I have a rare but recurring problem for the last 2 or so years. Sometime the car just won't start, randomly either in a cold or a warm start scenario. I am little hesitant to take it to the dealer or a mechanic without at least some idea of what could be wrong or being bale to recreate the problem.

The car is 2007 550i, with only about 107K kilometers on it.

1. Press the start button, starter spins for 1-2 secs, all warning lights come on and nothing happens. I get the engine warning light.

2. The brake pedal becomes stiff like hell and cannot be depressed anymore for 15 minutes up to one hour or more - kind of varies.

3. Lately I am also getting transmission errors:
Error: drive with caution as gears can be shifted without pressing the brake pedal.
Error: transmission in safety mode, drive slow.

4. When I check the control messages through the idrive menu screens, I get "All Systems OK".

5. As mentioned, after a while the brake pedal stops being stiff, it can be depressed and car starts normally. After some time the transmission errors got away and everything gets back to normal.

This happens about 2-3 times a month which drives me nuts. Any help is much appreciated.

Thanks.

 

If I were you, I'd concentrate around the gear-shifter area; specifically the cable(s) that connect from gear shifter to the brake pedal.

 

I found this post that seems to be a similar issue.

https://www.bimmerfest.com/forums/sh...d.php?t=639215