I own a 2014 Fiesta 1.0 Ecoboost, and the auto-start-stop hasn't kicked in since about 4 months. I'm worried there might be a problem causing the system to choose not to stop the engine so i got an OBDII tool and installed Forscan extended licence on my laptop hoping to diagnose it. Chat GPT told me there should be some values showing if the auto-start-stop system is working or the reason of it being inhibited, but i found none of those in Forscan.

Does the Fiesta show such values at all? or is it just my scan tool that's not able to read it? I have the "vLinker FS OBD2 Bluetooth Scanner".

Any ideas on how i can diagnose this on my own would be very welcome :)

Happens a lot, the stop start gives up when the battery gets to a certain percetage state of charge which I dont think is even that low. #Maybe 70 percent?) My start stop hasnt worked in 2 years lol

As above, your Battery is probably past its best and is not being charged enough because of its age and the car is not being used enough.

There should be lots of PID's in the PCM relating to Stop/Start. Do a search, bring them all up press Play and take the car for a drive.

You can revue the results later, there will most probably not be a Fault Code but one of the PID's should show why S/S has been inhibited. 

It's been a couple of weeks since I posted the battery SOC table 🤣

12 hours ago, Tizer said:

As above, your Battery is probably past its best and is not being charged enough because of its age and the car is not being used enough.

There should be lots of PID's in the PCM relating to Stop/Start. Do a search, bring them all up press Play and take the car for a drive.

You can revue the results later, there will most probably not be a Fault Code but one of the PID's should show why S/S has been inhibited. 

Currently my battery's SOC is at 90% according to the PID. So idk if it's a battery issue that I can't measure with the OBD2 tool. 

Also I searched a lot and couldn't find how to show the S/S parameters in Forscan. Can you maybe tell me how if you know it? (yes, I already tried choosing the option to show PIDs not just the PCM. Used the search bar and found nothing) 

here is an example of the things which have to be "just right" on a Focus Mk4 to get S/S to work.

 

2 hours ago, Euphorium said:

Currently my battery's SOC is at 90% according to the PID. So idk if it's a battery issue that I can't measure with the OBD2 tool. 

Also I searched a lot and couldn't find how to show the S/S parameters in Forscan. Can you maybe tell me how if you know it? (yes, I already tried choosing the option to show PIDs not just the PCM. Used the search bar and found nothing) 

The Battery at 90% is enough for S/S to work if everything else is ok.

Are you saying that when you do a search through the PID List there are no ones relating to Stop/Start in either the PCM or BCM like the list in the video above?, if so then I don't think FORScan can help you.  

I wish mine didn't work

8 hours ago, Tizer said:

The Battery at 90% is enough for S/S to work if everything else is ok.

Are you saying that when you do a search through the PID List there are no ones relating to Stop/Start in either the PCM or BCM like the list in the video above?, if so then I don't think FORScan can help you.  

exactly so all the PIDs with ss are just not there for me even when i choose PCM or ALL.. i just wanted to diagnose it on my own 😞

On 3/10/2025 at 1:34 PM, Tizer said:

The Battery at 90% is enough for S/S to work if everything else is ok.

Are you saying that when you do a search through the PID List there are no ones relating to Stop/Start in either the PCM or BCM like the list in the video above?, if so then I don't think FORScan can help you.  

If it's not FORScan then is there any other app that would work? 

12 minutes ago, Euphorium said:

then is there any other app that would work? 

Yes, this will work:

https://www.ebay.co.uk/itm/375324321191

It depends on how badly you need S/S to work.

20 minutes ago, unofix said:

It depends how badly you need S/S to work

It seems like it's working quite badly already!😀

Bizarrely, mine is now into its second month of operation after a 6 month lay off. Stopped at the post box 200 yards from.home the other day and it even worked then!

 

3 minutes ago, Eric Bloodaxe said:

Stopped at the post box 200 yards from.home the other day and it even worked then!

So sorry to hear your bad news, perhaps it will stop working soon 🤣

5 minutes ago, Eric Bloodaxe said:

Bizarrely, mine is now into ......

..and speaking of 'bizarre' things, I bought a 2022 Ranger Stomtrak on Friday and guess what ..... it does not have Stop/Start 😀

It's not that it's not working, it just doesn't have it. There is a blank space on the centre console where the button to turn it off would be.

30 minutes ago, unofix said:

.and speaking of 'bizarre' things, I bought a 2022 Ranger Stomtrak on Friday and guess what ..... it does not have Stop/Start 😀

That is weird - there's loads of stuff online about disabling S/S on a Ranger. Does the manual suggest it should have it? Or perhaps it's been "got at" already?

12 minutes ago, Eric Bloodaxe said:

Does the manual suggest it should have it? Or perhaps it's been "got at" already?

It seems that some do have the button and perhaps some like mine don't ?

Did notice the factory SOC set charge was only 75% which has now been changed to 90%. There is the means in the BCM settings to disable S/S but seems to be not selected . Also turned off the use fog lights as cornering lights and have possibly turned on Auto High Beam, but I'll have to wait until dark to test that.

2 hours ago, Euphorium said:

If it's not FORScan then is there any other app that would work? 

The one above that @unofix linked may work but it is not guaranteed.

1 hour ago, Tizer said:

The one above that @unofix linked may work but it is not guaranteed.

I'm not paying 1000£ for that 😅. Guess I have to live without it. 

 

On 3/10/2025 at 5:05 PM, jsk said:

I wish mine didn't work

Yeah, I'd echo this.

I recall once getting our start-stop to reactivate by performing a battery reset (instructions found here on the forum) and was patting myself on my back for having achieved this. As time went on, however, whenever it kicked in I was finding myself thinking how bad it likely is for the engine (starter, lubrication system, cooling system, turbo etc) and that actually I'd rather just pay what is likely a very small fuel cost to keep the engine running instead. I am sure it only really benefits the official fuel consumption test cycle and that the drawbacks outweigh the benefits in real life (particularly over the lifetime of the vehicle).

The start-stop recently stopped activating again - for reasons unknown - but this time I will let sleeping dogs lie and do nothing about it.

On 3/16/2025 at 10:43 PM, MJNewton said:

Yeah, I'd echo this.

I recall once getting our start-stop to reactivate by performing a battery reset (instructions found here on the forum) and was patting myself on my back for having achieved this. As time went on, however, whenever it kicked in I was finding myself thinking how bad it likely is for the engine (starter, lubrication system, cooling system, turbo etc) and that actually I'd rather just pay what is likely a very small fuel cost to keep the engine running instead. I am sure it only really benefits the official fuel consumption test cycle and that the drawbacks outweigh the benefits in real life (particularly over the lifetime of the vehicle).

The start-stop recently stopped activating again - for reasons unknown - but this time I will let sleeping dogs lie and do nothing about it.

I can imagine why, but am still curious to know your opinion on how it exactly is bad for the cooling system and the turbo? 

10 hours ago, Euphorium said:

I can imagine why, but am still curious to know your opinion on how it exactly is bad for the cooling system and the turbo? 

The coolant stops flowing around the system when the belt driven waterpump stops.  The turbo on 1.0 EcoBoost is watercooled.  However, Ford overcame this by fitting an electronic coolant pump to keep the coolant circulating while the engine is not running.  (It wasn't fitted to all of the earlier models though.)

12 hours ago, Euphorium said:

I can imagine why, but am still curious to know your opinion on how it exactly is bad for the cooling system and the turbo?

Sure, it is specifically that with the turbo being bolted to the exhaust manifold and sitting in the exhaust flow it is in a particularly hostile environment in terms of having to cope with incredibly high levels of heat. With the engine running it is cooled by a constant flow of both oil and coolant through it, and whilst with the engine off an inline electric pump does keep a certain amount of coolant flowing through it is inevitably considerably lower than the normal operating conditions that were present only seconds before the engine was shut down. Furthermore, this auxiliary coolant flow is limited in effectiveness by virtue of the fact it only flows through the coolant reservoir (i.e. not the radiator where the fan could assist). Given this design I think its purpose is as much to do with preventing localised boiling of coolant ('kettling') in both the turbo and cylinder head as it is to attempt to cool these components down given such low coolant volume in that circuit section. It also doesn't do anything for the lack of oil flow through the turbo so that will just sit there cooking.