FORK 0325126 - Caterpillar

Illustration 1 g01396003
Connections of the forward low solenoidThis diagnostic code is associated with the forward low 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 1401 FMI 03 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.System Response:When this diagnostic code is active, the ECM will turn off the current to the failed solenoid.Test Step 1. CHECK THE SOLENOID ENERGIZER CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT
Turn the starter keyswitch and the disconnect switch to the OFF position.
Disconnect the harness connectors from the solenoid and the ECM.
At the connector for the transmission harness for the ECM, measure the resistance from contact J1-65 (wire 752-YL) to all contacts that are used in the connectors for the transmission harness for the ECM.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The transmission 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 transmission harness. The short is between J1-65 (752-YL) and the circuit that has a low resistance measurement.Repair: Repair the transmission harness or replace the transmission harness.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE
Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, corrosion, or chafing.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Reconnect all harness connectors in order to make sure that the connectors are fully seated. Also, make sure that the clips for each connector are completely fastened.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Determine if the diagnostic code is active.Expected Result:The diagnostic code is active.Results:
YES - The diagnostic code is active. The problem has not been corrected.Repair: Check the circuit again. It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement,