Abs Layout

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1 - Hydraulic Unit and Control Module

2 - Brake Booster

The control module and hydraulic unit form one component. Separation is only possible when removed. The hydraulic pump must also not be separated from the hydraulic unit.

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

"Guided Fault Finding" is performed using the Vehicle Diagnostic Tester.

• Disconnect the battery ground cable when the ignition is switched off.
• Before welding with an electric welding tool, observe the information found in appropriate service information.
• When handling brake fluid, observe the relevant safety precautions and notes. Refer to BRAKE FLUID GENERAL INFORMATION .
• After finishing any work that required opening the brake system, bleed the brake system using the Brake Charger/Bleeder Unit:VAS5234  . Refer to HYDRAULIC SYSTEM, STANDARD BLEEDING .
• During the final road test, make sure a controlled braking maneuver is performed at least one time (pulsing must be felt in 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 connection points and their surrounding areas before loosening. However, do not use aggressive cleaning agents such as brake cleaner, gasoline, thinners or similar compounds.
• Place the removed parts on a clean surface and cover them.
• Carefully cover or seal opened components if the repair is not performed immediately. (Use plugs from repair set 1 H0 698 311 A)
• Only use lint-free cloths.
• Remove the replacement parts from their packaging just prior to installing them.
• Only use parts in their original packaging.
• If the system is open, do not work with compressed air and do not move the vehicle.
• The valve coils inside the control module cannot be readjusted.
• The valve coils inside the control module cannot be replaced.
• The pressure sensor must not be changed or damaged.
• The pressure sensor cannot be replaced.
• The sensor housing must not be under any mechanical load.
• No measurements may be performed on the contacts in the control module.
• No measurements may be performed on the contacts in the hydraulic unit.
• The valve bodies inside the hydraulic unit must not be damaged or bent.
• The contacts cannot be replaced.
• Using contact sprays on the contacts and pressure sensor are not permitted.
• Make sure there are no foreign objects between the control module and the hydraulic unit.
• When painting, 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 two hours). For long periods (two hours) the control module can only be exposed to a maximum of 85 °C (185 °F). Make sure that brake fluid cannot get into the connectors.