[Belginique]

Hi All,

I have had this problem for a two years and cannot figure it out. When I purchased the car, I had the classic trifecta of lights problem for the transfer case appear early on and I fixed it by replacing the nylon wheel in the x-drive actuator. I also performed an oil change of the transfer case when I was working on it. I also managed to reset transfer case with DIS after an epic battle of getting the software installed on my win7 laptop.

Everything has been working well for two years now apart from this specific problem: if the previous trip did not allow the car to warm up (it takes about a 20 minute drive) I get the trifecta of lights the next time I start it and the x-drive does not work (normal rear wheel drive mode). If I let it warm up the trip before, no lights and the 4wd works. It is important to note that if the lights appear, I need to warm up the car and RESTART the car for the lights to disappear.

Now that it is winter, this sucks... as when I need the 4wd in snow and my wife did a short drive the day before, I have no 4wd until I can warm it up and restart it.

Does anyone know what this could be?

[Belginique]

OK, after reading the fault codes, I got:

ABS:
5F3A[24378] Clutch gearbox-ECU: VG-Clutch defekt - Clutch is open - rear-wheel drive!

Transfer case:
54C4[21700] Failure of initial calibration
5462[21602] Transfer case actuator motor failure or increased friction

My guess would be that the cheap ebay nylon wheel I used might have higher than normal friction or the actuator motor is tired.

I can either buy the original BMW replacement nylon wheel with proper lubrication, or for twice the price replace with a new Bosch actuator motor with wormwheel.

My only question is... do I need to re-calibrate the transfer case if I replace the actuator?

I managed to win the battle of getting DIS installed on my old laptop once, but that has since died. I doubt whether I am going to go through that ordeal again. I think in the end I actually reset it with INPA, which was much easier to install.

[Belginique]

Ok, looks like I am talking to myself here, but for the benefit of others:

I decided to take the actuator motor off the transfer case and have a closer look.

Attention points for this system are:

• Condition of contacts was good
• Nylon wheel was in good shape and had lubrication
• Car battery is holding good voltage (lower voltage can cause transfer case issues)

It all looked fine, but I had a spare nylon wheel (also from eBay I think) that looked very similar but not identical. I replaced it and used a very high quality silicone grease with teflon.

So far so good. The issue has discappeared for the last two days at least. So my conclusion is that I think the issue is limited to the actuator motor. If the issue comes back after a while I will replace the entire motor and wormwheel.

So my main question to anyone that might know is: Can I re-calibrate a replacement actuator motor with INPA? I seem to remember doing this in the past with INPA as it had a couple of options, one was 'actuator motor replacement' another was 'oil wear numbers reset', etc. I hope to avoid DIS, as it was a super pain to install.

Thank you