The anti-lock braking system (ABS) controller for the VW Beetle reduces the braking force to any wheel that is rotating significantly more slowly than the others. This helps prevent the brakes from locking during an emergency stop. Your vehicle is not necessarily unsafe to drive if the ABS warning light comes on, but it may mean that you need to replace the ABS.
Determine which ABS controller your VW Beetle will need. You'll want to be sure the new controller is compatible with your make and model of Beetle. Some new Beetles have been equipped with ABS since it was introduced in 1998.
Disconnect the negative battery cable with a socket wrench. Remove the electrical connector for the mass air flow sensor so you can remove the air filter.
Unplug the relay above the brake booster if your vehicle has 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. Disconnect the electrical connector for the ABS controller and remove the brake lines with a socket wrench.
Unfasten the mounting bolts for the bracket of the hydraulic control unit with a socket wrench and remove the hydraulic control unit with bracket from your vehicle. Detach the electrical connector for the hydraulic pump motor from the ABS controller. Remove the bolts that mount the ABS controller to the hydraulic control unit with a socket wrench and separate the two units.
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 pounds. Torque the hydraulic control unit bracket bolts to 70 inch pounds. Tighten the fittings for the brake lines to the ABS controller to 10 foot pounds and torque all other brake line fittings to 15 foot pounds.