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Audi A8 Shorting the Front Brake Pad Sensor Warning Light to Ground

If you want to get rid of the brake pad warning light once and for all, follow this procedure. It will no longer work when the brake pads trip the sensor. If you'd like to keep this function, use this procedure to troubleshoot it.

The brake warning light circuit is normally shorted to ground from the instrument cluster through the pads. When a brake pad sensor has an open circuit (or the connections go bad at the plugs due to age), it opens the ground path and trips the pad warning light.

To prevent this from happening, you will pull the instrument cluster and short the wire to another ground wire at the cluster.

There are two procedures, one for a pre facelift car (97-99 US bound cars, up to 98 model year rest of the world) and one for the facelift cars (00-03 US bound cars, 99-02 rest of the world). Follow the wiring diagram for your car.

Pull the instrument cluster as shown here. Note that there are different connectors for the pre facelift and facelift cars.

Pre Facelift Cars
If you have a facelift car, follow the wiring diagram below, but use similar wiring connection techniques as shown below.

You will ground out pin 25 of the red connector, bypassing the whole ground circuit through the pads once and for all.

Pin 25 of the red connector is brown/black, cut it and add a jumper so it can reach the black connector.

You can use an insulation displacement connector to the brown wire of the black connector, but I ended up cutting the brown wire, adding a small jumper, heat shrinking it, then looping the brown wire around and connecting it to the short and long jumper, then heat shrinking everything. That's just my protocol, you or your mechanic will probably do it differently.

Facelift Cars
For the facelift cars, it will be slightly easier. The brake pad warning light is located on pin 17 of the Blue 32 pin connector. Also located on the 32 pin connector is ground, which can be found on pin 32 of the Blue 32 pin connector. You could easily use an insulation displacement connector to connect the two.

Remove the instrument cluster and pull back the black insulation tape. To ensure you have the proper wires, you can slide the pink plastic end off the connector, then remove the blue cover. It will be very easy to trace the wires then.

Cut the brown/black wire located on pin 17. Attach the instrument cluster side to the brown wire located on pin 32 either with an insulation displacement connector or via a soldering method outlined above.

Once that is complete, insulate everything and reinstall. Ensure you have the connectors very tight, if the cluster doesn't light up properly after installation or the car won't start due to the immobilizer, you'll need to remake the connections.

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