Turn OFF xDrive / transfer case
 

Is it possible to turn off transfer case / xDrive / 4x$ by pulling fuse?
DTC button are not working

I was able to pull the fuse to turn off the transfer case. It was in the hatch fuse area. Look for a gear on the diagram. 6 fuses were next to the gear. The 3rd one I tried worked.

Or you can disconnect the cable goes to the transfer gear motor.


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I was at the dealer today and asked about this. They said the fuse does not always work and that it is best to crawl under and disconnect it there.

Yes, just unplug the encoder motor. We have done this at my dealership a few times to move vehicles with seized transfer cases.

Where exactly is this plug for the transfer case?

Under a cover, right by the rear driveshaft. You'll see a rather large electrical connector going to the encoder assembly.

Thought I should post my findings here as it is the same topic.

A little background first, I am up for 2 new front tyres and have been reading that a difference in rolling diameter of more than like 4mm can cause the transfer case to crap it’s self. That being said the spare appears to be slightly different rolling diameter 275/40 r 20 (728mm) on the fronts vs 155/90 r 18 (736mm) for the spare, 8mm difference (not accounting for manufacture variations). So, I looked at disabling the transfer case in the event I have a flat and have to change wheels, to prevent damage to the TC.

Basically there are two fuses going to the TC control module fuse 92 & 125. Pouring through diagrams on Rheingold, these two fuses go only to the TC control and are the only two that go to there so, pulling these fuses should deactivate the TC control unit and therefore not give a signal to the TC actuator. They don’t seem to be linked to other things like the dashboard or indicators as seems to be the case in other BMW’s. Error codes are stored and shown relating to DSC and xdrive/transfer case failure that can be cleared.

I find it hard to believe BMW would supply a spare tyre that would destroy the car if used, but I’m not willing to bet $1000+ on it. Needless to say I have a tyre repair kit in the boot and a little 12v compressor on the way.

Does anyone have any experience, thoughts or input on this?

A disclaimer that this will also disable safety features and from my understanding will be a rwd only car with an open diff. I am only looking at this for an emergency means of getting home without destroying the transfer case and nothing else. I do not support the idea of doing this so you can do skids(as I have seen some posts about) , if you want a rwd car buy a rwd car, and be responsible, do it on a track or skid pan.


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That doesn't make any sense. The transfer case drives the front and rear driveshafts. Our front and rear tires are already different diameters so it is constantly equalizing that. The front differential spreads it side-to-side. If one tire is smaller than the other the differential would be turning to compensate but no where near as much as it has to do every time you turn the car. Think about those temporary spares and how great the size difference is when using those.

What?

Re spare, it's not meant for prolonged use, and few miles or even few 100s miles won't destroy TC.

I shouldn't answer posts first thing in the morning, I thought he was talking about a minor size difference between two tires side-to-side do to wear.

Does unplugging the transfer case essentially make the vehicle RWD?

Yes

Interesting question.

The rear driveshaft is connected to the output of the motor with a splined shaft so it is fixed. There is then a clutch pack that drives the front driveshaft and a motor that varies the pressure on the clutch pack and thus the power sent to the front. Can't say for sure that disconnecting the motor would eliminate all pressure on the clutch pack but it would be very little if any as there is no spring in the assembly to preload it.

Here's a picture if you're curious.

Very cool. Thanks!

So if my DTC button inside isn't working, simply just pull that plug?

I don’t believe the DTC button will turn off the transfer case, it just adjusts the mode of the traction control/stability control, I assume when you turn it off, the transfer case is still active, it will just let what ever wheels spin when they want to.


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