[pmass513]

Prerequisites:

• Read ATC13-1 functional description, attached.
• Read Transfer box service, attached.

The service instruction says:

"To ensure complete draining and filling of transfer box: During oil change, carry out the service function "oil change" with the diagnosis system."

The "diagnosis system" it's talking about is ISTA.

I searched high and low for pictures or videos of what the service looks like in ISTA (or any other OBD service tool/app for that matter), but I couldn't find anything for the F97. The only thing I could find was a video of someone using a Foxwell NT510 Elite on an E9X. Either the E9X transfer case doesn't have a two oil chambers, and therefore the service feature of opening the second chamber isn't needed, or the Foxwell couldn't access the feature. At no point in the video did the Foxwell screen say that the second chamber was open and instruct the user on when to change the oil, but it did seem to carry out a calibration routine.

So, I went down the path of installing ISTA and experiencing first hand what the TC service function does. I didn't grab a picture of every screen, but I think I got enough for you to get the gist of it (pics below). As you work through the prompts it explicitly tells you when the second chamber is open and to change the oil:

"The oil reservoir in the VTG was opened successfully. You can now carry out the oil change as per the regulations."

I haven't actually changed the oil yet, so I haven't followed the next step of resetting the wear indicators. But it's good to know what to expect from ISTA once I get there. As soon as my oil arrives I will actually do the service. Hope this helps.

[Skiddz]

Excellent post, thank you; looking forward to seeing the actual process in due time

[pmass513]

As I mentioned earlier, here is the only video I could find showing OBD screen prompts:

I dug a little further...

The car he is working on is a 2010 328i xDrive Wagon (E91) that has an ATC 300 Transfer Case, which is different from the ATC13-1 transfer case in the X3M (F97).

According to ISTA and Google, the ATC 300 does NOT have two oil chambers like the ATC13-1 does. So I'm assuming that's why we don't see the option in the video for opening the second chamber.

If someone could please post pictures of their OBD tool screens while performing TC fluid change on an ATC13-1 Transfer Case that would be awesome.

[MauricioG]

Has anyone tried to find this function of opening the chambers on Protool?

[matteblackf97]

Interesting I just had my transfer case fluid changed and I watched it done, he never opened my lower chamber