Electrical Problem - Ignition Switch/AirBag Sensor failure?

[z4m]

Hi Everyone:

Wanted to pick your brain to see if you could help me diagnose the issue I'm facing.

When I turn on the car, the Passenger Airbag light comes on and stays on (happens consistently).

This is combined with an erratic radio behavior. Intermittently the radio stops working and the SOS/Call message flashes on it. At times the message disappears all by itself a few (10-20) minutes into the drive and the radio starts working fine. Other times, the radio is fine when I start the car but then a few minutes in, it stops working and displays the SOS message.

In addition, there are times when the top doesn't come up or go down. The red light or orange flashing light doesn't come on either. This seems to fix itself when I start the car after a few hours.

Some things to note: I had a new battery installed a couple weeks ago, since the old battery was bad anyway. I also checked the voltage at on, idle and revved up, and it seems to show the proper voltage, so I've ruled out the alternator/voltage regulator.

Preliminary research is pointing me to 2 things – faulty ignition switch or passenger seat sensor failure, which apparently is being covered under the extended warranty by BMW.

What makes me think it's a faulty ignition switch is this – This morning I turned on the car and the radio came on fine. Low and behold 5 minutes later it stopped working. So I turned the car off, took out the key, and locked the door (to simulate a parked car condition) and then turned on the radio. It functioned perfectly. I then started the car, and the radio stopped working. I was able to reproduce this consistently.

I am trying to schedule an appointment with the local dealership but if it's a faulty ignition switch, I'd rather not pay them the diagnostic fee.

Any thoughts on what the issue could be?

PS: If this turns out to be Ignition switch after all, should I get an OEM, Febi, Uro or a generic aftermarket that typically sell on eBay for around $20.

https://www.pelicanparts.com/cgi-bin...on=61326901961

[hawkerone]

I have similar problems with the pax airbag warning light and radio. Paid $200 diagnostic fee and they came back with the almost standard Passenger Airbag Sensor fail. $$$ I ordered the bottom seat cushion (which has the airbag sensor built in) from bimmerworld.com. Going to have seats recovered so they'll just put this in at the time. The radio is even more expensive part to replace (OEM) so had local custom radio shop install a new Alpine unit w/ steering wheel module for about half the price. Radio works and looks great so that's solved. About another week before I'm scheduled in for upholstery so will post if that works as well as I hope. Alternative is get a bypass plug which doesn't fix anything except turn off the light. (look on ebay). Avoid the dealer if you at all can, but if you must, remember: they don't have debtors prisons anymore. ��

[z4m]

BMW has issued an extended warranty on the sensor for 15 years so make sure you get them to cover it.

[jclausen]

I’d start with the ignition switch

[z4m]

Thanks! That's what I thought as well. Here's the final resolution:

I scanned fault codes using Foxwell BMW scanner but since this faulty part triggered a bunch of them, couldn't really nail it down to one thing. Went with my hunch of ignition switch and it worked. Bought an OEM part.

Cleared codes, drove about 20 miles and rescanned, and everything cleared up with the exception of the fault codes for the passenger airbag sensor. Have scheduled a repair, which qualifies under the extended warranty.

[jclausen]

If the items that are failing are under he extended warranty, they will have you sign up for a diagnostic fee first

[hawkerone]

OK, follow up on the airbag warning lite. Had custom leather seat covers made and installed new foam pad (w/ sensor) on pax side. Plugged in properly and seat belt warning still there. Finally took it to the dealer and paid the $200 to have them initialize it and the warning light is now out. (at great cost). Apparently BMW's recall ends at 2007 and I'm a 2008. Along the line I ordered the warning bypass module (from China) which they shipped promptly. Three months later it finally showed up. (After I got the thing fixed the expensive way). New Alpine radio works great with better reception and much clearer. Only squawk is I have to re-read the manual every time I want to do anything. Random buttons with markings that make no sense.