Citroen 2017 C4 Picasso Flair EAT6 Auto

[Trick]

Have recently reported to my Citroen dealer that whilst in Start/Stop mode and stationery ie the engine not running, with my foot on the brake pedal and then when either the passenger door or the driver door is opened the engine Starts? They inform me that this is normal. Is this correct and why. Thanks

[GiveMeABreak]

I can't say for sure - except that one of the other conditions may have resulted in the engine restarting - but it wouldn't of happened if you had applied the parking brake.

Conditions that can cause the system to start can be for example when braking force is needed, when the temperature is below a certain level set (to maintain a comfortable setting) and some other features. Also, if the door had already been opened first of all, it wouldn't allow the engine to start after the event.

As you already mentioned you had your foot down on the brake pedal - that is using up pressure and expending force on the braking circuit and therefore the engine has likely started to ensure there is enough pressure for the system - so it's a safety feature.

[Paul-R]

That's certainly one of the conditions (opening a door) which causes the engine to restart in our Pug 308. I would think that Citroen is the same.

It is detailed in the handbook so probably somewhere in yours.

[Trick]

I can't say for sure - except that one of the other conditions may have resulted in the engine restarting - but it wouldn't of happened if you had applied the parking brake.

Conditions that can cause the system to start can be for example when braking force is needed, when the temperature is below a certain level set (to maintain a comfortable setting) and some other features. Also, if the door had already been opened first of all, it wouldn't allow the engine to start after the event.

As you already mentioned you had your foot down on the brake pedal - that is using up pressure and expending force on the braking circuit and therefore the engine has likely started to ensure there is enough pressure for the system - so it's a safety feature.

Thankyou Marc whilst I except that your abiove explanation maybe correct I have been informed by my Citroen dealer that this is normal with all citroen C4's?

[GiveMeABreak]

Yes, normal behaviour if you think about it. In traffic for e.g. and at standstill, SS (Stop Start) stops the engine. Opening a door or turning the steering wheel for example will start the engine again, as will unfastening your seat belt. Why? :- because with any of those actions, the car is thinking you are going to exit the vehicle and says basically no you can't - not until you put the car in Park / switch the ignition off!

Otherwise it would be possible for the car to start without you in it - for one of the reasons that I mentioned in the previous post. So it basically is starting the car to remind you that it is in a temporary stop state and to make sure you switch the ignition off first before exiting.

[voitureblanc]

I'm not sure if my stop start system ( SSS ) is functioning correctly and would appreciate some feedback. I've done a 140 mile round trip today, all on reasonably fast A roads with several towns waiting for my SSS to kick in but not once did it happen. The car is 15 months old with 12000 miles on the clock. I've had the car 10 weeks and the SSS has worked very infrequently up to now. A couple of weeks ago it needed 50 miles of motorway before the SSS operated and then on the same journey after a further 30 miles at a traffic jam the system worked faultlessly for about 30 min but then ran out of capacity ( this was whilst towing a caravan ) and has never worked since. I'm curious to know what sorted of mileage fellow owners are needing before their SSS kicks in. I am sure all the parameters are being met for my SSS to operate.
My car is a 2017 C4P 2.0 Diesel Auto 15 months old 12000 miles.
Thanks

[GiveMeABreak]

It’s got nothing to do with mileage as such, but the system requirements just have to be met to activate the system. In this weather for example, the car is going to remain running to provide air conditioning in the current climate.

The car won’t switch the engine off when it needs to keep the AC system running plus the engine fans for example. There is not enough stored energy to do all that and start the car from the regenerative system, so keeps the engine running.

These are some of the parameters that will prevent the stopping of the engine, split into user and system conditions:
User conditions prohibiting stopping of the engine:

• Driver’s seat belt not fastened
• Driver’s door open
• Stop and start function deactivated
• Changing out of reverse gear with a timeout of 10 seconds when exiting reverse mode on vehicle fitted with piloted manual gearbox
• Accelerator pedal pressed
• Deicing/demisting of the windscreen
• Cabin temperature not corresponding to the request from the driver (variation in cabin temperature ± 3°C relative to the request from the driver)

System conditions preventing stopping of the engine:

• Not having exceeded 10 km/h after the initial starting with the ignition switch
• Not having exceeded a timeout of 4 seconds between 2 stops
• Not having exceeded a timeout of 2 seconds since the previous restart
• When the authorisation to stop the engine occurs more than 4 seconds after the initial request by the driver
• Inadequate vacuum reserve
• Engine requirement (*)
• Fuel temperature above 60°C
• Thermal protection of the alternator
• Battery temperature above 60°C or below -5°C
• Power accumulator temperature above 55°C
• Central voltage retaining device ECU temperature above 90°C
• Battery charge status below 75%
• Reconnection of the battery
• Limit of 6 stops per minute
• Recalculation of the injectors drift
• Particulate filter regeneration
• Power accumulator voltage insufficient
• Internal resistance of the battery above 5,6 mΩ
• Regulation by the dynamic stability control system
• Not having exceeded 10 km/h after application of the electric parking brake
• Power steering system downgrade mode
• Altitude above 1700 metres for vehicles fitted with the DV6C engine and a piloted manual gearbox
• Wear of the components of the Stop and Start system
• Stop and Start system in downgrade mode

(*) The engine requirements are the following:

• Respect of the depollution norms
• Optimal engine operating temperature

[Paul-R]

That's a very interesting list there Marc as I've often wondered why the S&S hasn't operated on our 308 when I've thought it should. Maybe there's a clue in there for me.

Having said that our 308 was in at the dealers for quite a few times earlier this year when the S&S had ceased to operate at all. One of the items replaced was the battery; fortunately under warranty.

[GiveMeABreak]

It will probably have the Battery Charge Status Control Unit (BCSCU) attached to the negative terminal cable Paul. The system isn't tolerant of batteries below 75% charge for Stop Start it seems. Looking at the list, it is hard to see how the SS system can realistically last for very long, given the huge list of conditions required!

[Richard_C]

We have a C4 Pic 1.6 BlueHdi manual and a more recent C3 1.2 Puretech EAT, both with "S&S". The puretech EAT is 110 bhp but drive train is very similar to the OPs Picasso Flair which is 130. They only "S"top when conditions are perfect, Marc's list above is very good, for instance the Pic "S"topped in a level crossing queue yesterday but as the inside temperature went up and the AC had to work harder it "S"tarted long before we needed to set off. I find a tug on the steering wheel, which causes the system to need power and starts the engine, is very handy if you want a quick getaway when the lights change in the auto one.

My conclusions are:

• S&S is more about the manufacturers passing Euro 6 tests and consumption tests than any real advantage to owners or the broader environment

• I would much rather it failed to "S"top than "S"tart, so I am very relaxed about the fact the condition settings are conservative

[xantia_v6]

Wear of the components of the Stop and Start system

Would seem to be an interesting factor for the ECU to monitor...

[Richard_C]

Maybe it's a bit like inkjet printers, some do a count of ink shots aa a proxy for ink levels, some even say catch tank full and die completely after a few years.

Maybe the ECU will say "S&S operated X times, must be knackered by now, go buy a new car.... ".

No longer obsolescence planned by styling like the USA in the 50's, now it's obsolescence imposed by software. Or am I overly pessimistic about car manufacturers.