How to Replace an ABS Controller in a VW Jetta

The VW Jetta has an anti-lock braking system (ABS) that prevents the brakes from locking during an emergency stop. The ABS controller accomplishes this by reducing the braking force to any wheel that is rotating significantly more slowly than the others. You may need to replace the ABS controller if the ABS warning light comes on. However, it is not necessarily unsafe to drive your vehicle without an ABS.

Instructions

1

Determine which ABS controller your VW Jetta will need. You'll want to be sure the new controller is compatible with your make and model of Jetta. ABS was first offered on some versions of the Jetta beginning in 1984.

2

Disconnect the negative battery cable with a socket wrench. Locate the ABS controller bolted to the hydraulic control unit in the driver's side of the engine compartment. Detach the electrical connector for the hydraulic control unit from the filter tube of the mass air flow sensor. Remove the air filter.

3

Remove the relay above the brake booster if you have a diesel engine. Drain as much brake fluid as possible from the brake fluid reservoir and depress the brake pedal with a VAG 1869/2 brake pedal depressor. Release the electrical connector for the ABS controller. Disconnect the brake lines from the hydraulic control unit and plug the open ends.

4

Unfasten the mounting bolts on the hydraulic control unit bracket with a socket wrench and detach the hydraulic control unit assembly. Detach the electrical connector for the hydraulic pump motor from the ABS controller. Remove the mounting bolts for the ABS controller with a socket wrench and separate it from the hydraulic control unit.

5

Install the new ABS controller by reversing the removal procedure. Mount the ABS controller to the hydraulic control unit with new bolts and use a torque wrench to tighten them to 35 inch lb. Torque the hydraulic control unit bracket bolts to 70 inch lbs. Torque the fittings for the brake lines on the ABS controller to 10 feet lbs. Torque all other brake line fittings to 15 feet lbs.