Cat® Command For Hauling Caterpillar

MID 039 - Machine Control Module

CID 3731 - Autonomous Mode Indicator

FMI 03 - Voltage Above Normal

Illustration 1	g03197636

This diagnostic code is recorded when the Input/Output module (I/O module) reads the voltage of the Autonomous mode indicator being above normal.

Test Step 1. CHECK THE CIRCUIT FOR A SHORT TO THE + BATTERY.

1. Turn the keyswitch and the disconnect switch to the OFF position.

2. Disconnect the machine harness from the indicator lights.

3. Disconnect the machine harness connectors J1 and J2 from the I/O module.

4. At machine harness connector J1 and J2, measure the resistance from the signal contact J1-59 (wire 638-WH(White)) to all possible sources of +battery.

Expected Result:

The resistance should be greater than 5000 ohms for each measurement.

Results:

• OK - The resistance is greater than 5000 ohms. The machine harness is correct. Proceed to test step 2.

• NOT OK - The resistance is NOT correct. There is a short in the machine harness. The short is between signal contact J1-59 (wire 638-WH(White)) and the circuit with the low resistance measurement.

  Repair: Repair the harness or replace the harness.

  STOP

Test Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.

1. Inspect the contacts and clean the contacts of the harness connectors.

2. Reconnect all harness connectors.

3. Turn the disconnect switch and the keyswitch to the ON position.

4. Clear all inactive diagnostic codes.

5. Cycle the keyswitch position from ON to OFF to ON again and allow the machine electronic system time for the self check. The check will power the lights for 2 seconds.

6. Observe the status of CID 3731 FMI 03 for the indicator.

Expected Result:

The CID 3731 FMI 03 for the indicator is NOT present.

Results:

• OK - The diagnostic code is NOT present. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation -

  STOP

• NOT OK - The diagnostic code has not been corrected. The ECM may have failed.

  Repair: It is unlikely that the I/O module has failed. Exit this procedure and perform this CID 3731 FMI 03 again. If the cause of the diagnostic code is not found, replace the I/O module. Refer to Testing and Adjusting, KENR8394, "Electronic Control Module (ECM) - Replace".

  STOP