[swain90]

Hi All,

I think this is in the right place, however if a Mod want's to relocate this thread, feel free!

A little while ago I split a drink on my front passenger seat. For a short while the car was complaining that the front passenger wasn't wearing their seat belt.

I presumed it was the padding in the seat which was still wet which may have been heavy enough to make the car think someone was sat in the seat, or that the sensor in the seat is now broken.

After about a week of this the light on the dash disappeared and now when someone sit's in the front seat and they don't wear their seat belt I don't get any warnings.

My issue is, I don't want to end up in an accident and have a passenger with me and the air bag not go off.

I was wondering if anyone had, had a similar issue, or would be able to advise on what I would need to replace.

(p.s. I'm in the UK if that makes any difference)

Cheers

Swain90

[Dracon]

Only the passenger's seat has a occupancy sensor built into the seat. It's assumed that if the vehicle is in operation, there's a driver in the seat.

You may need to check the module on the underside of the seat as it may have been damaged by the liquid or if liquid got into the belt buckle receptacle the sensor in it can be damaged as well.

Originally Posted by swain90

Hi All,

I think this is in the right place, however if a Mod want's to relocate this thread, feel free!

A little while ago I split a drink on my front passenger seat. For a short while the car was complaining that the front passenger wasn't wearing their seat belt.

I presumed it was the padding in the seat which was still wet which may have been heavy enough to make the car think someone was sat in the seat, or that the sensor in the seat is now broken.

After about a week of this the light on the dash disappeared and now when someone sit's in the front seat and they don't wear their seat belt I don't get any warnings.

My issue is, I don't want to end up in an accident and have a passenger with me and the air bag not go off.

I was wondering if anyone had, had a similar issue, or would be able to advise on what I would need to replace.

(p.s. I'm in the UK if that makes any difference)

Cheers

Swain90

[swain90]

Thanks for the reply!

The belt buckle receptacle is fine, it just ended up all over the seat!

I've been given a price to have a new sensor in the seat but you're looking at about £300~ (or that's what I was quoted)

I've had a quick look into these http://www.ebay.co.uk/itm/Seat-Occup...-/200967932097 but seeing as I'm not getting any warning on my dash I'm not sure if it'll actually work!

[ctuna]

There was a recall on the 06's and 07's in the US
for the passenger seat sensor.
This should be on the general forum.

[Dracon]

Originally Posted by swain90

Thanks for the reply!

The belt buckle receptacle is fine, it just ended up all over the seat!

I've been given a price to have a new sensor in the seat but you're looking at about £300~ (or that's what I was quoted)

I've had a quick look into these http://www.ebay.co.uk/itm/Seat-Occup...-/200967932097 but seeing as I'm not getting any warning on my dash I'm not sure if it'll actually work!

About $350 USD is the going price for a new passenger cushion (the sensor is integrated with the seat cushion). But it also connects to a module on the underside of the seat which gets the signals from the sensor.

I'd check the control under the seat for damage first. As these leather/vinyl or cloth seats in the vehicle? If it's leather/vinyl I doubt the sensor in the seat is damaged it's probably the exposed control unit go liquid on it and shorted it out.

If you replace it yourself, you'll need to have ISTA/D and ISTA/P or INPA/NCSExpert handy because you'll have to recode the MRS5 module to initialize the seat sensor for the vehicle (there's a service procedure in ISTA/D for this).

BTW: I know all this because I had to replace the OC3 mat in my 2006 330i a few weeks back.

[riso1988]

Originally Posted by Dracon

About $350 USD is the going price for a new passenger cushion (the sensor is integrated with the seat cushion). But it also connects to a module on the underside of the seat which gets the signals from the sensor.

I'd check the control under the seat for damage first. As these leather/vinyl or cloth seats in the vehicle? If it's leather/vinyl I doubt the sensor in the seat is damaged it's probably the exposed control unit go liquid on it and shorted it out.

If you replace it yourself, you'll need to have ISTA/D and ISTA/P or INPA/NCSExpert handy because you'll have to recode the MRS5 module to initialize the seat sensor for the vehicle (there's a service procedure in ISTA/D for this).

BTW: I know all this because I had to replace the OC3 mat in my 2006 330i a few weeks back.

Sorry to resurrect a dead thread but Dracon - do you know how to perform this coding? BMW replaced my mat under the warranty but could not program it on ISTA, probably since I have a more recent VO for my cic/combox retrofit.

I have INPA/NCSEXPERT - just not sure how to initialize the seat sensor. Any help would be appreciated!

[ctuna]

You might start by using inpa to see if the seat senor works.
There is a place in Inpa where you should be able to see
the results of someone sitting in the seat or and empty seat.
Do you know if they actually replaced the old one?
Did you try clearing the error codes?

diagnostic manual ista/inpa
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...xo19teM9vkTF-C
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://www.bimmerforums.com/forum/s...-P-actually-do

[riso1988]

Originally Posted by ctuna

You might start by using inpa to see if the seat senor works.
There is a place in Inpa where you should be able to see
the results of someone sitting in the seat or and empty seat.
Do you know if they actually replaced the old one?
Did you try clearing the error codes?

diagnostic manual ista/inpa
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...xo19teM9vkTF-C
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://www.bimmerforums.com/forum/s...-P-actually-do

Thanks again ctuna. I have a Foxwell Scanner that I've been using in parallel. It is able to detect the seatbelt being inserted or not but the occupancy sensor just states 'not assigned' and brings up an oc3 code. BMW claims to have done the replacement, just couldn't 'program' it to my mrs5 module.

Yes I cleared codes with both Foxwell scanner and INPA but the 93C3 remains.

[ctuna]

https://www.eevblog.com/forum/repair...upancy-sensor/

Shouldn't you foxwell scanner be capable of what is done in the above thread.

See entry 8

I remember seeing the passenger seat and belt buckle display somewhere in Inpa and
exercising the buckles and sensors.

[riso1988]

Originally Posted by ctuna

https://www.eevblog.com/forum/repair...upancy-sensor/

Shouldn't you foxwell scanner be capable of what is done in the above thread.

See entry 8

I remember seeing the passenger seat and belt buckle display somewhere in Inpa and
exercising the buckles and sensors.

I am able to clear the code with the Foxwell as he does but my comes right back up. Thanks for the info though!

[ctuna]

That suggests the BMW dealership did not correct the problem and may
have made it worse. That is why you need to be able to test it with diagnostics. Not just clear the error code.

https://www.google.com/search?q=test...3PnPGDAcbMoPM:

https://z4-forum.com/forum/viewtopic.php?t=74902

I know these are not e90's but the selection or the test should be the
same.

https://www.bimmerfest.com/forums/sh...d.php?t=614533

[riso1988]

Originally Posted by ctuna

That suggests the BMW dealership did not correct the problem and may
have made it worse. That is why you need to be able to test it with diagnostics. Not just clear the error code.

https://www.google.com/search?q=test...3PnPGDAcbMoPM:

https://z4-forum.com/forum/viewtopic.php?t=74902

I know these are not e90's but the selection or the test should be the
same.

https://www.bimmerfest.com/forums/sh...d.php?t=614533

Thanks for all the help ctuna, your posts got me thinking. As it turns out there was an option to re-encode MRS unit for the passenger occupancy sensor on my handheld Foxwell scanner. Worked perfectly.

[ctuna]

Glad you got it.



Also glad you thought about it.

[duggboy]

Originally Posted by riso1988

Thanks for all the help ctuna, your posts got me thinking. As it turns out there was an option to re-encode MRS unit for the passenger occupancy sensor on my handheld Foxwell scanner. Worked perfectly.

Hi, which Foxwell have you got? can you explain exactly how you re-encoding the MRS unit please? Thanks