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

Illustration 1	g00617501
Schematic Of The Indicator Lamp For The Transmission Hold Indicator

This diagnostic code is recorded when the ECM reads the current of the bulb as being above normal.

Possible causes of this diagnostic code are listed:

• Wire G870-GY is shorted to ground.

• The bulb is faulty.

• The ECM is faulty.

Note: Ensure that CID 0968 FMI 06 for the bulb is present. The "SERV CODE" is showing.

As a result of this diagnostic code, the operator does not know if the "hold mode" is being accessed.

1. CHECK THE INDICATOR LAMP.

   1. Turn the disconnect switch and the key start switch to the ON position. DO NOT start the engine. Ensure that the diagnostic code for the indicator lamp is active.

   2. Disconnect the machine harness from the indicator lamp.

   3. Observe the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active.

      Expected Result: The status of the diagnostic code changes to "NOT active" when the indicator lamp is disconnected.

      Results:

      • Yes - The circuit is correct. The indicator lamp is faulty. Repeat this test "CHECK THE INDICATOR LAMP" in order to verify that the indicator lamp has failed. Replace the indicator lamp. STOP.

      • NO - The diagnostic code remains active. Proceed to 2.

2. CHECK THE SIGNAL CIRCUIT OF THE INDICATOR LAMP FOR A SHORT.

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

   2. Disconnect the machine harness from the indicator lamp.

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

   4. At the J1 and J2 machine harness connectors for the ECM, measure the resistance from the signal contact of the indicator lamp J2-7 (wire G870-GY) to ground. The possible sources of ground are connectors: J1-2 (wire 202-BK), J1-5 (wire 202-BK), J1-7 (wire F789-PU), J2-3 (wire F790-PK) and frame ground.

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

      Results:

      • YES - The machine harness is correct. Proceed to 3.

      • NO - There is a short in the machine harness. The short is between the signal contact of the indicator lamp and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness. 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 key start switch to the ON position.

   4. Clear all of the inactive diagnostic codes.

   5. Operate the machine.

   6. Stop the machine. Then place the parking brake switch in the ON position.

   7. Observe the status of the diagnostic code. The diagnostic code is present or the diagnostic code is NOT present.

      Expected Result: The diagnostic code for the indicator lamp is NO longer present.

      Results:

      • YES - The diagnostic code is NOT present. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection and/or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation. STOP.

      • NO - The diagnostic code has not been corrected. It is unlikely that the ECM is faulty. Exit this procedure and perform this diagnostic code again. Recheck the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active. Replace the ECM if the cause is not found. See Testing And Adjusting, "Electronic Control Module (ECM) - Replace". STOP.