwords have been entered, the changes can then be made. In order to obtain the proper factory passwords, certain information must be given to an authorized Caterpillar dealer. Since the factory passwords contain alphabetic characters, Cat ET can be used to perform this function. In order to obtain the factory passwords, proceed as if you already have the factory passwords. At some point, if the factory passwords are actually needed, Cat ET will request the factory passwords and Cat ET will display the information that is required to obtain the factory passwords.

Note: The old interlock code is required to change the interlock code on a used ECM. A new interlock code is also required to change the interlock code on a used ECM.

The Cat ET screen for factory passwords will display the following parameters:

• Serial number of the ECM

• Engine serial number

• Serial number for Cat ET

• Reason code

• Total tattletale number

Note: The factory passwords may only be used for one programming session. A different set of factory passwords will be required after you exit the Cat ET screen. A different set of passwords will be required to change information on another Cat ET screen.

Customer Passwords

Customer passwords allow the customer to restrict access to parameters that are programmable by the customer. The customer passwords cannot be longer than eight characters. The customer has the option of entering one or two customer passwords.

Note: If the owner loses the owner's customer passwords, the owner will not be able to program parameters that are protected by customer passwords. By using factory passwords, one can read customer passwords. Then use those customer passwords to program parameters that have been protected by customer passwords.

Connecting Cat ET and the Communication Adapter II

Illustration 36	g00647144
(1) Personal computer (2) 160-0141 Adapter Cable As (3) 171-4401 Communication Adapter II (4) 160-0133 Data Link Cable As

The service tool connector provides the Communication Adapter II with 24 VDC. Use the following procedure to connect Cat ET and the Communication Adapter II to the engine.

1. Turn the engine control to the OFF position.

2. Turn the Battery disconnect switch to the OFF position.

3. Connect the 207-6845 Data Link Cable . The cable connects between the J42 service tool connector and the control connector on the 171-4401 Communication Adapter II .

4. Connect the 160-0141 Data Link Cable . The cable connects between the laptop computer's RS232 serial port and the serial connector on the 171-4401 Communication Adapter II .

5. Turn the Battery disconnect switch to the ON position.

6. Start the program for Cat ET on the personal computer. Establish communication with the engine's ECM. If Cat ET and the Communication Adapter II do not communicate with the ECM, refer to the diagnostic procedure Troubleshooting, "Electronic Service Tool Will Not Communicate With ECM".

Flash Programming

This is the method of programming or updating the personality module in an ECM.Cat ET is utilized to flash new software into the personality module in the ECM.

Flash Programming a Personality Module

1. Start the Cat ET.

2. When possible, write down all of the current engine parameters.

3. Select "WinFlash" from the "Utilities" menu on the Cat ET. "WinFlash" will try to detect an ECM.

4. When an ECM has been detected, the "ECM Selector window" will appear. Select the appropriate ECM and then select "OK". The "Flash File Selection" window will appear.

5. The flash files are located on a disk drive and in a directory. Select the correct disk drive and the directory from "Drives and Directories" screen on Cat ET. A list of flash files will appear.

6. Select the correct file from the list of flash files. Read the "Description" and the "File Info" in order to verify that the correct file is selected. Select "OK".

7. Select the "Begin Flash" button in order to program the personality module. When the flash is completed, this message will appear: "Flash Completed Successfully".

8. Check all programmable parameters for correct settings.

   1. Access the "Configuration" screen under the "Service" menu in order to determine if any of the parameters require programming. Look under the "Tattletale" column. All of the parameters should have a tattletale of 1 or more. If a parameter has a tattletale of 0, program that parameter.

   2. If a diagnostic code of" 268-02 Check Programmable Parameters" is generated, program any parameters that were not in the old personality module.

9. Start the engine and check for proper operation.

"Winflash" Error Messages

"The engine ID in the flash file does not match the engine ID in the ECM."

This message means that the ECM has a personality module for a different engine. For example, the ECM has a personality module for a 3512B Engine and you are attempting to program another personality module into the engine. If you receive this message, stop the transfer. Access the information about the "ECM Summary" under the "Information Menu". Be certain that you are transferring the correct file for your engine.

"The application ID in the flash file does not match the application ID in the ECM."

This message means that the ECM has a personality module for a different application. If you receive this message, stop the transfer. Access the information about the "ECM Summary" under the "Information Menu". Be certain that you are transferring the correct file for your engine.

"The ECM ID in the flash file does not match the ECM ID in the ECM."

This message means that the ECM is not the correct ECM for the 3500B Engine. If you receive this message, stop the transfer. Access the information about the "ECM Summary" under the "Information Menu". Be certain that you are using the correct ECM for your application.

System Configuration Parameters

System configuration parameters are parameters that affect emissions, power of the engine, and other features. The parameters are programmed at the factory. In most cases, the parameters do not need to be changed. The system configuration parameters must be reprogrammed if an ECM is replaced and/or if the engine rating is reprogrammed. System configuration parameters do not need to be reprogrammed if the personality module is replaced. Proper values for these parameters are available on Cat ET. Certain configuration parameters are also stamped on the engine information plate.

Note: Changing the parameters that are protected by factory passwords may cause your Caterpillar warranty to be voided.

" Check Programmable Parameters (268-02)"

A "268-02 Check Programmable Parameters" diagnostic code will be generated if one or more of the programmable parameters have not been programmed. The unprogrammed parameters will be set to default. Certain aspects of the engine's performance and engine monitoring may be affected.

"Personality Module Mismatch (253-02)"

The ECM stores a code number in permanent memory. This code is called an Interlock Code that is associated with each personality module part number. The interlock code does not allow the engine to run if the wrong flash file has been downloaded into the ECM personality module.

Cat ET will warn you if a flash file that does not match the last file in the ECM has been downloaded. The interlock code must be reprogrammed with Cat ET in order to allow the engine to run with new software. For instructions on reprogramming the interlock code, refer to the Special Instruction, SEHS9343. Installing the incorrect flash file into the ECM may void the Caterpillar warranty. The 3500B ECM and another Caterpillar ECM may appear to be similar, but the electronic control modules are different. These different electronic control modules cannot be interchanged. For example, a 3412E ECM cannot be used to replace a 3500B ECM. The interlock code cannot be reset if the wrong ECM is installed. If an incorrect ECM is used, a "253-02 Personality Module Mismatch" diagnostic code becomes active. The fuel injection is disabled in order to prevent the engine from starting. Verify the correct ECM part number by checking the part number that is listed in the Parts Manual or by checking the last two characters of the ECM serial number. The correct ECM serial number ends with CD.

When the engine is rerated, programming the interlock code to zero will prompt the ECM. The ECM will read the stored code and the ECM will match the stored code to the new interlock code.

Engine Serial Number

Program the engine serial number to match the engine information plate. The serial number is not programmed on a new ECM.

Rated Fuel Position

This parameter is used to set engine power. A factory password is required to change this setting.

Table 23

Minimum	Default	Maximum
Minimum Rack	Engine Dependent	Engine Dependent

Low Idle

The parameter defines the lowest rpm level.

Table 24

Minimum	Default	Maximum
450 rpm	600 rpm	1000 rpm

Cooldown Speed

This parameter defines the engine speed when the engine shutdown is activated.

Table 25

Minimum	Default	Maximum
450 rpm	600 rpm	1800 rpm

Engine Cooldown Duration

This parameter defines engine operation at the cooldown speed. Programming this parameter to 0 will disable this function.

Table 26

Minimum	Default	Maximum
0 minutes	0 minutes	60 minutes

Engine Prelube Duration

The parameter sets the amount of time for prelubrication. Programming this parameter to 0 will disable this function.

Table 27

Minimum	Default	Maximum
0 seconds	0 seconds	210 seconds

Crank Duration

The crank duration determines when the starting motors will be energized. The crank duration determines when the starting motors will be disengaged. Programming this parameter to 0 will prevent the ECM from engaging the starting motors.

Table 28

Minimum	Default	Maximum
0 seconds	0 seconds	60 seconds

Maximum Number of Cranking Cycles

This parameter is the total number of crank cycles that can be performed.

Table 29

Minimum	Default	Maximum
0	0	10

Crank Terminate Speed

This parameter determines when the starting motor will disengage.

Table 30

Minimum	Default	Maximum
100 rpm	400 rpm	500 rpm

Air Shutoff

Programming the parameter to "DISABLED" will disable the air shutoff. Program this parameter to "DISABLED" if the function is not being used or installed on this engine. This will prevent air shutoff diagnostics from being logged.

Table 31

Minimum	Default	Maximum
Disabled	Disabled	Enabled

Fuel Ratio Control

The ECM determines the offset value for the Fuel Ratio Control (FRC). The FRC offset value is used to adjust the fuel ratio control. This minimizes the exhaust smoke when the engine is accelerated. An offset value of ± 25 kPa (± 4 psi) may be used for adjusting customer preference, fuel quality or other factors that affect engine performance. The default setting is 0.

Note: This parameter may not be available on all applications. This parameter serves the same function as a mechanical fuel ratio control in order to improve the engine response with improved emission levels.

Table 32

Minimum	Default	Maximum
-25	0	-25

Ether Control

Programming this parameter to "DISABLED" will disable the Ether functions. Program this parameter to "DISABLED" if the ether function is not being used or installed on this engine. This will prevent the diagnostic codes for the ether control from being logged.

Table 33

Minimum	Default	Maximum
Disabled	Disabled	Enabled

"CCM Interface"

The interface will allow you to control up to eight engines from a remote site. For a single engine application, this should be programmed to the minimum or the default value.

Table 34

Minimum	Default	Maximum
Engine Control 1	Engine Control 1	Engine Control 8

Engine Cooling System

The engine may use a separate circuit aftercooler and/or the engine may use a jacket water aftercooler.

Table 35

Minimum	Default	Maximum
SCAC	SCAC	JWAC

Cold Mode Cylinder Cutout

This parameter provides the strategy for the cold cylinder cutout.

Table 36

Minimum	Default	Maximum
Disabled	Enabled	Enabled

Fuel Position Multiplier

This parameter decreases the power output from the engine by reducing the fuel. This parameter is used to control the driven equipment by decreasing engine power without a change in the throttle.

Table 37

Minimum	Default	Maximum
Disabled	Enabled	Enabled

Engine Acceleration Rate

This parameter limits the rate of change for the desired engine speed. This parameter may also help reduce smoke during the engine start.

Table 38

Minimum	Default	Maximum
1 rpm/sec	250 rpm/sec	2000 rpm/sec

Factory Passwords Worksheet

Factory passwords are required to perform the following functions:

• Clear all of the logged events.

• Program the engine monitoring system.

• Program the parameter for the rack limit.

• Program the cooling system parameter.

• Reset the Interlock code for the Personality Module (PM).

View the factory password screen on Cat ET and record the following information:

Table 39

Serial number for the Cat ET
Engine serial number
Serial number for the ECM
Total tattletale
Reason code
Interlock code
Other parameters

Injector Codes

Table 40

Injector 1
Injector 2
Injector 3
Injector 4
Injector 5
Injector 6
Injector 7
Injector 8
Injector 9
Injector 10
Injector 11
Injector 12

Customer Parameters Worksheet

Record the following information before changing any programmable parameter.

Table 41

Equipment ID
Engine Serial Number
Serial number for ECM
Fuel Ratio Control (FRC) Offset.
Rated Fuel Position
Low Idle Speed
High Idle Speed
Fuel Correction Factor
Engine Cooling System
Cold Mode Cylinder Cutout
Identifier for Cat Data Link
Engine Acceleration Rate
Cooldown Speed
Engine Cooldown Duration
Engine Prelube Duration
Crank Duration
Maximum Number of Crank Cycles
Crank Terminate Speed
Air Shutoff
Ether Control
Fuel Position Multiplier

Record the engine serial number from the engine information plate.

Record the following information from the engine monitoring system. The engine monitoring system can be accessed through Cat ET. Select "Monitoring System" from the "Service" menu.

Low System Voltage

Table 42

Warning Trip Points
Warning Delay Time

Low Engine Oil Pressure

Table 43

Warning Trip Point
Warning Delay Time
Shutdown Trip Point
Shutdown Delay Time

High Coolant Temperature

Table 44

Warning Trip Point
Warning Delay Time
Derate Trip Point
Derate Delay Time
Shutdown Trip Point
Derate Delay Time

Low Coolant Temperature

Table 45

Warning Trip Point
Warning Delay Time

Engine Overspeed

Table 46

Warning Trip Point
Warning Delay Time
Shutdown Trip Point
Shutdown Delay Time

High Air Filter Restriction Pressure

Table 47

Warning Trip Point
Warning Delay Time
Derate Trip Point
Derate Delay Time

Altitude (Atmospheric Pressure)

Table 48

Derate Trip Point

High Exhaust Temperature

Table 49

Warning Trip Point
Warning Delay Time
Derate Trip Point
Derate Delay Time

High Engine Oil Filter Restriction Pressure

Table 50

Warning Trip Point
Warning Delay Time

High Fuel Filter Restriction Pressure

Table 51

Warning Trip Point
Warning Delay Time

High Crankcase Pressure

Table 52

Warning Trip Point
Warning Delay Time
Derate Trip Point
Derate Delay Time
Shutdown Trip Point
Shutdown Delay Time

High Aftercooler Temperature

Table 53

Warning Trip Point
Warning Delay Time
Derate Trip Point
Derate Delay Time
Shutdown Trip Point
Shutdown Delay Time

Reference information

Illustration 37	g01030335

Illustration 38	g01030336

Table 54

Number of Terminals	Receptacle Kit	Wedge	Plug Kit	Wedge	Seal
2	120-8802 (1)	3E-3365 (2)	155-2270 (1)	155-2261 (2)	175-3880
3	102-8803 (1)	3E-3371 (2)	155-2260 (1)	155-2276 (2)	175-3881
4	102-8804 (1)	3E-3377 (2)	155-2271 (1)	155-2262 (2)	175-3882
6	102-8805 (1)	3E-3383 (2)	155-2274 (1)	155-2263 (2)	175-3883
8	102-8806 (1)	3E-3389 (2)	155-2265 (1)	155-2259 (2)	175-3884
12	102-8801 (1)	3E-5180 (2)	155-2255 (1)	155-2258 (2)	175-3885

( 1 )	Always plug empty contact cavities.
( 2 )	147-6456 Wedge Removal Tool

Illustration 39	g01030339

Table 55

Wire Gauge	Pin	Socket	Plating	Plug	Notes
16-18	8T-8729 (1)	8T-8730 (1)	Nickel	8T-8737	DT, DRC, HD Deutsch connectors
	9X-3401 (1)	9X-3402 (1)	Gold
14	9W-0852 (1)	9W-0844 (1)	Nickel	8T-8737
	126-1767 (1)	126-1768 (1)	Gold
16-18	-	7T-9742 (1)	Nickel	8T-8737	Extended socket Deutsch connectors
	133-0967 (1)	133-0969 (1)	Gold
14-18	7N-7780 (2)	7N-7779 (2)	Nickel	9G-3695	Sure Seal connectors

( 1 )	Use a 1U-5804 Crimp Tool and a 151-6320 Wire Removal Tool .
( 2 )	Use a 6V-3001 Crimp Tool and a 6V-3008 Insertion Tool .

Table 56

Connector Service Kits
Part Number	Description
175-3700	This kit services HD & DT Deutsch connectors. Replaced by 9U-7246 Connector Repair Kit and 9U-7250 Connector Repair Kit
9U-7246	This kit services HD & DT Deutsch connectors. Supplied without 1U-5804 Crimp Tool
9U-7250	This kit services HD & DT Deutsch connectors. Supplied with 1U-5804 Crimp Tool
190-8900	This kit services HD Deutsch connectors. Supplied without 1U-5804 Crimp Tool
4C-3406	This kit services HD Deutsch connectors. Supplied with 1U-5804 Crimp Tool
6V-3000	This kit services sure seal connectors.

Illustration 40	g01030342

Illustration 41	g01030343

Illustration 42	g01030344

Illustration 43	g01030345