D6N Track-Type Tractor Caterpillar

Illustration 1	g02622516
Schematic of the 5 VDC Sensor Supply

This diagnostic code is associated with the 5 VDC sensor power supply of the Chassis electronic control module (ECM). The diagnostic code is activated even when no components are connected to the 5 VDC supply.

The CID 0262 FMI 04 diagnostic code is activated when the ECM detects a below normal voltage of the 5 VDC power supply circuit.

The following conditions could cause this diagnostic code:

• The power supply circuit is shorted to a ground source.

• The ECM has failed. A failure of the ECM is unlikely.

Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the problem has been corrected. Verify that the CID 0262 FMI 04 diagnostic code is active before performing this procedure.

System Response:

Level 1 warning will be generated.

Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE

1. Perform the following:
   • Visually inspect the harness connectors.

   • Clean the contacts of the harness connectors.

   • Visually inspect the insulation of the wires for damage that is caused by excessive heat, corrosion, or chafing.

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.

3. Reconnect all harness connectors. Verify the following:
   • Connectors are fully seated.

   • The clips for each connector are fastened securely.

4. Use the Caterpillar Electronic Technician (Cat ET) service tool in order to perform a wiggle test on the machine wiring harness. The wiggle test can detect intermittent shorts or opens in the machine wiring harness.

5. Turn the disconnect switch and the key start switch to the ON position.

6. Operate the machine.

7. Determine if the CID 0262 FMI 04 diagnostic code is active.

Expected Result:

The CID 0262 FMI 04 diagnostic code is active.

Results:

• YES - The CID 0262 FMI 04 diagnostic code is active. The problem has not been corrected. Proceed to Test Step 2.

• NO - The CID 0262 FMI 04 diagnostic code is not active. The problem 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. Resume normal machine operation.

  STOP

Test Step 2. CHECK THE POWER SUPPLY AT THE ECM

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

2. Insert a jumper wire in "J1-11" on the ECM.

3. Insert a jumper wire in "J1-21" on the ECM.

4. Turn the disconnect switch and the key start switch to the ON position.

5. Measure the voltage at the ECM pins between the contact "J1-11" of the power supply and the return contact "J1-21".

Expected Result:

The voltage measurement is 5.0 ± 0.4 VDC.

Results:

• OK - The voltage measurement is 5.0 ± 0.4 VDC. The voltage is correct. The ECM power supply is correct. Proceed to Test Step 3.

• NOT OK - The voltage measurement is greater than 5.0 ± 0.4 VDC. The ECM power supply is not correct.

  Repair: A failure fo the ECM is unlikely. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact the technical communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" Section of this manual.

  STOP

Test Step 3. CHECK FOR A SHORT TO GROUND

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

2. Remove the jumper wires from the previous test step.

3. Disconnect the machine harness connectors "J1" and "J2" from the Machine ECM.

4. Inspect the harness at the "J1" connector.

5. Reconnect the machine harness connectors "J1" and "J2".

Expected Result:

There is no connection at the "J1-11" connection. The harness is correct.

Results:

• OK - There is no connection at the "J1-11" connection. The harness is correct.

  Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors. Resume normal machine operation.

  STOP

• NOT OK - There is a connection at the "J1-11" connection. The harness is not correct. The ECM may have failed.

  Repair: A failure of the ECM is unlikely. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact the technical communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" Section of this manual.

  STOP