Car dies and starts back up

[SilverBeam]

This happened to me once before when I was pulling into work, but this morning it happened twice in a row. As I'm slowing to a stop (but am not yet stopped) the car completely dies. The RPMs drop the zero, lights turn off, radio turns off, etc. Then, as soon as I am able to register what happens, the car starts up again. I turned the AC off to see if that would make a difference. While it didn't happen again, I got on the freeway after I turned it off and didn't stop again until I was almost to work. I'm not sure if there is any correlation there.

[bluefox280]

Have you checked the output of the alternator to see what the voltage is?
Hooked it up to a OBDII scanner to see what codes are present?

- Erik

[SilverBeam]

Nope, don't have access to either tool. Perhaps related (although this hasn't happened for a few months) sometimes when I first start the car up, the RPMs fluctuate and then the car stalls.

[KeysCoupe]

The fluctuating idle sounds like mine. It started at about 60,000 miles and still under warranty for me. The dealer reflashed the ECU twice with the then-current updates, but it was never really cured. Mine has only stalled a couple times at stop lights, but a few times a week will get that real rough idle for a few minutes.
I just live with it, and chalk it up as one of the many quirks the car has. It never throws a CEL, and there are never any codes in memory. Voltages are always 12.7 plus and stable. BMW knows about this issue, but seems to have never found a correct fix. I will never see the dealer again, as every time they touch the car, I have "new" issues.