D250E Series II, D300E Series II, D350E Series II and D400E Series II Articulated Trucks Power Train Electronic Control System Caterpillar

Illustration 1	g00482764
Schematic Of The Parking Brake Switch

This diagnostic code is recorded when the ECM reads the voltage of the switch circuit as being above normal for two hours continuously.

Possible causes of this diagnostic code are listed:

• Wire 419-YL shorted to +battery.

• The switch is faulty.

• The ECM is faulty.

Note: Ensure that CID 0627 FMI 03 for the switch is active.

As a result of this diagnostic code, the transmission will not shift properly.

1. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO +BATTERY.

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

   2. Disconnect the switch with the diagnostic code from the machine harness.

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

   4. At the machine harness connector J1 and J2, measure the resistance from signal contact J1-26 (wire 419-YL) to all possible sources of +battery. The possible sources of positive voltage are contacts: J1-1 (wire 126-PK), J1-4 (wire A958-WH), J1-6 (wire 126-PK), J1-8 (wire 306-GN), J1-10 (wire 728-BU), J1-11 (wire 708-PK), J1-12 (wire 703-BU), J1-17 (wire 904-BU), J1-18 (wire 704-GY), J2-1 (wire K746-PK), J2-2 (wire 366-OR), J2-7 (wire G870-GY), J2-8 (wire K745-YL), J2-13 (wire G705-GN), J2-19 (wire G704-YL) and J2-37 (wire 321-BR).

      Expected Result: Each resistance should be greater than 5000 ohms for each measurement.

      Results:

      • YES - The resistance is correct for each measurement. The machine harness is correct. Proceed to 2.

      • NO - There is a short in the machine harness. The short is between signal contact J1-26 (wire 419-YL) and the circuit with the low resistance measurement. Repair the harness or replace the harness. STOP.

2. CHECK THE SWITCH.

   1. Turn the disconnect switch and the key start switch to the "ON" position.

   2. Access the service mode. Place the CID 0627 FMI 03 on-hold. Ensure that the "SERV CODE" indicator shows "SERV CODE".

   3. Observe the status of the "SERV CODE" indicator. Disconnect the machine harness from the switch. If the switch is not the cause of the diagnostic code, "SERV CODE" remains ON. If the switch is the cause of the diagnostic code, "SERV CODE" goes OFF.

      Expected Result: The "SERV CODE" remains ON.

      Results:

      • OK - The "SERV CODE" remains ON. The switch is NOT the cause of the diagnostic code. Proceed to 3.

      • NOT OK - The "SERV CODE" goes OFF. The switch has failed. Replace the switch. STOP.

3. CHECK IF THE DIAGNOSTIC CODE REMAINS.

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

   2. Reconnect all harness connectors.

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

   4. Enter the service mode of the Caterpillar Monitoring System and clear all the inactive diagnostic codes.

   5. Attempt to operate the machine in all gears. All gears may not be available.

   6. Stop the machine and engage the parking brake.

   7. Observe the status of CID 0627 FMI 03 for the switch. The "SERV CODE" is NOT showing.

      Expected Result: The CID 0627 FMI 03 for the switch is NO longer present. The "SERV CODE" is NOT showing.

      Results:

      • YES - The diagnostic code is NO longer present. The "SERV CODE" is NOT showing. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation. STOP.

      • NO - The diagnostic code remains present. The "SERV CODE" is showing. It is unlikely that the ECM is faulty. 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.