C4 Picasso (2016) starting issue

[swyftie]

Good morning all, this is my first post so please be gentle.

I work at a school and among our small fleet is our 2016 C4 Picasso.

In a nutshell, it doesn’t like to start! It is a push button start and initially we thought the battery was the issue as it had caused us some other problems, so we had that changed but it hasn’t solved the problem, we have been told by our regular mechanic that it is a fuel injection issue but I don’t think that is the case and this is why:

We know when it is going to fail to start because when we press the unlock button, the mirrors do not unfold. Surely a fuel injection issue wouldn’t cause this side effect? We then have to keep pressing the start button until eventually the mirrors pop out and the engine starts. Once it fires up we get a fault warning telling us to check the front fog lights, this clears by simply turning the fog lights on and then off again but appears to be linked to the overall issue as on the rare occasion we can just jump in and drive, we do not get this fault warning.

I am hoping somebody else has encountered this and knows the cure, as our mechanic wants to play with the fuel injection before he’ll entertain any other potential problems. Or maybe he’s right and I need to be more trusting?

Many thanks in advance.

[RichardW]

It's the battery management / protection unit located in front of the battery at fault. It's relatively common, and the mirrors not folding out and the fog light error are dead giveaways. Here's a thread about a DS5 suffering the same issue: viewtopic.php?t=73480 (although it took a bit to get to the bottom of it!)

[myglaren]

A quirk of PSA vehicles is their sensitivity to low voltage and the usual first thing to do is like the old Microsoft solution, turn it off and turn it back on again.
With a few proviso's as doing it wrong can make it all substantially worse.

Have a read through this and try it before doing anything else. Ideally check the battery voltage before disconnecting it.

If there is no improvement then the best next step is to have a diagnostic session that may point the way to a solution.

[Paul-R]

This sounds like a battery problem to me. How old is the battery? How many miles has the vehicle done? Can you measure the battery voltage at rest and then while trying to start the engine?

[myglaren]

As Paul says, despite the battery being changed it could be that the car isn't used sufficiently to properly charge the battery. Short, frequent trips and the current need for lights and blowers for heating can take a lot out of a battery.
If you try the BSI reset, if possible do it overnight and charge the battery.

[RichardW]

It's not the battery!! - OP says that has been changed; I have no doubt that when it does decide to start it does so without hesitation. The protection unit cuts power to all but essential items, and when it doesn't wake up those items are still isolated, hence no power to the mirrors, and the Start button not responding. The unit is about £300 however, and may be in short supply.

[swyftie]

It's the battery management / protection unit located in front of the battery at fault. It's relatively common, and the mirrors not folding out and the fog light error are dead giveaways. Here's a thread about a DS5 suffering the same issue: viewtopic.php?t=73480 (although it took a bit to get to the bottom of it!)

Thank you Richard, I'll have a proper read through the link. I'm relieved that we're not alone with this issue. We have a very limited budget and I was worried that diagnosing the fault alone could drain what is left of it as we currently have one of our other (non-French) vehicles sat in a garage undergoing works.

[swyftie]

A quirk of PSA vehicles is their sensitivity to low voltage and the usual first thing to do is like the old Microsoft solution, turn it off and turn it back on again.
With a few proviso's as doing it wrong can make it all substantially worse.

Have a read through this and try it before doing anything else. Ideally check the battery voltage before disconnecting it.

If there is no improvement then the best next step is to have a diagnostic session that may point the way to a solution.

Thank you, I will try this process as soon as I get the opportunity and will update accordingly

[swyftie]

Thank you for all of the responses.

I am doubtful that the battery would be directly responsible for this issue, although I really know very little about cars.

It is true that our fleet isn't used enough and this has caused many issues with flat batteries, however, when being driven, the stop/start feature on the C4 is still functioning, which I think is an indicator that the battery is still healthy? At least, that's what I have been telling myself with my own car.

Also, when the vehicle does start after the repetitive button pressing, it starts immediately, there is no struggle, it just kicks straight in.

I really appreciate all responses though, it's so nice to have so many people offering their help. I have clearly joined the right community and hope that in time, I'll gain enough experience to be able to pay it forwards.

I'll keep you all posted on how things go

[RichardW]

Unfortunately the part is not cheap (around £370) but it is easy to fit.

[Growler49]

Thank you RichardW.

I have the same issues as swyftie on my 2016 Exclusiive.

You have just confirmed my thoughts after reading and checking, fault is intermittent, but has been an issue for a few weeks now.

I have used a code reader but no code present, saying that it has not "Not Started" since I purchased the reader but as fault is intermittent the reader needs to be connected when fault is there to get a fault code.
I was holding back on buying due to cost of item but will now place an order
I now live in France but purchased car new in UK. I can get one for €330 delivered from Autopiéces here in France.

[Growler49]

It's the battery management / protection unit located in front of the battery at fault. It's relatively common, and the mirrors not folding out and the fog light error are dead giveaways. Here's a thread about a DS5 suffering the same issue: viewtopic.php?t=73480 (although it took a bit to get to the bottom of it!)

Hi RichardW

I purchased a new BPGA unit that I am about to fit to my C4 Picasso 2. due to mirror not unfolding and no start intermittently as you suggested in this forum.
Difficult toi answer but what other issues could a faulty BPGA unit give, ie. aircon blowing cold, stop start not working audio input stopped working but radio ok.

[swyftie]

Update:

Last week I completed the steps that Myglaren kindly linked me to, and this has resolved the issue.

Nobody was more surprised than I was, as everything to do with our vehicles tends to be costly, so this was a great result.

Again, thanks everybody for your support

[Dtp]

Ours also does this sometimes. Simply double pressing the start button quickly always results in it starting. Hope this helps

[Bilbo67]

Hi. I have just found out that I need a new battery management unit too and would appreciate any help in answering my question. When I install a new one will it work after I delete any codes etc or does it have to be main dealer with computer software?. All help would be gratefully appreciated. Billy