Engine Starts Whilst Start/Stop Activated

[malagabob]

I don’t usually use this function. But found it necessary yesterday. Was in a queue that was only moving every couple of minutes, sometimes 5. Engine started. Got a shock, as was parked on an incline, thought the car was going to roll back, wasn’t expecting it, happened a couple of times, thought I had accidentally touched the accelerator. I hadn’t. Any ideas why Thanks.

[JimF]

https://en.wikipedia.org/wiki/Start-stop_system

[Buenchico]

From Jim's link:
"The engine may also restart if there is a demand for power from, for example, the air conditioning system".

So that might offer an explanation for your (perceived) problem.

However I'm confused as to how the engine starting could possibly lead to the car rolling back. If the handbrake was on, as it always should be in any vehicle that's stationary (even when it's on a dead flat stretch of road and the car will only be stationary for a second or two), I can't see how it could possibly roll back.

[malagabob]

Thanks Chris. The car was in “ hillhold “ function. The normal mode for this situation, which disengages if accelerator is briefly touched which I thought I had but hadn’t. Rather than full electric parking hand break
Only power being used was radio and DDLs which are L.E.D that don’t drain much power.

[mjwman]

Perfectly normal. It will auto restart as above and after a while waiting too. In the situation you described I would push the over-ride button if moving is slow and intermittent.