BARREL AS 9T8637 - Caterpillar

Illustration 1 g00789954
Schematic of the Position Sensor for the Steering Circuit in the Joystick ControlThis diagnostic code is recorded when the ECM reads the sensor signal as being below normal. There is a short to ground. Note: The sensor is probably out of specification, if the diagnostic code is only present under certain operating conditions. As an example, the joystick is "full left" or the joystick is "full right". Replace the sensor and calibrate the new sensor. See Testing and Adjusting, "Position Sensor (Steering) of Joystick Control - Calibrate" for more information.The possible causes of this diagnostic code are listed:
The signal circuit is shorted to ground.
The sensor has failed.
The ECM has failed. This is unlikely. Note: Ensure that CID 1700 FMI 04 is on hold and that the diagnostic indicator is illuminated. 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:When this diagnostic code occurs, the action lamp and the action alarm is ON. The diagnostic code will cause the joystick to stop functioning. The machine will decelerate to a stop.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. Then, disconnect the sensor from the machine harness.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 The sensor is the cause of the diagnostic code if the diagnostic code is NO longer active.Results: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 ECM may have failed. Proceed to test step 2.
NOT OK - The diagnostic code is NO longer active. The machine harness and the ECM are operating properly.Repair: The sensor has failed. Replace the sensor. Calibrate the sensor. See Testing and Adjusting, "Position Sensor (Steering) of Joystick Control - Calibrate" for more information. Verify that the new sensor 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 J1-14 (wire C703-BR) to all possible sources of ground. Measure the resistance to all contacts of 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. Proceed to Test Step 3.
NOT OK - One or more of the measurements is NOT correct. There is a short in the machine harness.Repair: The machine harness has failed. There is a short in the machine harness between the signal circuit and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK IF THE