TH31-C9I, TH31-C9P, TH31-C9T, TH35-C11I, TH35-C13I, TH35-C13T, TH35-C15I and TH35-C15T Petroleum Power Train Packages and TH31-E61 and TH35-E81 Petroleum Transmissions Power Train Electronic Control System Caterpillar

Illustration 1	g01248775
Schematic of the Transmission 1 Solenoid

This diagnostic trouble code is associated with the transmission 1 solenoid valve. The FMI 06 means that the ECU has determined that there is a short to ground in the solenoid circuit.

The possible causes of this diagnostic trouble code are listed:

• The energize circuit of the solenoid is shorted to ground.

• The solenoid has failed.

• The ECU has failed. This is unlikely.

Note: The following test procedure may create other diagnostic trouble codes. Ignore these created diagnostic trouble codes and clear these diagnostic trouble codes when the original diagnostic trouble code has been corrected. Ensure that the diagnostic trouble code of CID 1401 FMI 06 is active before performing this procedure.

Note: Use a Digital Multimeter for the measurements in this procedure.

Test Step 1. CHECK THE SOLENOID.

1. Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.

2. Observe the status of the diagnostic trouble code.

3. Disconnect the solenoid with the active diagnostic trouble code from the machine harness.

Expected Result:

CID 1401 FMI 06 changes to CID 1401 FMI 05 when the solenoid is disconnected.

Results:

• YES - CID 1401 FMI 06 changes to CID 1401 FMI 05 when the solenoid is disconnected. The circuit is correct.

  Repair: The solenoid has failed. Replace the solenoid. Verify that the new solenoid corrects the problem.

  STOP

• NO - CID 1401 FMI 06 remains active. Proceed to Test Step 2.

Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT TO GROUND.

1. Turn the key start switch and the disconnect switch to the OFF position.

2. The solenoid remains disconnected from the machine harness.

3. Disconnect the machine harness connector(s) from the ECU.

4. At the machine harness connector, measure the resistance from the signal contact J1-59 (wire 751-GN) to all contacts that are used in the machine harness connectors for the ECU.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.

• NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J1-59 (wire 751-GN) and the circuit with the low resistance measurement.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC TROUBLE CODE REMAINS.

1. Inspect the harness connectors and clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.

3. Reconnect all harness connectors making sure that the connectors are fully seated and the clips for each connector are completely fastened.

4. Turn the disconnect switch and the key start switch to the ON position.

5. Operate the machine.

6. Check the status of the CID 1401 FMI 06.

Expected Result:

The CID 1401 FMI 06 is active.

Results:

• YES - The CID 1401 FMI 06 is active. The diagnostic trouble code has not been corrected.

  Repair: Check the relay circuit again. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform a "Wiggle Test" on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness. It is unlikely that the ECU has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic trouble code is not found, replace the ECU. Prior to replacing an ECU, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, "Electronic Control Unit - Replace".

  STOP

• NO - The CID 1401 FMI 06 is not active. The diagnostic trouble code does not exist at this time.

  Repair: The initial diagnostic trouble 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