Stop Start not working on 8.5

[Monkeymagik]

So my car had some element of the fuel system replaced by my local dealer a couple of weeks ago due to an issue with the car stalling, (25 plate) and since then the stop start doesn't work. Not that Im really complaining as I can't stand the function but clearly there could be a fault somewhere which Id rather get fixed. Anyone else had a similar issue on an 8.5. Ive got nothing turned on that could impact the stop start, and it worked fine previously. Coincidence

[Dav3smith]

I've had my car over three years and the start stop has only just started working after all this time but it doesn't work all the time just when it fancies it.

[Exonian]

Mine seems to have a mind of its own too.
Fuel level and battery charge will have a big effect.
Take it back to the dealer and mention it, they can scan the car T see if something is flagging in the ECU, there could well be a fault somewhere and that’ll quite likely be a sensor not plugged back in properly after the remedial work.

Stop Start has never bothered me, especially in a DSG car as it’s pretty seamless (when it’s behaving).
I mean, why sit there burning £1.50 a litre whilst sat stationary in the morning stop start commute while all the school kids walk past breathing in the noxious fumes…   
… from their own dodgy vapes! 😁

[SRGTD]

Mine seems to have a mind of its own too.
Fuel level and battery charge will have a big effect.

Yes, and there’s probably a list in the owner’s manual of conditions that need to be met for stop start to work. From memory, these are some of the conditions (there’s likely to be others too);

- The driver’s door must be closed.
- The driver's seat belt must be fastened.
- The bonnet must be closed.
- The engine has reached operating temperature.
- Reverse gear must not be engaged.
- The vehicle must not be on a very steep slope.

Stolen from the Seat / Cupra forum, below is a further list of situations when the engine won’t switch off. I’m assuming they’re relevant to VW’s too (I wasn’t aware of all of these - every day’s a school day );

- The temperature selected on the climate control has not been reached.
- The interior temperature is very high/low.
- Park assist is switched on.
- The battery charge is low.
- The steering wheel is being turned or is on full lock.
- If there is a danger of the windows misting up.
- In a traffic jam after stopping for the fifth time, the engine will not stop any more.
- If ESC is disabled.
- After emergency braking.
- If a trailer attached.
- While the particulate filter is regenerating.

[Ewankinch]

I have a 8.5 Gti and stop start rarely works. The car is a year old I've owned it for 7 months. Not long after I bought it I took to vw for them to see if there was a fault for stop start not working. It's a 20 mile drive there and when I arrived it worked and it worked for them with no fault codes recorded. They also checked the battery and all was ok.I only use my car mon-thurs 12 miles to work then 12 back each day. Maybe my car doesn't get a big enough run with it being sat for 3 days a week. If charge the battery with my ctek charger stop start works for 2 or 3 days then stops working again. Or if I do a long journey it works. It's like the car doesn't charge the battery enough. The technician did tell me that the car does use alot of power to run the headlights etc. I don't like stop start anyway so it's not bothering me and at least I don't have to switch it off everytime I get in the car. There's been a few reports on th R forum with people's stop start not working either. Maybe a possible software update would fix the problem but I would be reluctant to do that incase it causes other problems.

[Watts]

Just a thought but perhaps the new operating systems draw more power and combined with ota updates means battery power can be drained more quickly? Mine hasn't been working for a few days either and it gets regular decent drives.

[fredgroves]

Mine seems to have a mind of its own too.
Fuel level and battery charge will have a big effect.

Yes, and there’s probably a list in the owner’s manual of conditions that need to be met for stop start to work. From memory, these are some of the conditions (there’s likely to be others too);

- The driver’s door must be closed.
- The driver's seat belt must be fastened.
- The bonnet must be closed.
- The engine has reached operating temperature.
- Reverse gear must not be engaged.
- The vehicle must not be on a very steep slope.

Stolen from the Seat / Cupra forum, below is a further list of situations when the engine won’t switch off. I’m assuming they’re relevant to VW’s too (I wasn’t aware of all of these - every day’s a school day );

- The temperature selected on the climate control has not been reached.
- The interior temperature is very high/low.
- Park assist is switched on.
- The battery charge is low.
- The steering wheel is being turned or is on full lock.
- If there is a danger of the windows misting up.
- In a traffic jam after stopping for the fifth time, the engine will not stop any more.
- If ESC is disabled.
- After emergency braking.
- If a trailer attached.
- While the particulate filter is regenerating.

And on a mk8... Gearbox isn't in S

[Ewankinch]

Mine actually worked in sport once. 

[SRGTD]

Just a thought but perhaps the new operating systems draw more power and combined with ota updates means battery power can be drained more quickly? Mine hasn't been working for a few days either and it gets regular decent drives.

That’s a good shout.

[joe6]

If it is a low battery try an overnight charge. That will eliminate one possible cause. Then it is back to the to dealership.