HANDRAIL GP 1469750 - Caterpillar

Illustration 1 g00472349
Dual Horsepower Solenoid Valve SchematicCID 0688 FMI 06 service code is recorded when the power train electronic control module (ECM) reads the current of the dual horsepower solenoid valve circuit above normal (short to ground). Note: Ensure that the service code CID 0688 FMI 06 for the dual horsepower solenoid is active.Before performing this procedure, refer to table 1 in order to determine the connector contact and the wire number that corresponds to the failed circuit.
Table 1
Solenoid Valve Information    
Fault    Connector Contact No. (1)    Wire No.    
Dual Horsepower Solenoid     J1-10     795-YL    
( 1 ) Connector contact number of the power train ECM.Note: All solenoid return lines are joined in order to connect to contacts J1-7 and J2-3 (wire 975-WH) of the power train ECM.Note: The approximate coil resistance of the solenoid valve is 20 to 60 ohms.
Check the resistance of the solenoid.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the suspected solenoid.
At the solenoid, measure the resistance between the two contacts of the solenoid connector.Expected Result: The resistance should be between 20 and 60 ohms.Results:
OK - The solenoid resistance is correct. Proceed to Step 2.
NOT OK - The solenoid is faulty. Replace the solenoid. STOP.
Check the solenoid for a short to ground.The disconnect switch and the key start switch remain in the OFF position. The solenoid remains disconnected from the machine harness.
Measure the resistance from each solenoid contact to frame ground.Expected Result: Each resistance should be greater than 5000 ohms.Results:
OK - The solenoid and the solenoid harness are correct. The fault is in the machine harness. Proceed to Step 3.
NOT OK - The solenoid is faulty. Replace the solenoid. STOP.
Check the solenoid signal circuit for a short to ground.The machine harness remains disconnected from the solenoid.
The disconnect switch and the key start switch remain in the OFF position.
Disconnect machine harness connectors J1 and J2 from the power train ECM.
At machine harness connector J1 or J2, measure the resistance from the solenoid signal contact to all possible sources of ground. The following contacts are possible sources of ground: J1-2, J1-5, J1-7, J1-15, J1-16, J2-3 and frame ground.Expected Result: Each resistance should be greater than 5000 ohms.Results:
OK - The machine harness is correct. Proceed to Step 4.
NOT OK - There is a short in the machine harness between the wire for the solenoid signal and the circuit with low resistance. Repair the machine harness or replace the machine harness. STOP.
Check if the fault is still present.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Stop the machine and engage the parking brake.
Check whether the CID 0688 FMI 06 service code is active.Expected Result: The CID 0688 FMI 06 service code is active.Results:
YES - The fault has not been corrected. It is unlikely that the power train ECM is faulty. Perform the previous steps again. If