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Stop-Start - is there a trick to getting it working again?

14K views 12 replies 10 participants last post by  robert101  
#1 ·
Hi all!

I have a 2020 308 Active. After about 18 months of ownership the stop-start stopped working.

At its next scheduled service the garage charged the battery for me and said it should start working again after a little while. It never did.

6 months later I took it in for something minor and got them to look at the stop-start again. They said the battery was low again and said charging it again probably wouldn't help, so I got them to put in a new battery (obviously very expensive as it was a Peugeot branded one). Again they said it should start working soon, but again it never did.

Now I don't drive the car a lot and I understand that a low battery could prevent it from working, but then why did it work for 18 months when it was new? And why did it never start working again, after both charging and replacing the battery?

The Peugeot service guy insisted there's nothing wrong with it, but I'm wondering if that's really the case. Or is there some sort of "reset" trick that's needed to make it work again that they haven't done?

Or is stop-start just a gimick that really doesn't work all that well?
 
#2 ·
A lot of people consider it a blessing if the stop-start system doesn't work. These are intended to give better fuel economy and less pollution but the gain is quite small.

I don't know what version of the stop-start system you have. Some have a reversible alternator that the stop-start system uses to start the engine after an initial start with a conventional starter motor. Others just have an upgraded starter motor but in both cases there is just more kit to wear out or fail.

Which every stop-start system you have everything needs to be near perfect. There is usually a battery status monitor mounted on the battery negative terminal that monitors a number of battery parameters. I understand that new batteries are not normally fully charge so if you only do short trips it will never get enough charge for the engine ECU to allow the stop-start system to work. One forum member found that if he charged a new battery before fitting it the stop-start system would work straight away otherwise it will not work until the car charges it.
 
#3 ·
You really need to get the system read for error codes. You'll need a high end general code reader or Diagbox for this. Diagbox can also tell you what the system thinks the state of the battery is, maybe other readers can as well.
 
#4 ·
Thank you both your replies. I have been thinking of getting a code reader, although the Peugeot garage presumably checked the codes and apparently they showed no problems.

I'm honestly not too bothered by stop-start not working, it's more curiosity than anything - why did it work fine for 18 months, and then not work again even after charging and then replacing the battery? (The battery replacement was followed almost immediately by a two-week driving holiday covering several thousand KM, so it seems particularly odd).

If there's no magic "reset" switch that will make it work again I might just have to chalk it up as "one of those things" !
 
#5 · (Edited)
Thank you both your replies. I have been thinking of getting a code reader, although the Peugeot garage presumably checked the codes and apparently they showed no problems.
In many cases where the stop-start system doesn't work there are no fault codes so if the dealer just looked at the codes they were unlikely to find the problem. The Peugeot diagnostic tool can do at lot more than just report codes. For example it can look at the battery parameters and the stop-start system parameters. It can also display live data for most engine control unit parameters.

If you are interested you can buy good quality clone of the Peugeot diagnostic tool for about $Au160 but you need a laptop as well.

Edit
Here is a screen shot of the battery status from a Peugeot diagnostic tool. It shows several things including the battery temperature and charge level. Note this was from a car with a non functioning stop-start system. Changing the battery fixed it.

Image
 
#6 ·
You said "I don't drive the car a lot". That's the problem.
When you stop, does the green ECO light flash 3 times? Assuming it does, then the system is functioning properly but some parameters have not been met. In your case, most likely the battery is not charged to 80% of it's capacity. Try going for a long run and see if that helps.
But your battery is now over 3 years old, and that seems to be one of the issues.
 
#10 ·
Hi there, have you sorted the stop start? If not read my latest post (today) especially if you are getting service light and engine warning at start up. After changing the battery, having the alternator tested and various connections being tested, none having helped, I think I sussed the problem and fixed it! Ps my car is 2014 308 hdi with 110kmiles
 
#11 ·
We've had an Oct 2019 Peugeot 2008 1.2 puretech 130 EAT6 from new. The battery is original and we only do <6,000 miles a year so fuel economy is not an issue. Since its year old 'first service' it has never been back to a garage (apart from MoT) as I service it myself. The s/s only occasionally worked to begin with and hasn't activated at all in recent years. I am delighted. I wonder how much money the battery industry and associated mechanics are making out of this ridiculous (and in Peugeot's case, flawed) concept.
 
#12 ·
I was told by the dealers that it doesn't work if the engine is not up to temp and it also doesn't work when it's COLD outside i.e. Winter.
Not sure how true this is, but, they've not steered me wrong in the last 9yrs since moving and this (308 1.5Hdi 130 2021) is the first car I've had that has Stop/Start, my other car is a 508 GT SW 2.2 mk1 2013.