AdvanceTrac® System

The AdvanceTrac® system is controlled by the ABS module and uses the same wheel speed sensors and tone rings that are used for the anti-lock control system. The AdvanceTrac® system also uses input from the steering wheel rotation sensor on Hydraulic Power Assist Steering (HPAS) -equipped vehicles, the Power Steering Control Module (PSCM) on Electronic Power Assist Steering (EPAS) -equipped vehicles, and inertial signals from the Restraints Control Module (RCM) (yaw rate and lateral acceleration) to help maintain vehicle stability. The ABS module uses all of these inputs to continuously monitor the vehicle's direction of travel relative to the driver's intended course. If the ABS module determines from all these inputs that the vehicle is unable to travel in the intended direction, it modulates brake pressure to the appropriate brake caliper(s) by opening and closing the appropriate solenoid valves inside the HCU while the hydraulic pump motor is activated. At the same time, the ABS module sends a message over the HS-CAN bus that a stability event is taking place. When the PCM receives this message, it will assist with vehicle stability by adjusting engine timing and decreasing fuel injector pulses. When the IC receives this message, it will flash the sliding-car icon (twice per second). Once the stability condition has been corrected, the ABS module returns the solenoid valves in the HCU to their normal position, deactivates the hydraulic pump motor and sends another message over the HS-CAN bus indicating that the event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IC extinguishes the sliding-car icon.

If the anti-lock control system is disabled due to DTCs being present in the ABS module, the AdvanceTrac® system will also be disabled. When the AdvanceTrac® system is disabled due to DTCs being present, both the ABS warning indicator and the sliding-car icon will be illuminated.