sabca

Got my '18 Q7 in August. S/S worked all the time. I know it annoys most of those on this forum but it doesn't bother me and any gas mileage increase is welcomed. However, the past few weeks it no longer works. The S/S button has not been disengaged. I read up on it in the manual and just can't figure out why it isn't working. I haven't been driving any differently. Thoughts?

gsobol

Lucky you. No clue.

AndroidRobot

Is your A/C on? I know mine doesn't work if the A/C is running, or if the battery doesn't have a sufficicent charge to let the engine turn off.

Yamaha1

May check driver select

sr007

Couple of reasons for this -

1. If the external temperature is too hot and your AC is continuously running, that may cause the S/S to disengage.
2. The S/S is active in COMFORT mode, while other modes can disengage it.

sabca

Tested the A/C "theory" this morning and when I turned it off the S/S worked. I think it worked when I first got it in August was due to the fact the weather was cool. The last 3 weeks of Sept. and so far this month have been much warmer and humid thus it AC was running all the time. Mystery solved. Plus I do drive in Comfort mode. Husband has a lot of bone pain and I have to be very careful not to throw him around!

diffuser

Another reason could be faulty O2 Sensor. That happened to me a few months ago.
O2 Sensor fault came up, the auto start/stop stopped working.

Once the O2 sensor was replaced, it worked again.

Hope this helps.

-d

BigKutta

Also if you drive in "S" Sport mode, it wont work

sctrojan551

I had the same issue on my '16 Q5 3.0T. When I bought the car the auto start stop system would engage fairly regularly. At around 35k miles, it only engaged if I drove the car for at least 20 - 30 minutes and even that was rare. It got very annoying as all the conditions were right for the system to engage and there were no errors indicating a malfunctioning system, just the A with the line through it.


Apparently the system functions much less frequently when the service is due on the car. I was getting annoyed with the service reminder (SRI) appearing at every startup, so I just reset it using VCDS. After doing this, to my surprise, the start stop system now engages regularly, like every single time after the 2nd or 3rd full stop. It also engages in sport mode, with the A/C turned on, though the engine starts back up after about 20 seconds to keep the A/C cold. I'm guessing the reasoning behind this is that if service is due on the vehicle, the system engages much less frequently to put less strain on an engine that needs servicing.


So if you're having issues with your start stop system, either get your car serviced (make sure your mechanic resets your system) or just reset the Service Reminder yourself using VCDS. If you chose to do this yourself, you must use VCDS. Resetting the oil change interval in the MMI doesn't solve the issue.

sickk23

I’m at a thousand miles now. My start stop has only came on a few times.