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 03 means that the ECM has determined that both contacts are open.

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 03 is active before performing this procedure.

Test Step 1. CHECK THE GROUND CIRCUIT OF THE SWITCH IN THE HARNESS

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

2. Disconnect the machine harness connectors from the ECM.

3. Measure the resistance between frame ground (wire 202-BK) of the machine harness and contact 2 (wire 202-BK).

Expected Result:

The resistance is less than 5 ohms.

Results:

• YES - The resistance is less than 5 ohms. The circuit is correct. Proceed to Test Step 2.

• NO - The resistance is greater than 5 ohms. The circuit is open. The machine harness has failed.

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

  STOP

Test Step 2. CHECK THE SWITCH CIRCUITS FOR A SHORT TO THE +BATTERY CIRCUIT

1. The machine harness connectors remain disconnected from the ECM.

2. The disconnect switch and the key start switch remain in the OFF position.

3. Disconnect the connector for the switch from the machine harness.

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. The harness is correct. Proceed to Test Step 3.

• NO - One or more of the measurements are 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 SWITCH CIRCUITS IN THE HARNESS

1. The disconnect switch and the key start switch remain in the OFF position.

2. The machine harness remains disconnected from the ECM and the switch.

3. At the harness connector for the switch, connect a jumper wire between contact 7 (wire F785-WH) and contact 8 (wire F783-GN).

4. At the harness connector for the ECM, measure the resistance from contact J1-42 (wire F785-WH) to contact J1-43 (wire F783-GN).

Expected Result:

The resistance is less than 5 ohms.

Results:

• YES - The resistance is less than 5 ohms. Proceed to Test Step 4.

• NO - The resistance is greater than 5 ohms. The circuit is open.

  Repair: The machine harness has failed. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE OPERATION OF THE SWITCH

1. The disconnect switch and the key start switch remain in the OFF position.

2. Remove the jumper that was installed in the previous Test Step.

3. The machine harness remains disconnected from the ECM and the switch.

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

5. 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 5.

• 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 5. 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. 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 6.

• 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 6. CHECK IF THE DIAGNOSTIC CODE REMAINS

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

2. Reconnect all the harness connectors.

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

4. Operate the machine.

5. Check the status of CID 0621 FMI 03.

Expected Result:

CID 0621 FMI 03 is active.

Results:

• YES - CID 0621 FMI 03 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 03 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