Collective failures today: trifecta lights + airbag + + steering wheel
 

Had an unusual string of symptoms today driving the X5. Started with the red airbag warning light coming on and staying on, followed by the trifecta lights (4x4, dsc, yellow brake warning, etc) about a minute later. Vehicle still ran ok but I headed home to try and diagnose. Ran codes via INPA and the only code that showed up was an MFL toggle bit error. Sure enough, none of the buttons on the steering wheel were working either. When I tried to access the specific sections in INPA for the MFL multifunction steering wheel stuff or the airbag, I just kept getting 'NO RESPONSE FROM CONTROL UNIT' errors.

Do y'all think that all of these issues are related to a single cause, or am I dealing with more than one problem? Thanks for any help!

Sounds like a failed ignition switch to me...Search and read up on symptoms.

Its actually pretty common on E53..It happened to my '05 3.0..

+1
It sure sounds like the ignition switch, just know that if it is then it will go out 100 miles from home or on a super hot day when you just bought frozen food..


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@Effduration and @EODguy, thanks for the replies. Unfortunately, I'm no stranger to failed ignition switches on my E53. At 200k miles currently, I'm on my 3rd replacement switch already, and it's only 15k miles old. However, none of the previous failures showed symptoms like these. I've got a spare I will go ahead and install to test, but if it's not the switch what are some other possibilities? Thanks again-

Maybe try the visor test before swapping out the ignition test? If not familiar have a search.

You know, re-reading your post, you may have a problem with your ABS module. Is it original? Search on your symptoms and ABS module.

I would verify that the battery/charging system is actually working with a digital volt meter. A few years ago my E53 alternator died without notice and the battery light did not come on. Even though I did confirm the light did work.

So the trifecta lights have disappeared, but my airbag light is still on. When I do the visor test, the airbag light goes off, but the visor light doesn't come on. So now I am starting to believe it is the ignition switch. If that is the case this will be my 4th ignition switch replacement. I'm baffled as to why my X5 is eating through these things?!?!

Are you buying a good brand of switch? …FCPEuro sells only Febi and Genuine.

ECS is selling several from less reputable manufacturers, like Hamburg Technik

One in there currently is a Febi from FCPEuro.

I'd buy BMW Genuine ignition switch.