768C, 769C, 769D, 772B, 773B, 773D, 776C, 777B, 777D, 784B, 785, 785B, 789, 789B, 793, 793B and 793C Off-Highway Truck/Tractors and 771C, 771D and 775D Quarry Trucks Automatic Retarder Control (ARC) System Caterpillar

Note: Ensure that the CID 0712 FMI F05 fault is on hold and that the fault is present. This fault may cause other faults to be created.

Place the display in the detected fault mode (mode 1).

1. CHECK THE INDICATOR LAMP.

   1. Ensure that the fault is still present.

   2. Disconnect the retarder lamp from the machine harness.

   3. Observe the ON/OFF status of the fault present indicator.

   4. Install a jumper wire from wire 454-GN-16 to wire 202-BK. The retarder lamp should change states.

      Expected Result: The CID 0712 FMI 05 diagnostic code is present.

      Results:

      • OK: The CID 0712 FMI 05 is present. The retarding indicator lamp is not causing the diagnostic code. Proceed to Step 2.

      • NO: The CID 0712 FMI 05 is NO longer present. The indicator lamp is faulty or the socket of the indicator lamp is faulty. Replace the retarding indicator lamp. STOP.

      Note: The correct resistance for an indicator lamp is greater than 10 ohms for the purposes of this procedure.

2. CHECK THE HARNESS FOR GROUND.

   1. Remove the jumper wire that was connected in Step 1.d. Observe the ON/OFF status of the fault present indicator.

   2. At the machine harness, connect a jumper wire from wire 454-GN-16 to the frame ground.

      Expected Results: The fault present indicator should change from ON to OFF.

      Results:

      • OK: When the fault indicator changes states, this means that there is an open in wire 202-BK. Replace the machine harness and/or repair the machine harness. STOP.

      • NO: The fault present indicator remains in the ON position. The fault is still present. Go to Step 4.

3. CHECK THE LAMP CIRCUIT.

   1. Turn the disconnect switch to the OFF position. The jumper from Step 2 will remain connected.

   2. Disconnect the machine harness connector (A) from the ARC.

   3. Measure the resistance between connector A-A5 (wire 454-GN-16) and frame ground at the machine harness connector for the ARC.

      Expected Result: The resistance is less than 5000 ohms.

      Results:

      • OK: The resistance is less than 5000 ohms. The harness resistance is correct. Proceed to Step 4.

      • NO: The resistance is greater than 5000 ohms. The harness is faulty. Repair the machine harness or replace the machine harness. STOP.

4. CHECK THE ARC.

   1. Remove contact A-A4 from the machine harness connector for the ARC.

   2. Reconnect the harness connector to the ARC.

   3. Turn the disconnect switch and the key start switches to the ON position.

   4. Check the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active.

      Expected Result: The CID 0712 FMI 05 diagnostic code is active.

      Results:

      • OK: The CID 0712 FMI 05 diagnostic code remains active. The ARC is faulty. Replace the ARC. See Testing And Adjusting, "ARC - Replace". STOP.

      • NO: The CID 0712 FMI 05 diagnostic code has changed. The ARC is not causing the diagnostic code. The diagnostic code is intermittent. The probable cause of the diagnostic code is a poor electrical connection at the harness connectors or a damaged harness. Check the harness for damage. Clean the harness connectors if it is necessary. STOP.