Steering Wheel Rotation Sensor

The steering wheel rotation sensor (on vehicles equipped with HPAS) measures the rate of rotation of the steering wheel by monitoring a clock spring slotted-wheel as it passes through the sensor gap. The rotation sensor uses 2 signal lines to transmit information to the ABS module about whether the steering wheel is being turned left or right and how far it is being turned. The rotation sensor used on HPAS vehicles is a relative sensor and does not indicate the position of the steering wheel relative to straight-ahead. At each consecutive ignition cycle, the steering wheel angle sensor will "zero" itself and transmit the 0 value to the ABS PID SWA regardless of steering wheel position.

If the front wheels are not turned to the straight ahead position when the ignition is turned on, the zero position will be taken at the initial wheel position. If the wheels are then turned to the straight ahead position, the value read in the SWA PID will no longer transmit 0. This is normal operation and does not indicate a problem in either the steering wheel angle sensor or the ABS module. Vehicles equipped with EPAS do not have a steering wheel rotation sensor. Vehicles equipped with autopark have an absolute steering wheel angle sensor module that transmits the steering wheel angle over the HS-CAN bus. For more information on EPAS, refer to STEERING SYSTEM - ELECTRONIC POWER ASSIST STEERING (EPAS) .

For more information about the Active Park Assist steering wheel angle sensor, refer to ACTIVE PARK ASSIST .