Seatback lock switch

[Derekwh]

I am getting SRS codes (w/BMW scanner) for the seatback locks, driver and passenger sides. I pulled the driver side microswitch and tried jumping the switch (got short to ground code) and leaving it out of the circuit (no change). Does anyone have any experience with these switches? Is there a resistor in them that presents a prescribed resistance in the circuit? Or is there something else in the system that could be an issue? The reason I ask this is that it seems coincidental that they are both bad. This doesn't seem to be a common problem because I am not getting much in my searches. Both seat backs are locked and I am getting the flashing seatbelt light (no airbag light), no other SRS codes.

[MarcoZandrini]

Hmmm, I have the same basic car. I've had the seat backs off, but I don't remember seeing any switches in the seat backs. I've looked at realoem (www.realoem.com) and didn't see any switches in or around the seat backs. I don't have my Bentley manual with me so I didn't check it.

[Derekwh]

Marco - the switch is part #7 on realoem. It is mounted under the outside hinge cover.

[MarcoZandrini]

Could you please post the link. I just went through the seats section of realoem and didn't see it. Is you car a coupe or vert?

[Derekwh]

Seat frame.pdf

Convertible

[MarcoZandrini]

<img src="http://www.bimmerforums.com/forum/attachment.php?attachmentid=564821"/> Convertible

That's why realoem didn't show the switch for my coupe! I have a link to realoem that'll show parts specific to my car!

[Derekwh]

No one else has had an issue with these switches or seatback lock codes? Or could it be the hall effect sensors causing the codes?

[Derekwh]

Bump

[mattman928]

I am having the same problem, I pulled the seat today and checked the microswitch. It seems to be working but I did find the the connector was loose. For fun I measured the resistance and it was 0.751kohms with seat forward and 4.665kohms with the seat latched back, so ovviously it's not a simple open close. I think the designers can tell the difference between the switch working and an open or broken wire

[Gtravers]

I am having the same problem, I pulled the seat today and checked the microswitch. It seems to be working but I did find the the connector was loose. For fun I measured the resistance and it was 0.751kohms with seat forward and 4.665kohms with the seat latched back, so ovviously it's not a simple open close. I think the designers can tell the difference between the switch working and an open or broken wire

Did you ever find a solution? I’m getting a short to ground code for the microswitch. I replaced the switch and reset the codes it comes right back. I get the same resistance measurements at the junction box as you got, so I’m confident the switch is good. Others have said the seat occupancy mat is the fault. I’m probably going to try a mat emulator next. I’ve been over all of the wires an can’t find anything broken.