Cruise Control Switch Replacement
By Dennis Medvetsky
Background
The A8 seems to have mysterious ways with its cruise control system. Sometimes it just stops working, but nobody can figure out why. One of the piece of equipment that can go bad is the actual cruise control switch and its associated contacts. This procedure describes how to replace the switch.
Ensure You Have the Correct Part
The cruise control switch is different for the 97 and some of the 98's as compared to the late 98's and all of 99. I purchased a switch off ebay with a "C" revision and when installing it, found that it would not work in my 99 which had a "N" revision.
The N revision has an extra plug not found on the C revision, which has 4 pin locations, two on the bottom, two on the top. Ensure you have the correct piece for your car before starting. There is one more picture at the end of this procedure that shows the pin holes on the revision C switch.
Replacing the Switch
The first set of pictures below are from Paul Waterloo's ignition switch replacement procedure. These pictures are from a 97 A8. Even though the components are slightly different, the same basic procedure applies.
Note: This procedure is in the Bently under "94, Lights, Switches - Exterior". It is shown on audipages under "96, Lights, Switches - Interior, Anti-Theft".
Replacement of the switch is an easy task. Tools required are:
15/16" socket (or metric equivalent to remove steering wheel)
Torx screwdrivers
Very small standard screwdriver
Small phillips head screwdriver
10 mm open ended wrench
The first step is straighten the steering wheel with the car running. Get it as straight as possible and turn off the car. Adjust the steering wheel all the way out and as far down as it will go.
Consult the Bently manual regarding airbag warnings and precautions.
Ensure you have the radio security code prior to disconnecting the battery. Disconnect the battery ground strap. The battery is found in the trunk on the passenger side. This is IMPORTANT so that the airbag will not go off for any reason.
Disconnect the battery negative ground strap.
It is the right hand connection shown in this picture.
Using a Torx 30 screwdriver, remove screws for airbag by inserting them in the back of the steering wheel. It should find the torx screw head easily. If it is too tight to turn, turn the screwdriver with a pair of pliers to break the screws loose. The screws won't fall out, they will stay in place once unscrewed, see pictures. Tightening torque for the screws is 7 Nm (62 in-lb).
See airbag screw. It will stay in place once unscrewed. There are two total. After the airbag is unscrewed, disconnect airbag connector (red piece) and place airbag face up in secure location. If a multi-function steering wheel, remove additional airbag electrical connector. Tightening torque for the screws is 7 Nm (62 in-lb).
Refer to this image for screw removal.
Remove screws (8) (quantity 2) and carefully pull out upper steering column trim (1).
After removing the upper steering column trim, disconnect steering wheel electrical connector and airbag electrical connector.
Using a 15/16" socket (or metric equivalent, it's a metric nut) remove the steering wheel nut, remove the steering wheel.
Note: At this point forward, the pictures in the procedure shows a 99 A8.
Remove the screw right above the steering column.
Remove the screw that holds the bracket on the steering column.
Disconnect the electrical connectors off the the left (cruise and turn signal) and the right side (windshield wipers and trip computer) by prying the purple latches.
Disconnect electrical connectors from switch and remove switch.
After the switch is removed, remove the screw shown in the picture below on the back of the switch. Swap new cruise control switch in.
Remove screw and swap switches. Note pins on the rev C switch in upper portion
of picture versus connector on rev N switch in lower portion of picture.
Get the right part before you start.
Installation is reverse of removal.
To reset the radio with the security code, see your radio manual or visit Ti Kan's Audi radio page. To reset the climate control from degrees C to degrees F, press the recirc button and the driver's side "+" temperature control. This will toggle from degrees C to F. To reset the auto down/up function on the windows, cycle them all the way down and up a few times, the function will be restored.
