Start Stop issue Fiat 500

[Beautiful South Martin 24]

Looking for some advice on a Fiat 500 1.2 petrol convertible with a start stop issue. After driving the car for about 5-6 miles the S start stop disconnected light comes on the dash together with a warning triangle. When you drive it from cold and stall it intentionally the SS works ok but won't come on a junctions etc. Had it to the local auto electricians who has changed the battery and the brake switch which he said was faulty, its still no different. Its looking like its going to have to go a fiat main dealer. Anybody had a similar issue and a cure?

[Lambchop 4]

Had a ford ka which has same engine, if there isn’t enough power in battery stop start won’t come on, you’ll get that warning yellow light. Also it should have  an actual stop start battery or will run the power down pretty quick .

[justina3 518]

5 minutes ago, Lambchop said:

Had a ford ka which has same engine, if there isn’t enough power in battery stop start won’t come on, you’ll get that warning yellow light. Also it should have  an actual stop start battery or will run the power down pretty quick .

Agreed seen loads of these with a chepo 063 stuck on it the stop start battery is almost twice the size and for sure three times the price, the fault really does sound power related.

[Darkbluecars 10]

57 minutes ago, Beautiful South Martin said:

Looking for some advice on a Fiat 500 1.2 petrol convertible with a start stop issue. After driving the car for about 5-6 miles the S start stop disconnected light comes on the dash together with a warning triangle. When you drive it from cold and stall it intentionally the SS works ok but won't come on a junctions etc. Had it to the local auto electricians who has changed the battery and the brake switch which he said was faulty, its still no different. Its looking like its going to have to go a fiat main dealer. Anybody had a similar issue and a cure?

I had this issue with one bought at auction and was within the 3 year manufactures warranty. Took to dealership “sorry sir that’s not covered in the third year” 

Really?? that’s a surprise bearing in mind it’s even called Fiat Stop Start on the V5 you’d have thought that it may have been covered. 

 It was a software update at the dealership and was £60, about half the price of battery so not too bad

[Halfpenny 114]

I would say over 90% of the SS issues we see are battery related.  You need the correct SS battery and it must be in good condition. The voltage may read OK but if the battery is down on cranking current (as detected by battery management system) then the SS will be disabled.

[BHM 994]

I’ve never had a S/S issue that wasn’t a battery. Years ago any cheap battery would do on a car but nowadays even I go brand name only. As the old saying goes, ‘Buy cheap, buy twice’.

I do save a few quid buying via eBay from Tayna etc. as Varta/Exide AGMs, or similar,  seem to run at about £100 inc. VAT delivered which the local factors can’t get near to.

[It's me 615]

Looking at a traders 500 few weeks back and he had fitted a £32     063

I warned him problems would develop, I moved the car and dash was flashing, the proxy thing

[Blenheim Car Sales 111]

There may also be a  SS battery fuse on the Negative terminal that monitors things, This is sometimes an issue

[Halfpenny 114]

5 hours ago, Blenheim Car Sales said:

There may also be a  SS battery fuse on the Negative terminal that monitors things, This is sometimes an issue

That's not a fuse, that's the Intelligent Battery Sensor (IBS). It sits between the battery negative and the false negative.

If you are working on a SS NEVER connect a charger to the battery without disconnecting the battery first. Also if you boost or jump a car the negative terminal of the booster goes to chassis, NOT to battery negative (potential big bill).

Always use a branded SS battery and note that the system might take a few runs to relearn a new battery. Also won't stop if HRW is on, A/C is on or any large electrical loads.