Technical start&stop doesn't work

[Super Uwe]

mine does WORK , (15 mile each way commute helps)

but when it kills the engine, only to start it again after 10 seconds idle..,:bang:

I'm just left thinking.. that's doing more harm than good
( wear + tear on starter, etc)

of course as others have said..it wouldn't be TAX free without it,

I think that's the way I've started to view S/S; it just helps to keep tax down. Which is a good thing of course!

I understand the science behind the various constraints when using S/S, but looking at it purely as a device, it really doesn't seem to offer much help in the grand scheme of things.

I suppose the good thing with S/S enabled cars is that they have the higher rated battery and starter motor, so you could just keep it disabled all the time and then start/stop the engine when you wanted...
I

 

[sablade]

This is terrible, it seems no-one has a 100% perfectly working car.

 

[GCFIAT500]

Hi

I purchased my fiat 500 lounge in sept 2013. It was 3 years old at the time. I have had NON stop problems with my start stop. So much so it was back in the dealership garage 8 times between purchase dated and NYE.

It plays up so much sometimes that the start stop activates while im driving and cuts the engine out. I have experienced more problems this weekend on long journeys but am so fed up of going back to the dealership.

The dealership have never been able to confirm the issue, just done software up date each time.

 

[sablade]

Hi

I purchased my fiat 500 lounge in sept 2013. It was 3 years old at the time. I have had NON stop problems with my start stop. So much so it was back in the dealership garage 8 times between purchase dated and NYE.

It plays up so much sometimes that the start stop activates while im driving and cuts the engine out. I have experienced more problems this weekend on long journeys but am so fed up of going back to the dealership.

The dealership have never been able to confirm the issue, just done software up date each time.

I would ask them for a full refund - trading standards will agree

 

[sablade]

I have emailed Fiat UK with this...


Hello, I have just acquired a 3 year old 11k miles fiat 500, but the start&stop seems temperamental. Even on the day I picked it up from the main dealer, I had a drive the engine was warm it didn't work. Is it true many people have problems with this please can you confirm the exact requirements for it not to work please as the handbook is a bit woolly. The dealer said they will check it but they are not sure the exact requirements for this to be available or not available.

 

[varesecrazy]

Hi

I purchased my fiat 500 lounge in sept 2013. It was 3 years old at the time. I have had NON stop problems with my start stop. So much so it was back in the dealership garage 8 times between purchase dated and NYE.

It plays up so much sometimes that the start stop activates while im driving and cuts the engine out. I have experienced more problems this weekend on long journeys but am so fed up of going back to the dealership.

The dealership have never been able to confirm the issue, just done software up date each time.

don't quite understand the problem..

if you drive it with a fully charged battery , what happens..??

apparently if the S+S cycles 2 times,
ie. stops + starts 2 times in a 5 minute period ( sat at busy junction ),
then it will post up S+S unavaialble.. this is within the design paprameters.

OR

it doesn't cut the engine when parked / stationary..,
plenty of variables here - so NOT necessarily a fault..,

however IF it kills the engine while being driven ( moving) then I would say it's a fault within something OTHER than the S+S system,

Charlie

 

[GCFIAT500]

Hi Charlie

Thanks for your reply. When the start stop has activated and I am in neutral sat at a junction, when I got to set off again and do everything correctly, the start stop blips, reactivates itself and shuts the car off completely.

I have also experiences start stop unavailable when all the the determining factors are not affecting it. I have also experienced start stop deactivating when using clutch control and the gear position sensor breaking (since been replaced).

Thanks

GC

 

[varesecrazy]

OK , so the S+S works..!!

BUT after it has "cycled" ...depressing the clutch on a running engine = has the effect of bringing in S+S and killing engine again,

or as your text suggests,
it "shuts-down" all the vehicles electrics,

could you please elaborate..?

thanks,
Charlie

 

[GCFIAT500]

Works when it wants to...

Shuts down. Sat at junction, start stop activates, go to set off, s/s blips and reactivates and then shuts down.

 

[Most Easterly Pandas]

This is terrible, it seems no-one has a 100% perfectly working car.

Did you miss post 18?!?

apparently if the S+S cycles 2 times,
ie. stops + starts 2 times in a 5 minute period ( sat at busy junction ),
then it will post up S+S unavaialble.. this is within the design paprameters.

Not sure where you've got that from Charlie, I've caused one of the 500's we had to engage SS about 14 times in a 4 mile / 30min drive during the middle of summer. Only drain was radio as it was a none AC model, and didn't have any issues what so ever with the way it operated, and was completely flawless in fact IMO and expectation of what the system should be doing..

 

[varesecrazy]

I got stuck in a HUGE queue on the A303 last year,
the S+S worked perfectly, and the clutch switch meant my dodgy right leg did NOTHING for the hour it took me to cover 1.5 miles

I've read / heard somebody( 500C?) say that at a really bad junction they use almost daily it becomes "unavailable" after a while..just sitting idling

works fine for them everywhere else

Charlie

 

[Jonothan]

The gear stick needs to be in neutral, preferably with your hand off it. Many is the number of times I've seen people complaining of the stop start not working when their hand is resting on the gear stick. This may not be the fault here but please tell me first that you've tried that.

 

[sablade]

I need an official list from Fiat on when it doesn't work


eg in gear, outside temp above xxx, temp of car xxxx, wipers off


etc

 

[Most Easterly Pandas]

I need an official list from Fiat on when it doesn't work


eg in gear, outside temp above xxx, temp of car xxxx, wipers off


etc

There is no official list as it'll vary depending upon the software the car is using.

This might help though

https://www.fiatforum.com/500-faqs/340248-start-stop-faq.html

 

[sablade]

Thanks MEP, I expect there are 'official lists' as someone wrote the code and the parameters on what sensors are checked within the ECU.


The engine does not stop in special conditions, such as:

• [FONT=&quot]engine still cold; (I wonder how cold)[/FONT]
• [FONT=&quot]especially cold outside temperature; (I wonder how cold)[/FONT]
• [FONT=&quot]battery not sufficiently charged; (NB: I hear it needs be over 70% charged )[/FONT]
• [FONT=&quot]particulate filter regeneration (DPF) in progress (diesel engines only);[/FONT]
• [FONT=&quot]driver's door not shut;[/FONT]
• [FONT=&quot]driver's seat belt not fastened;[/FONT]
• [FONT=&quot]reverse gear engaged (for example, for parking manoeuvres);[/FONT]
• [FONT=&quot]automatic climate control, if a suitable thermal comfort level has not yet been reached or MAX-DEF function activation;[/FONT]
• [FONT=&quot]during the first period of use, to initialise the S/S system as this take several Hrs to stablise[/FONT]

 

[sablade]

maybe more here https://www.technicalinformation.fiat.com/tech-info-web/web/index.do

 

[Most Easterly Pandas]

Thanks MEP, I expect there are 'official lists' as someone wrote the code and the parameters on what sensors are checked within the ECU.


The engine does not stop in special conditions, such as:

• [FONT=&quot]engine still cold; (I wonder how cold)[/FONT]
• [FONT=&quot]especially cold outside temperature; (I wonder how cold)[/FONT]
• [FONT=&quot]battery not sufficiently charged; (NB: I hear it needs be over 70% charged )[/FONT]
• [FONT=&quot]particulate filter regeneration (DPF) in progress (diesel engines only);[/FONT]
• [FONT=&quot]driver's door not shut;[/FONT]
• [FONT=&quot]driver's seat belt not fastened;[/FONT]
• [FONT=&quot]reverse gear engaged (for example, for parking manoeuvres);[/FONT]
• [FONT=&quot]automatic climate control, if a suitable thermal comfort level has not yet been reached or MAX-DEF function activation;[/FONT]
• [FONT=&quot]during the first period of use, to initialise the S/S system as this take several Hrs to stablise[/FONT]

External air temp is a grey area discussed in depth a few months back, seems a fair point however we've come (or I have) that it's unlikely a factor as not all 500's with SS fitted have external temp displays or sensors, so it can't be something that's taken into account.

Rebattery charge, it's voltage that's heavily monitored. I don't know the exact voltages required, but again have been mentioned on here a few times before

 

[UFI]

Rebattery charge, it's voltage that's heavily monitored. I don't know the exact voltages required, but again have been mentioned on here a few times before

S/S doesn't monitor battery voltage at all

When I built my LiFe battery and I was playing around with the IBS/ smart alternator, at one point I had a 14.8v resting voltage with the car off (vs ~12.8v for a standard battery), and S/S still didn't work.

S/S monitors charge acceptance and LiFe will keep accepting charge until they burst :devil: I did come up with a theoretical solution but have since started more important projects. If (when) S/S dies after warranty, I'll simply fit a manual kill switch to the gear lever that way it will stop regardless of the Fiat/ Bosch parameters being met. Just need to use a CCA tester to make sure the battery is healthy once in a while.

 

[Most Easterly Pandas]

S/S doesn't monitor battery voltage at all

So how does it judge if battery capacity is full or not then

If the battery has a dead cell it may stop accepting charge, but doesn't mean its any good for SS to work?

It's just stuck on the car if left off for about 30 mins which it will be if pulse charged. the car then relearn what a healthy battery looks like after about 5 journeys......

If you still have issues get a decent multi meter which will give dc voltage to 2 decimal places... After you drive home pop the bonnet get out and lock the cat and time 10 mins from engine off lift bonnet and measure battery voltage without unlocking the car it should read higher than 12.72 v. (from memory) if not the battery is goosed

12.72v seems to be the important figure from what I've seen in various threads.

 

[UFI]

So how does it judge if battery capacity is full or not then

If the battery has a dead cell it may stop accepting charge, but doesn't mean its any good for SS to work?

12.72v seems to be the important figure from what I've seen in various threads.

Google can tell us the fully charged voltage of a 12v battery. 12.72 means jack all to the S/S system as the car runs at 13.8-14.8v. S/S can't use voltage as a means of monitoring a battery in a running car, even the most dead of batteries will read 14+ volts with the engine running.

S/S cannot make the decision to stop the engine based on voltage. It can only do this based on internal resistance. If the battery develops a dead cell, I presume S/S will stop working before it becomes an issue. The internal resistance will rise above the pre-programmed threshold and register as a defective battery.

If voltage was important, my high voltage LiFe would have made S/S VERY happy.

FWIW, I reset my IBS mid trip today to get the S/S working (back to the original battery for now). The smart alternator spazzed out and was holding a steady 14.0v. Reset IBS, alternator's back and the S/S works