Pinpoint Test Ad: Stability System Active Too Long Concern: Notes

Refer to VEHICLE DYNAMIC SYSTEMS for schematic and connector information.

Normal Operation and Fault Conditions 

On chassis cab vehicles, the ABS module uses information from the wheel speed sensors, the RCM, the steering wheel rotation sensor and brake pedal input to determine if anti-lock control intervention is necessary to help stop the vehicle. The ABS module uses the HCU to modulate the brake fluid pressure to the brake calipers and continues to monitor the sensor and module input until the wheel lock up has been corrected. Once the sensors and modules indicate the wheel lock up event has been corrected, the ABS module deactivates the HCU. On stripped chassis vehicles, the ABS module uses information from the wheel speed sensors, the yaw rate sensor, the steering wheel rotation sensor (sent from the SCCM and brake pedal input to determine if stability control intervention is necessary to help stabilize the vehicle. The ABS module uses the HCU to modulate the brake fluid pressure to the brake calipers and continues to monitor the sensor and module input until the instability event has been corrected. Once corrected, the ABS module deactivates the HCU. Under inflated tires, wheels and tires that do not match VC label specifications, suspension and steering damage, and one or more sensor failures contribute to the ABS module setting this DTC.

REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

DTC Fault Trigger Conditions 

Possible Sources 

• Tire pressure
• Wheel and tire size
• Chassis damage
• Steering damage or alignment
• Wheel speed sensor
• Steering wheel rotation sensor
• RCM module