SOLENOID AS 3E7770 - Caterpillar

Illustration 1 g01941579
Connections of the primary shifter and the secondary shifterThis diagnostic code is associated with the sensor for the transmission gear selector. The FMI 08 means that the ECU has determined that the signal of the circuit for the sensor is not valid.The possible causes of this diagnostic code are listed:
Wire K900-YL is shorted to the sensor return (J2-67).
The sensor is not installed correctly.
The sensor has failed.
The ECU has failed. This is unlikely.Note: If the machine is shut down and the diagnostic code is active, the machine will NOT start again until the diagnostic code has been cleared. In order for the machine to start, the sensor must indicate the NEUTRAL position.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 CID 0702 FMI 08 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.System Response:The results of this diagnostic code are listed:
The machine will not shift.
The transmission will remain in the current gear.
The solenoid for the lockup clutch solenoid will disengage.Test Step 1. CHECK THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Ensure that the diagnostic code is active.
Observe the status of the diagnostic code. Disconnect the machine harness from the sensor.Expected Result:The diagnostic code will remain active if the sensor is not the cause of the diagnostic code. The sensor is the cause of the diagnostic code if the diagnostic code is NO longer active.Results:
OK - The diagnostic code remains active. The sensor has not failed. The machine harness may have failed or the ECU may have failed. Proceed to test step 2.
NOT OK - The diagnostic code is NO longer active. The machine harness and the ECU are operating properly.Repair: The sensor has failed. Replace the sensor.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, 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 of the 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 CID 0702 FMI 08 is active.Expected Result:The CID 0702 FMI 08 is active.Results:
YES - The CID 0702 FMI 08 is active. The problem has not been corrected.Repair: Check the circuit again. It is unlikely that the ECU has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECU. Prior to replacing an ECU, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time.