Traction Control

WARNING: This page is about a different car, the 2016 Lincoln MKS. However, it is still accessible from the selected car via links, so may be relevant.

The ABS module continuously monitors and compares the rotational speed of the drive wheels in relation to the non-driven wheels. When the drive wheels begin to spin faster than the non-driven wheels, the ABS module 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 calculates how much engine torque reduction is required to eliminate the wheel slip and sends this torque reduction message to the PCM over the HS-CAN. The ABS module also sends a traction event message to the IPC over the HS-CAN. When the PCM receives the torque reduction message, it adjusts engine timing and decreases fuel injector pulses to reduce the engine torque to the requested level. When the IPC receives traction event message, it flashes the sliding car icon.

Once the driven wheel speed returns to the desired speed, the ABS module returns the solenoid valves in the HCU to their normal position, deactivates the hydraulic pump motor and stops sending the traction event and torque reduction messages. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the sliding car icon. After the vehicle speed exceeds 100 km/h (62.1 mph), traction control is accomplished only through the PCM torque control.

The traction control system can be disabled by the driver through the menu in the message center by changing the TRACTION CNTRL setting in the message center from ON to OFF. This is independent of the ABS and ESC functions, which cannot be disabled by the driver. When the driver disables the traction control function through the message center, the IPC communicates traction control system status to the ABS module over the HS-CAN and illuminates the sliding car OFF icon. The ABS module takes no further action in regards to traction control until the driver activates the function or until the ignition is cycled from OFF to ON.

The ABS module disables the traction control function if there are any wheel speed sensor or solenoid valve DTCs present in the ABS module. The traction control function is also disabled if there is a communication error between the ABS module and the PCM. When the traction control function is disabled, the ABS module sends a message to the IPC over the HS-CAN to illuminate the sliding car OFF icon.