The Steering angle sensor(SAS) is composed of main gear, serve gear1 and serve gear2 to determine the turning direction. The SAS is a CAN communication type sensor. If main gear is rotated according to the rotation of steering wheel serve gear1 and serve gear2, which is contact with main gear, will be rotated. The HECU detects the absolute angle by using magnetic MR effect and the difference gear ratio of each serve gear and then send to the CAN comunication line. The HECU detects the steering wheel's operating speed and operating angle by using absolute angle, and this signal is used in a input signal of anti-roll control.
The HECU checks the CAN communcation lines for normal ESP control, and sets this code if an WAS message is not received within predefined time.
Item
Detecting Condition
Possible cause
DTC Strategy
CAN massage monitoring
Faulty SAS
Faulty HECU
Monitoring Period
Continuous
Enable Conditions
Faults are detected if SAS message was not received on time by the CAN controller of HECU.
Fail Safe
Inhibit the ESP control and allow the ABS/EBD control.
Meanwhile, stop checking the ESP switch failure under the ESP control.