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Moving front seat forward when switches not working
2008 A8L, located in Kansas City. Got water in the floorboard after heavy rain. All issues fixed except front passenger seat now dead. Have replacement control module ready to install. Seat is in the full rear position, so cannot get to the 2 star bolts on the rear of the seat to remove it. In other cars, I have attached leads to the fore/aft adjustment motor and used a battery to move the seat forward. However, in this car, I just can't seem to get under there. The seat base is in the lowest position in the rear, so darn near nothing to work with there. Does anyone have any tips?
I see in this thread:
There is a diagram attachment that shows the Emergency Power Supply plug. To be honest, there seems to be some conflicting info in that thread as to whether you put your power source on the top or bottom row of plugs. I will try to figure it out and take some photos while I'm at it to maybe clarify.
Last edited by kcattorney; 09-23-2017 at 12:58 PM.
That emergency connector plug is essentially just a splice point in the wires between the switch/module and the appropriate motor power terminals. Putting 12v (+ and -) to pins 5&6 will operate the forward/back motor in whichever direction that polarity moves it. Switch polarity and the motor goes the other way. Same for the height motor which is connected to pins 7&8. https://www.audiworld.com/forums/att...y_interior.pdf
That emergency connector plug is essentially just a splice point in the wires between the switch/module and the appropriate motor power terminals. Putting 12v (+ and -) to pins 5&6 will operate the forward/back motor in whichever direction that polarity moves it. Switch polarity and the motor goes the other way. Same for the height motor which is connected to pins 7&8. https://www.audiworld.com/forums/att...y_interior.pdf
Thanks Dave! I just finished up and thought I'd post a few pics to clarify for the next guy. First, here's a picture of the Seat Emergency Power Supply Connector Coupling, which is located under the leading edge of the front seat:
If you look closely, you can see each pin is numbered and the pdf document that Dave attached above shows what each pin does. Basically, top row goes to switches and bottom row goes to motors (the motors are what we want in order to get the seat to move):
Next is a pic that shows what the coupling looks like after you've removed the cover (the cover is the thing that has the wire loops sticking out of it):
And here's the cover after it is removed:
Last edited by kcattorney; 09-24-2017 at 07:23 AM.
The next step is to split the cover into two halves. Look closely at the pic above and you can see a little arm with a notch. There is one of those on both sides. Once you hold both down, you can slide the cover into 2 halves:
Then, plug the bottom half of the cover (with wires numbered 5,6,7,8) back into the bottom half of the connector:
I used two short pieces of bare wire (yeah, I know, don't try this at home, but the stiff wire works well) to plug into pins 5 and 6. Then I used a battery charger to power the seat. As others have said, change polarity to get the seat to move the opposite way. After moving the seat forward to expose the rear bolts, I plugged the leads into pins 7 and 8 and raised the seat as high as it would go. If you are replacing the control module, you'll definitely want to do that.
Last edited by kcattorney; 09-23-2017 at 03:16 PM.
Now, I had the seat unbolted and I rocked it back to expose the underside of the seat. I searched earlier today for a photo of the underside of an Audi A8 D3 seat bottom showing the seat motors and control modules, but I couldn't find any. So, here are several shots I took that might help someone who wants to see the layout of the electronics of the seat and cannot find a diagram:
That gray module with the purple sticker is the seat occupancy sensor for the airbag system. The driver side does not have one.
Last edited by kcattorney; 09-24-2017 at 07:28 AM.
Since most people who can't move the seat are probably going to need a seat control module, I'll show some pics of that. I also noticed that my seat ventilation wasn't working, and a used control module for the seat ventilation was only about 7 bucks, so I ordered one of those also. Here's the seat control module in the wild (it is the flat black module to the left of the gray module and right below the big gray tag in the center of the pic):
Sitting right behind it, attached to the same mounting bracket, is the seat ventilation control module:
Last edited by kcattorney; 09-24-2017 at 07:32 AM.
I noticed in some threads people complaining about getting the back 2 plugs (green and blue) out. The reason is that the retaining clip will not lift all the way back without first removing the control module from the bracket (there is a rod sitting right above the retaining clips):
Last edited by kcattorney; 09-24-2017 at 07:29 AM.
Lastly, there is a screw at the back of the seat control module that a bracket on the module slides under. It sits next to the seat ventilation module. You can see it in this picture between the green plug and the seat ventilation module. Don't worry about loosening this screw - it would be a pain to get to. Just remove the two screws (T-20 torx) on each side of the control module, then slide the module out. When putting the new on in, you can easily slide the back bracket back underneath the head of that screw.
09-23-2017, 10:59 AM
Moving front seat forward when switches not working
