Electronic Brake Distribution (EBD)

The ABS module incorporates a strategy called Electronic Brake Distribution (EBD). The EBD strategy uses the HCU as an electronic proportioning valve. On initial application of the brake pedal, full pressure is applied to the rear brakes. The ABS module uses wheel speed input to calculate an estimated rate of deceleration. Once vehicle deceleration exceeds a certain threshold, the ABS module closes the appropriate solenoid valves in the HCU to hold the rear brake pressure constant while allowing the front brake pressure to build. This creates a balanced braking condition between the front and rear wheels and minimizes the chance of rear wheel lockup during hard braking. As the vehicle decelerates, the valves are opened to increase the rear brake pressure in proportion to the front brake pressure.

If there is a DTC in the ABS module specifically for the HCU or there are 2 or more wheel speed sensor DTCs, EBD will be disabled. When EBD is disabled, the ABS warning indicator, the red brake warning indicator and the sliding-car icon will be illuminated.