Anybody know what this is? UPDATED

"I like cars: Jim Spanfeller is one ugly motherfucker" (qaaaaa)
12/21/2018 at 12:30 • Filed to: None

(Update at bottom, original post first)

I was doing something in my Golf, sitting in the passenger seat, when I slid the seat and this snapped off of something under the seat. My first thought was it’s something related to the passenger airbag, probably the weight sensor. Here’s a pic of the back:

Clearly it snapped off of something, but I’m not sure what and didn’t see anything left over.

Also @Kinja, can you fix the way photo cropping is handled? Whenever I upload a picture in portrait and try to crop a landscape out of the pic, the picture reorients itself to landscape and the crop is of a totally different part of the pic. I had to zoom the pic on my computer and use snipping tool to get these pics to work.

Update, as of 21 December 2018

I pulled the passenger seat out, and the other half of the relay was attached to this harness with part number 1HO 382, which seems to be (per my brief googling) a part of the wiring for heated seats, as many had suggested. That’s a relief. Wait, I had heated seats?

Just for kicks, here’s some more pictures. Here’s the underside of the seat:

Further poking around online, it looks like these seats were from either a GTI or a Jetta GLX. They’re super nice and quite comfortable, moreso than most seats in new cars that I’ve been in.

And here’s the view from the backseat with no front passenger seat installed. I’m convinced that if you go on a solo roadtrip, this is the way to do it. You’ll have more room for cargo and can plop a big cooler right next to you for snacks. Also note that there are a bunch of dangling wires. Don’t question them.

I also found that the area under the seat was actually pretty clean. I don’t know when the previous owner swapped the whole interior, but they did a good job cleaning the carpets before putting in the GTI seats. The only thing I found was this little guy:

Which is likely a part of a since destroyed seat glide, explaining why the passenger seat shimmies a little bit. Finally, I put the seat back in and secured the dangly wires. Now there’s nothing passengers can complain about when riding with me.

Another Kinja complaint- every picture uploaded between 2 and 5 times in the writing of this post. I also still can’t upload a picture in portrait and have it stay in portrait.

DISCUSSION (33)

VincentMalamute-Kim > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 17:09

Looks like a relay with overly complicated electronics attached to it. Power seat control motor relay?

I like cars: Jim Spanfeller is one ugly motherfucker > VincentMalamute-Kim
12/20/2018 at 17:10

Maybe? Control module would make sense if I didn’t have manual seats.

GoodIdeaAtTheTime > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 17:11

relay soldered to a printed circuit board. looks expensive. any warning lights on? anything not working?

VincentMalamute-Kim > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 17:16

I knew you were going to say that to my otherwise brilliant answer.

Next: Your kid broke some toy of his and kicked the remnants under the seat? Now y ou’ll say “I have no kids”.

Are you sure that’s part of the car? It’s strange that it doesn’t have VAG markings (although it’s only a part of the board). The PCB looks a bit frail for car electronics.

I like cars: Jim Spanfeller is one ugly motherfucker > VincentMalamute-Kim
12/20/2018 at 17:40

I looked around online and it looks similar to other VAG relays, but without the plastic cover. Methinks it's a relay for the passenger occupancy sensor. The car has a fully swapped interior (including dash) so the airbags might not really be a thing anyways.

I like cars: Jim Spanfeller is one ugly motherfucker > GoodIdeaAtTheTime
12/20/2018 at 17:41

No new warning lights, but now my idle is at 1200 instead of 800. So that's unique, if nothing else.

TysMagic > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 17:41

I’ve wasted a solid 15 mins googling this at work and I’ve got nothing for you. That said, the seats look to mount the same way my 96 Audi seat did (sides with that weird center thing). Idr anything being under there that matter.

I like cars: Jim Spanfeller is one ugly motherfucker > TysMagic
12/20/2018 at 17:47

Working hard?

And my assumption is it is a relay on the occupancy sensor. I'm pulling the seat out tomorrow to figure it out.

VincentMalamute-Kim > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 18:04

I wouldn’t have thought the occupancy sensor needs a relay. Nor should any sensor really. Relays allow low volt/current control of high volts/current - not something sensors do or control.

I would have thought the occupancy sensor sends it’s signal directly to the ECM or whatever computer controls interior stuff. The ECM then controls any relays, if needed, to turn the airbags on or off. I’m assuming the only airbags is in the dash?

But i f any airbags are in the side of the seat, then you’re probably right - not directly the occupancy sensor but a relay to turn on/off the seat airbag.

I like cars: Jim Spanfeller is one ugly motherfucker > VincentMalamute-Kim
12/20/2018 at 18:33

My understanding of this scheme is the input of the relay is the analog output of the occupancy sensor, then if the threshold is exceeded, the appropriste hi/lo signal is sent to the controller, which turns the airbag on or off. I have a controls/system integration background, not automotive safety though.

TheRealBicycleBuck > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 20:04

It’s how they were tracking you.

VincentMalamute-Kim > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 20:18

oh, you’ve got way more credentials than I do. I’ll ask you then. Does it make sense to use a relay to send a signal to the controller? I would have thought the controller could read the sensor state after a little signal cleanup with a support chip.

Use a mirror and light to examine the underside of the seat for the companion part of the PCB? Easier than removing the seat.

For our edification, l et us know what the final answer is.

Spamfeller Loves Nazi Clicks > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 20:23

Ohhhh, that’s not good.

Obviously that’s a shattered relay. The only identifiable part on the back is a TI LM2903 low power, low offset voltage dual comparator.

Well, uh, this here is the style of occupant sensor VW uses:

Kinja'd!!!

So, good news, it’s not the airbag sensor!

Bad news, I think you just did a heated seat delete.

I like cars: Jim Spanfeller is one ugly motherfucker > Spamfeller Loves Nazi Clicks
12/20/2018 at 21:09

Wait, I had heated seats?

A comparator would be in line for a digital output of a occupancy sensor, though. I plan to pull the seat out tomorrow, then swing by the Pull-A-Part after to get a replacement.

I like cars: Jim Spanfeller is one ugly motherfucker > VincentMalamute-Kim
12/20/2018 at 21:14

I mean, the relay IS the cleanup. An occupancy sensor would send an analog output from 0-100% full scale, which is sent to a comparator (that’s the chip on the backside), which takes two inputs. One is the output of sensor, one is the threshold voltage. If the analog output is below the threshold, the output of comparator sends either hi or lo voltage to the computer, turning off the airbag. In the o ther case, the other output of the comparator is sent and the airvag is turned on. At least, that’s my understanding of the circuit.

In any rate, the seat is slammed to the floor. Could hardly fit my hand in to find the other side of the wire. Pulling the seat is only a few bolts, anyways. Will update.

Spamfeller Loves Nazi Clicks > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 21:35

Uhoh. That makes it significantly worse.

I looked up the parts diagrams and there isn’t any electrical component like this in the seat besides the seat heater relay . The airbag occupancy sensor is literally the part I posted the photo of, and that cable connects to a harness before going to the ACM located on the center console tunnel or behind the dash.

That’s why I guessed heated seats. Those also use a comparator and a relay to handle the on/off cycling to maintain the desired temperature. (Low voltage, high amperage.)

Airbags, for reasons which I HOPE are obvious, do not use relays in the system. Then again, it probably ISN’T obvious. So, basically it comes down to this: relays fail and are vulnerable to shock. Smack a relay, it’ll shake loose internally. This is VERY BAD in an airbag system, which uses explosives. You do NOT want somebody tripping while exiting or entering the car to set off your airbags. So airbag systems are, in fact, really really simple .

When the crash sensor triggers, it signals the ACM (Airbag Control Module.) The ACM determines which airbags to deploy based on the sensor input - in less than 50 milliseconds. A fast acting relay also isn’t fast enough , so the ACM directly sends a 5V or 12V electrical pulse directly to a literal blasting cap (aka the inflator.)

So that’s how I know it can’t be part of the airbag system, or at least, it most definitely should not be.

VincentMalamute-Kim > I like cars: Jim Spanfeller is one ugly motherfucker
12/20/2018 at 22:37

Nice. We have two smart people here.

You don’t have (had ) heated seats? W hat @ The Actual RootWyrm says makes sense to me. So i f you don’t have heated seats, I’m confused. And will wait for the answer.

I like cars: Jim Spanfeller is one ugly motherfucker > Spamfeller Loves Nazi Clicks
12/21/2018 at 08:44

Hm. That makes sense. I don't really know anything about airbag circuits, homestly. My assumption that there was a relay was driven by the existence of DIY guides for passenger occupancy sensor bypasses so airbags would always deploy in the event of a crash (which you want if you have aftermarket seats with no occupancy sensor). Oh well. I'm pulling it today to get a better look.

I like cars: Jim Spanfeller is one ugly motherfucker > VincentMalamute-Kim
12/21/2018 at 08:46

Eh, "smart". And I know I don't have a button to turn on heated seats- I believe my seats are out of either a Mk3 Cabrio of GTI- I don't know for sure if those were generally speced with heated seats. If you're confused, that makes at least two of us.

TysMagic > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 08:52

v hard - am swamped but enjoyed the break

I like cars: Jim Spanfeller is one ugly motherfucker > TysMagic
12/21/2018 at 09:42

You got to 10k, so that's cool

TysMagic > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 11:52

true that! I am quite surprised and excited about it

farscythe - makin da cawfee! > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 12:37

*questioning the wires*

me: ..wire... where were you last monday between 9 and 10 pm

wire:.......................................

me: oh tough guy are you

*grabs snippers*

wire :......................

*snip*

well... fuck.. we learnt nothing... dude was hard as nails

I like cars: Jim Spanfeller is one ugly motherfucker > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 12:39

Oh, weird. In editing mode, the pictures defaulted to landscape, but then published as portrait.

I like cars: Jim Spanfeller is one ugly motherfucker > farscythe - makin da cawfee!
12/21/2018 at 12:40

I’m not confident that cutting them would actually do anything. They all go into the door, but the only electronics in the door are the locks. So I’d lose power locks and probably set the alarm off if those were cut.

farscythe - makin da cawfee! > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 12:43

dunno about golfs.... but recently learnt if you take the front passenger seat out of a smart and try to drive it it will brick the car.... that being equally german... i wouldnt snip any

I like cars: Jim Spanfeller is one ugly motherfucker > farscythe - makin da cawfee!
12/21/2018 at 12:45

That’s... weird but makes sense? But also, why were you driving a smart with no seats in it?

farscythe - makin da cawfee! > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 12:50

i wasnt.. a while back i suggested to miss merc she could fit her scooter in the smart by removing the front passenger seat and strapping the scooter in with the seatbelt... it was something to do with the gambler rally i think

anyhoo.. she’s who told me it would brick the car... airbag sensors i think it was

to me it boiled down to all this newfangled tech is needlessly fuckupable

Spamfeller Loves Nazi Clicks > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 13:15

Sure, you could absolutely use a relay as part of a ‘dead-head’ circuit both directions. Basically, something that fools the airbag system into either deploying or intercepting a deployment event w ithout breaking the logic. But I really don’t think that’s the case here if it’s a stock seat.

Definitely very curious what it is now, because I’m legitimately stumped, unless VAG always includes a chunk of the power seat harness for some reason.

Duck Duck Grey Duck FTMFW! > I like cars: Jim Spanfeller is one ugly motherfucker
12/21/2018 at 13:20

Other reasons to pull passenger seat, MAAYBE you bought a truck transmission off Craigslist and only have a car. Did you know truck transmissions fit right there? I do. Maybe you need to haul a welding tank home, out comes the passenger seat. I actually made tie down attachment points that bolted in with the seat bolts.

I like cars: Jim Spanfeller is one ugly motherfucker > Duck Duck Grey Duck FTMFW!
12/21/2018 at 13:51

This is something I anticipate doing when I’m a real adult. This car is just shitty enough that I don’t feel bad hauling messy things in it and I don’t feel bad for leaving it dirty. When I have a real car, I intend to keep this one as a beater/autox/rallyx/shit hauler.

I like cars: Jim Spanfeller is one ugly motherfucker > Spamfeller Loves Nazi Clicks
12/21/2018 at 13:52

Turned out to be a relay for heated seats. These are not the stock seats, probably from a higher spec’d Jetta or Golf.

I like cars: Jim Spanfeller is one ugly motherfucker > farscythe - makin da cawfee!
12/21/2018 at 13:53

Ah, makes sense. Those cars brick easily, as I’m sure you know if you read her posts regularly. That actually makes sense as a safety measure in something so small where safety systems are more import ant.