Traction Control System

The traction control system uses the ABS and the PCM to limit wheel spin. When the ABS module detects a wheel spinning excessively, brake pressure to the appropriate brake caliper is modulated. This is accomplished 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 that a traction control event is taking place. When the IPC receives this message, it flashes the stability/traction control indicator (sliding-car icon). If the event is severe enough, the ABS module sends a message to the PCM over the HS-CAN to assist with traction control. When the PCM receives this message, it adjusts engine timing and decreases fuel injector pulses. Once the affected wheel returns to normal speed, 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 indicating the traction event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the sliding-car icon.

Once vehicle speed reaches or exceeds 100 km/h (62 mph), traction control is accomplished only through PCM intervention.

Certain DTCs in the ABS module disable the traction control system. Depending on the DTCs present, the yellow ABS warning indicator and/or the sliding-car icon is illuminated.

The driver is able to enable and disable the traction control portion of the Advance Trac®. This is independent of the ABS and ESC functions, which cannot be disabled by the driver. To disable or enable the traction control system, the TRACTION CNTRL setting in the message center is changed from ON to OFF. When the driver disables the traction control system, the IPC communicates traction control system status to the ABS module over the HS-CAN bus. The ABS module will no longer intervene when a traction event is detected. The ABS module sends a message to the IPC over the to HS-CAN bus illuminate the stability/traction control OFF indicator (sliding-car OFF icon), which indicates to the driver that the traction control system is disabled. The system automatically restores to full functionality when the ignition is cycled to OFF and then back to RUN.