GUARD G-SHEAVE 3F6648 - Caterpillar

Illustration 1 g01238970
Schematic of the transmission lockup clutch solenoidThis diagnostic trouble code is associated with the transmission lockup clutch solenoid. The FMI "6" means that the ECU has determined that there is a short to ground in the solenoid circuit. The possible causes of this diagnostic trouble code are listed:
The energize circuit of the solenoid is shorted to ground.
The solenoid has failed.
The ECU has failed. TheECU failing 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 SPN 740 FMI 6 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.System Response:The solenoid will not engage.Test Step 1. CHECK THE SOLENOID.
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Observe the status of the diagnostic trouble code.
Disconnect the solenoid with the active diagnostic trouble code from the machine harness. Expected Result:The FMI 6 changes to FMI 5 when the solenoid is disconnected.Results:
YES - The FMI 6 changes to FMI 5 when the solenoid is disconnected. The circuit is correct.Repair: The solenoid has failed. Replace the solenoid. Verify that the new solenoid corrects the problem.STOP
NO - The SPN 740 FMI 6 remains active. Proceed to Test Step 2.Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT TO GROUND.
Turn the key start switch and the disconnect switch to the OFF position.
The solenoid remains disconnected from the machine harness.
Disconnect the machine harness connector from the ECU.
At the machine harness connector, measure the resistance from the signal contact J1-62 (wire 705-PK) to all contacts that are used in the machine harness connectors for the ECU. 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 3.
NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J1-62 (wire 705-PK) and the circuit with the low resistance measurement.Repair: Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK IF THE DIAGNOSTIC TROUBLE CODE REMAINS.
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, battery acid, 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 fastened.
Turn the disconnect switch and the key start switch to the ON position.
Operate the vehicle.
Check the status of the SPN 740 FMI 6. Expected Result:The SPN 740 FMI 6 is active. Results:
YES - The SPN 740 FMI 6 is active. The diagnostic trouble code has not