NUT 4J8265 - Caterpillar

Illustration 1 g01318019
Schematic of the Hystat Joystick Control BaseThis diagnostic code is associated with the Hystat Joystick Left/Right Position Sensor. This diagnostic code is recorded when the ECM reads the sensor signal as being below normal. The possible causes of this diagnostic code are listed:
The sensor supply wire is open.
The signal circuit is shorted to ground.
The sensor has failed.
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 connections in the circuit are clean, secure and in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: Ensure that CID 1700 FMI 04 is active. Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected.System Response:A level 2 warning will be generated. Functionality is lost and ECM cannot determine desired steering. The machine will not be able to be moved.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.
Disconnect the sensor from the machine harness.
Observe the status of the diagnostic code. Expected Result:The diagnostic code will remain active.Results:
OK - The diagnostic code remains active. The sensor has not failed. The machine harness may have failed or the ECM may have failed. Proceed to test step 2.
NOT OK - The diagnostic code is NO longer active. The sensor has failed.Repair: Replace the joystick base. Recalibrate if necessary. Refer to Testing and Adjusting, KENR5148, "Calibration" procedure. Verify that the new joystick base corrects the problem.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND.
The sensor remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 and J2 machine harness connector from the ECM.
At the J1 machine harness connector, measure the resistance from contact J2-25 (wire C703-BR) to all contacts that are used in the machine harness connectors for the ECM.Expected Result:The resistance is greater than 5000 ohms for each measurement.Results:
OK - The resistance is greater than 5000 ohms for each measurement.Repair: If the cause of the problem is not found, contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, see Troubleshooting, "Electronic Control Module (ECM) - Replace".STOP
NOT OK - The resistance is less than 5000 ohms for one or more of the measurements.Repair: The machine harness has failed. There is a short in the machine harness between the signal circuit and ground. Repair the machine harness or replace the machine harness.STOP