How to troubleshoot BMW seats?

[Richfj60]

Hi, Need more help. My 62 came with BMW seats, unfortunately, the Driver's side doesn't work, meaning it doesn't move forward out back, or any other seat function other than lumbar support. Furthermore, when I went to visit Torfab about an unrelated issue, they told me it wasn't installed properly and was dangerous. I've had so many other issues that I hadn't really gotten there yet. Anyway, the seat was wired to the working passenger seat, so "its not hooked up" isn't true (or maybe it is kinda true). So, I pulled the seat and am digging in. Question is how do you trouble shoot? I searched the interweb and it suggested that the controls fail, which is totally plausible, but I hate throwing good money after bad. Any BMW seat experts out there?

 

[TLC Norway]

Not sure if I can help, but I have 8 series bmw seats, and to operate functions besides heat, I've only pulled fused power to the two big pins in the big yellow connector in front of the seats. Enough for me.

Harder to hook up the heat, needs the bmw controller, or done electromagically.

Is your connector like this?

 

[FJ40Jim]

Be careful with modern seats. The brightly colored connector usually contains at least some wires that are part of the SRS. Don't blow yourself up.

 

[gt7058a]

What year are the BMW seats? Mine are from a 2008, I think E92, and the driver side has a timeout feature that makes it only adjust forward/backward for 15 seconds or so after power is on.

This thread has a pin diagram for E90 seats.

My BMW E90 seat install

Ok, this is what we have for E90 manual seats with heat. I'm assuming 8 and 9 are power, 1 is the signal from the hvac module or whatever in the dash that the e90 switch ribbon cable connects to, and 5 is some sort of unloader signal for ignition startup. The arrows are the pins that exist...

forum.ih8mud.com

 

[LCnAZ]

You likely have E90 seats like mine. You need to make sure you have the seats installed safely. The Torfab BMW brackets are the correct thing.

@86aggie has done the most thorough breakout of the electrical on these seats. He was hugely instrumental in getting me going with the color coding of the various items. The "problem" you are experiencing is by design. A timer in in the driver's seat electronics that gives you 15 seconds to adjust the seat as soon as it has power...then cuts off power for all but lumbar. To get adjustment enabled again, you must first remove power from the seat for two minutes. When you turn power back on after that you can adjust again...for 15 seconds. I had to learn these by R&D with the seats on a bench with a battery. The passenger seat does not have this feature, therefore works whenever you wish.

The first thing you must do for safety is separate out the wires for the airbag and permanently terminate them so that you cannot accidentally detonate them. Another thing to watch out for is that the color coding changed a little in March 2007, but it is fairly inconsequential to the basics. The 12AWG red is seat adjustment power. The two grounds (seat and lumbar) are both 12AWG brown...so you will have to experiement a little to know which is which.

In my build thread you can see a photo of the driver seat, Torfob brackets, and the switch I added to enable removal and restoration of power. Builds - Sentimental Restoration of Family 1990 FJ62

I could not get the memory function to work, and mine do not have heating.

Good luck. You'll love them.

 

[Richfj60]

Thanks all for the info. You had me at "don't blow yourself up" ha. I believe they are E90 seats (99% sure) from a 2006/2007. Not heated as far as I can tell (at least not advertised as such). The research I was able to do last night implied that the seat controls go bad and would need to be replaced. The timer thing is new. I have the Torfab brackets, but wasn't installed correctly because PO couldn't tilt the seat back. I'll digest the new info tonight and post a couple of pictures.

 

[SteveH]

I found a nice round switch at Autozone (NLA, but surely an eBay item) and installed it in a blank area on my seat. My routine is this: turn on seat power, adjust seat, turn off seat power. That way, there's no '2 minute delay' if you ever need to adjust the seat. Silly, but that's the way it is. I have '06 E90 seats.

Oh, and I must add - I bought 2 seats, and the pass. seatback 'tilt' function was broken. Never could get it to work. This is not uncommon, so test any BMW seats if you can before you pay serious money for them. So, yes - one of your seats could simply be broken. I dread the thought of trying to fix them.

 

[Richfj60]

I think disconnecting power and reconnecting it is the place to start. I know it has continuous power because it is wired to the passenger seat. You guys are brilliant! Appreciate the insight.

 

[LCnAZ]

I found a nice round switch at Autozone (NLA, but surely an eBay item) and installed it in a blank area on my seat. My routine is this: turn on seat power, adjust seat, turn off seat power. That way, there's no '2 minute delay' if you ever need to adjust the seat. Silly, but that's the way it is. I have '06 E90 seats.

That's the same technique/procedure I use. It's the only reason to have the power switch.

 

[blbuck12]

Usually a few of the motors have the same plug on them, so you can swap'em to test if it's the motor or the controls. I did this on mine and found that it was the motor that was bad. I was able to pull the motor and and pop it apart. It was gross inside and the brushes were sticky. Couple sprays of electrical cleaner and it works perfectly again

 

[Richfj60]

I unhooked the battery for 15 minutes, hooked it up and ran over and tried the seat. No luck. Ordering a used switch controller and we'll see if we get lucky. There are only a few things for me to try, so we'll start there.

 

[86aggie]

Here is a link to a site that has the pin out for all BMW components, by model. there are b/w pictures as well. Even if you don't know the exact model/vin they came from, you should be able to find the correct information by using the info on the large controller box.

newTIS

This happens to be the starting page of my seats

 

[Shes Mad]

I have a pair of 2000 ES300 seats. Anybody know where I can get a pin out for them? Not concerned with heat—-just power

 

[86aggie]

When I first started on my seats, one thing I did was go to the BMW dealer on a Saturday, and ask if I could talk to a mechanic about what I was trying to do. He was able to pull up pin outs by using the vin I had of the donor bmw. I’d think Lexus would have the same type of database.

 

[Richfj60]

Problem solved! After much troubleshooting and probably an extra part, I solved the problem. It was a back memory module (the square box under the seat). I bought a used one on Ebay for $50 and its now working!! Yeah! One down, many more to go....