988G Wheel Loader Electrohydraulic System MID 082 - CID 0490 - FMI 03 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g00388737
Schematic of the Rocker Switch (Implement Lockout)

This diagnostic code is associated with the Rocker Switch (Implement Lockout). The switch is connected to two inputs of the ECM. One contact is open and the other contact is grounded during proper operation.

This FMI 03 means that the ECM has determined that the normally open contact and the normally closed contact 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 0490 FMI 03 is active before performing this procedure.

System Response:

The implements will not work.

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

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

2. Disconnect the machine harness connector(s) from the ECM.

3. Measure the resistance between contact J1-15 (wire 299-BK) of the machine harness for the ECM and contact 2 (wire 299-BK) at the switch.

Expected Result:

The resistance is less than 5 ohms.

Results:

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

• NOT OK - The resistance is greater than 5.0 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 connector(s) remains disconnected from the ECM.

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

3. Disconnect contact 3 (wire E917-WH) and contact 1 (wire E918-GN) from the connector of the switch.

4. At the machine harness connector for the ECM, measure the resistance from contact 3 (wire E917-WH) and contact 1 (wire E918-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 5000 ohms.

Results:

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

• NO - One or more of the measurements were less than 5000 ohms. There is a short in the machine harness.

  Repair: The short is between wire E917-WH and the circuit with the lowest resistance measurement or the short is between wire E918-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 machine harness remains disconnected from the ECM and the switch.

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

3. At the harness connector for the switch, connect a jumper wire between contact 3 (wire E917-WH) and contact 1 (wire E918-GN).

4. At the harness connector for the ECM, measure the resistance from contact J1-13 (wire E917-WH) to contact J1-14 (wire E918-GN).

Expected Result:

The resistance is less than 5 ohms.

Results:

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

• NOT OK - The resistance is greater than 5.0 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 switch.

4. Connect one lead from a multimeter to contact 2 (wire 299-BK) of the harness connector for the switch.

5. Connect the other lead from a multimeter to contact 3 (wire E917-WH) of the harness connector for the switch.

6. Measure the resistance between contact 2 (wire 299-BK) and contact 3 (wire E917-WH). Note the resistance.

7. Disconnect the lead from contact 3 (wire E917-WH) and connect the lead to contact 1 (wire E918-GN).

8. Measure the resistance between contact 2 (wire 299-BK) and contact 1 (wire E918-GN).

Expected Result:

The resistance from contact 2 to contact 1 is less than 5 ohms, and the resistance from contact 2 to contact 3 is greater than 5000 ohms.

Results:

• YES - The resistance from contact 2 to contact 1 is less than 5 ohms, and the resistance from contact 2 to contact 3 is greater than 5000 ohms. The switch is operating correctly. Proceed to Test Step 5.

• NO - The resistance measurements do not differ for both contacts, or the measurements have not changed from the previous Test Step. The switch has failed.

  Repair: Replace the switch.

  STOP

Test Step 5. CHECK THE OPERATION OF THE SWITCH

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

2. The machine harness remains disconnected from the switch.

3. Press and hold the switch.

4. Connect one lead from a multimeter to contact 2 (wire 299-BK) of the harness connector for the switch.

5. Connect the other lead from a multimeter to contact 3 (wire E917-WH) of the harness connector for the switch.

6. Measure the resistance between contact 2 (wire 299-BK) and contact 3 (wire E917-WH). Note the resistance.

7. Disconnect the lead from contact 3 (wire E917-WH) and connect the lead to contact 1 (wire E918-GN).

8. Measure the resistance between contact 2 (wire 299-BK) and contact 1 (wire E918-GN).

Expected Result:

The resistance from contact 2 (wire 299-BK) to contact 3 (wire E917-WH) is less than 5 ohms, and the resistance from contact 2 (wire 299-BK) to contact 1 (wire E918-GN) is greater than 5000 ohms. These measurements are opposite of the measurements from the previous Test Step.

Results:

• YES - The resistance from contact 2 to contact 3 is less than 5 ohms, and the resistance from contact 2 to contact 1 is greater than 5000 ohms. These measurements are opposite of the measurements from the previous Test Step. The switch is operating correctly. Proceed to Test Step 6.

• NO - The resistance measurements do not differ for both contacts, or the measurements have not changed from the previous Test Step. 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. Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.

4. Operate the machine.

5. Check the status of the CID 0490 FMI 03 diagnostic code.

Expected Result:

The CID 0490 FMI 03 diagnostic code is active.

Results:

• YES - The CID 0490 FMI 03 diagnostic code is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP

• NO - The CID 0490 FMI 03 diagnostic code 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 or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP