COVER AS-VALVE 2048987 - Caterpillar

Illustration 1 g03811823
Schematic of the Reversing Fan Solenoid circuit
This diagnostic code is associated with the "Solenoid Valve (Fan Reversing)". The FMI 03 means that the ECM has determined that the voltage of the solenoid circuit is above normal. The possible causes of the diagnostic code are listed below:
The energize circuit of the solenoid is shorted to the +battery circuit.
The ECM has failed. This condition is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 485 FMI 03 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:When this diagnostic code occurs, the direction of the engine fan will always be reversed.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 OFF position.
Disconnect the machine harness connectors from the solenoid and the ECM.
At the machine harness connector for the ECM, measure the resistance from contact J1-5 (wire H704-PK(Pink)) to all contacts that are used in the machine harness connectors for the ECM. Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 2.
NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J1-5 (H704-PK(Pink)) and the circuit that has a low resistance measurement.Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. Check The Operation Of The ECMThe disconnect switch and the key start switch remain in the OFF position. The machine harness connectors for the solenoid and the ECM remain disconnected.
At the harness connector for the Machine ECM J1, use a 151-6320 Removal Tool to remove the signal wire of the solenoid H704-PK(Pink) and the socket at contact J1-5 from the harness connector.
Reconnect the machine harness J1 connectors to the ECM.
Turn the disconnect switch and the key start switch to the ON position.
Observe the status of the active CID 485 FMI 03 diagnostic code. Expected Result:The CID 485 FMI 03 diagnostic code is no longer active. ACID 485 FMI 05 diagnostic code is now active.Results:
YES - The CID 485 FMI 03 diagnostic code is no longer active. A CID 485 FMI 05 diagnostic code is active after the energize circuit of the solenoid is disconnected. The ECM has responded correctly to the open circuit condition in the solenoid circuit. Reinstall the signal wire of the solenoid in the connector of the ECM. Proceed to Test Step 3.
NO - The CID 485 FMI 03 diagnostic code remains active. The active status of the diagnostic code did not change when the signal wire of the solenoid was disconnected from the ECM.Repair: The ECM has not responded correctly to the open condition in the solenoid