Hello

I bought a 2nd hand Fiesta Ecoboost 1.0 2012 about 6 months ago and the stop/start was working as it should do. Over the past week or so it seems to have suddenly stopped working; there's no warning light on, the a/c isn't on and I can't work out why it would suddenly stop working. One thing is that I only do short trips (6 mile round trip) every day but that has not been a problem before. I'm not bothered about it really but I'm not sure whether it matters if it isn't working (eg is it doing any damage?). Any advice would be very helpful. Thanks

Lots of factors come into it, battery condition, engine temp, outside temp, the most common one is low battery, if you are still on the original battery it's probably on its way out as its about 6 years old according to you profile. The short journeys wont be helping with the battery life Now either 

Hi pragmatix Thanks for your reply. I thought that might be it. Unfortunately I didn't know when I bought the car that the battery was going to cost a lot more money to replace. My garage have quoted me £66 to run diagnostic tests (this includes 1 hrs labour). If I'm not bothered about the SS not working do you think it's ok to keep driving as it is? Cheers

Yes it will be fine but  be on the look out for some strange electrical  and starting problems with the colder weather coming.

Hi, mine is the same, i only do short runs 6 to8 miles stop/start not working, but if go on a 30ish mile run 

Stop/xtart working again untill back to short runs !!!  Suspect battery is past its best (4 years old) ,first

sign of any starting problems this winter will change it , expensive £100 + .

When I bought mine the stop start didn't work.   I bought it from a Ford dealer so I took it back.   They fitted a new battery but that didn't cure the problem.   The then changed the battery monitoring module and that cured it.   All week I do a lot of very short journeys.   On a Thursday I sometimes do 45 miles and sometimes over 100 miles.   On Friday the stop start works perfectly.   By the following Wednesday it's stopped again.   Obviously down to battery charge. 

Thanks for the advice guys! My opinion is S/S is rubbish in that case 🤣. I've seen that the batteries for the Fiesta are about £200?!! I'm just going to keep on driving until I notice any electrical problems.

i swapped my 60ah efb battery which died at 15 months for an AGM 75ah battery.  I do a lot of very short trips and it's very rare for the stop-start to not kick in cost around £100 mark off eBay. i also run a dash cam with parking mode off the battery so it gets a hammering. 

Evening

stop/start works on my car even on a 2 mile commute to work. sometimes it doesn't work but as said above it could be down to engine temp, outside temp, heater blowing hot or cold at full blast.

i can be sat in traffic with the stop/start activated thinking to myself 'i'm not damaging the planet because my engine is off and think how much money i'm saving.'