Pinpoint Test V : Steering Wheel Position Sensor Signal Failure Faults: Notes
Normal Operation and Fault Conditions
On vehicles with adaptive steering, the SASM uses the steering angle sensor to monitor steering wheel rotation speed, angle and direction of rotation and sends the information to the SCCM over a private CAN. The steering angle sensor in an internal component of the SASM-clockspring assembly. The SCCM relays the information to the ABS module over the HS-CAN2.
On vehicles without adaptive steering, the SCCM uses the steering wheel rotation sensor to monitor steering wheel rotation speed, angle and direction of rotation and sends the information to the ABS module over the HS-CAN2. The steering wheel rotation sensor is mounted to the SCCM.
A failure of the HS-CAN2, SCCM, SASM, the steering angle sensor or the steering wheel rotation sensor causes the ABS module to set one or more Diagnostic Trouble Codes (DTCs).
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| C0051:23 | Steering Wheel Position Sensor: Signal Stuck Low | This DTC sets in continuous memory if the steering wheel position sensor signal value remains unchanged for the duration of the test period with vehicle speed above 5.4 km/h (3.36 mph). |
| C0051:27 | Steering Wheel Position Sensor: Signal Rate of Change Above Threshold | This DTC sets in continuous memory if the steering angle sensor input gradient value is greater 30 degrees for the duration of the test period. |
| C0051:54 | Steering Wheel Position Sensor: Missing Calibration | This DTC sets in continuous memory if the steering angle sensor center has not been found and certain time and vehicle speed thresholds have been achieved. |
| C0051:62 | Steering Wheel Position Sensor: Signal Compare Failure | This DTC sets in continuous memory when there is a time-out, quality factor failure, plausibility failure of the yaw signal or a plausibility failure of the wheel speed data. |
| C0051:64 | Steering Wheel Position Sensor: Signal Plausibility Failure | This DTC sets in continuous memory if the difference between the steering wheel angle signal and the calculated reference signal is too high or if the steering wheel angle sensor does not match other stability control sensor inputs (yaw rate, lateral acceleration, longitudinal acceleration, roll rate). |
| C0051:86 | Steering Wheel Position Sensor: Signal Above Allowable Range | This DTC sets in continuous memory when there is a time-out, quality factor failure, plausibility failure of the steering angle sensor data. When this occurs, the steering sensor center position cannot be determined to be valid and the system triggers the re-learn center process. |
Possible Causes
- Incorrectly mounted RCM
- Network communication concern
- Incomplete or incorrect stability control sensor calibration
- Wheels and tires
- Front suspension components
- Steering system components
- Wheel speed sensor
- SASM-clockspring (vehicles equipped with adaptive steering)
- Steering wheel rotation sensor (vehicles not equipped with adaptive steering)
- RCM
- ABS module