Help please - Electric seat retrofit - stopped working??

[youngsyr]

Hi all, I've just retrofitted a fully electric adjustment heated seat in place of my manual adjustment (electric lumbar) heated seat in my 2014 A6 C7 Avant and initially it worked perfectly.

However, my wife took the car and reported back that the seat didn't work from the first moment she tried it. I've checked the fuse (It's a RHD car, so position C10, red fuse box on driver's door side of the dashboard) and it's a 5A, and it hasn't blown. The lumbar adjustment also still works, but not the height and tilt buttons.

This has me stumped as I expected it to be the blown 5A fuse?

Are there any other fuses I need to check - strange that the lumbar support works but not the rest of the adjustment.

I fitted the seats this afternoon and played around with all the adjustments and heating - all worked perfectly?

 

[RAF_S7]

Can you scan for any codes?

 

[NHN]

Check the wiring backwards but on allot of chassis if its only got lumbar that usually isn't good enough to handle full electric seats as the load is higher, the circuit has to have a 10amp supply iirc, so unless it's the wrong fusepoint, it's strange it's stopped working.

I assume they don't have a module on the bottoms of the seats?

The fact you said heating works assumingly indicates they're basic seats not network connected with modules.

Any underside images?

Did you compare the old & new seat connectors?

 

[youngsyr]

Can you scan for any codes?

I have scanned and nothing related comes up - but that's to be expected as my car wasn't originally fitted with memory seats, so it doesn't have the control module to interrogate.

However, several other people with non-memory seats have retro fitted the memory seat and just upped the fuse for the lumbar support and this gives them the electrical adjustment that the memory seats have (but obviously no memory function) without any issue.

 

[youngsyr]

Check the wiring backwards but on allot of chassis if its only got lumbar that usually isn't good enough to handle full electric seats as the load is higher, the circuit has to have a 10amp supply iirc, so unless it's the wrong fusepoint, it's strange it's stopped working.

I assume they don't have a module on the bottoms of the seats?

The fact you said heating works assumingly indicates they're basic seats not network connected with modules.

Any underside images?

Did you compare the old & new seat connectors?

Thanks for your help. I was expecting a blown fuse - this is quite typical when retrofitting the electric seats - you have to up the fuse one rating.

However, the only way the seat can get power is from the lumbar support circuit or the heated seat circuit - my car doesn't have fuses for the the electrical adjustment of the seat, those slots in the fuse box are empty and the lumbar support fuse is fine - evidenced by a visual check and the lumbar support adjustment still working.

The fact that it did work as intended, then abruptly stopped working for the recline and forward/backwards adjustment, without apparently blowing a fuse suggests to me that it's something gone wrong inside the seat with either wiring, control module (not sure if it has one in the seat?) or the motors. The seat is obviously not new, it's apparently from 2014 (but so is my original seat!).

No underside images I'm afraid - my thoughts were to dry fit it, see if it works and if not , just remove it and return it. However, as it did work perfectly, I installed it fully and now it's not working I can't get it out as the rear two bolts are fully obscured by the seat.

Any ideas how to get the seat out - it needs to slide forward but obviously can't do it by its own power.

The plugs on the old and new seats are identical. I didn't compare wiring as this is not the first time someone has retrofitted this seat as I have - they didn't encounter any problems though.

 

[NHN]

With respect I've advised what to check for & you can't just plug in memory seats unfortunately, that's not how it works as memory seats have bus modules that have to be matched to the car in most instances via component protection.

I suspect it's related to this but until we see the undersides of the seats we can't advise further.

The seats may just have stopped because it's not seeing the bus signals, it's happened before.

Unfortunately it's hard to diagnose this over the net worth very little data & no images.

So without being blunt, it's a case of help us to help you.

 

[youngsyr]

With respect I've advised what to check for & you can't just plug in memory seats unfortunately, that's not how it works as memory seats have bus modules that have to be matched to the car in most instances via component protection.

I suspect it's related to this but until we see the undersides of the seats we can't advise further.

The seats may just have stopped because it's not seeing the bus signals, it's happened before.

Unfortunately it's hard to diagnose this over the net worth very little data & no images.

So without being blunt, it's a case of help us to help you.

Thanks, I appreciate I'm not giving you much to go on, but I don't have much info to give - I can't get under the seat to access the wires and plugs because the seat is blocking two of the bolts that hold it to the floor.

This retrofit does work - you don't need the memory control unit or wiring to just move the seats electrically by the switch - others have dones this with no problem:

Retrofitting memory seats

Hi I've a history of retrofitting to many of my previous Audi's and can read a wiring diagram quite happily and have full VCDS. I've a 2011 3.0tdi Quattro Avant with mechanical S-line,heated fronts and unheated rears and am looking at retrofitting electric/memory fronts and heated rears...

www.vwaudiforum.co.uk

Here's what the bottom of a memory seat looks like:

Here's a parts diagram, it suggests that n.20 is a control module:

 

[NHN]

Mate I know the differences as I do these installs for a living lol, hence why I'm advising you.

You're misunderstanding, there are 2 types of electric seats, one with memory option & one without, so yes people can fit electric seats but to get memory they have to 1st be connected as in bus modules & matched to the car & wiring changes.

Lumbar cars are not setup to take fully electric seats as the full electrics use more load, so if it's connected to the 5 amp circuit, you're lucky it's not blown tbh.

Btw that pic of the seat is not a memory seat, it's a plain electric seat.

 

[youngsyr]

Thanks, so regardless of whether it works or won't work, can you advise how to remove the seat at all? At the moment it's stuck in position, obscuring the rear mounting bolts, so I can't get it out.

If I undo the nuts on the front of the rods that the seat moves forwards and backwards on, will I be able to lift the seat (still attached to the rods) off of the runners?

 

[youngsyr]

OK, I've managed to get access to the seat adjustment switch wiring and a wiring diagram.

I'm hoping I can just apply 12v to the Green/Blue wire (height adjustment) and it will raise the seat - giving me access to the rear bolts under the seat to remove the seat.

Can anyone more auto-electrically minded tell me if this will work?


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[youngsyr]

OK, so my seat has a memory control module (part 4G8959760A ) which sits between the switches and the motors. This is on the underside of the seat near the front inboard side. The plug from it to the motors is the black one in the centre at the bottom. this has 4 pairs of wires, wiring diagram below.

To get to it even with the seat in its lowest position, you need to remove the front storage bin. To do that, you need to remove the seat's side trim (with the switches on). There are one or two fasteners on either side at the back of the seat on the underside of the seat. You need to push the centre of these in (careful not to lose the pins) and then pull the fasteners out. Then remove that side trim from the back pulling it outboard and concentrating on the top first, unhook the top using a trim tool by pulling it up and over the lip of the seat all the way along. You may need to be quite forcefull with it.

You can then access the sides of the front lower storage bin (no trim piece on inboard side of seat). The bin hinges on a tiny torx screw, think it's a T10, but might be a T8. Undo the screw on each side and pull the outer bracket holding the bin in outwards on each side and pull the storage bin out. You now have more an inch or so more access to the underside of the seat than before.

If you need even more access, you can remove the bracket that holds the storage bin in place. There is a Torx screw (T30 I think)on each side of the bin holding the bracket to the underside of the seat. The screws are in recesses, have a feel either side of the underside of the seat where the bracket sits and you should be able to find them. Undo both of these and you should be able to wriggle the storage bin bracket out, giving you another inch or so of access from the front. This is enough to access the memory control unit.

Once you have access to the memory control module, you can either just pinch the tab on the plug and pull it out, or if it's still tight, pull down hard on the control unit and it will pop off of its bracket, allowing you to bring it a few inches closer to the front of the seat to unplug it.

Then apply 12v and ground to the green/brown and green/red wires in the plug to move the seat forwards/backwards. Reversing polarity reverses direction.
You can do the same to the blue/brown and blue/red wires to adjust the height.

NB: the image of the seat controller installed on the bottom of the seat below is from an A8 just to give you and idea of what it looks like installed. It's not identical to an A6, but very similar.

 

[ea020]

Hi, I know it’s been a while the last message but I’m facing with same issue…

These informations are really helpful for me. Have you solved your problem completly?

My car was sitting for a month at outside, When I went back to my car, there was some water in the back seat and car didn’t started well after one month.

And after that day, passenger seat doesnt move nor massage/heating/cooling is not working. But Driver seat is working both movements and massage/ heating except the interface which is no longer works.

So could it be a battery related issue that I need to re-code the car again? I didn’t do the retrofit so I don’t have any information.

What did you do after you moved the seat via cables? How can we check the coding is ok? did you do the coding by yourself?

What did you use as 12V power supply to move the seats?

Have a good day!