Steering Wheel Position Information

On vehicles equipped with Electronic Power Assist Steering (EPAS) (2.5L, 3.0L and Hybrid vehicles), the steering wheel position information is sent to the ABS module from the PSCM along the HS-CAN bus. The PSCM calculates steering position based on motor position within the EPAS steer gear. For information on EPAS, refer to STEERING SYSTEM - ELECTRONIC POWER ASSIST STEERING (EPAS) article.

On vehicles equipped with Hydraulic Power Assist Steering (HPAS) (3.5L vehicles only), the steering wheel rotation information is sent from the steering wheel rotation sensor. The steering wheel rotation sensor measures the rate of rotation of the steering wheel by monitoring the steering wheel rotation ring 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 does not indicate the position of the steering wheel relative to straight-ahead. The ESC system learns this position by comparing the steering wheel position with other signals and storing the position it has learned. The ESC system confirms this position and modifies it as necessary during every new driving cycle.