HOUSING-PLUG 9G3668 - Caterpillar

Illustration 1 g01242599
Schematic of the CAN Data Link Circuit
This diagnostic code is recorded when the Monitor does not receive expected information from the machine ECM for more than 5 seconds.For machines equipped with the E-Fence feature, reference Troubleshooting, "E-Ceiling and Cab Avoidance - Troubleshoot"Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes now, but clear those codes after the original diagnostic code has been corrected. Note: Poor connections are often the cause of a problem in electrical circuits. Before performing this procedure, inspect all of the harness connectors involved in the circuit. Verify that all of the connections in the circuit are clean, secure, and in good condition. If a problem is found with any of the connections: correct the problem and verify that diagnostic code CID 1130 FMI 04 is still active, before performing the following procedures. System Response:This failure results in events that are logged against an ECM that cannot be explained directly. The Monitor cannot communicate with the Machine ECM, or the ECM appears to communicate intermittently with the Monitor. Test Step 1. CHECK THE HARNESS FOR A SHORT TO GROUND.
The key start switch and the disconnect switch remain in the OFF position.
Disconnect the machine harness from all electronic control modules that use the CAN Data Link.
At the machine harness connector for the ECM, measure the resistance between the frame ground and the CAN Data Link circuits (contacts J2-50 and J2-51). Expected Result:The resistance measurement should be greater than 5000 ohms.Results:
YES - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 2.
NO - The resistance is less than 5000 ohms. Repair: The machine harness has failed. There is a short between the CAN Data Link circuit and frame ground in the machine harness. Repair, or replace, the machine harness. STOPTest Step 2. CHECK THE HARNESS FOR A SHORT TO A VOLTAGE SOURCE.
The key start switch and the disconnect switch remain in the OFF position.
All related control modules remain disconnected from the machine harness.
At the harness for the ECM, measure the resistance between the +battery circuit (contact J1-1) and the CAN Data Link (contacts J2-50 and J2-51). Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. Proceed to Test Step 3.
NOT OK - The resistance is less than 5000 ohms. Repair: The harness has failed. There is a short between the +battery contact and the CAN Data Link circuit in the machine harness. Repair, or replace, the machine harness. STOPTest Step 3. CHECK FOR AN OPEN IN THE HARNESS.
The key start switch and the disconnect switch remain in the OFF position.
All related control modules remain disconnected from the machine harness.
Check the continuity of the CAN Data Link circuit in the machine harness.
Measure the resistance between the contact J2-50 of the Machine ECM (wire 251-YL(Yellow)) and the corresponding connection (wire 251-YL(Yellow)) of the switch panel. Measure the resistance between the