Normal Operation

The ABS module uses information received from several sensors (wheel speed sensors, steering wheel rotation sensor, stability control sensors, etc.) to determine if vehicle stability or traction warrants Electronic Stability Control (ESC) interaction. If interaction is warranted, the ABS module will adjust brake torque at specific wheels and the PCM will reduce engine torque to make the vehicle more stable. Once the ABS module has determined that the stability event has been corrected, it will return brake and engine torque to normal and continue to monitor the vehicle.

If conditions exist during normal operation that prevent the ESC  system from operating, DTC C1963 will be set. This DTC is usually set due to the steering wheel rotation sensor or the Restraints Control Module (RCM) being damaged or installed incorrectly. This DTC will not clear until the vehicle has been driven above 48 km/h (30 mph) with input from the steering wheel rotation sensor.

• DTC C1963 (Stability Control Inhibit Warning) - Once every key-cycle the ABS module will determine the straight-ahead or center position of the steering wheel by monitoring the steering wheel rotation sensor while the vehicle is being driven. If the vehicle reaches a speed of 75 km/h (47 mph) without finding the center position or if 30 seconds has passed since the initial drive-off without finding the center position, DTC C1963 will set.

This pinpoint test is intended to diagnose the following: 

• Steering wheel rotation sensor
• Stability control sensors
• Wheel speed sensors
• ABS module