I stalled my car. How? It's automatic!

[BlueQuinn]

This morning, not far from my home when the engine would not have been too warm I was coming up to a set of lights and they went green but the car in front was a learner who stalled their car.

No problem I thought, but then I saw all my dash lights on and realised my engine was no longer running. Like I'd somehow stalled mine too!
It's an auto, so is that even possible? Maybe I gassed it a bit and then applied the brakes, but I was cruising gently, not speeding and then braking sharply, so I'm properly puzzled.

I had to put it in park, then turn the key back to off to start it up again (due to the interlock system). It ran perfectly well after that. Now warning lights, nothing untoward on the dials.

So, is it something I did? A common W124 or M104 problem? An electrical problem? Something I can fix easily? A sensor I can clean? Is it going to keep doing it?

 

[Bobby Dazzler]

I had the same symptoms albeit with a different engine and it was the Cank Positin Sensor or CPS

 

[grober]

Clean the throttle body throat and plate with solvent [ carefully] Check and reseat the OVP relay.

 

[camerafodder]

Was there a UFO nearby?

 

[John]

I have a friend who used to own an N reg 730i auto and that would stall due to crazy electrics.

 

[Dieselman]

A gummed throttle plate, worn ignition switch or air leak could cause this.

 

[E55BOF]

I really REALLY want a "Cank Positin" sensor. Lovely name; sounds like an Eastern European footballer. Oh, it's a Crank Position Sensor? How disappointing....

Seriously, though, I'd wait and see if the problem recurs before doing anything. It may turn out to be a one-off; it's happened to me before (not in the E55), but only once. HTH