Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The steering angle sensor supplies input circuits to the electronic brake control module (EBCM) from the Phase A and Phase B, the Index Pulse Phase C circuits, and 1 Analog signal circuit for steering wheel angle. The analog signal is used along with the index pulse to calibrate the steering angle sensor (SAS). The SAS position is then determined by Phase A and Phase B signals. The 2 input signals Phase A and Phase B are approximately 90 degrees out of phase. Once calibrated, the EBCM dynamically interprets the relationship between the Phase A and Phase B inputs, and determines the position of the steering wheel and the direction of the steering wheel rotation.