1. Preparation:
* Safety First: Always disconnect the negative battery terminal before starting any work on your vehicle's electrical system. This prevents accidental shorts and damage.
* Gather Supplies: You'll need a shop rag, brake cleaner (non-chlorinated), a wire brush (optional, for stubborn dirt), and possibly a small flathead screwdriver or similar tool to help maneuver the sensor (depending on the location of the sensor in relation to other components). Wear safety glasses.
* Locate the Sensors: The wheel speed sensors are typically located near the wheel hub, inside the brake rotor or behind the dust shield. You'll likely need to remove a wheel to access them fully (Consult your owner's manual for the exact location on your specific Impala model). There's usually one sensor per wheel.
2. Cleaning Process:
* Remove the Wheel: Loosen the lug nuts before jacking up the vehicle. Use jack stands to support the vehicle securely, never work under a vehicle supported only by a jack. Remove the wheel.
* Locate the Sensor: Carefully inspect the area around the wheel hub to locate the sensor. It's usually a small, cylindrical unit with a wire harness attached.
* Clean the Sensor:
* Spray the sensor: Gently spray the sensor's tip (the part facing the wheel's reluctor ring) with brake cleaner. Avoid spraying directly into the sensor's connector. The brake cleaner will dissolve grease, grime, and brake dust.
* Let it dry: Allow the brake cleaner to evaporate completely. This is crucial, as residual cleaner can interfere with the sensor's operation.
* Use a brush (optional): If there's stubborn dirt or debris, use the wire brush (gently!) to remove it. Be very careful not to scratch or damage the sensor's tip. The sensor tip is easily damaged, and a damaged tip will render it useless.
* Clean the reluctor ring: The reluctor ring is a toothed metal ring attached to the wheel hub. This ring is what the sensor reads to determine wheel speed. You can lightly clean the reluctor ring as well using brake cleaner and a rag or brush, but be very gentle.
* Reassembly:
* Inspect the sensor connector: Ensure the sensor connector is clean and free of corrosion.
* Inspect the sensor wire for damage: The wire should be free of any bends or cuts. If it's damaged, it needs replacing.
* Reconnect and test: Carefully reattach the wheel, lower the vehicle, and reconnect the battery. Test drive the vehicle to see if the issue is resolved. Check your dashboard for any ABS or other warning lights that might have been present before the cleaning.
Important Considerations:
* Replace, don't just clean: If the sensor is damaged (bent, cracked, or corroded), cleaning won't help. Replacement is necessary.
* Reluctor Ring Condition: If the reluctor ring is severely damaged or missing teeth, it needs to be replaced as well. A damaged reluctor ring can cause inaccurate speed readings.
* Professional Help: If you're uncomfortable performing this procedure yourself, it's best to take your vehicle to a qualified mechanic.
Remember to consult your vehicle's repair manual for detailed diagrams and specific instructions. This process is a general guide, and specifics might vary slightly depending on your Impala's year and trim level.
