IDLER GP-TRACK 9W9989 - Caterpillar

Illustration 1 g01736114
Steering Control Position Sensor 2 connectionsTwo 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 will indicate the position of the steering control handle.The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width of the Steer Position Sensor 2 is not within the expected range.The Steer Position Sensor 2 receives power from the Machine ECM 8 V power supply circuit and the 5 V return circuit.The position sensor is a PWM sensor that operates at a frequency of approximately 500 Hz. The position sensor sends a PWM input signal to the Machine ECM. The duty cycle of the signal will vary from approximately 10 percent when the steering control handle is at the full left position to approximately 90 percent when the steering control handle is at the full right position. When the steering control handle is at the center position, the duty cycle will be approximately 50%. The possible causes of this diagnostic code are listed below:
The sensor has failed.
Intermittent connections or poor connections in the sensor circuit.
The ECM has failed. This is unlikely.Note: If a CID 0041 diagnostic code for the 8 V power supply has been activated by the Machine ECM (MID 039), investigate and fix the problem before proceeding with this procedure.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: 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 DUTY CYCLE AND THE SIGNAL FREQUENCY AT THE SENSORTurn the key start switch and the disconnect switch to the OFF position.
At the machine harness side of the steering control connector, use a 151-6320 Removal Tool to remove the signal wire 830-OR and socket at contact 6 from the harness connector. The machine harness connector remains connected to the steering control connector.
Insert the other probe along the sensor return contact 5 (wire J767-GY). At the vacant space in the machine harness connector where the signal wire was removed, use the positive side 7X-1710 Multimeter Probe to insert into the connector contact 6 to make contact with the signal pin on the steering control handle connector. Ensure that a good contact is made between the probes and the sensor contacts.
Turn the disconnect switch and the key start switch to the ON position. DO NOT START THE ENGINE.
With the Speed / Direction handle stationary, measure the frequency of the signal from the sensor.
While observing the measurement, wiggle the steering control connector. Gently pull on the wires and move the wires