Electronic Stability Control (ESC)

WARNING: This page is about a different car, the 2018 Ford EcoSport. However, it is still accessible from the selected car via links, so may be relevant.

The ABS module continuously monitors the vehicle motion relative to the intended course. This is done by using sensors to compare the steering wheel input and the yaw rate sensor input with the actual vehicle motion. The PSCM sends steering wheel angle and rate of change information, while the RCM sends yaw rate and longitudinal acceleration information to the ABS module. All 3 modules communicate over the HS-CAN2. If the ABS module determines from the inputs the vehicle is unable to travel in the intended direction, it modulates the brake pressure to the appropriate wheel ends 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 reduce vehicle speed to help stabilize the vehicle and sends this torque reduction message to the PCM over the HS-CAN1 through the GWM. The ABS module also sends a stability event message to the IPC over the HS-CAN3 through the GWM. 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 this message, it flashes the stability-traction control indicator (sliding car icon). Once the vehicle instability has been corrected, 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.

The ESC feature does not operate with the transmission in REVERSE. The ESC feature is disabled if there is a wheel speed sensor, stability sensor or steering angle sensor DTC present in the ABS module. Also, if there is a communication error between the ABS module and the PSCM or the ABS module and the RCM, the ESC feature is disabled. When the ESC feature is disabled, the ABS module sends a message to the IPC over the HS-CAN3 through the GWM to illuminate the stability-traction control OFF indicator (sliding car OFF icon).