scottalexander

When you look at the electrical wiring diagram charts mapping the wires from the oil sensor inside the crank case back to the iDrive unit, what other devices are on the same bus?

- Are those devices working?
- can you run fresh wire from the oil sensor back to the iDrive?

Chris Mac

Found a wiring diagram and found that the oil sensor is on the same bus as all the oxygen sensors. Traced where and what the fuse is for them and definitely not a blown fuse.
Not getting any codes for oxygen sensors so don’t think it’s any wiring problems. Everything else seems to be working fine.
I’m gonna have to get back under her and get a multi meter to check the wiring harnesses.

donpb

I had the same exact problem. My mechanic changed my oil and could not reset the service interval. I tried resetting it a billion times but to no avail. Ended up being the wiring to the oil sensor. You need to check it with a meter because if the wire is broken inside the insulation, you won't be able to tell that it is broken visually. BMW wiring seems to be infamous for that.

Chris Mac

Thank you for your response and information. I was thinking that was the problem, but hoping it wasn’t.
Just wondering did you have to re wire, or run new wire?

donpb

My Indy mechanic located where it was broken and repaired it. The oil service light was then magically able to reset.

aNo94

Old thread but thought this might be worth mentioning: it might not be an issue for the OP because of low miles, but once you hit higher miles (over 300,000km according to BMW) the oil change indicator stops working because BMW programmed a set amount of resets into the software. It'll reset briefly and then quickly revert back to 0 miles remaining.

Chris Mac

Update!!!
so after doing research over the years I found that the oil level sensor is on the same bus as the alternator, starter, and IBS. I changed the IBS over a year ago and that wasn’t it. So I’ve been doing some other work on the car and figured while I was in there I would remove the alternator and change the voltage regulator. After removing the alternator I found that oil might be the problem. The previous owner had the alternator bracket gasket replaced by a mobile mechanic and I don’t think he cleaned any of the oil from the wiring or plugs. After a good cleaning and replacing voltage regulator and put everything back together……SUCCESS!!!
The oil level sensor now works and I am able to reset oil service light. No more maintenance required light on dash and no more triangle light!!!
it’s such a good feeling!!!

ZeroDfx

Where exactly did you find oil and what exactly did you clean? I'm not able to reset any of my service indicators on my 530i or my 550i; I did have the alternator gasket replaced a year or so ago so wondering if I have the same issue as you.
Thanks for your thoughts.

seanjordan20

There is only one plug that goes to the alternator so I am assuming that is the wire and plug he cleaned up. That is whats on the BSD

ZeroDfx

Ok so it's the electrical connector that plugs into the alternator; got it, thanks.