Pinpoint Test O : Stability Control Sensor Signal And Circuit Faults: Notes

Refer to Vehicle Dynamic Systems , for schematic and connector information.

Normal Operation and Fault Conditions 

The ABS module uses information received from several sensors (wheel speed sensors, steering wheel rotation sensor, stability/traction control system sensors, etc.) to determine if vehicle stability, traction or roll warrants ESC or RSC ® interaction. If a stability or traction event is going to occur, the ABS module adjusts the brake torque at specific wheels and the PCM reduces engine torque to help make the vehicle more stable. Once the ABS module has determined the stability or traction event has been corrected, it returns the brake and engine torque to normal and continues to monitor the vehicle. DTCs set in the ignition cycle can only be cleared by cycling the ignition off and on once the fault has been corrected. The RCM measures the yaw rate and vehicle acceleration, then sends the signal through a secondary, private HS-CAN to the ABS module. The ABS module uses this information for AdvanceTrac ® and RSC ® system operation. The ABS module also compares this information to other information it receives from other sensors (brake pedal input, steering wheel) to determine how valid the information is and to determine if an instability event is about to occur.

The RCM and the ABS module communicate along a secondary, private HS-CAN. An open circuit or a short to power or ground on any one of these circuits causes the ABS module to set a DTC. Also, if the RCM is not mounted in the correct position, the ABS module also sets DTCs.

Possible Causes 

• Wiring, terminals or connectors
• Wheels or tires
• RCM