Electronic Brake Force Distribution (EBD)
Electronic brake force distribution (EBD) is integrated in the ABS system and controls the braking forces to the rear wheel brakes. Electronic brake force distribution controls the hydraulic pressure in the brake circuit for the rear wheels the rear wheels slip considerably less than the front wheels under braking. This ensures optimal and stable braking.
The brake control module (BCM) regulates the brake pressure by controlling the inlet and outlet valves in the brake circuits for the rear wheels.
The brake pressure in the rear wheel circuits varies, depending on how much the rear wheels slip in relation to the front wheels. The purpose of the control is to keep the rear wheel slippage to 0-2% lower than the front wheels. This means that the function is load sensitive.
Generally, the difference between the rear wheel and front wheel slippage under braking is dependent on how hard the brakes are applied and on the load of the car. Hard braking /light loads cause more slippage, light braking/heavy loads cause less slippage.
Therefore the requirement for brake fluid when the hydraulic pump is not activated during electronic brake force distribution (EBD) control is less than during stability and traction control. The fluid volume returned from the brake circuits is taken up by the accumulators.