2003 Seats in a 2005

[ANUSTART]

I'm considering avoiding the sensor fixes fitting 2008 seats in my 2005 and found a set of 2003 seats in good shape. Are there any electrical/sensor issues I need to consider if I decide to go this route? Don't want to jump from one set of issues to another.

Thanks!

[WestCDA]

Originally Posted by hogzilla

I'm considering avoiding the sensor fixes fitting 2008 seats in my 2005 and found a set of 2003 seats in good shape. Are there any electrical/sensor issues I need to consider if I decide to go this route? Don't want to jump from one set of issues to another.

Thanks!

The only real concern should be the seat occupancy sensor in the passenger seat, which was changed on the facelift cars - the two versions are not compatible. 2003 and 2005 seats should both be using the early sensor arrangment.

If the new seats are optioned the same for power and heat, then the wiring for those is obviously already in place. If you are adding one or both of these feature you may have the wiring already to support it, as the early cars had the full wiring harness including both heat and power adjustment regardless of seats installed. Opinions vary about when they changed from this to using option specific wiring harnesses, so you should check the large connector under the seat to confirm that it has the extra wiring in it. My 2006 had a limited wiring harness, and I had to add extra wiring for power seat adjustment.

The bolt pattern is the same if you are moving from sport seats to standard or vice-versa, so there are no mechanical/fitment issues when changing.

Check the seats you are considering purchasing to ensure one or both of the seat belt pre-tensioners haven't fired (common if the seats are from an accident car). If so, you'll need to replace it (one bolt) or it will trigger the airbag warning light.

Also ensure your battery is disconnected before changing the seats, and not reconnected until the new seats are electrically connected.

[ANUSTART]

Thanks for all the info.

Full disclosure, I already put 2008 M Sport seats in the car and they are fabulous, BUT, I have been looking at all options due to the sensor compatibility issue. I am going to give the sensor bypass a shot first, as DSC_OFF did, and see if that clears things up. If not, going with older seats will be my plan B. Install, clear the codes, walk away.

It's been an ongoing annoyance. I had planned to do the sensor transplant, but half way through removal of the old one, realized this could go very sideways, very quick and didn't want to destroy a good M seat. So my old seats are half apart in the basement. Once this is done, I'll just put them back together and call it good.

BTW, excellent reminder on the seat belts!

[pokeybritches]

Do the part numbers for the occupancy sensors match up on realoem.com?

I vaguely remember that the sensor changed between 2003 and 2004. I haven't dug into it.

[ANUSTART]

Excellent call on checking realoem.com. Turns out, if want to get a drop in seat the only years that are plug and play are 2004-2006. Thanks for leading me down the right path!

[CFoote]

Hey there, I used to have a 2005 Z4 3.0 and it came with manual leather seats. I purchased a set of used power heated seats off an owner with a 3.0, and I did in fact have to change the passenger seat occupancy sensor. The 2003-2004 cars came with the same sensor, but in 2005 they changed it. I am not sure if the 2006+ cars use the same sensor as the 2005s.

Having said that, you will need to change the sensor. It really isn't bad, but it will take you a good 3-4 hours to do it. There are metal rings which hold the leather to the foam -- you'll need a good solid set of wire cutters to 'snip' each ring and undo the leather the foam -- you can reuse these rings after you are done moving the pads.

It isn't a bad job at all, just tedious and time consuming. Do it on a day when you have nothing else to do

Chris

[ANUSTART]

Chris, Thanks for the guidance. I took out my stock seats with the intension of doing the transplant and became concerned half way through that it could go horribly awry when I started digging into the M seats. Really didn't want to have an "oops" moment with those.

So... I picked up the sensor bypass off eBay. So far, still haven't gotten it to work either. It's a "domino effect" project. I am in the process of setting up the INPA software on a PC so I can clear the codes and see if the bypass functions after that. Would need to be done anyway. I'll post back on my epic journey to get functioning airbags with my M transplanted seats.