789D CMD Off-Highway Truck Chassis Electronic Control System (Command For Hauling) Caterpillar

MID 087 - Chassis ECM

CID 2851 - Idle Shutdown Timer Relay

FMI 03 - Voltage Above Normal

Illustration 1	g06351814
"Idle Shutdown" timer relay

Illustration 2	g06351807
"Idle Shutdown" timer relay circuit

This diagnostic code indicates the "Chassis" ECM detects the "Idle Shutdown" timer relay voltage is above normal.

The following can cause this code:

• Relay failure

• Shorted circuit

• ECM failure

Note: The following test procedure may create other diagnostic codes. Ignore these created codes and clear these created codes after the original diagnostic code has been corrected. Ensure diagnostic code CID 2851 FMI 03 is active before performing this procedure.

Note: Use a calibrated digital multimeter for this procedure.

System Response:

• ECM logs the diagnostic code.

• Diagnostic code viewed on a display module or Cat^® ET.

• Idle shutdown timer lighting disabled.

Possible Performance Effect:

• Hard starting

Test Step 1. CHECK THE RELAY

1. Turn on the disconnect switch and the key switch.

2. Observe the status of the diagnostic code.

3. Disconnect the shutdown timer relay from the harness.

Expected Result:

FMI 05 changes to FMI 06 after the relay is disconnected.

Results:

• OK - FMI 05 changes to FMI 06. The shutdown timer relay has failed.

  Repair: Replace the shutdown timer relay.

  STOP

• NOT OK - FMI 05 does not change to FMI 06. Proceed to Test Step 2.

Test Step 2. CHECK THE RELAY ENERGIZE CIRCUIT FOR A SHORT

1. Turn off the key switch and the disconnect switch.

2. Disconnect the harness connectors from the relay and the ECM.

3. At the harness connector for the ECM, measure the resistance from contact J2-5 (wire K953-GY(Grey)) to all contacts used in the harness connectors for the ECM.

Expected Result:

Each resistance is greater than 5000 ohms.

Results:

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

• NOT OK - A resistance is less than 5000 ohms. There is a short between J2-5 (wire K953-GY(Grey)) and the circuit with low resistance.

  Repair: Repair or replace the harness.

  STOP

Test Step 3. CHECK THE ECM OPERATION

The disconnect switch and the key switch remain in the off position.

The harness connectors for the solenoid and ECM remain disconnected.

1. At the J2 connector for the ECM, use a wire removal tool to remove wire K953-GY(Grey)from contact J2-5.

2. Reconnect the harness J1 and J2 connectors to the ECM.

3. Turn on the disconnect switch and the key switch.

4. Check the CID 2851 FMI 03 status.

Expected Result:

The CID 2851 FMI 03 changes to CID 2851 FMI 05.

Results:

• OK - CID 2851 FMI 03 changes to CID 2851 FMI 05. The ECM has responded correctly.

  Repair: Reinstall the disconnected wire to the correct space in the ECM connector.

  Proceed to Test Step 4.

• NOT OK - CID 2851 FMI 03 does not change to CID 2851 FMI 05. The ECM may have failed.

  Repair: Exit this procedure and perform this procedure again. Contact the technical communicator at your Cat® dealer. If the ECM requires replacement, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP

Test Step 4. CHECK THE DIAGNOSTIC CODE

1. Inspect the harness.

   Clean the harness connector contacts.

   Inspect the harness connector contacts for corrosion or damage.

   Inspect the wire insulation for damage caused by heat, corrosion, or chafing.

2. Perform a 45 N (10 lb) pull test on each circuit wire.

3. Reconnect all harness connectors.

   Verify that the connectors are fully seated and the clips are fastened.

4. Check for intermittent problems. Using Cat^® Electronic Technician (Cat^® ET), perform a wiggle test on the harness.

5. Turn on the disconnect switch and the key switch.

6. Operate the machine.

7. Check the CID 2851 FMI 03 status.

Expected Result:

The CID 2851 FMI 03 is not active.

Results:

• OK - CID 2851 FMI 03 is not active.

  Repair: The initial diagnostic code was probably caused by a poor connection at one of the connectors that was checked.

  Resume normal operation.

  STOP

• NOT OK - CID 2851 FMI 03 is active. The ECM may have failed.

  Repair: Exit this procedure and perform this procedure again. Contact the technical communicator at your Caterpillar dealer. If the ECM requires replacement, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP