HARNESS AS-SENSOR 3518441 - Caterpillar

Illustration 1 g01121129
Schematic for the Power Train ECM
This diagnostic code is associated with the harness code from the Caterpillar Monitoring System ECM. The information is sent via the Cat Data Link. The Cat Data Link is connected to two inputs of the Power Train ECM.This FMI 02 means that the Power Train ECM does not recognize the harness code that is received from the Caterpillar Monitoring System ECM.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0650 FMI 02 is active before performing this procedure.Test Step 1. CHECK THE CIRCUIT FOR SHORTS TO GROUND
Turn the key start switch to the OFF position.
Disconnect the machine harness from the Power Train ECM.
Measure the continuity from frame ground (wire 202-BK(Black)) to contact 3 (wire 892-BR(Brown)). Measure the continuity from frame ground (wire 202-BK(Black)) to contact 9 (wire 893-GN(Green)). Expected Result:There is NOT continuity.Results:
YES - There is NOT continuity. The circuitry for the harness is functioning correctly. Proceed to Test Step 2.
NO - There is continuity. The circuitry for the harness has failed.Repair: Repair the harness or replace the harness.STOPTest Step 2. CHECK THE HARNESS CODE
The key start switch remains in the OFF position.
Disconnect the machine harness from the Caterpillar Monitoring System.
Measure the resistance at the Caterpillar Monitoring System harness connector from connector contact 6 (wire 201-BK(Black)) to frame ground. Note the resistance.
Measure the resistance at the Caterpillar Monitoring System harness connector between frame ground and connector contact 3, connector contact 12, connector contact 16, connector contact 22, and connector 31. Expected Result:The resistance from frame ground and connector contact 6 is less than 5 ohms. The resistance between frame ground and connector contact 3, connector contact 12, connector contact 16, connector contact 22, and connector 31 is greater than 5 ohms .Results:
YES - The resistance from frame ground and connector contact 6 is less than 5 ohms. The resistance between frame ground and connector contact 3, connector contact 12, connector contact 16, connector contact 22, and connector 31 is greater than 5 ohms. The circuitry for the harness is functioning correctly. The Power Train ECM may have failed. This is unlikely. Proceed to Test Step 3.
NO - The resistance from frame ground and connector contact 6 is less than 5 ohms. The circuitry for the harness has failed. The resistance between frame ground and connector contact 3, connector contact 12, connector contact 16, connector contact 22, and connector 31 is greater than 5 ohms.Repair: Repair the harness or replace the harness.STOPTest Step 3. RECHECK FOR THE DIAGNOSTIC CODE
Connect the machine harness to the Power Train ECM.
Connect the machine harness to the Caterpillar Monitoring System.
Turn the key start switch to the ON position.