ESP_a139_steeringAngleWrongSign
Not Available
What does the ESP_a139_steeringAngleWrongSign alert mean?
Steering Wheel Position Sensor: Plausibility fault
What you'll see in your Tesla
- Not Available
What triggers it
This monitoring detects a wrong sign of steering angle signal. The yaw rate calculated from steering angle and the yaw rate calculated from the wheel speed sensors are compared. If the measured yaw rate fits to the model yaw rate positive integrals (IVzLwVA and IVzLwHA) are calculated but if the negative values fits the integrals will become negative. A fault is determined if the integral value is negative and forward driving is recognized. This fault will cause a release test in the following ignition cycle to assure that the sensor is build in correctly. This fault can also be caused by swapped WSS lines at one axle. It requires a release check in the following ignition cycle to prevent system release when the fault is still present. The conditions for release is positive integrals (IVzLwVA and IVzLwHA) > +180 deg.
When it clears
Verify EPAS is awake, in good state, and there is traffic present on the bus. Review EPAS/DI alerts for other indicators of failure
Potential impact
May fault VDC/TC, ABS performance degradation
Affected models
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