I've not seen many guides online about this process (only on older models) so I thought I'd write one for the C7 models.
I have a 2015 A6 allroad with standard manual, heated leather seats with electric lumbar support and I upgraded to electric seats from a 2017 A6 allroad, however, I didn't install the memory function part as it was not needed. Subsequently, I've not needed to add any looms, door trim, coding or removal of component protection on VCDS. This guide is purely to switch the seats and take no responsibility for anything that might go awry on your part.
So here's my crappy flat, standard leather seats against the new, better looking, supportive electric ones...
As previously stated, I wasn't interested in the memory function, I just wanted bolstered seats without 'S-line' or' S4' embossed into the seats since I drive an allroad. The electric movement is a bonus.
So first thing is to remove the head rests, front and back. It'll give you more space when you lift stuff out. You can remove the front headrests by applying pressure about an inch below the steel struts of the headrest, on the rear of the front seats. This link shows you how to do it on a B8 but the principle is the same for most models.
hg
The rear headrests have side 'buttons/pressure switches' on one of the round plastic cuffs the headrest steel rods go into. If you press these in, it will allow you to raise the headrests as high as possible. Once there, look on the opposite round, plastic cuff, and you'll see a rectangular hole where you have to get a flathead screwdriver to poke with. Push it in and you'll be able to lift the rear headrests off.
Next, set your front seats as far forward as possible and raise them up as high as they'll go. This will expose the triple square bolts on the back of the rails (H10 - see pics), 2 on each seat.
Remove those and then set about detaching the seat belts from the bottom of the front seats. To remove, unclip the plastic covers at the bottom of the front seat belts. The plastic cover stays on the belt but can be moved upwards to access the mechanism holding the belt in place. Underneath is a metal bracket. All you need to do is pull circled part of the metal bracket (see pic) outwards, and then push the bracket downwards and off the attachment.
Now adjust your seats as far back as possible to remove the plastic caps on the front of the rails (pic below) that cover the front 2 pairs of square bolts.
Unscrew these and then you can tilt your seats back, exposing the wiring trunk (pic shows with cover taken off).
Before you get to these, turn on your ignition and get to your battery, Loosen the bolt around the negative terminal and pull the negative cable away and cover with a rag until you reconnect it. Some people won't do this step but since we're working with airbags I'd rather be safe in the knowledge that they won't deploy in my face.
Once the power is gone, you can pry off the plastic flap which covers the cabling. There are 4 connectors to remove: Yellow = Airbag, Green = Heated seats, Red = Power supply for movement and Black = Seat belt (see pic).
Additionally, there is a large black clip that holds the cable trunking in place that also needs to be removed by pressing the two outer parts (I wasted a huge amount of time trying to push the inner clips). At this point, lay a blanket or or something on the door thresholds to protect yourself from scratching up your interior... The seats aren't ridiculously heavy, but they are awkward to move out of a confined space (hence removal of the headrests).
To remove the back bench, the first thing you need to do is remove the isofix caps and their plastic surrounds. The top caps just unclip, but the plastic surrounds will need to be pushed in, then pulled out. Difficult to explain but when you look closely it'll make more sense and you can do it with your fingers.
From this point all you need to to is put your hands under the seat and yank it up from the footwell side, hard and fast, one side at a time. The bench is only held in by way of two copper, rectangular, loops which are set into their own retaining clips (see pics).
These will definitely break when you pull the bench up and you'll need to replace these when you put the new bench back in. You can buy them for under a fiver on ebay...
https://www.ebay.co.uk/itm/2x-Plast...2349624.m46890.l49286&mkrid=710-127635-2958-0
Once the bench is up, just gently bring the bench towards you and it's out. Next you want to remove the 2 side bolsters that sit between your rear doors and the back, split seat rests. Each bolster is only held in by one torx screw at the bottom (see pic) and once that's out, you can just tug in a downward direction to release it, making sure the top doesn't catch on anything.
So just the two 2/3 and the 1/3 back rests to go. Before that, locate the two black boxes with 2 black plastic sheathed cables in them (see pic).
These cables allow the folding action of the back rests when you need to utilise the full rear space. One cable leads to the handles in the boot and the other directly to the back rests.
Opening the black box will reveal the spindle and the steel cables which are wound around. The cable you need to remove is the one with a tiny steel cylinder on the end of it (see pic). This cable is the one attached directly to the back rests and are very easy to remove and replace. Do it on both sides.
Each back rest is held in place by way of a steel peg on the outer sides (red circles in pics) and on the inner side which has steel pins with a large circular piece of steel (green circles in pics).
The two pins from each back rest sits in place by way of a steel bracket affixed to the chassis.
(above pic is a photo I took after I removed the backrests)
This steel bracket is then covered with a piece of metal, screwed in by a torx screw.
To uncover the bracket, you need to fold down the 1/3 backrest and look down where the backrests pivot, and where it sides up to the 2/3 backrest, you'll notice the metal, gloss black cover piece where one torx screw holds it in (pic shows the piece with the screw out). Unscrew this and bring your hand round the front of the back rests and you'll be able to lift that black cover off.
At this point, the back rest should be in the folded down position, and you can remove the 1/3 backrest by pushing it towards the middle of the car (away from the aforementioned steel pegs and towards the steel pins in the middle) and lifting up.
The 2/3 backrest still needs a seat belt detached before it can be removed in the same way. It'll be the middle seat belt which can be unbolted by way of 17mm socket (long).
Once this bolt has been removed, detaching the belt will become obvious. And now you can remove the back rest in the same way as above.
At this point if you're anything like me, you'll probably want to break out the vacuum and give your interior a good going over!
Since we're going from non-electric seats to full electric, you to up rate two fuses from 5a to 10a. The fuses you need to change are the 'Lumbar support' ones for both driver and passenger. You can find the location of these fuses in your manual. I found that for my car, the front driver one used mini fuses and the passenger one used standard size ones. If you don't replace the 5a fuses, they will short on you.
Once they've been replaced, all you need to do is install the new back rests, bench, side bolsters and front seats in reverse, connect the plugs from the front seats in and re-attach the negative terminal on your battery.
Although the new seats are fully electric, I have no use for the memory function, and just happy with the extra seat bolsters and gimmick of having electric movement. Subsequently, I didn't have to add any extra cabling, door trim or switches to this upgrade. Apart from the two fuses, the front seats were simply plug and play.
There is a module under the new driver seat which I didn't plug anything in for this swap (see pic).
Presumably, this is where you would add a loom for the memory function but this will also require the above extra parts, as well as coding and removal of CP (Component Protection) for it to work.
Note that although the passenger side will move as long as you keep your finger pressed on the switches, the driver side will only move in increments. This is normal due to the way the seat was intended for use with the memory function. I've read other forums which confirm this happening, and since I only need to find the right seat potion for myself, this won't specifically bother me for my purpose.
I've had this system working for the last few days with no issues... But because this is the first time I've done this, I've kept some spare fuses in my boot just in case.
I hope this information is of some use to others.
I have a 2015 A6 allroad with standard manual, heated leather seats with electric lumbar support and I upgraded to electric seats from a 2017 A6 allroad, however, I didn't install the memory function part as it was not needed. Subsequently, I've not needed to add any looms, door trim, coding or removal of component protection on VCDS. This guide is purely to switch the seats and take no responsibility for anything that might go awry on your part.
So here's my crappy flat, standard leather seats against the new, better looking, supportive electric ones...
As previously stated, I wasn't interested in the memory function, I just wanted bolstered seats without 'S-line' or' S4' embossed into the seats since I drive an allroad. The electric movement is a bonus.
So first thing is to remove the head rests, front and back. It'll give you more space when you lift stuff out. You can remove the front headrests by applying pressure about an inch below the steel struts of the headrest, on the rear of the front seats. This link shows you how to do it on a B8 but the principle is the same for most models.
hg
The rear headrests have side 'buttons/pressure switches' on one of the round plastic cuffs the headrest steel rods go into. If you press these in, it will allow you to raise the headrests as high as possible. Once there, look on the opposite round, plastic cuff, and you'll see a rectangular hole where you have to get a flathead screwdriver to poke with. Push it in and you'll be able to lift the rear headrests off.
Next, set your front seats as far forward as possible and raise them up as high as they'll go. This will expose the triple square bolts on the back of the rails (H10 - see pics), 2 on each seat.
Remove those and then set about detaching the seat belts from the bottom of the front seats. To remove, unclip the plastic covers at the bottom of the front seat belts. The plastic cover stays on the belt but can be moved upwards to access the mechanism holding the belt in place. Underneath is a metal bracket. All you need to do is pull circled part of the metal bracket (see pic) outwards, and then push the bracket downwards and off the attachment.
Now adjust your seats as far back as possible to remove the plastic caps on the front of the rails (pic below) that cover the front 2 pairs of square bolts.
Unscrew these and then you can tilt your seats back, exposing the wiring trunk (pic shows with cover taken off).
Before you get to these, turn on your ignition and get to your battery, Loosen the bolt around the negative terminal and pull the negative cable away and cover with a rag until you reconnect it. Some people won't do this step but since we're working with airbags I'd rather be safe in the knowledge that they won't deploy in my face.
Once the power is gone, you can pry off the plastic flap which covers the cabling. There are 4 connectors to remove: Yellow = Airbag, Green = Heated seats, Red = Power supply for movement and Black = Seat belt (see pic).
Additionally, there is a large black clip that holds the cable trunking in place that also needs to be removed by pressing the two outer parts (I wasted a huge amount of time trying to push the inner clips). At this point, lay a blanket or or something on the door thresholds to protect yourself from scratching up your interior... The seats aren't ridiculously heavy, but they are awkward to move out of a confined space (hence removal of the headrests).
To remove the back bench, the first thing you need to do is remove the isofix caps and their plastic surrounds. The top caps just unclip, but the plastic surrounds will need to be pushed in, then pulled out. Difficult to explain but when you look closely it'll make more sense and you can do it with your fingers.
From this point all you need to to is put your hands under the seat and yank it up from the footwell side, hard and fast, one side at a time. The bench is only held in by way of two copper, rectangular, loops which are set into their own retaining clips (see pics).
These will definitely break when you pull the bench up and you'll need to replace these when you put the new bench back in. You can buy them for under a fiver on ebay...
https://www.ebay.co.uk/itm/2x-Plast...2349624.m46890.l49286&mkrid=710-127635-2958-0
Once the bench is up, just gently bring the bench towards you and it's out. Next you want to remove the 2 side bolsters that sit between your rear doors and the back, split seat rests. Each bolster is only held in by one torx screw at the bottom (see pic) and once that's out, you can just tug in a downward direction to release it, making sure the top doesn't catch on anything.
So just the two 2/3 and the 1/3 back rests to go. Before that, locate the two black boxes with 2 black plastic sheathed cables in them (see pic).
These cables allow the folding action of the back rests when you need to utilise the full rear space. One cable leads to the handles in the boot and the other directly to the back rests.
Opening the black box will reveal the spindle and the steel cables which are wound around. The cable you need to remove is the one with a tiny steel cylinder on the end of it (see pic). This cable is the one attached directly to the back rests and are very easy to remove and replace. Do it on both sides.
Each back rest is held in place by way of a steel peg on the outer sides (red circles in pics) and on the inner side which has steel pins with a large circular piece of steel (green circles in pics).
The two pins from each back rest sits in place by way of a steel bracket affixed to the chassis.
(above pic is a photo I took after I removed the backrests)
This steel bracket is then covered with a piece of metal, screwed in by a torx screw.
To uncover the bracket, you need to fold down the 1/3 backrest and look down where the backrests pivot, and where it sides up to the 2/3 backrest, you'll notice the metal, gloss black cover piece where one torx screw holds it in (pic shows the piece with the screw out). Unscrew this and bring your hand round the front of the back rests and you'll be able to lift that black cover off.
At this point, the back rest should be in the folded down position, and you can remove the 1/3 backrest by pushing it towards the middle of the car (away from the aforementioned steel pegs and towards the steel pins in the middle) and lifting up.
The 2/3 backrest still needs a seat belt detached before it can be removed in the same way. It'll be the middle seat belt which can be unbolted by way of 17mm socket (long).
Once this bolt has been removed, detaching the belt will become obvious. And now you can remove the back rest in the same way as above.
At this point if you're anything like me, you'll probably want to break out the vacuum and give your interior a good going over!
Since we're going from non-electric seats to full electric, you to up rate two fuses from 5a to 10a. The fuses you need to change are the 'Lumbar support' ones for both driver and passenger. You can find the location of these fuses in your manual. I found that for my car, the front driver one used mini fuses and the passenger one used standard size ones. If you don't replace the 5a fuses, they will short on you.
Once they've been replaced, all you need to do is install the new back rests, bench, side bolsters and front seats in reverse, connect the plugs from the front seats in and re-attach the negative terminal on your battery.
Although the new seats are fully electric, I have no use for the memory function, and just happy with the extra seat bolsters and gimmick of having electric movement. Subsequently, I didn't have to add any extra cabling, door trim or switches to this upgrade. Apart from the two fuses, the front seats were simply plug and play.
There is a module under the new driver seat which I didn't plug anything in for this swap (see pic).
Presumably, this is where you would add a loom for the memory function but this will also require the above extra parts, as well as coding and removal of CP (Component Protection) for it to work.
Note that although the passenger side will move as long as you keep your finger pressed on the switches, the driver side will only move in increments. This is normal due to the way the seat was intended for use with the memory function. I've read other forums which confirm this happening, and since I only need to find the right seat potion for myself, this won't specifically bother me for my purpose.
I've had this system working for the last few days with no issues... But because this is the first time I've done this, I've kept some spare fuses in my boot just in case.
I hope this information is of some use to others.