Usage:
C-10 (3CS1-Up),
C-12 (2KS1-Up),
3406E (1MM1-Up, 2WS1-Up) Truck Engines
Reference: This Issue, "Caterpillar Driver Information Display (Cat ID) Version 2.0 Release for On-Highway Truck". This Issue, "Electronic Controller Analyzer Programmer (ECAP) Truck SPM Version 2.3 Update". This Issue, "Electronic Technician (ET) Version 2.3 Update". This Issue, "On-Highway Heavy Duty 1999 Model Year Truck Software Release".
This article provides an overview of the On-Highway Heavy Duty 1999 Model Year Truck Electronic System. This topic is covered more extensively in LEVN4533 November 1998 Truck Tech Tips Video.
The following table lists the part numbers for the electronics on the 1999 Model Year Engines listed above:
The external housing of the new ECM is identical to the present 3126B Basic and Full Feature ECM, but the new ECM is different internally. Also, the new ECM is not fuel cooled and is seven pounds lighter.
The following table lists the tools needed to service the ECM connectors. These tools are identical to those used with the 3126B full Feature ECM. Specifically, these require the use of gold plated terminals instead of nickel plated terminals.
The three temperature sensors and the camshaft and crankshaft position sensors are new. The temperature sensors are identical to those used in the 3126B engines. The boost and oil pressure sensors are different from the sensors used on 1998 Model Year and prior engines because the range of the sensors has been increased.
The camshaft and crankshaft position sensors are two wire sensors which are similar to what is used in the 3126B. For the heavy duty engines, the two sensors are in different locations, one on the crankshaft and one on the camshaft. The system has the capability to start and run on either one of the two sensors, providing redundancy in the case of a sensor failure. The camshaft position sensor for the C-10 and C-12 has a different part number than the 3406E, but all use the same crankshaft position sensor.
When troubleshooting the camshaft and crankshaft position sensors, as with any sensor, thoroughly inspect the connector to make sure it is fully latched. Check to make sure the bolt holding the sensor bracket is tight and that the sensor is properly aligned in the hole. If the connector is properly latched and the sensor is properly installed, then take the necessary resistance measurements to check the harness and the sensors. The resistance of the camshaft position sensor is 600 - 1,800 ohms and the resistance of the crankshaft position sensor is 75 - 230 ohms. It is important to remember not to replace a sensor due to a logged diagnostic code if you cannot recreate the problem. If the connector, wiring, and resistance checks are good, leave the sensor alone unless the problem is active. If a sensor must be replaced, make sure the O-ring is installed on the replacement sensor and the sensor is seated to the flange before tightening the bolt. Also, route and tie wrap the harness correctly. The sensor and the bracket are serviced together as one part. Unlike the 3126B, the heavy duty camshaft and crankshaft position sensors are individually serviceable. Also, a timing calibration is not required following sensor replacement.
For the vehicle system, more inputs and outputs are available and all ECMs have the SAE J1939 data link. There are three more outputs available for controlling relays or solenoids, an extra lamp output, seven more switch inputs, two more pulse width modulated (PWM) inputs, and four sensor inputs as compared to the 1998 Model Year engines. This allows more customization for the vehicle manufacturer and the customer. There are now 92 customer parameters, so there are several new parameters available. A significant change rolled in is "Input and Output Selections" in Electronic Technician. These features allow the ECM to be customized for the customer's application. This allows the ECM to provide more options than inputs and provides for future expansion. The service tool will indicate the state of the input or output, and will provide the ECM connector and terminal used for the feature.
It takes from 12 to 20 minutes to FLASH program the 1999 Model Year engines, depending on the computer and the vehicle. When using Pro-Link as a communications adapter it will take significantly longer than this, so a Cat Communications Adapter is recommended for FLASHing at this time. If FLASHing takes significantly longer than 20 minutes with a Cat Communications Adapter, or the FLASH aborts before completion, use a 167-9225 or 135-5063 Bypass Communication Harness and FLASH directly to the ECM. Do not replace the ECM without trying this step first.
There are some errors in the ET Status screens of ET Version 2.3. The first error is in the Engine Retarder level switch status. To check if the ECM is reading the switch correctly, use status "Retarder Off/Low/Med/High" status parameter in default group 12. Do not use "Engine Retarder Switch" in default group 5. The status parameter in group 12 will always read "off" regardless of the actual switch status. Another problem is the "Engine Retarder" status, which should indicate "enabled" when the retarder comes on, and "disabled" when the retarder is off. The status will always indicate "disabled", so you will have to listen for the retarder to come on. If you can't hear the retarder, use the Retarder/Exhaust Brake Special Test with the ignition key ON, engine OFF to test the circuit.
Lastly, another problem discovered is with the ET snapshot viewer. This affects 1998 and 1999 model year engines. ET incorrectly describes the diagnostic codes when viewed from the ET "Select ECM Snapshot" window. The last digit of the actual failure mode identifier (FMI) is truncated, causing an open circuit code (-03) or a short circuit code (-04) to be displayed as if the FMI were "-0". It is important to note that ET correctly displays the FMI and code when you go to review either the data or the graph as shown.
The following table illustrates the capability of ET Version 2.3, ECAP Version 2.3, and Pro-Link Version 1.07 to work with the heavy duty 1999 truck engines.
NOTE: Pro-Link can be used as a communication adapter for flashing new software to the ECM. 1999 model year engines will experience significantly longer flash time with Pro-Link vs. the Cat Communications Adapter.
There are two new service tool harnesses needed for the 1999 model year C-10, C-12, and 3406E engines. The first harness is the 140-2266 70-pin Breakout "T". This "T" is also used for the 3126B engines. This harness is intended for use with the ignition key switch ON, engine OFF to test for open circuits and short circuits, and also to test the ECM outputs. This harness has a universal connector so it can be used on either the engine harness or the vehicle harness connector. The second harness is the 167-9225 Communication Bypass Harness which has already been mentioned. This harness can be used if there are problems with the ECM communicating with the in-cab connector or if there is a battery power and ground circuit problem between the batteries and the ECM. This harness bypasses all of the truck wiring and allows you to go directly from the ECM to the batteries.
The following table lists the electronic service manuals for these engines. The Application and Installation, Electronic Troubleshooting, PTO Special Instruction, Color Wiring Diagrams, and the Operation and Maintenance Manual cover all three engines, The C-10, C-12, and 3406E.
