ABS General Information

ABS General Information

The ABS brake system is divided diagonally (two circuits). The vacuum brake servo unit boosts the brakes pneumatically.

Vehicles with ABS Mark 60 or ABS Mark 70 do not have a mechanical brake pressure regulator. A specially coordinated software program inside the ABS control module (J104) determines brake pressure allocation at the rear axle.

ABS malfunctions do not affect the brake system and the booster. Conventional brake system stays operative even without ABS. A change in braking behavior should be checked. When the ABS Warning Lamp (K47) is lit up, the rear wheels may lock prematurely during braking!

ABS Location






1. ABS Hydraulic Unit (N55) with ABS Control Module (J104)

2. Brake booster with tandem master cylinder


The ABS control module - 1 - and the ABS hydraulic unit - 2 - are a single unit. Separation can only be performed when removed from vehicle. The hydraulic pump - 3 - may not be separated from the ABS hydraulic unit.






Separation is not possible on vehicles with ABS/EDL/ASR/ESP with hydraulic brake booster or hill assist.