The ABS module is attached to the bulkhead on the left-hand side for all vehicle markets.
Modules pre-filled with brake fluid are available for service operations.
Diagnosis is done using WDS.
Communication with other control units is done on the high-speed CAN bus. The exception to this are the yaw rate and lateral acceleration sensor modules which communicate with the electronic stability programme module via a special CAN bus.
Combined yaw rate sensor and lateral acceleration sensor
Active sensors are used to determine the rotational speeds of the wheels at the hub. After the ignition is switched on, the ABS module supplies the sensors with power. The sensors work in accordance with the Hall effect principle and generate a square wave output signal. The signal acts in proportion to the rotational speed of the sensor ring.
The ABS sensor rings are built into the seals in the front wheel bearings.
The wheel sensors are joined to the main wiring harness using a separate connecting cable.
Rear wheel sensors
The ABS Anti-lock Brake System sensor rings are built into the hubs of the rear axle.
When installing a replacement bearing, ensure that the new part is aligned correctly.
The sensors are joined to the main wiring harness using a separate connecting cable.
The ABS module evaluates the signals from all four sensors to calculate road speed based on all wheel rotational speeds. The road speed is transmitted on the CAN bus. The powertrain control module (PCM) uses this signal and the programmed tyre size to calculate road speed.
The calculated vehicle speed is forwarded on the CAN bus and is requested by other control units that need this input information.
