Stop start not working
 

Had the car a year, Volvo s90 D4.

Today on 3 occasions the stop start kicks in and engine goes off, but then when I go to move it asks me to place it in park. The engine has a really turned off. I've been beeped as I have cars waiting behind me.

Only happened 3 times today so not always, but enough that it's causing a problem and something is wrong.

Any ideas? The car starts back OK, but cuts out and doesn't start again.

Thanks

Having just picked up a v60 with start/stop service needed on dash I have read a few things about it.
There is a smaller battery that runs start stop and park assist ( good idea as Ford destroy batteries running everything off one). On my car the message has flashed up because of low voltage in the battery and turned off start stop. Your car may not have picked up a problem with the battery and not have enough power to restart the car with it.
Like I say I am new and just an idea.

I haven't had any error messages on my dash come up yet.

It is due for a service in a couple of months so I will ask and might just have to disable stop/start until then.

Could I use Volvo recovery/on call to have an engineer come out to diagnose it? I get a year's free with a service, but I feel a bit cheeky doing it. It's not like the car has broken down

I would turn stop start off via sensus screen tab or use dynamic mode or individual mode with stop start set to off each time you use your car until you get it sorted. (if you have drive modes) it happened to me once over a year ago when at traffic lights but has not happened again.

Yeah I'll do that thanks.

Maybe the stop start battery is on the way out. As I believe there's two, one battery to start the engine and another separate one for stop start.

There is a second support battery to run things while engine is stopped, but I doubt that this is the problem as the usual symptom of battery problem is stop start is disabled and will not stop the engine. More likely to be a software glitch.

Sometimes disconnecting the main battery earth for 15 minutes can reset glitches. (Do not remove live connection)

Usually if it's a battery charge issue, the stop/start doesn't cut the engine when you stop, it keeps it running (many people on here have had this issue due to car being used much less during the pandemic).

The issue you are describing is something different, so as others have said, disable stop/start until you can get the codes read and identify what the issue actually is. There are many factors affecting the operation of the S/S system. For instance, my S/S stopped working and it was due to the Steering Wheel module, so it's not always obvious issues that can affect the system.

Ahhh, I think that explains it then!

I was told around 9 months a go that there was an error code showing and it was the steering wheel module. Volvo reset it and said that if I still have an issue the steering wheel module might need replacing.

I haven't yet had it done because the only issue I've had with it is that every so often my wipers will come on even in direct sunlight. Didn't want to spend to have it replaced at the time, but obviously needs doing now

It's due in for a service soon so I have temporarily disabled it but will mention it when I take it in

Don’t think the wiper issue is to do with the S/S problem. Many people, including me, have commented that, if the rain sensor/ auto wipe is on, the wipers will often do a sweep on start up when car is left in sunlight. Don’t think there is a fix for that, apart from switching off rain sensor.