Technical Start / Stop Not Working - Possible Fix

[LovelyRed500XCross]

Me too....I like the stop /start as well

Gave mine an overnight charge and at the end of a run today, it stopped and restarted. Also stumbled across battery charge indicator and oil temp gauges in the central binnacle controlled by the l/h steering wheel buttons.

 

[twobigdogs]

There are quite a few functions on that menu which seemed to be tucked away[emoji15]

 

[shelleyamy]

Story of my daughters 2012 500 Twin Air.

She lives away from home in London, and doesn’t use her car, (mileage is about 12000).
I use it every now and then just to keep it working. A few months ago I went to take it to Fiat for its 3 year service, and it wouldn’t start, flat battery.
Using a battery conditioner charger, got it up and running and took to the dealer, noticed the stop/start wasn’t working and no power steering,so asked them to look at whilst being serviced.

Had to have the battery replaced,(about £160 from memory) not covered by warranty, but did argue the toss about the ½ labour to reset the ecu.
They did point out we should have been disconnecting the battery if not using for a while, and it does state that in the owner’s manual, and the reason they fitted the quick release connector.

Have been using the car a little more and disconnecting when not, but again SS has stopped working.

Is the IBS cable easy to get at?

Also, not sure if related, radio interference is building from none to unusable on journeys.

Mike

 

[LovelyRed500XCross]

Story of my daughters 2012 500 Twin Air.

She lives away from home in London, and doesn’t use her car, (mileage is about 12000).
I use it every now and then just to keep it working. A few months ago I went to take it to Fiat for its 3 year service, and it wouldn’t start, flat battery.
Using a battery conditioner charger, got it up and running and took to the dealer, noticed the stop/start wasn’t working and no power steering,so asked them to look at whilst being serviced.

Had to have the battery replaced,(about £160 from memory) not covered by warranty, but did argue the toss about the ½ labour to reset the ecu.
They did point out we should have been disconnecting the battery if not using for a while, and it does state that in the owner’s manual, and the reason they fitted the quick release connector.

Have been using the car a little more and disconnecting when not, but again SS has stopped working.

Is the IBS cable easy to get at?

Also, not sure if related, radio interference is building from none to unusable on journeys.

Mike

From reading earlier in this thread and looking at my battery there seems to be an additional lead onto the negative terminal, presumably it's the IBS cable. Can't speak for a 500 setup however.

 

[shelleyamy]

From reading earlier in this thread and looking at my battery there seems to be an additional lead onto the negative terminal, presumably it's the IBS cable. Can't speak for a 500 setup however.

Found it, a little black connector that runs left from the battery terminal at the top of the battery.
Disconnected it (and the snap battery connector) for 5 minutes, and it work perfectly.
This morning, nothing. Just did a 35 mile motorway run, still nothing.
Tried the stall the engine trick, and it restarted when depressed the clutch, but nothing else.

Mike

 

[LovelyRed500XCross]

Found it, a little black connector that runs left from the battery terminal at the top of the battery.
Disconnected it (and the snap battery connector) for 5 minutes, and it work perfectly.
This morning, nothing. Just did a 35 mile motorway run, still nothing.
Tried the stall the engine trick, and it restarted when depressed the clutch, but nothing else.

Mike

Seems one's motoring ducks have to be in line for it to work. From reading the thread earlier they include climate control temp., fully charged battery and the IBS sensor playing ball. My issue ( stopping and then a message saying s/s unavailable and no restart) was solved by a 24 hour trickle charge on a 10 month old battery and a run. However not used since so maybe still an issue. Speaking to my local dealer they said s/s puts the most strain on the battery of all the systems in the car so it has to be right. I don't do a lot of commuting so it is not a deal-breaker for me, just a nice to have.

 

[shelleyamy]

Just Spoke with Fiat service, and a 35 mile drive with no lights AC or other electrical systems being used, is not enough to fully charge the batter, and I have to put it on a charger.
I’ll do that tonight and she if that works.

 

[LovelyRed500XCross]

Just Spoke with Fiat service, and a 35 mile drive with no lights AC or other electrical systems being used, is not enough to fully charge the batter, and I have to put it on a charger.
I’ll do that tonight and she if that works.

Well mine seems to work every time now: hope yours gets sorted.

 

[Red Van Man]

Does this hopeful looking post suggest the SS can be deleted 'permanently' by removing a lead from the battery? Will it throw up a warning light or error code?

I hold my breath for a reply...

R-V-M (not a lover of the silence under the bonnet when it needs to be breathing)

Well I've found the cause of the problem in my 500X and how to resolve the non functioning without disconnecting the problem.

I could not get Start/Stop to work even after parking and stopping the car. So this time I disconnected the quick release battery terminal only. Still no go.

So then I disconnected and reconnected (after about 10 seconds) just the Start/Stop lead by the battery terminal and *bingo* all back to normal.

 

[TrevC]

The Stop/Start on my 500X has always worked fine, but during the hot weather early in the summer I switched it off so that the climate control would continue to blow cold air when I was stationary (if the engine stops, so does the a/c compressor). This led to the discovery that, unlike the 500 I had previously, if you disable the 500X's s/s it remains disabled for subsequent journeys. Does that help Red Van Man?

 

[Alanw47]

Since the strange electrical gremlins from earlier in the year I have it disabled almost all of the time

 

[s130]

As the OP of this thread I've not revisited the SS not working issue. What I have noticed is that on my daily runs of 7 miles, park up for a few hours and 7 miles back the SS never cuts in. On the few occasion I've been on a much longer run and tried SS it appears to work.

This leads me to my conclusion that the SS software battery condition metrics are just too aggressive.

As for unplugging the SS sense wire as a way to knobble SS then I've no idea what the outcome would be.

 

[robotdancer]

Does this hopeful looking post suggest the SS can be deleted 'permanently' by removing a lead from the battery? Will it throw up a warning light or error code?

I hold my breath for a reply...

R-V-M (not a lover of the silence under the bonnet when it needs to be breathing)

Why would you do that? You can just turn it off and disable it via the dash if you don't like it.

 

[Red Van Man]

The Stop/Start on my 500X has always worked fine, but during the hot weather early in the summer I switched it off so that the climate control would continue to blow cold air when I was stationary (if the engine stops, so does the a/c compressor). This led to the discovery that, unlike the 500 I had previously, if you disable the 500X's s/s it remains disabled for subsequent journeys. Does that help Red Van Man?

That sounds promising! Looking forward to trying it out, thanks!

R-V-M

 

[s130]

The 500X SS on/off state is not reset when your start the car. I have mine off for well over 6 months and never had it turn itself back on.

There are many reasons / triggers for SS not working when enable. Battery condition is one. Also cabin "environment" is another. If you have 20 degC set and the temperature is above that and the aircon is trying to pull it down then SS will/should not operate.

 

[TrevC]

Apparently another parameter is the turbo temperature - obviously not good to switch off the engine with a red hot turbo, for instance when having to stop immediately after a motorway thrash.

 

[s130]

Apparently another parameter is the turbo temperature - obviously not good to switch off the engine with a red hot turbo, for instance when having to stop immediately after a motorway thrash.

Almost certainly. I do know when I was looking with the technician on my car then there were *many* parameters and detailed data (sadly not available in MES) for SS go/no go criteria. His view was focused on why I was having an issue and that was being flagged as "battery condition". Didn't really get a chance to examine all the other stuff.

 

[twobigdogs]

Mine has always worked perfectly but I don’t really like it to be honest so I have it turned off.

 

[Garree001]

Almost certainly. I do know when I was looking with the technician on my car then there were *many* parameters and detailed data (sadly not available in MES) for SS go/no go criteria. His view was focused on why I was having an issue and that was being flagged as "battery condition". Didn't really get a chance to examine all the other stuff.

Apparently another parameter is the turbo temperature - obviously not good to switch off the engine with a red hot turbo, for instance when having to stop immediately after a motorway thrash.

Many modern engines have the ability to keep the turbo lubricated after the engine has switched off. So the days of turbos going bang because the oil has drained out are largely gone.

 

[TrevC]

As I understand it, the problem is the oil carbonising from the heat soak, rather than it draining away. This can gum up the bearings, and over time gradually block the oil feed pipes to the turbo. Petrol cars tend to have their turbos water cooled (hotter exhaust than diesel?), so after hard running a brief idle period should allow the water to take away the excess heat. I haven't heard of any measures being taken after switch off but it's possible. For instance, some BMWs have electric water pumps, so it would be relatively simple to keep that going for a short time after switch-off, or indeed during s/s operation.