The power distribution system includes the following components:
- Interface harnesses
- Power distribution panels
- Fuses
- Circuit breakers
- Relays
- Switches
The components that are listed are serviceable at the lowest component level.
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| Illustration 1 | g02527560 |
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Components of the power distribution circuits (right side engine view) (1) Control box connectors for the interface harness to the low current power distribution panel and the high current power distribution panel (2) Control box (3) Low current power distribution panel (4) High current power distribution panel | |
Interface harnesses are used to route the power from the power distribution panels to the control box and other electrical or electronic components.
Low Current Power Distribution Panel
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| Illustration 2 | g02528017 |
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Locations of the circuit breakers, relays, and connections that are in the low current power distribution panel (5) 20 Amp breaker for the primary ECM (6) Power relay for the primary ECM circuit (7) Power relay for the secondary ECM circuit (8) 20 Amp breaker for the secondary ECM (9) 20 Amp breaker for the #1 auxiliary power circuit to the Engine Interface Connector (EIC) (10) 20 Amp breaker for the #2 auxiliary power circuit to the Engine Interface Connector (EIC) (11) 20 Amp breaker (unused) (12) 6 Amp breaker for the Aftercooler Temperature Control Module (ATCM) (13) 6 Amp breaker for the Temperature Control Module (TCM) (14) 6 Amp breaker for the keyswitch circuit for the secondary ECM (15) 10 Amp circuit breaker for the override control relays (16) 6 Amp circuit breaker for the digital return (No. 2) (17) 6 Amp breaker for the keyswitch circuit for the primary ECM (18) 6 Amp circuit breaker for the digital return (No. 1) (19) Connections for the secondary keyswitch relay (20) Connections for the primary keyswitch relay (21) Primary power distribution block (22) Secondary power distribution block | |
The low current power distribution panel is used to accommodate the fuses, the circuit breakers, and the relays. The low current panel is for electrical components that draw less than 25 A of current.
High Current Power Distribution Panel
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| Illustration 3 | g02533277 |
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Locations of the circuit breakers and switches that are at the high current power distribution panel (23) 80 Amp circuit breaker for the main power (primary) (24) 80 Amp circuit breaker for the main power (secondary) (25) 100 Amp circuit breaker for the alternator (optional) (26) Secondary starting motor magnetic switch (optional) (27) 30 Amp circuit breaker for the prelube pump (optional) (29) 40 Amp circuit breaker for the starting system (optional) (29) Primary starting motor magnetic switch (optional) | |
The high current power distribution panel is used to accommodate the circuit breakers, the relays, and the switches. The high current panel is for electrical components that draw current that is equal to or greater than 25 A.
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| Illustration 4 | g02533757 |
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Diagram of the Engine Management System (EMS) (1) Secondary engine ECM (2) Control assembly (3) Primary engine ECM (4) Local CAN data link (5) Global CAN data link (6) Caterpillar Electronic Technician (ET) (7) Temperature Control Module (TCM) for the engine coolant (8) TCM for the Separate Circuit After Cooler (SCAC) (10) Primary controller for the fuel control valve (11) Secondary controller for the fuel control valve (12) Exhaust temperature module (12) Engine interface connector (70-pin connector) (13) Interconnect harness (14) Color Multi-Purpose Display (CMPD) and PL100T Communications Module (15) Cat ET | |
This engine is designed for electronic control of most engine operating functions. The Engine Management System (EMS) provides this control. The EMS is made up of a network of electronic controllers. These controllers communicate through the data link network to share information that is related to the operation of the engine. The EMS also provides information to external devices, such as the operator display panel. The electronic system consists of the control modules that make up the EMS, the wiring harness, switches, sensors, and fuel injectors. The control modules receive information from the sensors and the switches on the engine. The information is shared over the data link. This information is then processed in order to provide engine control. Refer to Troubleshooting, "Data Link Features" for an overview of the data links for this engine.
Primary and Secondary Electronic Control Module (ECM)
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| Illustration 5 | g01496913 |
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Engine ECM | |
The engine ECM consists of two main components, the control computer (hardware) and the flash file (software). The control computer consists of a microprocessor and electronic circuitry. The flash file contains the engine operational characteristics. The operating maps that influence the engine performance are also contained in the flash file.
The engine ECM provides engine control by altering the signal that is sent to the fuel injector solenoids. By controlling the signal timing and duration, the engine ECM controls the engine speed and the engine power.
The engine ECM provides control for various subsystem components. The following subsystem components are controlled by the engine ECM:
- Air shutoff system
- Engine prelube system
- System for engine cranking
- Ether system
- Fuel system
- Various other components
The engine ECM also collects data in order to provide information on various aspects of engine operation.
Redundant Engine Control Feature
This engine is equipped with a redundant engine control system. The engine incorporated dual ECM engine operation to provide for this redundancy. In a dual ECM engine operation, the primary ECM controls the engine operation majority of the time. The secondary ECM takes over control of the engine from the primary ECM to provide for the redundancy feature.
The primary ECM periodically broadcasts a message over the CAN data link and CDL Data Links that communicates the condition of the primary ECM. This message is recognized by the secondary ECM as an ECM heartbeat status of the primary ECM. If the heartbeat message is lost or unreadable, the secondary ECM will assume control of the engine.
The secondary ECM continuously transmits a ready status message over the CAN data link and CDL Data Links. As long as the secondary ECM is broadcasting a status of "Ready", the secondary ECM is eligible to take control of the engine.
The following conditions may initiate control of the engine by the secondary ECM:
- Multiple injector failures are detected
- Failure of the primary high-pressure fuel pressure sensor
- Detection of a high pressure or low-pressure fuel rail pressure event
- Failure of the controller for the primary Fuel Control Valve (FCV)
- Failure of the primary FCV
- Power supply diagnostic codes are active for the primary ECM.
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| Illustration 6 | g02541156 |
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Control assembly | |
The control assembly uses electronic switches to isolate the signals from the ECM that is currently providing control for the engine systems. Power rectifiers are used to switch engine control from the primary ECM to the secondary ECM, when necessary. The control assembly isolates the following circuits:
- Fuel injector signals
- Fuel priming pump signals
The following circuits are wired through the control assembly for providing a splice in the wiring:
- Speed/timing sensor signals
- Throttle signals
The use of the control assembly enables the engine to utilize unique electrical components while providing a redundant control system.
Note: The internal components of the control assembly are not serviceable.
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| Illustration 7 | g02543077 |
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Location of the fuel system components (16) Secondary power module (17) Primary power module (18) Primary controller for the FCV (19) Secondary controller for the FCV | |
The controller for the FCV receives throttle commands from the engine ECM. The controller translates the command to a valve position for the FCV. The ECM provides a PWM output in order to drive the throttle signal for the controller. Messages are communicated over the local CAN data link in order to provide a backup signal for the throttle control.
A power module is used to supply electrical power to the controller for the fuel control valve. The power module is used to convert battery voltage (24 VDC) to 14.0 ± 1.5 VDC that is used by the controller. This power is uninterrupted except for any emergency shutdown overrides.
A keyswitch input is provided in order to bring the controller out of sleep mode.
Temperature Control Module (TCM)
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| Illustration 8 | g02544197 |
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Components of the electronic fluid temperature control (20) Temperature Control Module (TCM) (21) Electric motor (22) Three-way valve | |
The electronic fluid temperature control consists of a three-way valve that directs coolant flow. The valve assembly incorporates a TCM, a coolant temperature sensor, and a piston that rides on a lead screw. The lead screw is turned by an electric motor. The electric motor is controlled by the TCM.
This engine utilizes two separate temperature control modules for controlling engine temperature. One TCM controls the temperature of the jacket water coolant. The other TCM is used to control the temperature of the coolant in the Separate Circuit Aftercooler circuit SCAC.
The TCM receives the signal from the coolant temperature sensor. As the coolant temperature varies, the sensor signal also varies. The controller detects the change in coolant temperature and the electric motor is energized. The electric motor turns the lead screw. The lead screw repositions the piston in the bore of the valve body.
When the temperature control module is powered, the controller drives the piston to the position of zero percent bypass. This action provides a reset for the electric motor and for the position of the piston. When the piston hits the stop, a clicking sound can be heard from the unit. This reset function will be performed by the controller in approximately 80 seconds. The reset establishes the position of the piston prior to the controlled movement of the piston.
The desired temperature for the TCM is communicated from the engine ECM via the local CAN data link during normal operation. A default setting for the desired temperature is also stored in the control module internal memory. If the communication to the control module is lost, the TCM will use the default value as the desired temperature. The TCM will continue to control the coolant temperature without interruption of the operation of the engine. The default setting for the desired temperature for this application is
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| Illustration 9 | g01497914 |
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Exhaust temperature module | |
The exhaust temperature module receives the signals from the exhaust temperature sensors. These sensors are located at each of the cylinder exhaust ports. The exhaust port temperatures are monitored by the ECM.
The exhaust port temperatures and the diagnostic information are also transmitted via the global CAN data link. Any of the display panels that are on the network can be used in order to display this information. The exhaust port temperatures can be monitored on the display panel.
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| Illustration 10 | g02544099 |
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Connectors that are on the harness for the left rail (1) Control box connector for the left exhaust temperature sensors (2) Left rail connector at the control box (70-pin connector) (3) Turbocharger compressor inlet pressure sensor (No. 2) (4) Turbocharger compressor inlet pressure sensor (No. 1) (5) Left turbocharger speed sensor (6) Exhaust thermocouple (typical) (7) Injector connector (typical) (8) Left turbocharger turbine inlet temperature sensor (9) Inlet air temperature sensor (10) Tertiary speed/timing sensor (LH) (11) Connector for the air shutoff switch (12) Coolant temperature sensor at the engine block outlet (13) Coolant pressure sensor at the engine block outlet (14) Left fuel rail pressure sensor (primary) (15) Connector for the prelubrication solenoid (16) Connector for the starter relay circuit (17) Intake manifold pressure sensor (LH) (18) Intake manifold temperature sensor (LH) (19) Connector for the primary speed/timing sensor (20) Connector for the tachometer magnetic pickup (LH) | |
The harness for the left rail contains the wiring for the electrical components that are on the left side of the engine.
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| Illustration 11 | g02544636 |
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(21) Right turbocharger speed sensor
(22) Right rail connector at the control box (70-pin connector) (23) Control box connector for the right exhaust temperature sensors (24) Air shutoff solenoid connector (25) Right turbocharger turbine inlet temperature sensor (26) Exhaust thermocouple (typical) (27) Injector connector (typical) (28) Intake manifold pressure sensor (RH) (29) Intake manifold temperature sensor (RH) (30) Right fuel rail pressure sensor (secondary) (31) Termination resistor for the CAN data link (32) Connector for the tachometer magnetic pickup (RH) (33) Crankcase pressure sensor (34) Connector for the aftercooler temperature control module (35) Connector for the fuel transfer pressure sensor (unfiltered) (36) Connector for the FCV controller (37) Temperature sensor for the high-pressure fuel system (38) Connector for the temperature sensor at the water pump outlet for the separate circuit aftercooler system (39) Connector for the pressure sensor at the water pump outlet for the separate circuit aftercooler system (40) Power connector for the electric fuel priming pump | |
The harness for the right rail contains the wiring for the electrical components that are on the right side of the engine.
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| Illustration 12 | g02545379 |
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(41) Connector for the Temperature Control Module (TCM) for the engine coolant
(42) Front harness connector (43) Fuel temperature sensor for the low-pressure fuel (44) Fuel transfer pressure sensor (filtered) (45) Fuel transfer pressure sensor for the secondary ECM (filtered) (46) Fuel transfer pressure sensor (unfiltered) (47) Secondary ECM sensor harness connector (48) Secondary ECM fuel harness connector (49) Engine oil pressure sensor at the block inlet (primary) (50) Engine oil pressure sensor at the block inlet (secondary) (51) Engine oil pressure sensor at the filter inlet (52) Engine oil temperature sensor at the block inlet (primary) (53) Engine oil temperature sensor at the block inlet (secondary) (54) Engine coolant temperature sensor at the block outlet (secondary) (55) Engine coolant pressure sensor at the block inlet (secondary) (56) Engine coolant pressure sensor at the block inlet (primary) (57) Engine coolant temperature sensor at the block outlet (primary) (58) Controller for the Fuel Control Valve (FCV) (secondary) (59) Fuel level sensor for leak detection | |
The engine front harness contains the wiring for the electrical components that are at the front of the engine.
Crossover Harness in the Control Box
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| Illustration 13 | g02547682 |
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(60) Termination resistor for the global CAN data link (secondary)
(61) Termination resistor for the local CAN data link (primary) (62) Jumper connector for the local CAN shield to ground circuit (primary) (63) Power module for the primary FCV controller (64) Termination resistor for the global CAN data link (primary) (65) Power module for the secondary FCV controller (66) Atmospheric pressure sensor (secondary) (67) Atmospheric pressure sensor (primary) (68) Exhaust temperature module (69) Manual override relay for the right starting motors (+) (70) Manual override relay for the right starting motors (−) (71) Manual override relay for the left starting motors (+) (72) Manual override relay for the left starting motors (−) (73) Power mode relay for the power module at the FCV controller (74) Relay for the secondary keyswitch circuit (75) Relay for the primary keyswitch circuit (76) Relay for the electric fuel priming pump | |
The crossover harness in the control box contains the wiring for the electrical components that are in the control box.
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| Illustration 14 | g02549096 |
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Color Multi-Purpose Display (CMPD) (1) Control panel (2) Operator keypad for the control panel (3) Annunciator panel (4) Start/stop switch (5) Local/remote switch (6) Engine speed potentiometer (7) Emergency stop button | |
The main panel on the CMPD includes the operator display and the operator keypad that is used for display navigation.
The annunciator panel provides visual indications and audible indications of diagnostic codes and events that become active.
The start/stop switch, local/remote switch, speed potentiometer, and the emergency stop button are located on the lower panel.
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| Illustration 15 | g02724401 |
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Location of the operator switches (8) Crank override switch (9) Manual select switch for starter selection (10) Low idle select switch (11) Engine protection override switch (12) Rapid start/stop switch (13) Manual prelube | |
There are several operator switches located inside the generator control panel. The switches provide the operator a selection of controls and overrides that can be used during abnormal engine operating conditions. The following switches are available:
"CRANK OVRD" - This switch allows for a manual crank override for the starting system. The switch can be used to crank the engine manually using the starting motors on the left side or the right side of the engine.
"CRANK MTR SEL" - The operator can use this switch to select between the starting motors on the left side or the right side of the engine.
"LOW IDLE SEL" - Use this switch to select the low idle speed or the desired speed.
"ENG PRTN OVRD" - When this switch is activated, the engine protection that is provided by the engine monitoring system is ignored. If a diagnostic condition that requires an engine shutdown is detected monitoring system, the engine ECM will ignore the shutdown request
"RAPID ST/STOP" - This switch is used to initiate an immediate start or shutdown.
"MNL PRLUB" - This switch is used to initiate a manual prelubrication.
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| Illustration 16 | g02551281 |
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Configuration of the data links for the C175 engines (1) Secondary engine ECM (2) Control assembly (3) Primary engine ECM (4) Global 1 CAN data link (primary ECM) (5) Global 2 CAN data link (secondary ECM) (6) Cat Data Link (7) Local CAN data link (8) Primary TCM (9) Primary controller for the FCV (10) Secondary TCM (11) Secondary controller for the FCV (12) CMPD and PL1000T communications module (13) Exhaust temperature module (14) Service tool connectors for Cat ET | |
The data links for C175 engines provide communication among the various controllers on the engine. These data links also provide communications with engine supervisory systems that are not located on the engine.
This data link is exclusively used for communications between the engine ECM and Cat ET. The functionality of the service tool will be limited if dual data link communication is not established during sessions with Cat ET. Dual-data-link-communications utilizes the Cat Data Link and the global CAN data link during communications with Cat ET.
Global CAN Data Links (Engine)
The global CAN data links allows communication with the following control systems and engine supervisory systems that are not located on the engine:
- Engine ECMs
- Exhaust temperature module
- CMPD
- Service tool connector that is located on the generator set package
Note: Some service tool connectors may not provide a global CAN data link for Cat ET. The functionality of the service tool will be limited if Cat ET is not using dual data link communication. Also, if Cat ET is not connected to a service tool connector that is connected to the global CAN data link, functionality will be limited.
The local CAN data link allows communication with the following control systems and engine supervisory systems that are located on the engine:
- Engine ECMs
- TCMs
- Controllers for the FCVs
- Service tool connector that is located on the engine
Note: Some service tool connectors may not provide a global CAN data link for Cat ET. The functionality of the service tool will be limited if Cat ET is not using dual data link communication. Also, if Cat ET is not connected to a service tool connector that is connected to the global CAN data link, functionality will be limited.
Diagram for Engine State Control
The engine operation is controlled by the engine state control. The engine state control defines the logical sequence of events for proper engine operation. Each state in the engine state control is defined by conditions that must be achieved by the engine or by the engine subsystem. Each engine subsystem control communicates the current state of the subsystem. The engine state control uses this information to determine the operational condition of the engine. Once the conditions are achieved, the engine is considered to be in the related state.
The desired state of the engine is communicated via the CAN data link from the CMPD to the engine ECM. The actual state of the engine is communicated from the engine ECM to the CMPD. The state of the engine management system can be viewed on Cat ET or on the CMPD.
The engine is allowed to change states when all of the conditions for the desired state of the engine are achieved. The different states of the engine state control are described below:
Engine Stopped - In this state, the EMS is powered but the engine is stopped.
Engine Prestart - During the prestart, all engine control logic that is necessary to prepare for engine starting is completed. The following prestart conditions must be completed prior to exiting this state: prelubrication of the engine, initialization of the starting aid system and other engine starting preparations. All of the other subsystems have similar control strategies. These subsystems report to the engine state control during engine operation.
Engine Cranking - Engine cranking is between zero rpm and the engine speed which allows the engine to accelerate to engine idle after starting. During this engine state, the EMS controls the engine starting function. If the engine starting function is controlled by an external source, the EMS monitors engine speed in order to detect the completion of engine cranking.
Engine Running - The engine remains in this state while the engine is idling and while the engine is producing power.
Engine Cooldown - During the state for the engine cooldown, the engine operates at reduced speed and load to allow the engine to cool before the engine stops. This action prevents damage to engine components. The driven equipment must unload the engine before this state is initiated in order to prevent the engine from stalling.
Engine Stopping - During the state for engine stopping, the engine is not producing power. The engine is turning due to inertia from the driven equipment and the inertia from the engine after fuel injection is stopped. Control subsystems may continue operation in order to prevent engine damage. This operation will extend the life of engine components.
Engine Postrun - During engine postrun, the engine crankshaft is not turning. Actions may be taken by control subsystems in order to prevent engine damage. The engine postrun is used to extend the life of engine components. These actions may be a continuation of the actions that have been initiated in the state of engine stopping.
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| Illustration 17 | g02551608 |
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Location of the position sensors for the air shutoff (1) Solenoid for the air shutoff (2) Air shutoff mechanisms (3) Position sensors for the air shutoff | |
The air shutoff mechanisms are closed during an emergency shutdown or during an overspeed event.
The engine is equipped with two air shutoff mechanisms. There is one air shutoff mechanism on each side of the engine. The air shutoff mechanisms are hydraulically actuated by engine oil pressure. There is a hydraulic valve on the right side of the engine that is electronically controlled by the engine ECM. When the solenoid valve receives a signal from the ECM, the air shutoff mechanisms are closed.
Position sensors are installed on the air shutoff mechanisms. These sensors allow the ECM to detect the position of the air shutoff mechanisms. The ECM can also detect the activation of the air shutoff mechanisms while the engine is running. Through control of the air shutoff mechanisms, the ECM may shut down the engine. Also, the ECM can use the air shutoff to prevent the engine from starting.
The electronic fluid temperature control provides accurate control for the jacket water cooling system and the separate circuit aftercooler system for this engine. The control systems provide self-diagnostic functions and increased service reliability that help to reduce cooling system repair times and warranty claims.
The TCM controls the coolant temperature to a desired value. This desired value is based on a signal from the coolant temperature sensor and a known desired temperature. The desired temperature is communicated over the data link from the engine ECM.
There are several states of operation for the TCM. The operating conditions of the engine will dictate the state of operation for the TCM. The cooling system is allowed to change states when all of the conditions for the desired state are achieved. The different states of the electronic fluid temperature control are described below:
Ambient - In the ambient state, the engine is not running and the engine has cooled down. The cooling system is nominally the same temperature as the surrounding environment. In this state, no action is being taken in order to control the coolant temperature. The TCM will power down if the keyswitch is not powered. In this state, the TCM normally commands the control valve to 100 % Bypass. The coolant is allowed to recirculate through the inlet of the engine.
Warmup - In the warm-up state, the engine is rejecting heat. The cooling system is operating at a temperature that is below the temperature necessary for operation of the valve in closed loop mode. In this state, the TCM normally commands the control valve to 100% bypass. This valve position recirculates all of the coolant to the inlet of the engine.
Regulating - The TCM enters the regulating state when the engine is warmed up enough to allow regulation of the coolant temperature to the desired setpoint. In this state, the TCM will adjust the position of the cooling valve in order to maintain the desired temperature. The Electronic Fluid Temperature Control system operates in closed loop mode of operation.
Cooldown - The TCM enters cooldown state when the engine is stopped and the engine has partially cooled. The TCM will set the cooling valve to a position that will allow the engine coolant to cool to the ambient temperature. The position of the valve may be adjusted with the service tool in order to affect the cooling rate of the engine.
If the temperature sensor fails, the control valve position will be overridden by the ECM. The ECM will normally control the valve to zero percent bypass. This position provides full cooling in order to allow the engine to continue running.
Note: If the engine is operated with a failed sensor, the engine may be overcooled. Remove the engine from service and repair the problem immediately.
Upon an occasion, the ECM may take control of the cooling valve position. The ECM may override the valve while the TCM is in a state of temperature control. This functionality depends on the application of the engine. One example is during the starting of the engine. Some applications command the control valve to less than 100% Bypass. At this valve position, air is more easily purged from the cooling system.
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| Illustration 18 | g02551901 |
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Components for the engine starting system (1) Jumper harness for the starting system circuit (2) Starting motor solenoids (3) Main circuit breaker (4) Circuit breaker for the engine starting system (5) Starting motors (6) Starting motor magnetic switches for the starting motors | |
The ECM accepts a request for engine cranking from the CMPD. The ECM determines if the engine is ready to be cranked. The ECM also determines if the starting motors are in danger of being overheated.
High Pressure Common Rail Fuel System
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| Illustration 19 | g02426157 |
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Fuel system components (typical right side engine view) (1) Fuel injectors (left side) (2) Secondary and tertiary fuel filter assemblies (filter-in-filter) (3) Fuel rail pressure sensor (4) Temperature sensor for the low-pressure fuel (5) Pressure sensor for filtered fuel (6) Pressure sensor for filtered fuel (secondary ECM) (7) Fuel filter duplex valve (8) Pressure sensor for unfiltered fuel (9) High-pressure fuel pump (10) Fuel rail pressure sensor (secondary) (11) Primary fuel control valve and controller (12) Fuel injectors (right side) (13) Fuel transfer pump (14) Fuel pressure regulating valve (15) High-pressure leak detection sensor (16) Block assembly that contains the in-line high-pressure fuel filter (17) Temperature sensor for the high-pressure fuel (18) Fuel control valve and controller (secondary) (19) Electric fuel priming pump | |
The controller for the high pressure common rail fuel system receives a desired rail pressure from the engine ECM. This signal is used to determine a setpoint for the fuel control valve. The controller adjusts the fuel control valve in order to match the actual rail pressure to the desired rail pressure.
The fuel control valve is a suction throttle that regulates the fuel by limiting the volume of fuel available at the inlet of the pump.
Electrical power to the controller for the fuel control valve is supplied by the power module. Power to the power module is supplied by the battery for the engine. Voltage from the keyswitch is supplied directly to the controller in order to power up the controller during an ECM powerup.
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| Illustration 20 | g03523877 |
An excessive concentration of oil mist in the engine crankcase can result in an explosion when the mist comes in contact with a hot surface. Marine Classification Societies (MCS) require all engines rated at
- Oil mist detection system
- Bearing temperature monitoring system
- Alternative system
For low speed diesel engines, the protection system is to initiate an alarm and automatic slowdown of the engine. For medium to high-speed diesel engines, the system is to initiate an alarm and automatic shutdown of the engine.
The Caterpillar C175-16 engine utilizes the Graviner© Mk7 Oil Mist Detector from Kidde Products Ltd. The oil mist detectors are mounted on engine side covers on the right side of the engine.
The Installation, Operation and Maintenance Manual is available for download from:
http://www.kfp.co.uk
Integrated control of the engine starting sequence and the engine prelubrication system is required in order to guarantee that proper engine starting procedures are followed. The system prevents excessive engine wear and damage to engine components. The Engine Management System (EMS) provides automatic control of the engine prelube system.
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| Illustration 21 | g02724995 |
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Components for the air prelube system (1) Air powered prelube pump (2) Prelube solenoid | |
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| Illustration 22 | g02725005 |
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Components for the electric prelube system (1) Electric prelube pump (2) Prelube relay | |
The following types of prelube control options are available for this engine:
Automatic Prelube - For this setting, the engine prelube sequence is automatically initiated during engine startup. During engine startup, the prestart state of the EMS requests a pre-lube prior to engine cranking. The pump will run continuously until the lubrication system is pressurized to a predetermined pressure. Once this pressure is achieved, engine cranking will begin. If the pressure is not achieved, the pump will time out according to the setting of the Engine Pre-lube Time Out Period parameter. If this time limit is reached, the attempt to start the engine will be aborted.
Continuous Prelube - For this prelube setting, the delay that is experienced during the engine start sequence for the prelubrication of the engine is removed. While the engine is in continuous prelube, the prelube cycle will begin upon power-up. The pump will run continuously until the lubrication system is pressurized to a predetermined pressure. Once this pressure is achieved, the pump will shut down, If the pressure is not achieved, the pump will time out according to the setting of the Engine Continuous Pre-lube Duration parameter. This cycle will repeat according to the Engine Continuous Pre-lube Interval.
The engine prelube sequence may be manually requested when the engine is not running. A manual toggle switch is located in the control panel.
A circuit breaker will be installed in the high current power distribution panel if an electric prelube pump is used on the engine.