COUPLER-A/C 2081339 - Caterpillar

Illustration 1 g00439248
Schematic for the Lift Lower SolenoidThis diagnostic code is recorded when the ECM detects a short to the +battery in the electrical path that goes from the ECM to the solenoid back to the ECM.The possible causes for this diagnostic code are listed:
The signal circuit from the ECM to the solenoid is shorted to the +battery.
The return circuit from the solenoid is shorted to the +battery.System Response:The machine response is listed:
All electrohydraulic valves are turned off.
The pilot on/off solenoid valve is turned off.
Implement functions are disabled until the fault is corrected and the levers are centered.Note: All solenoid return lines connect to contacts J1-7 and J2-3 (wire 716-WH) of the implement ECM.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code is corrected.Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.Test Step 1. CHECK THE SOLENOID.
Turn the key start switch to the OFF position.
Disconnect the solenoid with the diagnostic code from the harness.
Turn the key start switch to the ON position.
Place the direction lever in the NEUTRAL position.
At the harness connector for the solenoid, measure the voltage from the ECM between contact 1 (wire H716-WH) and contact 2 (wire H714-OR). Expected Result: The voltage is approximately 5 DCV.Results:
YES - The voltage is approximately 5 DCV.Repair: The solenoid has failed. Replace the solenoid. Stop.
NO - The voltage is approximately battery voltage. Proceed to Test Step 2.Test Step 2. CHECK THE HARNESS.
Turn the key start switch to the OFF position.
Disconnect the harness from the ECM.
Turn the key start switch to the ON position.
At the harness connector for the ECM, measure the voltage between contact J1-2 (wire A272-BK) and contact J1-4 (wire H714-OR).Expected Result:The voltage is approximately battery voltage.Results:
YES - The voltage is approximately battery voltage.Repair: There is a short to the +battery in the harness. Repair the harness or replace the harness. Stop.
NO - The voltage is approximately 0 DCV. The cause or the diagnostic code has not been found. Proceed to Test Step 3.Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Turn the key start switch to the OFF position.
Inspect all harness connectors and reconnect.
Turn the key start switch to the ON position.
Enter service mode.
Operate the machine and ensure that the same diagnostic code is active.Expected Result: The diagnostic code is active.Results:
YES - The diagnostic code is active.Repair: The diagnostic code has not been corrected. It is unlikely that the ECM has failed. Exit this procedure and perform this troubleshooting 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.
NO - The diagnostic code is inactive.Repair: 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.