General Fiat 500 Stop/Start Sensor Location ?

[ChemicalWifi]

Hi
Can anyone please advise where the stop start sensor is located on a Fiat 500 1.2S .

It's a 2015 model year if that helps .

Thanks

 

[Ralf S.]

I'm not sure there is a sensor. The ECU measures various parameters like vehicle speed, gearbox (gear) and clutch pedal position, battery voltage, whether a/c or the rear window demister are on, engine temperature etc. and decides whether or not to activate the S/S.

If the car is stationary, in neutral with the clutch out, up to operating temperature, with a spunky battery and no a/c or rear window demister on, then it'll cut the engine. Anything else, it won't.

If your car isn't cutting in the S/S then the battery is probably the wrong type, or not at "peak". Early S/S and non-S/S cars had a weedier battery that loses the S/S mojo quite early in its life. If you fit a new battery of the later S/S type (which are twice the price, hence a lot of second owners fit the cheap one) then it should re-vitalise the S/S.

If you trickle charge the old battery off the car, and clean up the battery posts with wire wool (don't short wire wool out across the battery.. ) and fettle the insides of the connector clamps, then the S/S may work for a few days until the battery fades below the threshold again. A non-working S/S doesn't mean the battery is no good, just not A1 condition, so it could last another 4 or 5 years yet...

The battery condition sensor is next to the earth battery post. If you charge the battery, make sure you attach the charger to the earth post, not the bracket on the other side of the battery condition sensor (otherwise it'll get burnt out) - or (some models) use a separate "falso earth" charging post, which is nearer the front of the car. If you have three terminals on the battery, use the one without the sensor attached to it, for the earth.


Ralf S.

 

[ChemicalWifi]

I'm not sure there is a sensor. The ECU measures various parameters like vehicle speed, gearbox (gear) and clutch pedal position, battery voltage, whether a/c or the rear window demister are on, engine temperature etc. and decides whether or not to activate the S/S.

If the car is stationary, in neutral with the clutch out, up to operating temperature, with a spunky battery and no a/c or rear window demister on, then it'll cut the engine. Anything else, it won't.

If your car isn't cutting in the S/S then the battery is probably the wrong type, or not at "peak". Early S/S and non-S/S cars had a weedier battery that loses the S/S mojo quite early in its life. If you fit a new battery of the later S/S type (which are twice the price, hence a lot of second owners fit the cheap one) then it should re-vitalise the S/S.

If you trickle charge the old battery off the car, and clean up the battery posts with wire wool (don't short wire wool out across the battery.. ) and fettle the insides of the connector clamps, then the S/S may work for a few days until the battery fades below the threshold again. A non-working S/S doesn't mean the battery is no good, just not A1 condition, so it could last another 4 or 5 years yet...

The battery condition sensor is next to the earth battery post. If you charge the battery, make sure you attach the charger to the earth post, not the bracket on the other side of the battery condition sensor (otherwise it'll get burnt out) - or (some models) use a separate "falso earth" charging post, which is nearer the front of the car. If you have three terminals on the battery, use the one without the sensor attached to it, for the earth.


Ralf S.

Hi Thanks for the detailed info . The engine management light comes on and also S/S with a strike through it and exclamation mark over it . Both are Amber in colour . The condition is sporadic and when it does happen it states the S/S isn't availble (Not deactivated) . Ive even deactivated the S/S when the fault doesnt show but the engine management light still comes on with notification the S/S isnt availble. The engine performance and everything else is fine . Infact you wouldn't know anything had been flagged up by the car .

 

[John202020]

Eml is telling you there's a different fault, you need the codes read, disabling the ss ii normal with the eml on

 

[Ralf S.]

Hi Thanks for the detailed info . The engine management light comes on and also S/S with a strike through it and exclamation mark over it . Both are Amber in colour . The condition is sporadic and when it does happen it states the S/S isn't availble (Not deactivated) . Ive even deactivated the S/S when the fault doesnt show but the engine management light still comes on with notification the S/S isnt availble. The engine performance and everything else is fine . Infact you wouldn't know anything had been flagged up by the car .

Yes.. if the car thinks there's an engine management issue, then the S/S is deactivated automatically, in case (I suppose) the car can't re-start again.

Ignore the S/S issue (that's normal) and get the ECU error code read to see what it thinks the problem is. Could be just a duff lambda sensor or something fairly simple. If the car is running okay then that's a good sign.


Ralf S.

 

[AndyRKett]

The Stop start "sensor" is a little electronic box attached to the negative terminal of the battery its obvious as there is a large metal pole coming off it with a quick release clamp to make it easy to isolate the battery.

This is not your problem as if the stop start system was a problem it just stops working but you would not get an engine management light. As others have said the engine management light is an indication of something else, and the stop start warning is a symptom of that and not the cause.
If anything is detected that the stop start system does not like, then the stop start deactivates.

 

[z rider]

The little box at the battery is the battery sensor. It tells start stop the condition of the battery and if it can be activated. I think it is a box beond my parcel shelf that is quite prominent in the footwell. One day I had a loud relais clicking from there in a start stop situation that stopped when I deactivated start stop. I must say that my car is LHD, so I don't know where it is on RHD cars.
Start Stop unavaible is the normal message, the ecu thinks you have stalled the car, but is unable to restart so prompts the message.
Have the codes read to find out what causes the MIL warning.