Stop Start not functioning

[tomo2001]

Hi, stop/start not functioning on 2019 Focus. Only really happened since the outside temperatures have dropped and wife only uses the car for shortish trips anyway. I know there are a number of reasons for this not working, but anyone know what the minimum battery voltage needs to be for the system to function correctly?

I was going to give the battery a charge to see if the system returned to normal working but thought I'd ask here first. With the engine stopped the battery reads 12.2V Not checked the voltage when running as the battery has not gone flat or failed to start the car yet. 

 

[Buxty]

IIRC 12.2V is around 60% state of charge, common for stop/start to not work on Mk4 Focus; searching the forum will show you we’ve all had the issue! Solutions range from leaving it, going for more long drives, setting the target state of charge higher in FORSCAN or using a battery charger. 

I’d say don’t pay it too much mind, if you start to notice keyless doors (if you have them) stop working on any other door than the drivers, or the infotainment screen always say its turning off to save battery as soon as you open a door…at that point I’d probably look at doing something.

[tomo2001]

7 minutes ago, Buxty said:

IIRC 12.2V is around 60% state of charge, common for stop/start to not work on Mk4 Focus; searching the forum will show you we’ve all had the issue! Solutions range from leaving it, going for more long drives, setting the target state of charge higher in FORSCAN or using a battery charger. 

I’d say don’t pay it too much mind, if you start to notice keyless doors (if you have them) stop working on any other door than the drivers, or the infotainment screen always say its turning off to save battery as soon as you open a door…at that point I’d probably look at doing something.

Thanks Buxty, might give the battery a boost in preparation for the winter months. Missus been using heated seats and steering wheel already instead of putting heating on in the house 😀

[TomsFocus]

12.2v is pretty low.  Regardless of stop start, I'd say it is worth giving it a full charge before winter to keep the battery in the best possible condition.

[unofix]

The State Of Charge needs to be at least 70% to stand any chance of S/S to work. As there are many, many things that prohibit the system (which is only a gimick) then I'd not even waste time thinking about trying to make it work. One day when you least expect it, you can rely on it to cut your engine at the worst posible moment.