Circuit Description

Under normal driving conditions, EBCM monitors steering angle sensor inputs to see if steering wheel is moving. If steering wheel is not moving for a set period of time, EBCM assumes vehicle is going in a straight line. At this point, EBCM looks at steering angle sensor inputs and considers degree angle to be zero. This is called offset value. Steer angle centering is process by which EBCM calibrates steering sensor output so that output reads zero when steering wheel is centered.

DTC sets if one or more of following conditions exist and vehicle speed is greater than 25 MPH.

• Steering angle sensor detects an internal malfunction and sends a Controller Area Network (CAN) message to EBCM.
• If offset value is higher than 15 degrees, a malfunction is detected. Malfunction time depends on driving distance, vehicle speed and amount of malfunctioning steering angle signal.
• Rapid changes of steering angle sensor signal cannot occur under normal driving conditions. If signal change is higher than 2000 degrees per second or steering angle acceleration is higher than 37500 degrees per second squared, a malfunction is detected.
• A reference steering angle signal based on a vehicle model is used to check actual steering angle. If measured steering angle varies from reference steering angle by more than a predetermined value, a malfunction is detected.