Anti-Lock Brake System (ABS)

WARNING: This page is about a different car, the 2017 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

The ABS module continuously monitors brake pedal input, longitudinal vehicle motion and the rotational speed of each wheel. The ABS module receives the brake pedal input from the PCM and the longitudinal acceleration sensor information from the RCM. The PCM sends the information to the GWM over the HS-CAN1. The GWM then relays the information to the ABS module over the HS-CAN2. The RCM sends the information directly to the ABS module over the HS-CAN2. Wheel speed information is received by the ABS module using 4 wheel speed sensors. When the ABS module detects an impending wheel lock during a braking event, 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. Once the affected wheel(s) return to the desired speed, the ABS module returns the solenoid valves in the HCU to their normal position.

When the ABS module is initialized (ignition ON), a preliminary electrical check of the system sensors is carried out and hydraulic pump motor is activated for approximately one-half second. During this time, a buzzing or humming noise may be heard and a vibration may be felt in the brake pedal, this is a normal condition. During the module initialized self-test, the pump motor check is carried out at approximately 10 km/h (6 mph). Any malfunction detected in the system causes the ABS module to set a DTC, disable the ABS function and send a message over the HS-CAN2 to the GWM. The GWM relays the message to the IPC over the HS-CAN3 to illuminate the ABS warning indicator. The base hydraulic power assist braking system functions normally.