Heated Seat Problem

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
Hello, this is my first post, but I've been lurking awhile and learning a ton about my, new-to-me, 2015 Sportwagen SE TDI.

I'm having a problem with my passenger side heated seat. When I turn on the heater, the indicator lights turn on to whatever setting I choose, but turns off shortly after (~5-10 seconds).

So far I've:
  • Verified that the car recognizes that someone is sitting in the seat. The passenger airbag light turns off.
  • Checked all the large fuses in the internal fusebox.
  • Checked under the seat for loose connections. I haven't taken off the seats yet and I'd like to avoid that if I can.
  • Used my OBD2 scanner to check for errors, but scan came up clean.

I've read that these cars can have problems with the heated switch, but I'm at a loss for what they're talking about. Are people referring to the actual button that you push on the dash going bad or is there a switch/relay under the seat that's bad?

I'm also thinking that there may be a temp sensor in the seat that may have gone bad so the car thinks the seat is hot when it isn't. Does this sound plausible? If so, how would I go about troubleshooting that?

It's starting to get chilly in the mornings around me and I know my wife would be very pleased if I could get this figured out. Thanks in advance.
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
No answers for you but you did remind me that I have to fix the heated seat in the JSW before the wife starts complaining about cold cheeks. Something got shoved under the seat a few years back and disconnected the bottom cushion heater. The back still works.
 

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
Glad I could help!

Speaking of disconnected wires, is there a schematic or service manual floating around out there that I can use to figure out what's going on under my seat?

When I looked under there yesterday I noticed that a magnetic sensor fell of one of the rails. I reinstalled it, but I have no idea what it's for. There's also a control box of some sort down there and another 3-4 wires that go... places. I traced one to the seat belt buckle and I assume one is for the air bag and one for the heater, but I'm just guessing which is which.
 

hskrdu

Top Post Dawg
Joined
Oct 17, 2003
Location
Maryland and New England
TDI
2003 Golf GLS 4D 5M, 2015 GSW SE 6M
What OBD2 scan tool are you using? Generic ones may not provide the best results.
When you refer to reading about problems with the switch, do you have links to the threads? The MKIV was known for flakey switches (the actual switch on the dash).

Taking the seat out (or lifting it up) to check connections and wiring is easy. Don't avoid it if it's preventing you from checking the wires.

Here's a link to heated seat retrofit on the MK7 forum. Southpawboston has been giving me some intermittent assistance with heated seat questions, and this thread has some good info on wiring and connections which may help:
https://www.golfmk7.com/forums/showthread.php?t=38808&page=2

Here's some wiring info, although not a full schematic (the other thread has a few euro schematics):
https://drive.google.com/file/d/1PyumaFCJL4OmU78j9Ft13sAXzZxkjwfP/view
 
Last edited:

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
Thanks for the links. I skimmed the retrofit thread quickly and it looks like it'll be helpful in my troubleshooting. Lots of people post about the heated seats not working, but few go into detail other than saying the heater doesn't work. In my case the button is lighting up for a brief moment before turning off, so it's hard to say what's going wrong.

I think I'll start by checking continuity through the heating element and, if good, check to see if it getting power. If those both check out, I may pull the switch from the driver's side and test it on the passenger circuit to see if that works.

To remove the seat, do you unbolt the rails from the floor and remove the entire unit? Are those torx fittings?

I found a thread that talks about replacing a MOSFET, but didn't realize the model it was referencing was so old. The hardware is likely much different for my car. https://forums.tdiclub.com/showthread.php?t=455475
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
sounds like it could just be the button. Not sure how easy they are to swap.
 

hskrdu

Top Post Dawg
Joined
Oct 17, 2003
Location
Maryland and New England
TDI
2003 Golf GLS 4D 5M, 2015 GSW SE 6M
Thanks for the links. I skimmed the retrofit thread quickly and it looks like it'll be helpful in my troubleshooting. Lots of people post about the heated seats not working, but few go into detail other than saying the heater doesn't work. In my case the button is lighting up for a brief moment before turning off, so it's hard to say what's going wrong.

I think I'll start by checking continuity through the heating element and, if good, check to see if it getting power. If those both check out, I may pull the switch from the driver's side and test it on the passenger circuit to see if that works.

To remove the seat, do you unbolt the rails from the floor and remove the entire unit? Are those torx fittings?

I found a thread that talks about replacing a MOSFET, but didn't realize the model it was referencing was so old. The hardware is likely much different for my car. https://forums.tdiclub.com/showthread.php?t=455475

Seat removal for the Mk7 (I've only done GSW) is very similar to our MkIV's, with the exception that the wiring loom runs to plugs hidden just underneath the carpet and sound damping material. There are also little plastic "pins" which need to be removed. If none of that is helpful, I'll post some links (and I'm sure videos are available). The process for both seats to be removed from the car is less than 30min once you are familiar with it, and only 2-3 minutes to just pop up the pax seat to look underneath. Oh, the pax seat also has a module underneath which (I believe) turns the passenger airbag on/off. This is likely the additional wiring you've already seen.

From memory: Slide the seat to the rearmost position. Remove the two bolts (XZN? Torx? Cant't remember) at the front rails. Raise the seat all the way up. Slide the seat the foremost position. Remove the two bolts at the rear rails. The seat can now be lifted for easy inspection underneath. The wiring loom runs to connectors under the carpet. Look for a small black piece of plastic, possibly covered by a cap, which holds the carpet down in that area. Remove these and you can check the connections.

https://www.golfmk7.com/forums/showthread.php?t=36993

https://forums.vwvortex.com/showthr...fficial-MKVII-Golf-and-GTI-DIY-FAQ-thread****
 

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
Great info here, thanks. I'll try taking things apart this weekend and see what happens.
 

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
I finally got around to removing the seats and nothing looks amiss underneath. All plugs are connected securely and all wires look to be in good shape.

I pulled the seats and put the drivers seat in the passenger side and the button still isn't working. Unfortunately I was crunched for time so I didn't put the passenger seat in the driver's side to confirm it works there, so there's still some chance that something in the seat is bad.

I also pulled the controls out of the dash and everything looks good as far as my untrained eye can tell there. No signs of shorts or other disconnections.

At this point is it safe to say the controls need to be replaced or should I take the time to swap the passenger seat to the drivers side and confirm? (I should probably do this, but I'm hoping someone will convince me there's something else going on)

Is there anything else that might be the issue?

Also, I didn't know I needed to disconnect the battery prior to removing the seats and now I have an Error:Airbag message on my dash when I start the car. Can this only be turned off via VCDS or the dealer? Does it mean the airbag won't work or is it just an informative light?
 

amitsekhon

Veteran Member
Joined
Jan 8, 2007
Location
Langley,BC (Canada)
TDI
2015 Golf TDI,,,,,, 2010 X535D Diesel ,,,,,,,,,,,, 2002 Jetta manual TDI ALH (Sold)
I am having exactly same problem on my 2 years old 2015 TDI.Heating indicator lights stops after 4~5 secs on passenger side.Made an appointment with the dealer for next week as its still under warranty.
 

aTALLasian

Member
Joined
Sep 12, 2019
Location
TX
TDI
2015 Sportwagen
Hey amitsekhon, was the dealer able to sort out your issue? I'm curious what they diagnosed the problem to be.
 

amitsekhon

Veteran Member
Joined
Jan 8, 2007
Location
Langley,BC (Canada)
TDI
2015 Golf TDI,,,,,, 2010 X535D Diesel ,,,,,,,,,,,, 2002 Jetta manual TDI ALH (Sold)
Hey amitsekhon, was the dealer able to sort out your issue? I'm curious what they diagnosed the problem to be.
Hi,
Sorry not yet as i had to cancel my appintemrnt.My next appointment is on jan 4.Will update the results.
 

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
Good timing, the heater in my passenger seat has stopped working. All lights function as they should but it's not getting hot. I am assuming the kids jammed something under the seat.

But, it's still under warranty so I might just bring it in.
 

Nutty 5.0

Veteran Member
Joined
Aug 22, 2014
Location
SE PA
TDI
15 GSW SEL TDI 6MT
Apples and oranges here, but I had the same light on for a few seconds and shut off on my F150. Yeah it’s in a different universe compared to these. However, it was the seat heating pad was broken (later found out why I had an occasional pinch in my butt cheek!) and the switch turning off wasn’t making continuity. The pads in them were cheap and easy to swap and I was back with a warm butt.

Again, this a generic answer, but maybe easy to check resistance of both seat heaters.
 
Last edited:

amitsekhon

Veteran Member
Joined
Jan 8, 2007
Location
Langley,BC (Canada)
TDI
2015 Golf TDI,,,,,, 2010 X535D Diesel ,,,,,,,,,,,, 2002 Jetta manual TDI ALH (Sold)
Hey amitsekhon, was the dealer able to sort out your issue? I'm curious what they diagnosed the problem to be.

UPDATE:
Took it to the dealer under warranty and they found one connector under the passenger seat was not making connection as if it was not fully inserted.They just pressed it in and now its working.It must have been some tired production worker left it loose...
 
Last edited:

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
It could have gotten knocked loose by something getting shoved under the seat. I know that's what happened to my driver's side. I finally got it plugged back in over the weekend.
 

adjat84th

Veteran Member
Joined
Dec 13, 2008
Location
Virginia Beach, VA
TDI
'01 Jetta TDI/'15 Golf TDI
UPDATE:
Took it to the dealer under warranty and they found one connector under the passenger seat was not making connection as if it was not fully inserted.They just pressed it in and now its working.It must have been some tired production worker left it loose...
First thing to check on any electrical issue with a VW is the connector!
Have had similar issues before, hopefully the engine assemblers drink more coffee, haha.
 

amitsekhon

Veteran Member
Joined
Jan 8, 2007
Location
Langley,BC (Canada)
TDI
2015 Golf TDI,,,,,, 2010 X535D Diesel ,,,,,,,,,,,, 2002 Jetta manual TDI ALH (Sold)
Another Update:

It stopped working again and i didn't even touch anything under the seat.So its going back to the dealer end of this month.
 
Top