Traction Control
When the drive wheels lose traction and begin to spin, with vehicle speed under 100 km/h (62 mph), the ABS module commands the hydraulic pump motor on and commands the HCU to open and close the appropriate solenoid valves to modulate the brake pressure to the brake caliper(s) while simultaneously sending a request to the PCM over the High Speed Controller Area Network (HS-CAN) bus to reduce engine torque to maintain vehicle traction. The PCM accomplishes this by minor incremental timing changes and fewer fuel injector pulses until the ABS module ends the request. The request ends when the driven wheel speed returns to the desired speed. After the vehicle speed exceeds 100 km/h (62 mph), the traction control is accomplished only through the PCM torque control. The traction control system can be deactivated by pressing the traction control switch in the instrument panel.
When the traction control system activates, any of the following can occur:
- A rumble or grinding sound much like ABS
- A small deceleration or a reduction in the acceleration of the vehicle
- The stability/traction control indicator "sliding-car icon" in the Instrument Panel Cluster (IPC) flashes
- If the driver's foot is on the brake pedal, a vibration can be felt in the pedal much like ABS