R1600H Load Haul Dump Power Train Caterpillar

Illustration 1	g02831837
Schematic of the transmission control

This diagnostic code is associated with the transmission downshift switch. The transmission downshift switch is connected to two inputs of the Power Train Electronic Control Module (ECM). One contact is open and the other contact is grounded during proper operation.

FMI 04 means that the ECM has determined that both circuits are grounded.

Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0621 FMI 04 is active before performing this procedure.

Test Step 1. CHECK THE SWITCH

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

2. Disconnect the machine harness from the switch.

3. Move the key start switch and the disconnect switch to the ON position.

Expected Result:

CID 0621 FMI 04 has been replaced by CID 0621 FMI 03.

Results:

• YES - CID 0621 FMI 04 has been replaced by CID 0621 FMI 03. The machine harness and the ECM are correct. Proceed to Test Step 3.

• NO - CID 0621 FMI 04 is still active. Proceed to Test Step 2.

Test Step 2. CHECK THE HARNESS

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

2. The machine harness remains disconnected from the switch.

3. Disconnect the machine harness connectors from the ECM.

4. At the machine harness connector for the ECM, measure the resistance from contact J1-42 (wire F785-WH) of the machine harness to all the contacts that are used in the machine harness connectors for the ECM.

5. At the machine harness connector for the ECM, measure the resistance from contact J1-43 (wire F783-GN) of the machine harness to all the contacts that are used in the machine harness connectors for the ECM.

Expected Result:

Each resistance measurement is greater than 5 ohms.

Results:

• YES - Each resistance measurement is greater than 5 ohms. Proceed to Test Step 3.

• NO - One or more of the measurements were less than 5 ohms. There is a short in the machine harness.

  Repair: The short is between wire F785-WH and the circuit with the lowest resistance measurement, or the short is between wire F783-GN and the circuit with the lowest resistance measurement. Repair the machine harness or replace the machine harness.

  STOP

Test Step 3. CHECK THE OPERATION OF THE SWITCH

1. The machine harness remains disconnected from the switch.

2. Measure the resistance between contact 2 (wire 202-BK) and contact 7 (wire F785-WH) of the harness connector for the switch.

3. Measure the resistance between contact 2 (wire 202-BK) and contact 8 (wire F783-GN) of the harness connector for the switch.

Expected Result:

The resistance from contact 2 to contact 7 is less than 5 ohms. The resistance from contact 2 to contact 8 is greater than 5 ohms.

Results:

• YES - The resistance from contact 2 to contact 7 is less than 5 ohms. The resistance from contact 2 to contact 8 is greater than 5 ohms. The switch is operating correctly in the released position. Proceed to Test Step 4.

• NO - The resistance from contact 2 to contact 7 is not less than 5 ohms. Alternatively, the resistance from contact 2 to contact 8 is not greater than 5 ohms. The switch has failed.

  Repair: Replace the switch.

  STOP

Test Step 4. CHECK THE OPERATION OF THE SWITCH

1. Depress the downshift switch. Hold the switch in the depressed position.

2. Measure the resistance between contact 2 (wire 202-BK) and contact 7 (wire F785-WH) of the harness connector for the switch.

3. Measure the resistance between contact 2 (wire 202-BK) and contact 8 (wire F783-GN) of the harness connector for the switch.

Expected Result:

The resistance from contact 2 to contact 8 is less than 5 ohms. The resistance from contact 2 to contact 7 is greater than 5 ohms.

Results:

• YES - The resistance from contact 2 to contact 8 is less than 5 ohms. Alternatively, the resistance from contact 2 to contact 7 is greater than 5 ohms. The switch is operating correctly in the depressed position. Proceed to Test Step 5.

• NO - The resistance from contact 2 to contact 8 is not less than 5 ohms. The resistance from contact 2 to contact 7 is not greater than 5 ohms. The switch has failed.

  Repair: Replace the switch.

  STOP

Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS

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

2. Reconnect all harness connectors.

3. Move the disconnect switch and key start switch to the ON position.

4. Operate the machine.

5. Determine if CID 0621 FMI 04 is active.

Expected Result:

CID 0621 FMI 04 is active.

Results:

• YES - CID 0621 FMI 04 is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: The ECM is unlikely to have failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Troubleshooting, Testing. and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP

• NO - CID 0621 FMI 04 is not active. The diagnostic code does not exist at this time.

  Repair: The initial diagnostic code was probably caused by:

  • A poor electrical connection

  • A short at one of the harness connectors that was disconnected and reconnected

  Resume normal machine operation.

  STOP