CAMSHAFT AS 2835736 - Caterpillar

Operation Description:Use this procedure under the following situation:Use this procedure if one of the following diagnostic codes is present:
CID 253-FMI 02 Personality Module mismatch
CID 254-FMI 12 Electronic Control Module Error
CID 268-FMI 02 Check Programmable ParametersAlso, use this procedure if the integrity of the Customer Parameters or the System Parameters in the ECM is questionable. Also, use this procedure if the data for the Engine Lifetime Totals is questionable.The following background information is related to this procedure:The Electronic Control Module (ECM) is the computer that controls the Caterpillar engine. The personality module contains the software that controls the operation of the computer (ECM).The personality module software is the instructions that are used by the ECM to control the engine. For this reason, updating the personality module to a different version may cause some engine functions to behave in a different manner.Performance MapsPerformance maps define characteristics for various operating conditions. These characteristics are used to achieve optimum performance while emissions requirements are being met. Examples of these characteristics are included in the following list:
Fuel rate
TimingThese characteristics are programmed into the personality module at the factory only.MicroprocessorThe ECM uses a microprocessor to perform the computing that is required to perform the following functions:
Governing
Controlling timing
Generating diagnostic codes
Communicating with service toolsThe microprocessor reads the instructions from the software in the personality module.Programmable ParametersSystem Configuration parameters are stored in permanent memory. This includes both ECM Identification Parameters and Selected Engine Rating Parameters. Refer to Troubleshooting, "System Configuration Parameters" for more details.Logged DiagnosticsLogged diagnostics are stored by the ECM into memory so a permanent record of the diagnostic code is retained. Logged faults that are not critical are automatically cleared after 100 hours.Input CircuitsInput circuits filter electrical noise for sensor signals. Also, input circuits protect internal circuits from potentially damaging voltage levels.Output CircuitsOutput circuits provide the voltage or current that is required to energize components that are connected to the ECM. Power CircuitsPower circuits provide clean stable electrical power to internal circuits and external sensors.Test Step 1. Check for 254-12 Electronic Control Module Error.Connect an electronic service tool and check for this diagnostic code.Results:
Yes - Repair: Perform the following repair:
Temporarily connect a test ECM.
Remove all jumpers and reconnect all connectors.
Recheck the system for active diagnostic codes.
Repeat the test step.
If the problem is resolved with the test ECM, reconnect the suspect ECM.
If the problem returns with the suspect ECM, replace the ECM.
Verify that the repair eliminates the problem.STOP
NO - Proceed to Test Step 2.Test Step 2. Inspect Electrical Connectors And Wiring.
Thoroughly inspect ECM engine harness connector J1/P1 and the battery connections. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the following wires in the ECM Connector:
P1:70 (Switched Positive Battery)
P1:48, P1:52,and P1:53 (Unswitched Positive Battery)
P1:61, P1:63, and P1:65 (Negative Battery)
P1:8 and P1:9 (CAT Data Link)
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasion and pinch points from the data link connectors