Driver's heated seat fault?

[derin100]

Hi,

I've just bought an E83 3.0Si and just getting used to it.

Just now I noticed whilst driving along that if I put the driver's heated seat on it comes on for a while (even as little as a few seconds) but the spontaneously turns itself off.

The passenger one seems fine and stays on.

I've already searched the internet and seen EXACTLY the same problem reported by other BMW drivers and even indeed not just for this model.

However, what is strange is that I don't be able to find one single definitive answer for what seems an identical problem amongst many drivers.

Any ideas?

Thanks in advance.

[Horizon]

If you can access the wiring to the seats heating element, maybe an idea to do a resistance ohms check to compare to the other seats element.
It could be a thermal overload device that would prevent a faulty element causing a fire/ damage.
No idea if it is an accessible job, maybe the seat needs to come out, if this is the case a battery disconnect or fuse removal might be advisable to prevent an accidental triggering of an airbag fault.

[derin100]

Thanks!

A bit of an update...

I think the problem lies in the seat pad!

If switched on without me sitting on it, it comes on and stays indefinitely.

If I then, with a fist, apply pressure to the lower seat pad it goes off. You have to press in one specific place i.e. to the rear, right half of the seat pad and after a couple of seconds it goes off. Pressing nowhere else elicits this.

So does this indicate a break in the wiring in the pad itself at that particular point?

Bit of a pain if it is because I've had to strip a seat in the past to get to renew a seat pad and that was a PIA. That was on an E36 with manual seats. I shouldn't think it would be easier on an E83! 

[AW8]

If it was bought from a trader then ask them to sort it and any other issues....unless they notified you of issues prior to agreeing to buy with same present

[derin100]

I did buy it from a trader. He told me the parking sensors were dodgy but not the driver's heated seat.

(Been round the parking sensors and I reckon that at least 3 at the front are not clicking...I'll have to deal with that myself)

[AW8]

Try swapping suspected dodgy sensors with decent one and walk testing. Hopefully you will be able to ascertain if issue is individual sensor(s) , loom (unlikely) or PDC control unit. Also maybe check/clean connections first &/or use alcohol wipe to clean each sensor  before shelling out on new parts.

As for the seat - go back to seller. Even if he says go away you haven't lost anything.

[derin100]

Thanks AW8.

I think when the weather is a little more reliably dry I'll tackle the seat myself.  The trader is a looooong way from me. I do have a 6 months warranty with it but my experience with 3rd party warranties is that they always find an exclusion or way of getting out of things and are only useful to cover the drive homwe in terms of the gearbox falling on the floor!  )

Also, reading on various forums this seat issue isn't going to be something even a BMW tech is going to have had need to fix many times before. I think BMW would have just swapped it out for a whole new seat base! Looking at the availability and price of a leather seat base in my colour on a "Comfort" seat is either NLA or astronomically expensive and a warranty company I'm sure will either try to get out of it ("not covered") or techs will never have effected a repair.

A quick question though on seat removal...

On the E83 do I actually have to disconnect the battery (and risk losing any stored data) or is it sufficient to make sure that I don't have the key in the ignition to avoid setting off a) the airbags themselves or b) ending up with an airbag warning light?

The rest of the repair should be just 'time and tedious effort'....I hope! :'(  My interior is a light tan leather and in really clean condition and my BMW Indie is likely to get it filthy so that's another reason I'd rather do it myself.

[gs223]

Hmm, I've disconnected the battery several times and not felt that I've missed any significant "stored data". If you do disconnect it, make sure not to close the rear hatch, as otherwise you'll have to crawl into the back and poke around the lock from the inside to reopen it.

The seat fix I've seen in a YT vid looked like quite a lot of effort...

[derin100]

Thanks! That's a great tip about not closing the hatch after disconnecting the battery....I would definitely not have thought about that!  )

I think I will disconnect it when I come to do it then...just to avoid any unexpected pyrotechnics!

I'll leave doing it until the days are longer and warmer...as you rightly say, I'm not expecting it to be a quick job!