SHUT-OFF GP 5N3633 - Caterpillar

Illustration 1 g01298884
Schematic of the solenoid valveThis diagnostic trouble code is associated with the solenoid valve. The FMI 03 means that the ECU has determined that the voltage of the solenoid circuit is above normal.The possible causes of the diagnostic trouble code are listed:
The energize circuit of the solenoid is shorted to the +battery circuit.
The ECU has failed. This is unlikely.Note: The following test procedure may create other diagnostic trouble codes. Ignore these created diagnostic trouble codes and clear these diagnostic trouble codes when the original diagnostic trouble code has been corrected. Ensure that the diagnostic trouble code of CID 2859 FMI 03 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT TO THE +BATTERY CIRCUIT.
Turn the key start switch and the disconnect switch to the ON position.
Disconnect the wires from the back of the connector at the ECU.
At the machine harness connector for the solenoid, measure the voltage from contact 1 (wire X956-OR) to frame ground. At the machine harness connector for the solenoid, measure the voltage from contact 2 (wire K952-BR) to frame ground. Expected Result:The voltage is 0 VDC.Results:
OK - There are no shorts in the wires. Proceed to Test Step 2.
NOT OK - A voltage is present in the wires. There is a short in the machine harness or in the wires. The short is to a separate voltage source.Repair: Repair the machine harness or replace the machine harness. Ensure that the fix has corrected the problem.STOPTest Step 2. CHECK THE OPERATION OF THE ECU.The disconnect switch and the key start switch remain in the OFF position. The machine harness connector for the solenoid and the ECU remains disconnected.
Use a wire removal tool. Disconnect wire X956-OR at connector contact J1-65.
Reconnect the machine harness connectors to the ECU.
Turn the disconnect switch and the key start switch to the ON position.
Observe the status of the active diagnostic trouble code.Expected Result:The diagnostic trouble code of a FMI 03 changes to a FMI 05.Results:
OK - The FMI 03 changes to a FMI 05. The FMI 05 was activated after the energize circuit for the solenoid was disconnected. The ECU has responded correctly to the condition of an open circuit in the solenoid circuit. Reconnect the disconnected wire. Wire (X956-OR) connects to the ECU at connector contact J1-65. Proceed to Test Step 3.
NOT OK - The FMI 03 does not change to a FMI 05. The active diagnostic trouble code did not change.Repair: The ECU has not responded correctly to the condition of an open circuit in the solenoid circuit. The operation of the ECU is not correct. Replace the ECU. Prior to replacing an ECU, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, "Electronic Control Unit - Replace".STOPTest Step 3. CHECK IF THE DIAGNOSTIC TROUBLE CODE IS STILL ACTIVE.
Inspect the harness connectors. Clean the contacts of the harness