Grand C4 Picasso Start Stop issue

[mastercare]

Hi guys, thank you all for your kind answers.
I have managed to resolve the issue.

Filled up the tank. Switch off all electronic devices. Switched all auto sensors (rain, lights). Started the car and left it running for 1 hour exact.
Drove the car while all electronic items were switch off on Motorway for 50 miles at 60MPH.
Stopped car and then started to test and it worked all fine.
Tested for 7 days and it is still running.

I will consider this as a fix.
Thanks all.

[GiveMeABreak]

I think this still points to the battery not having sufficient charge to enable the STOP START system - probably as a result of the short journeys / long periods of inactivity as Paul mentioned. The electronic systems of modern cars will drain the battery slowly when not in use - and therefore may not get a chance to sufficiently charge on short runs - especially with the other electrical systems in use.

I'm glad you've now got a solution , but I suspect it will happen again shortly if the same sort of driving conditions prevail that led up to the issue in the first place.

[mastercare]

[Alasdair B]

I had the same problem - the stop/start on my C4 Grand Spacetourer stopped working, although everything else was OK. My car is nearly 2 years old and most of my journeys are quite short.

I have found the solution. The manual recommends in these conditions the battery should be charged regularly from a charger to prevent deterioration. I bought a modern 6 amp 'smart charger' from Halfords for less than £50. A smart charger doesn't just charge the battery - when necessary it also goes through special cycles to recondition the battery (removing deposits on the plates etc.), so it can extend the life of the battery.

I connected the charger and left it to do its work. The display on it showed it going through several cycles before it showed that the battery was 'Full', so it appears that my battery condition had been below par. On the first drive afterwards the Start/Stop still didn't work but on the second outing it started working again and has worked perfectly ever since.

Although the start/stop system is powered by capacitors, not the battery, it seems that it is affected by the battery voltage and it doesn't work if the battery voltage is low because of deterioration in a car which runs a low mileage on short trips. In this situation the solution is to charge the battery regularly with a smart charger (as recommended by the manual). As well as keeping the start/stop system working, this should also extend the life of the battery, so over time the charger will probably pay for itself.

Moral of the story? "When all else fails, read the instructions"!