Anti-Lock Brake System (ABS) Repair Information

Anti-lock Brake System (ABS) Repair Information

• Before carrying out repair work on the ABS system, as well as the control module coding, determine the cause of the malfunction using "Guided Fault Finding".

"Guided Fault Finding" is performed with On Board Diagnosis (OBD), using the vehicle diagnosis, testing and information system (VAS 5051).

• Turn off the ignition and disconnect the battery ground cable.

• When working with brake fluid, observe relevant safety precautions and notes. Refer to => [ Brake System, Bleeding ] Service and Repair.

• After finishing any work that required opening the brake system, bleed the brake system using the brake charger/bleeder unit (VAS 5234). Refer to => [ Brake System, Bleeding ] Service and Repair.

• During the final road test, carry out at least one ABS controlled braking operation (appropriate pulsations must be felt at brake pedal).

• It is necessary to maintain a high level of cleanliness when working on the ABS system. It is not permitted to use any products which contain mineral oil, such as oils, greases, etc.

• Thoroughly clean all unions and the adjacent areas before loosening them. Do not use aggressive cleaning agents such as brake cleaner, fuel, thinners or similar chemicals.

• Place parts that have been removed on a clean surface and cover them.

• After disconnecting the control module from the hydraulic unit, use the valve dome transport protection.

• Carefully cover or seal open components, if repairs are not carried out immediately. (Use the plugs from repair kit 1 H0 698 311 A)

• Only use lint free cloths.

• Only unpack replacement parts immediately prior to installation.

• Only use parts that were in their original packaging.

• Do not work with compressed air and do not move the vehicle while the system is open.

• Do not touch the contact surface of the connector, the pressure sensor and control module, as well as the silicone gel.

• When painting, the electronic control module can be exposed to a maximum temperature of 95 °C (203 °F) only briefly, and to a maximum of 85 °C (185 °F) for longer periods (approximately 2 hours). Make sure that brake fluid does not enter the harness connectors.