[AussieV40]

Hi has anyone had any problems with the auto start / stop not working, I know form the manual that there are a whole lot of conditions where it won't.

The other night driving home it failed to come on at all despite the conditions being ok. Turned it on and off the next day and seemed to be working ok. Will keep an eye on it and take to the dealer if occurs again.

Anyone else had issues?

 

[MissusK]

Hey, I've noticed with the melbourne weather being so hot mine hasn't been working everytime. I noticed when cools down it works. I think it's temperature sensitive.

 

[lmafudd]

It's been crazy down in the South UK weatherwise and with so many road closures the trip home has been a nightmare most evenings. Nose to tail with many stops. The first day the stop-start worked as expected but the second day it stopped stopping!

I can only think that the electronics detected the battery drain and did what it is supposed to do and kept the car running.

Went out in light traffic yesterday and it's back to normal.

I know if the battery drain is too high then it will isolate the stop-start. Maybe your air-con was on or perhaps had been, as I understand that it can be quite warm in Oz, something that we rarely encounter in the UK!

 

[raytint]

My experience from Greece. Last summer (2013) was the first summer the car was on the road. As the climate here implies, there was heavy use of air condition, accompanied by radio use many times. The system worked ok, till the end of summer. Occasionally I noticed that the engine was restarting by itself while at traffic lights, showing that there was a significant battery drain. Then, at the end of summer (September 2013) the car remained stationary for almost a month. That was it ! Start stop refused to work after that, despite three long visits to the dealer. They recharged the battery several times, disconnected the alarm, downloaded new software (according to directions they were receiving from the factory), nothing happened, the start stop system was not complying. As they told me later, the battery recharges rather made things more bad than good. Finally, they changed the battery, and that was it, system OK. It is worth mentioning that their diagnostics system suggested "recharge the battery" till the end, to no avail of course. They bypassed the system and changed the battery. Start stop now works ok (for more than two months) and I have learned my lesson for the summer to come !

 

[wizzy]

I don't know how the start/stop battery is linked to the main one, but at my service last November I was advised my battery wasn't fully charged. As I was going to be away for two months I left it (the main one) on trickle charge for the duration. On my return everything was absolutely fine. Plenty of oomph for starting and start/stop works fine.

 

[KevininSydney]

Hey, I've noticed with the melbourne weather being so hot mine hasn't been working everytime. I noticed when cools down it works. I think it's temperature sensitive.

As per other updates. If the weather is hot and the AC is on the stop/start does not function so that the engine keeps charging the battery.

 

[techwatcher]

As we have seen, there are a fair number of scenarios where start/stop is temporarily unavailable. You can check the particular reason at the time in the My Car->DrivE->Start/Stop settings. One of the more interesting reasons is 'Driver Unbelted'...

 

[MissusK]

To be honest I don't use it.

Has anyone found if it actually helps with fuel economy to have it on?

 

[denn1s]

I worked out some figures and it was pretty much pointless on a normal journey I.e just stopping at traffic lights rather than an hour or 2 in a stationary traffic jam on the motorway.

Re it not working, I had this on my 118d msport in 2009, it completely stopped working, I took it to the dealer, they said no fault in fact it had worked for them, I had it back, still didn't work, they again said no fault, eventually it was found they had never got it to work and the issue was the battery.

Re the op, it sounds like the situation was just not right if it worked the day later

 

[MissusK]

I guess you are right, it would only be useful if traffic is horrendous

 

[Toolmantim]

hi guys the offical cut out temp is 30 degs c so it starts to give up at 29 deg c but as mine is disabled i dont worry about it

 

[denn1s]

I guess you are right, it would only be useful if traffic is horrendous

But the daft thing is after a little while it stop functioning as power drops so the engine then starts up, it really is pointless in the real world

 

[DarrenCC]

I don't know how the start/stop battery is linked to the main one, but at my service last November I was advised my battery wasn't fully charged. As I was going to be away for two months I left it (the main one) on trickle charge for the duration. On my return everything was absolutely fine. Plenty of oomph for starting and start/stop works fine.

The second smaller battery in the front nearside (UK) is the start stop battery ie to re-start the engine...if there is excessive drain on the main battery i.e. seats/fans/aircon etc. being on then the start/stop won't engage...as equal a summer quirk as much a winter.

 

[MissusK]

But the daft thing is after a little while it stop functioning as power drops so the engine then starts up, it really is pointless in the real world

You are right. The revs would go up. I dont bother using it.

Dont know about the non-aussie versions but here we cant seem to turn it off permanently. I just have to remember to keep turning it off when I start the car.

 

[OldCroc]

In my opinion the stop/start should default to "on" in the manual (as it does) but should default to "off" in the auto cars. Reason is that it is a pain in the auto when creeping in traffic.

 

[Bugsy]

To be honest I don't use it.
Has anyone found if it actually helps with fuel economy to have it on?

I don't remember to turn mine off each time!
Not sure about the V40, but others with more sophisticated computer systems suggest auto stop saved them ~ 5 litres p.a. (from memory) in metro conditions.
Good for the emission testing they have to do I guess.
Edit: Agree totally with OldCroc.

 

[denn1s]

1 gallon a year.......or £6, is it really worth it and does it really make the slightest difference to the emissions.

When I has a little calculation, I recorded it may save a bit more but not much more over a year

And what about all the damage caused to the environment when making the extra batteries.

Who remembers when some guy in America proved a Prius caused more damage than a hummer?

 

[MissusK]

I don't remember to turn mine off each time!
Not sure about the V40, but others with more sophisticated computer systems suggest auto stop saved them ~ 5 litres p.a. (from memory) in metro conditions.
Good for the emission testing they have to do I guess.
Edit: Agree totally with OldCroc.

I think it would help if you travelled in a lot of peak traffic. Husband drove the V40 to work in the CBD in peak hour and said it was useful when hes trying to get out of the CBD as it comes to a stand still for while. But I drive mainly in the suburbs and work close to home so I don't think it makes a difference to me.

 

[AussieV40]

I know some of the VW guys especially Golfs are turning theirs off via VCDS which let's you change lots of fun stuff. Be nice if Volvo had something similar.

 

[Spruce Moose]

My start/stop has been "unavailable" for a month now. All conditions are good (not too hot), and on one occasion it was unavailable during a single day 800km trip so can't have been needing a battery charge. I use the car daily. Tried without radio or a/c on, nothing.

I actually don't like it so in some ways this is a blessing, it just has me worried that's all. Service is due in a few weeks so maybe I'll find out more then.....