GUARD GP-REAR 3920663 - Caterpillar

Illustration 1 g02718828
Steer Control #3 sensor connectionsA CID 1473 is associated with the Steer Control #3 sensor. An FMI 12 means the machine ECM has determined the Steer Position #3 sensor circuit is not sending the correct, or expected, values.Note: Multiple steer position sensors are required for correct operation of the steering control. The steer position sensors are located in the Speed / Direction Handle. Each sensor provides an input signal to the machine ECM that indicates the position of the Steering Control handle. The sensors output a PWM signal of approximately 500 ( 80) Hz that ranges in voltage from 0.0 VDC to 5.0 VDC. The signal duty cycle is approximately 10% when the steering control handle is rotated to the full forward position. The signal reaches approximately 90% when the steering control handle is rotated to the full rearward position. With the steering control handle at center position, the duty cycle is approximately 50%, and the signal voltage is approximately 2.5 VDC. An open or disconnected PWM sensor triggers an FMI 03 because of the voltage "Pull-Up" resistor configuration at the sensor ECM input pin.Possible causes for this diagnostic code are:
Sensor failure.
Machine ECM failure. Note: Poor connections are often the cause of a problem in electrical circuits. Before performing this procedure, inspect all the machine harnesses and connectors involved in the circuit. Make sure to verify that all of the connections in the circuit are clean, secure, and in good condition. Correct any problems found with any of the connections. Verify the diagnostic code CID 1473 FMI 12 is still active, before continuing this procedure.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Test Step 1. CHECK THE SENSOR
Turn the disconnect switch, and the key start switch, to the OFF position.
Disconnect the steering control machine harness connector from the Speed / Direction Handle.
Turn the disconnect switch, and the key start switch, to the ON position.
Observe the status of the active CID 1473 FMI 12 diagnostic code.Expected Result:The diagnostic code remains active and does not change. Results:
YES - The diagnostic code remains active and unchanged. The sensor is not causing the problem.
Go to Test Step 2.
NO - The