How to Change an ABS Sensor on a 2002 Passat

The 2002 Volkswagen Passat came standard with a 1.8-liter turbocharged engine and a five-speed manual transmission. Each of your Passat's wheels has an anti-lock brake sensor -- or wheel speed sensor -- that tells the computer what the speed of each wheel is, so that it can signal ABS operation accordingly. A faulty wheel speed sensor can cause the ABS system to engage incorrectly or not at all, and should be replaced immediately. The process to replace any of the wheel speed sensors is the same and can be completed with basic hand tools.

Instructions

Park the vehicle on a level surface and set the parking brake. Place wheel chocks around the tires that will remain on the ground during this procedure. Loosen the wheel bolts for the wheel to be serviced with the lug wrench, but do not remove them.

Lift the front or rear of the vehicle into the air with a floor jack and place jack stands under the front subframe. Lower the floor jack until the vehicle rests securely on the jack stands. Remove the wheel bolts. Remove the wheel and tire from the vehicle.

Follow the wheel speed sensor pigtail from the steering knuckle up to the wiring harness connection, at the top of the wheel well. Pry out the grommet with a flat-head screwdriver and disconnect the sensor pigtail from the wiring harness.

Follow the pigtail down to the sensor and separate the pigtail from the harness retainers with a flat-head screwdriver. Lift the locking tab on the lower part of the brake wear sensor connector, if equipped, then rotate the connector 90 degrees then pull the connector from the bracket. Pull the wheel speed sensor out of its bore in the steering knuckle.

Clean the wheel speed sensor bore in the steering knuckle with a wire brush until it is completely smooth and free of any debris. Apply a small amount of automotive-grade grease to the sensor bore.

Press the wheel speed sensor into its bore in the steering knuckle until it sits flush; the pigtail should face up the steering knuckle. Route the pigtail up the steering knuckle and secure all four retainers by clipping the retainers closed.

Slide the rubber grommet over the sensor pigtail and connect the pigtail to the vehicle wiring harness. Push the grommet into the hole in the wheel well. Connect the brake wear indicator connector by sliding it into the sensor and rotating it 90 degrees clockwise, if equipped.

Turn the wheels to the full left and full right to check for proper pigtail clearance, and adjust the wiring as necessary, if replacing a front speed sensor. Install the wheel and tire to the vehicle and install the wheel bolts hand tight.

Lift the front or rear of the vehicle off the jack stands and lower the vehicle to the ground. Tighten the wheel bolts to 89 foot-pounds with a torque wrench. Test drive the vehicle to ensure proper operation of the ABS system.