VALVE-EXHAUST BACK PRESSURE 3629021 - Caterpillar

Illustration 1 g01455631
Connections of the air conditioner clutch solenoid
This diagnostic code is associated with the air conditioner clutch solenoid. The code FMI 03 means that the ECM has determined that the voltage is above normal.The possible causes of the diagnostic code are listed below:
The solenoid has failed.
The solenoid energizer circuit of the modulating valve is shorted to the +battery circuit.
The ECM has failed. This is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all of the connections in the circuit are clean and secure. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.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 2671 FMI 03 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE SOLENOID CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the solenoid and the ECM.
At the machine harness connector for the ECM, measure the resistance from contact J2-6 (wire E554-BR(Brown)) to all contacts that are used in the machine harness connectors for the ECM. Expected Result:Each resistance measurement should be 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 contact J2-6 (wire E554-BR(Brown)) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE OPERATION OF THE ECM.The 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 J1 connector for the ECM, use a wire removal tool to remove wire E554-BR(Brown) from contact J2-6.
Reconnect the machine harness J1 and J2 connectors to the ECM.
Turn the disconnect switch and the key start switch to the ON position.
Observe the status of the active diagnostic code. Expected Result:The FMI 03 changes to an FMI 05 after the wire is disconnected.Results:
YES - The FMI 03 changes to a FMI 05 after the wire is disconnected. The ECM has responded correctly to the condition of an open circuit. Reinstall the disconnected wire to the correct space in the ECM connector before proceeding to the next Test Step. Proceed to Test Step 3.
NO - The FMI 03 remains active. The status of the active diagnostic code did not change when the wire was disconnected from the ECM.Repair: The ECM has not responded correctly to the condition of an open circuit. The