[M2Dynamic]

So I get this malfunction now when I start to drive away after I turn the car on. It doesn't turn on until I start driving away usually. About 1 week ago it only turned on randomly while driving not immediately when I started driving away after turning the car on like it does now.

Another thing to mention is that from what I feel so far it does not affect anything at all performance wise or suspension wise. The car still feels exactly how it did before the malfunction.

I am pretty heavily modified. BM3 tune, catless dp, FMIC, MPE, Chargepipes, Aquamist Meth Kit, Eventuri Intake, Ohlin Coilovers. This malfunction happened on its own out of no where. I've had all of these mods installed for some time now with no issues whatsoever. So before I have to take almost everything off and go to the dealer I want to know if anyone here has any experience or insight as to what this could be. I'm a 2016 car with DCT. I know there were some recalls on the differentials but when I had my car for the first 4-5 months I called the dealer numerous times and they checked many times for me to see if my car was under the recall for the differentials and they were adamant about it not being affected by it. So I asked one of my buddies who was a bmw tech and he said it could very well just be a sensor or harness that got messed up; He said he's seen that many times and it just was a sensor or something similar usually.

I don't want to take the chance and leave it like this much longer so I'm planning to flash back to stock and hit the dealer next week in hopes of them fixing it under warranty.

Anyone have any ideas or clues?? Thanks!!

[McPurrs]

Jack up the back of the car and spin the wheel.. see if it is locked...

[M2Dynamic]

Originally Posted by McPurrs

Jack up the back of the car and spin the wheel.. see if it is locked...

Okay thanks for the heads up. So just get both rear tires off the ground and spin the manually with my hands? See if they spin? Thanks sorry never knew this before. Appreciate the help!

[McPurrs]

Well in N of course, so make sure to block the front wheels. Safety first. If the Diff is not locked, only one will spin (the other might go backwards). If locked, they should both spin the same way. Wont fix your error, but at least you will have piece of mind that it is either the diff, or the computer

[M2Dynamic]

Originally Posted by McPurrs

Well in N of course, so make sure to block the front wheels. Safety first. If the Diff is not locked, only one will spin (the other might go backwards). If locked, they should both spin the same way. Wont fix your error, but at least you will have piece of mind that it is either the diff, or the computer

Yes that will definitely alleviate a lot of the stress and I'll know if it's something I have to get taken care of immediately or if it's the computer and I'll feel a little safer and get it taken care of. Thanks so much for the help. Much appreciated!!

[David1]

Jacking the car up and rotating the tires is not a true test of an active diff. That warning is telling you that there is a problem with the diff. If it was "locked" you would have difficulty steering the car.

[chillindrdude]

This happened to my stock F80, both times at the end of a track day.

They eventually replaced the differential control unit. My suspicion was damage from heat/overheating, but even after a regional BMW NA M-technician looked at it, they never did give me a clear root cause.

I sold my M3 short thereafter. I'm pretty bummed, this is still an issue.

[Zippster]

Originally Posted by David1

Jacking the car up and rotating the tires is not a true test of an active diff. That warning is telling you that there is a problem with the diff. If it was "locked" you would have difficulty steering the car.

agree, I think turning sharply you might hear the outside wheel squealing or feel some dragging if its truly locked.

[M2Dynamic]

Originally Posted by Zippster

agree, I think turning sharply you might hear the outside wheel squealing or feel some dragging if its truly locked.

Originally Posted by David1

Jacking the car up and rotating the tires is not a true test of an active diff. That warning is telling you that there is a problem with the diff. If it was "locked" you would have difficulty steering the car.

Originally Posted by chillindrdude

This happened to my stock F80, both times at the end of a track day.

They eventually replaced the differential control unit. My suspicion was damage from heat/overheating, but even after a regional BMW NA M-technician looked at it, they never did give me a clear root cause.

I sold my M3 short thereafter. I'm pretty bummed, this is still an issue.

Originally Posted by Zippster

agree, I think turning sharply you might hear the outside wheel squealing or feel some dragging if its truly locked.

Thank you all for the insight and the help it's much appreciated. 2 days ago I decided to go in and flash back to stock and everything was fine with bmw. Long story short it was a sensor failure because of voltage drop. That's the code that came up. Which makes a lot of sense now because my battery had completely died like 2 weeks prior and it started then. Anyways they cleared the code and I drove it stock tune for a while then flashed it back to BM3 tune and everything is perfect thank God. They said if it comes back at all bring it back (obviously) so hopefully it's good to go!! Thanks again!!

[Zippster]

Originally Posted by M2Dynamic

Thank you all for the insight and the help it's much appreciated. 2 days ago I decided to go in and flash back to stock and everything was fine with bmw. Long story short it was a sensor failure because of voltage drop. That's the code that came up. Which makes a lot of sense now because my battery had completely died like 2 weeks prior and it started then. Anyways they cleared the code and I drove it stock tune for a while then flashed it back to BM3 tune and everything is perfect thank God. They said if it comes back at all bring it back (obviously) so hopefully it's good to go!! Thanks again!!

Thanks for sharing, we all learn something from it.