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	g01251041
Schematic of the Primary and Secondary Keypad Shifters

This diagnostic trouble code is associated with the gear lever selector sensor(s). The FMI 02 means that the ECU has determined that the voltage of the circuit for the position sensor is below normal.

The possible causes of this diagnostic trouble code are listed below:

• The signal circuit for the sensor is shorted to ground.

• The sensor 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 the diagnostic trouble codes when the original diagnostic trouble code has been corrected. Ensure that the diagnostic trouble code of CID 0702 FMI 02 is active before performing this procedure.

Note: Use a digital multimeter for the measurements in this procedure.

Test Step 1. VERIFY SOFTWARE VERSION

Note: From SIS or the latest release of the CD for SIS check and record the latest software version for the machine electronic controls.

1. Verify the transmission ECU has the latest software version loaded.

2. Verify that the valve ECU's have the latest software loaded.

Expected Result:

All of the software is up to date.

Results:

• OK - All of the software is up to date. Proceed to Test Step 2.

• NOT OK - There is a more recent software release available.

  Repair: Flash all controls with the latest software release. Refer to Testing and Adjusting, "Electronic Control Unit - Flash Program".

  STOP

Test Step 2. CHECK THE HARNESS.

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

2. Inspect the harness.

3. Check for the proper mating.

4. Check the exposed wires for nicks and abrasions.

5. Check for moisture, dirt, or corrosion.

6. Check the pin/socket for a proper fit.

7. Disconnect the machine harness connectors from the transmission ECU.

8. At the machine harness connector, measure the resistance from connector contact 1 (wire K900-YL) to J2-67 (wire K900-YL) of the transmission ECU.

Expected Result:

The resistance should be less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. The machine harness is correct. Proceed to test step 3.

• NOT OK - The resistance is greater than 5 ohms. There is an open in the machine harness. The open is between the modules for the signal (wire K900-YL).

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

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC TROUBLE CODE IS STILL ACTIVE.

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. Determine if the CID 0702 FMI 02 is active.

Expected Result:

The CID 0702 FMI 02 is active.

Results:

• YES - The CID 0702 FMI 02 is active. The problem has not been corrected.

  Repair: Check the 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 0702 FMI 02 is not active. The problem 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