Poss Electrical Fault on E90

morpah · 03-28-2023, 08:22 AM

Hi All,

Looking for some guidance

I've a possible electrical fault on my 2006 320d E90 that I'm looking for some guidance on. Two weeks ago I started getting an intermittent right rear (UK drivers side) ABS fault which is now a permanent fault upon starting her up. No problem I thought, I'll order an ABS sensor and look at replacing. However, today when driving into work I got a CCID-97 fault (airbag) and to top it off - an eratically fluctuating fuel gauge!

Can a faulty ABS sensor also start interfering with things or is there a wiring harness that could be at fault here? I started looking around the right rear to see what drops down by the wheel without taking it all off (the wheel's pretty solidly stuck to the hub and needs some force I just don't have today) and I can see these two cables, any idea if these are relevant?

Some other things to note:-

* I'm fairly sure it's worse when wet, though the ABS fault is obviously now permanent.
* The battery was replaced with a new halfords one about a year ago.

Am i barking up the wrong tree here? Any guidance appreciated.

BRG_N54 · 03-28-2023, 02:14 PM

You did not mention mileage, but since it's an '06 I am going to guess your voltage regulator is in need of replacement. I'm not sure if you are aware, but there is a "secret menu" you can pull up on the instrument cluster that will display the voltage of the running car. It should be over 13v while running, but not over 15v. If you see either, replace the voltage regulator with a genuine Bosch part, it's only about $50 US.

Just because the battery is newish, does not mean your electrical system is working normally. In fact, if it had to be replaced, it points to some weakness in the charging portion of the car, which is handled by the voltage regulator. Low voltage could also be caused by a faulty alternator pulley, but the regulator should be replaced with some regularity as it has brushes that wear away with usage.

ptpending · 03-28-2023, 03:08 PM

since you car is m47 06 car, than it is quite usual that abs magnet in wheel hub is failing and there are a lot of such issues in a forum
so you have to replace a magnet, but higher end e90 have magnet integrated in a bearing and lower end e90 have sort of magnetic ring
it is corrode and start to provide not correct info to DSC module, and that lead to very strange behavior sometimes because DSC want to know that all wheel rotating correcly before allow engine management to go to some higher speed

morpah · 03-29-2023, 05:24 AM

Thanks for the feedback guys. It's a high miler now with 190k miles on the clock. I plugged in the carly instead on a 50 mile trip today and the voltage maintained between 13.8v and 14.2v (mostly in the 14's).

It's a dry day out today so I'll keep an eye on it as I have a feeling the airbag fault will probably return when it's wet out again but we'll see.

Out of interest does anyone know what the white box is and the 2 connectors in the photo?

03-28-2023, 08:22 AM	#1
morpah Registered 0 Rep 2 Posts Drives: bmw 320d e90 m47 Join Date: Mar 2023 Location: United Kingdom iTrader: (0)	Poss Electrical Fault on E90 Hi All, Looking for some guidance I've a possible electrical fault on my 2006 320d E90 that I'm looking for some guidance on. Two weeks ago I started getting an intermittent right rear (UK drivers side) ABS fault which is now a permanent fault upon starting her up. No problem I thought, I'll order an ABS sensor and look at replacing. However, today when driving into work I got a CCID-97 fault (airbag) and to top it off - an eratically fluctuating fuel gauge! Can a faulty ABS sensor also start interfering with things or is there a wiring harness that could be at fault here? I started looking around the right rear to see what drops down by the wheel without taking it all off (the wheel's pretty solidly stuck to the hub and needs some force I just don't have today) and I can see these two cables, any idea if these are relevant? Some other things to note:- * I'm fairly sure it's worse when wet, though the ABS fault is obviously now permanent. * The battery was replaced with a new halfords one about a year ago. Am i barking up the wrong tree here? Any guidance appreciated. Attached Images
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03-28-2023, 02:14 PM	#2
BRG_N54 Second Lieutenant 297 Rep 246 Posts Drives: Green '07 & Arctic '08 335i's Join Date: Jan 2023 Location: Monterey Peninsula iTrader: (0) Garage List 2008 BMW 335i [0.00] 2007 BMW 335i [0.00]	Voltage Regulator? You did not mention mileage, but since it's an '06 I am going to guess your voltage regulator is in need of replacement. I'm not sure if you are aware, but there is a "secret menu" you can pull up on the instrument cluster that will display the voltage of the running car. It should be over 13v while running, but not over 15v. If you see either, replace the voltage regulator with a genuine Bosch part, it's only about $50 US. Just because the battery is newish, does not mean your electrical system is working normally. In fact, if it had to be replaced, it points to some weakness in the charging portion of the car, which is handled by the voltage regulator. Low voltage could also be caused by a faulty alternator pulley, but the regulator should be replaced with some regularity as it has brushes that wear away with usage.
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03-28-2023, 03:08 PM	#3
ptpending Colonel 456 Rep 2,749 Posts Drives: e91 Join Date: Dec 2013 Location: Poland iTrader: (1)	since you car is m47 06 car, than it is quite usual that abs magnet in wheel hub is failing and there are a lot of such issues in a forum so you have to replace a magnet, but higher end e90 have magnet integrated in a bearing and lower end e90 have sort of magnetic ring it is corrode and start to provide not correct info to DSC module, and that lead to very strange behavior sometimes because DSC want to know that all wheel rotating correcly before allow engine management to go to some higher speed __________________ E81 2007 130i 6cylinder Montego blue Retrofits: Harman Kardon, High-beam assistant, Removable tow hitch. Auto-dim folding exterior mirrors. Lumbar support. Perfomance Brakes.
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03-29-2023, 05:24 AM	#4
morpah Registered 0 Rep 2 Posts Drives: bmw 320d e90 m47 Join Date: Mar 2023 Location: United Kingdom iTrader: (0)	Thanks for the feedback guys. It's a high miler now with 190k miles on the clock. I plugged in the carly instead on a 50 mile trip today and the voltage maintained between 13.8v and 14.2v (mostly in the 14's). It's a dry day out today so I'll keep an eye on it as I have a feeling the airbag fault will probably return when it's wet out again but we'll see. Out of interest does anyone know what the white box is and the 2 connectors in the photo?
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