BUSHING 4501493 - Caterpillar

Illustration 1 g01243832
Connections for Steering Position Sensor 1
Three steering position sensors are required for correct operation of the steering control lever. The steering position sensors are located in the left assembly of the joystick. Each sensor provides an input signal to the Implement ECM and to the Transmission/Chassis ECM. This diagnostic code is activated when the ECM detects that the signal voltage from the steering position sensor 1 is below normal. The steering position sensor 1 receives power from the 8 volt power supply of the Implement ECM. Steering position sensor 1 is internally connected to the ground that is supplied by the 8 volt sensor return of the Transmission/chassis ECM (ground of the ECM) and to the ground that is supplied by the 8 volt sensor return of the Implement ECM (ground of the ECM). The steering sensor must lose both grounds in order to lose a ground connection. The illustration above indicates the power and ground connections for the steering sensor 1.The position sensor is a PWM sensor that operates at a frequency of approximately 500 80 hertz. The position sensor sends a PWM input signal to the Implement ECM and to the Transmission/Chassis ECM. The duty cycle of the signal will vary from approximately 10 5% at the full left position of the joystick to approximately 90 5% at the full right position of the joystick. When the joystick is in the center position, the duty cycle will be approximately 50%.The possible causes of this diagnostic code are listed:
The signal circuit is shorted to a ground source.
The sensor has failed.
The ECM has failed. This is unlikely. Note: The Transmission/Chassis ECM (MID 027) and the Implement ECM (MID 082) receive an input signal from the steering sensor 1. Both ECM modules can activate a CID 1471 FMI 04 diagnostic code when the signal voltage is below normal. If one ECM has activated a CID 1471 FMI 04 diagnostic code and the other ECM has not, the sensor is probably operating correctly. When this occurs, a poor connection in the machine harness would be suspected. When both ECM modules have activated the diagnostic code, either the sensor OR a harness problem could be the cause. If both ECM modules have activated the diagnostic code, it is very unlikely that either ECM is causing the problem. For either condition, proceed with this procedure in order to verify the cause of the problem.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, that all connections are secure and that all connections are 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