Start stop on the Peugeot 3008 not working

[SlimJim]

Hi everyone,

Mindful the start stop is something that wouldn’t work unless it is above a percentage. But is there any reason why, the start stop doesn’t charge up ? Also, when driving up a hill, I notice the engine is straining and not sure if it’s the alternator.

Thanks
A

[GiveMeABreak]

The 'Stop Start' isn't a device, it's a name for a technology.

The system has many, many variables in order for it to function, including things such as engine temperature (so it won't stop when the engine is cold as this is where most of the damage is done when the engine is cold), battery condition and charge, Ultracapacitor charge (if fitted), number of stop / start cycles the car has done over a certain mileage, main battery charge, the outside temperature and whether the Air Conditining is enabled and what temperature the passengers are requesting, etc. etc.

Put it this way, it hasn't worked on my new car since we've had it - but I'm not that fussed as to be honest I would rather save the alternator / starter and the only traffic lights we have are 18 miles away and they are temporary, so wouldn't save us much to be honest.

The engine will work harder to maintain desired speed up a hill, but that has nothing to do with the Stop Start system.

[SlimJim]

Would you recommend getting a different alternator ? Perhaps a more powerful one ?

[GiveMeABreak]

Hi Jim

Just an update on my particular situation:

Whilst getting the ADAS camera calibration done after a windscreen replacement at my Citroen dealer, I asked them separately under warranty to check the Stop Start system - told them it had never worked and that despite charging the battery, still no change.

So to do the proper test which is needed for any battery warranty claim by the dealer, they have to test and measure the battery following a procedure, then charge it up fully, then leave it for 6 hours or so before taking another measurement. So we left it with them overnight.

The results were that it is all working now and the battery measured 98%. He said that after fully charging the battery, it does need resting and no use for at least 6 hours for the system to self-calibrate.

So I don't know if this will be relevant in your case, but our worked all the way home - to the point I thought I had stalled the car when it first kicked in before the realisation!

Of course you have a reversible alternator and ultracapacitor on this earlier system, so more areas to check potentially, whereas they did away with all that gubbins on mine.

[SlimJim]

That’s great, thank you. It’s a newish battery (a year old) which is why I’m concern it’s doesn’t kick in after driving for an hour continuously.

Which is why I was wondering whether the alternator or the BSI may be at fault

[GiveMeABreak]

Very unlikely to be BSI related - but certainly battery. Even after a full charge with the system working, it can still stop working again after a few months I was told. The Service Manager drives a new C5 Aircross and does a 45 minute motorway journey twice a day and despite this, his also stopped after a few months. If it was your alternator - that would probably show other symptoms like you battery running right down if it wasn't charging I suspect.

So the later systems are very battery-charge intolerant it seems. But in my case, as long as I know it is nothing else (which it really can't be as it doesn't have a reversible alternator or capacitor), then I'm content to leave it. If it starts failing again, I'll just trickle charge the battery during the day and night, then leave it after refitting for the said time period and see if that does indeed sort it.

[SlimJim]

Hi

Could it have anything to do with the alarm in the car? Mindful it uses the battery every time the door is locked ?

Thanks
Anthony

[GiveMeABreak]

At the end of the day there is always some electrical drain on these cars - alarm ultrasonic sensors, the RCD circuit waiting to detect an unlock signal request or other feature etc., then there is the battery charging status unit that monitors the battery, and if you have the Direct Tyre Pressure Monitoring System, these also poll the ECU unit periodically. Then there is the EGR cleaning system that operates the valve a few times to help prevent sticking after the engine is switched off and then the various ECUs that write their data after engine switch off and probably half a dozen other things.

So there will be power usage Jim. But the alarm flashing LEDs or ultrasonic detection sensors will contribute along with anything else to this, so over months and depending on how the car is driven / journey length / time to recharge the battery from all the normal starting and electrical consumer devices / heating / A/C / Audio etc. it will all take its toll.

I found this a major issue in lockdown that the battery could really become discharged on both the C5 and the C3 with standing still after 2 weeks or longer - and with intermittent driving it was never long enough to replenish the battery.

So I put my C5 into Park Mode using the shunt fuse which disabled some electrical functions to prolong the charge. It helped a lot.

I think I will just charge mine every 4 or 5 months now to keep it healthy.

[SlimJim]

Ok. I may just test the battery and come back to you with an update

[SlimJim]

So the battery has a maximum capacity of 760 and the reading was 470. So it seems there is a problem somewhere for it to be so low. Any ideas ?

[GiveMeABreak]

Not sure what you used, but batteries need a dedicated battery measurement device specifically designed to test the health of the battery. It has to be fully charged, then the 'surface' charge has to be removed by discharging with say the headlights on for several minutes, then leaving it for 6-12 hours before testing (which is why they kept my car overnight to allow it to rest) before testing. Mine returned 98% - so anything 80% or less would of been replaced.

But if this is a new battery and it's only charging to 62% of capacity then I would suggest you may have a duff battery or it's not getting charged.

You should have an AGM battery which was fitted as standard at factory and is should be 760 Amp and 70Ah.

[SlimJim]

Hi

Just popped into the garage and took a reading. It shouldn’t be that low really, considering I’ve been on quite a few long drives.

[SlimJim]

QQ other than the dashboard lights flickering, are there any signs of a alternator going bad ?

Thanks
A

[GiveMeABreak]

Your power steering uses an electrically operated pump, so at some point I would expect that to start feeling heavier (even more rapidly if it was purely electrically operated without a pump as fitted to some vehicles now) if your battery was not getting charged and fell below the required voltage. But I would think you would start getting other systems problems if the voltage got too low, with the engine management detecting problems as various sensors fell below required voltages for example.

Have you tried checking the battery voltage with a multimeter when the vehicle is being charged? It should be somewhere in the 14.3 - 14.7 V range if it is being charged.

[wheeler]

Your choice here but if this was my car & there was no other issues apart from the stop start not working id just leave it alone. The £1.50 that you may save per year on fuel wont be anywhere near the cost of a new starter or reversible alternator (whichever your system has) which will be getting excess wear on it.
Yes the first signs of a failing alternator would be loss of power steering, ABS & Airbag lights coming on, wipers moving slowly, dash cutting out when heated screen operated etc.