[eljay]

I am posting this as I didn't find a solution anywhere for this scenario.
If you have iDrive-equipped car and the monitor or iDrive fails and you happen to get a flat tire warning message/icon, there is no way to reset or re-initialize FTM (Flat Tire Monitor, aka RPA - Reifen Pannen Alarm) via the steering column stalk. You must use iDrive menu and controller.

In my case, I installed new tires and my iDrive screen is blank, so I was driving around with the FTM warning icon and no way to reset it.
I searched around ISTA, but there was no option I could find to reset it. I finally found a way to do so in INPA.

Steps to reset FTM (Flat Tire Monitor aka RPA) warning:

1. Load INPA and press F3 (or click E90) to select E90
2. Select Chassis > Dynamic Stability Control DXC (this is for xdrive cars, select the option above for RWD)
3. Press F5 (or click on 'Status')
4. Press F3 (or click on 'RPA')
5. Press F1 (or click on 'RPA Reset')
6. There will be a brief message confirming a successful reset (RPA Data Written OK)
DONE