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Technical Start / Stop Not Working - Possible Fix

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Technical Start / Stop Not Working - Possible Fix

s130

s130

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I don't normally use (actually have really never using it other than for fun) Start / Stop on my 500X but due to a motorway accident and stationary traffic I decided to switch it on.

Sadly it did not work. Tried Sport, Old Fart and Traction modes but still no joy.

Now having had a recent vehicle software update I thought (like the dead lock issue reported in another thread) this was a side effect of the update as there were no associated error messages.

After booking the car in with the dealer I just thought ...... why not :D

I disconnected the quick release battery negative terminal. Also disconnected the Start/Stop sensor wire and left to stand for a few minutes.

Reconnect the Start/Stop sensor wire and then the quick release negative terminal connection.

Problem sorted :slayer:

I have no idea if this was a software update related issue (e.g. some form of additional reset initialisation/reset required) or the car thew a wobbly on the Start/Stop a while ago. Either way may actions seems to have covered the Start/Stop operation.

Certainly worth a try if you ever have a similar issue.

Small warning. You will lose your Trip A and Trip B data so if this important to you then you should note the data before disconnecting the battery. All other vehicle setting appear to be unaffected.
 
Normally it has to do with battery level, what you have running and engine temperature.
Having had SS in my previous Punto, I know it works less through winter because of more demand on the electrics. Now with the 500X, it hasn't worked for the last couple of days but I am only doing short journeys so the battery isn't getting sufficient charge to kick it in.

If it continues to cause problems, one way to rule out the battery itself is disconnect it and give it a full charge overnight using a charger (ideally a conditioning charger), that way once it is connected it should work straight off the bat. If it doesn't, it's likely not the battery.
 
Mine works all the time. The only time it doesn't switch on is when the car is first started and cold and sometimes if aircon/heater is full on. My previous Punto worked exactly the same way.
 
Well with a cart less than 12 months old and only 3K miles on the clock and regularly used I would be concerned if it was a battery issue. On-board battery voltage meter shows no issue either.

However it is still possible that during the last 6 winter months conditions got a little stressed (low temperature and low battery charge) and the Start/Stop system dropped out. Regardless the real head puzzler is that the dash and instrument panel correctly reported system engaged and disengaged but in the engaged mode (with no reported errors) it just did not function. (bad software IMHO. No checking of actual function operation against demanded operation. A chimp could do better)
 
s130 said:
I don't normally use (actually have really never using it other than for fun) Start / Stop on my 500X but due to a motorway accident and stationary traffic I decided to switch it on.

Sadly it did not work. Tried Sport, Old Fart and Traction modes but still no joy.

Now having had a recent vehicle software update I thought (like the dead lock issue reported in another thread) this was a side effect of the update as there were no associated error messages.

After booking the car in with the dealer I just thought ...... why not :D

I disconnected the quick release battery negative terminal. Also disconnected the Start/Stop sensor wire and left to stand for a few minutes.

Reconnect the Start/Stop sensor wire and then the quick release negative terminal connection.

Problem sorted :slayer:

I have no idea if this was a software update related issue (e.g. some form of additional reset initialisation/reset required) or the car thew a wobbly on the Start/Stop a while ago. Either way may actions seems to have covered the Start/Stop operation.

Certainly worth a try if you ever have a similar issue.

Small warning. You will lose your Trip A and Trip B data so if this important to you then you should note the data before disconnecting the battery. All other vehicle setting appear to be unaffected.
Click to expand...

Good advice, I have seen similar posts on the 500 and Panda/Punto 2012 section before. Sometimes it just needs to be switched off and switched on again:p

As you say, it doesn't cost anything and is very simple.

My 62 plate Punto's S/S hasn't worked since late 2014 lol:) It worked for the first three months, then started getting a bit flaky towards winter, and stopped before Christmas.

However, the restart function by depressing the clutch will work if I stall the engine (once the engine is warm). So that part of the system is fine, it's just the main S/S functionality that doesn't work.

I am guessing either the battery doesn't quite have enough charge to meet the threshold, or maybe there is some other fault that a code reader would suss out. As you have probably gathered, I really don't care that much(y):D
 
Super Uwe said:
Good advice, I have seen similar posts on the 500 and Panda/Punto 2012 section before. Sometimes it just needs to be switched off and switched on again:p

As you say, it doesn't cost anything and is very simple.

My 62 plate Punto's S/S hasn't worked since late 2014 lol:) It worked for the first three months, then started getting a bit flaky towards winter, and stopped before Christmas.

However, the restart function by depressing the clutch will work if I stall the engine (once the engine is warm). So that part of the system is fine, it's just the main S/S functionality that doesn't work.

I am guessing either the battery doesn't quite have enough charge to meet the threshold, or maybe there is some other fault that a code reader would suss out. As you have probably gathered, I really don't care that much(y):D
Click to expand...

I dunno why Fiat seem to find it so difficult to produce a reliable stop/start system on their cars. I can sort of understand cars like the 500 & Panda (with their small batteries) struggling at times, especially with only short journeys round town, but I see people with Giulietta's that do decent mileage and now 500X's struggling to get a consistent stop/start performance too. If all cars were the same then I'd understand, but other makes just seem to work.

I thought the stop/start was an off-the-shelf system used by several makes, so whether it's Fiat's other vehicle software or poor original batteries or what, I dunno.

Incidently my MiTo stop-start nearly always works when I have it activated, even when I've got the aircon running in the height of summer - go figure! However I invariably have it switched off - easier on my car as it's a later model that doesn't need you to switch it off every time you re-start. I'm with you about not really caring about it v much though - I do wonder why in some cases people get so worked-up about stop/start. It'll likely cost you more in replacement batteries, starter motors etc than it'll save in fuel, so if it doesn't work properly I'd just switch it off. It's one of those things that's not worth falling out with an otherwise decent car for! :)
 
I must be one of the lucky ones, both my Fiats have had no issues with stop start . When I first had it I wasn't sure if it would be any good but I really quite like it after using it for a few years.
 
twobigdogs said:
I must be one of the lucky ones, both my Fiats have had no issues with stop start . When I first had it I wasn't sure if it would be any good but I really quite like it after using it for a few years.
Click to expand...

I think it's a bit of a love-hate thing - if it works well, you can become quite fond of it, but equally when it doesn't work, it really grates!

What engine does your 500X have? I suspect the type of driving has more to do with stop/start function, but would be interesting to see if there's any correlation between how well the stop/start works and the engine its connected to.
 
Well I've found the cause of the problem in my 500X and how to resolve the non functioning without disconnecting the problem.

Today I accidentally stalled the car whilst stationary and with the handbrake set. The immediately produced a message on the dash "Start/Stop System not Available" (or similar words). At the time of the stall Start/Stop was disengaged.

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.

All this has been fed back to the dealer to report back to Fiat.

This looks very much like a software bug where the Start/Stop system does not reset itself after an ignition on/off cycle.

This info could save you and expensive trip to the dealer when your vehicle is out of warranty :)
 
Last edited:
Well sadly the start stop failed again.

Sat with Fiat technician and we looked at the Start/Stop parameters on WiTech. No formal error codes but a "Battery Level Insufficent" (or similar wording) occurrence count of over 100.

Tested battery voltage at 13.8x V with engine running.

I understand their normal procedure in cases likes these is to put the battery on charge overnight and see what happens.

Guess what.....system is happy and running again. I'm assuming the battery was removed or at least disconnected from the car for charging. Doing this would be the same as what I did so I'm expecting the system to fail to operate again in a short while.

Meanwhile as battery tested good they can not replace it under warranty.

Initial suspicions are that the Start/Stop system go/no go metrics regarding battery condition have been set to aggressively.

Interestingly the dealer will not get paid for their work and I was without the car for over a day.

I'll keep you all posted as and when anything else develops.
 
s130 said:
Well sadly the start stop failed again.

Sat with Fiat technician and we looked at the Start/Stop parameters on WiTech. No formal error codes but a "Battery Level Insufficent" (or similar wording) occurrence count of over 100.

Tested battery voltage at 13.8x V with engine running.

I understand their normal procedure in cases likes these is to put the battery on charge overnight and see what happens.

Guess what.....system is happy and running again. I'm assuming the battery was removed or at least disconnected from the car for charging. Doing this would be the same as what I did so I'm expecting the system to fail to operate again in a short while.

Meanwhile as battery tested good they can not replace it under warranty.

Initial suspicions are that the Start/Stop system go/no go metrics regarding battery condition have been set to aggressively.

Interestingly the dealer will not get paid for their work and I was without the car for over a day.

I'll keep you all posted as and when anything else develops.
Click to expand...


Had similar on my previous Punto... Despite the battery passing their tests, I still got them to replace it under warranty and it worked fine since.

Prior to this I got an intelligent Ring charger that restores battery performance and this did get the S/S working for couple of weeks until it decided not to bother again.
 
Well as suggested the "computer says" .... "no go" for whatever calculated states it attributes to battery "good".

I'll see what happens but if driving 7 to 15 miles with undue loads (i.e just the front daylight running lights) and the system says battery not good but battery passes all accepted tests then sorry but the vehicles software is stuffed.

Time will tell.......
 
90% of stop start failures we see are battery condition related (voltage may be fine, but if the conditioning or amperage fall below 75% system will not work) so a decent battery charge is first port of call. Disconnecting the IBS* sensor (next to the battery) causes it to lose its memory. As such, it will happily work til it figures out, or thinks, the battery amps are too low, at which point it disengages the system. We have replaced some IBS sensors, and some batteries. There are also a massive amount of software issues currently being address, mainly with the Jeep Renegade, but seeing as they are practically the same car it may filter to the 500x in the near future

*Intelligent Battery Sensor. It's not that intelligent.

I work for an Alfa/Fiat/Jeep main agent
 
Start/stop on my 500X works fine, but its a bit "slow" to wake up, compared to my german cars. On the Merc, once I depress the clutch pedal, the engine wakes up immediately, while on the 500X it sometimes requires me to engage 1st gear for the engine to wake up.

What is interesting in the 500X, is that sometimes the engine wakes up when I depress the clutch pedal (just like in the Merc) but not always and not as fast.

In the Merc, its of course always quick and flawless.
 
Asa James said:
90% of stop start failures we see are battery condition related (voltage may be fine, but if the conditioning or amperage fall below 75% system will not work) so a decent battery charge is first port of call. Disconnecting the IBS* sensor (next to the battery) causes it to lose its memory. As such, it will happily work til it figures out, or thinks, the battery amps are too low, at which point it disengages the system. We have replaced some IBS sensors, and some batteries. There are also a massive amount of software issues currently being address, mainly with the Jeep Renegade, but seeing as they are practically the same car it may filter to the 500x in the near future

*Intelligent Battery Sensor. It's not that intelligent.

I work for an Alfa/Fiat/Jeep main agent
Click to expand...

Thanks for this.

The day before yesterday the S/S would not work despite a 15 mile run. Yesterday it was working again.

With what you have said it sounds very much like over sensitive software on a far from ideal IBS.

What I'm struggling to understand is that if 75% (good condition) is the threshold then why a long run with just the front running lights on the battery good condition is not being restored via the alternator. 500X alternator is probably rated at 140A or more so there should be more than enough juice left (even allowing for engine/aircon/power steering/etc) to charge the battery back up.

I guess for all we know when the no go threshold is reached then despite the condition being restored there may also be some additional time period (24 hours or more) to allow the battery to "settle" before the SS is reactivated.

Would be nice if the SS system informed you instead of saying Engaged when clearly it is not.
 
Ok, so got these pics today from two separate cars. We test every battery that comes into the workshop. First is from a 30,000 mile 2.0jtd giulietta (service), second is a brand new giulietta (PDI)

ImageUploadedByFIAT Forum1463002891.969215.jpgImageUploadedByFIAT Forum1463002907.389693.jpg

SOC is state of charge, it's rare to see one at 100%. Most are 80 - 90.

I'm sure I heard recently that Fiat/Alfa are doing away with stop start, the engines are now efficient and eco enough to not need it. Don't take that as gospel
 
Asa James said:
I'm sure I heard recently that Fiat/Alfa are doing away with stop start, the engines are now efficient and eco enough to not need it. Don't take that as gospel
Click to expand...

I hope that is not true ... I love the SS on my 500X. Nothing to do with saving fuel, just that I can stop in traffic and enjoy the silence of not having the engine running. An unexpected advantage of the SS for me.
PS The only time my SS didn't work, temporarily, was because the temperature in the car was not within 2°C of what was dialed into the climate control (at least that's according to the dealer, but I think he is correct).
 
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