Help! B9 S4 Passenger Seat Loss of Control

[Audi_Blvck]

Hi all,

I have a 2018 s4 Prestige w/Napa Leather Sports seats. The passenger seat recently lost some functionality. Slide still works in both directions, as well as massage and heating. But raise/tilt lower and backrest movement have been lost. I’m assuming the fuse is fine given half the seats functions still work. You hear the button click when attempting to adjust the seat but no motor ignition for either function. Assuming the motors are fine and this is something with connections. Any help / pictures you can provide are much appreciated before I tear into this next week. Thanks in advance!

[oesman]

Not much personal insight, I would recommend getting the factory manual (grab a day-pass and download it from erwin) as there is a ton of detail, like pages and pages of it, on taking the seats apart, but maybe this diagram will help:



1. Seat control module.
2. Seat position sensor.
3. Passenger occupancy sensor.
4. Forward / back adjustment motor.
5. Seat belt switch.
6. Backrest adjustment motor.
7. Lumbar support.
8. Seat/Backrest bolster adjuster valve block.
9. Backrest blower fan.
10. Front thorax airbag.
11. Footwell lamp.
12. Seat cushion blower fan.
13. Seat height adjustment motor.
14. Seat adjustment control head.
15. Massage button.
16. Lumbar support adjustment switch.
17. Seat angle adjustment motor.
18. Lumbar support adjustment pump.

The seat itself is just held on with four bolts, its pretty obvious. You do have to disconnect the electrics from the chassis and they recommend unhooking the battery ground lead. But to remove basically:

1. Put headrest in lowest position.
2. Remove belt end fitting by moving seat all the way forward and up (guess yours cant go up) and then pull the cover off the fitting and release the spring catches with a screw driver. Pull fitting downward and disengage.
3. Remove the rear bolts.
4. Move seat all the way back and up.
5. Remove the front bolts.
6. Disconnect the battery ground.
7. Disconnect the seat. You're supposed to use a airbag lockout adapter, basically a little pigtail that plugs into the airbag connector.
8. Pull the seat out without jacking up your interior or door sills, prolly throw a blanket over it or similar.
9. Reassemble in reverse.

[AlCapwn072]

Anybody have any success with this? I have a B9 S5 that I just picked up yesterday and am having the same issue. Passenger seat heating works just fine but no lumbar, forward/back, or tilt.

[A4 Centaur]

Can you get any feedback from a VagCom scan?

[Audi_Blvck]

Still no luck. Just checked lumbar fuses and they seem to be in tact. Such a weird issue. I forgot about it but then my GF complained and I figured I’d resurface this post before I take it to the dealer. Anybody have any other thoughts on this issue?

[VroomTT]

Bumping this since I am having the same issue. '18 S4 P+. Passenger goes up and down, but no front to back.

Was thinking it might be related to doing the seat sensor recall a couple months ago... maybe not?

Anyone have any further info on this? Also, location of the passenger seat fuses?

[VroomTT]

Follow-up on this issue (and keeping to the existing thread). Looked up the fuse locations using this: https://fuse-box.info/audi/audi-a4-s...017-2018-fuses

Nothing seat related appeared blown. That said, I certainly don't know how accurate or comprehensive this is. Just checked the lumbar fuses.

OBD11 had a intermittent fault for driver seat communication, but once cleared it didn't return. Also noticed there is only a 'driver seat' control module, nothing for passenger.

Anyone have any ideas and/or suggestions???

Also reached out to Audi service advisor who did my seat airbag recall. Waiting on a call back from him...

[VroomTT]

Keeping this thread alive in the hopes someone has any input or updates from the prior posters.

I have an appointment at local Audi this week to get it checked out. This happening right after the seat recall work being done is just too suspect for me.

PS: Here is some info on the seat PODS recall that affected our cars for context/reference. https://static.nhtsa.gov/odi/rcl/202...1V874-1654.pdf

[Bobby Kinstle]

My B9 S4 just started diong this too. No idea what's wrong with it but its so far back that back seat passengers can't fit anymore

[Ejr]

Have you guys tried replacing the seat adjustment switch like the switch by the bottom cushion on the side used to adjust the actual positions? It usually goes bad before the motor does.


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