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

MID 087 - Chassis ECM

CID 2851 - Idle Shutdown Timer Relay

FMI 05 - Current Below 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 current is below normal.

The following can cause this code:

• Driver output off.

• ECM detected an open or short to a +battery at the lighting shutdown timer relay output for one second.

• "Idle Shutdown Timer" relay enabled.

• Current draw from the "Idler Shutdown Timer" is less than the expected.

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 05 is active before performing this procedure.

Note: Use a calibrated digital multimeter for this procedure.

System Response:

• ECM logs the diagnostic code.

• The "Idle Shutdown Timer" relay is disabled.

Possible Performance Effect:

• The "Idle Shutdown Timer" relay is disabled.

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:

The CID 2851 FMI 05 changes to CID 2851 FMI 06.

Results:

• OK - The CID 2851 FMI 05 changes to CID 2851 FMI 06. The shutdown timer relay has failed.

  Repair: Replace the shutdown timer relay.

  Verify that the new "Shutdown Timer Relay" has corrected the problem.

  STOP

• NOT OK - The CID 2851 FMI 05 does not change to CID 2851 FMI 06. Proceed to Test Step 2.

Test Step 2. CHECK THE HARNESS FOR AN OPEN

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

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

3. At the harness connectors for the ECM and the relay, measure the resistance of the following:

   • From contact J2-5 (wire K953-GY(Grey)) to contact of the relay C14 (wire K953-GY(Grey))

   • From contact J2-4 (wire H867-YL(Yellow)) to contact of the relay E13 (wire H867-YL(Yellow))

   • From contact J1-1 (wire 308-YL(Yellow)) to contact of the relay C13 (wire 308-YL(Yellow))

Expected Result:

The resistance is less than 5.0 ohms.

Results:

• OK - The resistance is less than 5.0 ohms. Proceed to Test Step 3.

• NOT OK - The resistance is greater than 5000 ohms. There is an open in the harness.

  Repair: Repair or replace the harness.

  STOP

Test Step 3. CHECK THE DIAGNOSTIC CODE

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

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 diagnostic code status.

Expected Result:

The diagnostic code is not active.

Results:

• OK - The diagnostic code 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 - The diagnostic code 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