Hi to all, driving my focus x active for some time, lately noticed that the start/stop function is not functioning. When coming to a stop, a grey symbol

lights up crossed out meaning the function is deactivated. When I check information and scroll to start/stop it shows battery charge.

 I didn't see any problem with the battery since the car starts and behaves normally. I don't really care for the function since it is always deactivated

with the push button. I just wonder about the  car's electrical reliability.  Is it a common problem with Ford Focus? The car shows the same readout

after a long distance drive too.

If you're not bothered about having the stop/start function working I wouldn't worry too much. The battery may not meet the state of charge required by the system but it will probably carry on perfectly fine for years yet. Stop/start didn't work on our Mk3 when we bought it nearly 5 years ago and I didn't need to renew the battery until a few weeks ago by which time it was around 8 years old. Stop/start works with the new battery, for now at least, but I'd be perfectly happy if it stopped working again. Not having it working saves a lot of wear on your starter motor.

Yes, it's a common problem.

The smart charge system is designed to only charge the battery to 80% in order to save the fuel that would be used to drive the alternator to give it a full charge.

The only time that the battery gets above 80% is if you are going downhill as the alternator is switched on to provide a bit more engine braking and get a bit of free charge into the battery. 

The stop/start system needs the battery to be near 80% in order to work. So one piece of fuel saving technology prevents the other piece of fuel saving technology from working.

As you don't care for the function just be grateful that the system is disabling it for you automatically.

https://www.fordownersclub.com/search/?q=stop start&updated_after=any&sortby=relevancy&search_in=titles&search_and_or=and

From personal experience, I'd put it in your diary and set a reminder , 5th November 2021, car did not stall at the lights, stop/start worked for it's annual once only event

11 hours ago, pcaouolte said:

Yes, it's a common problem.

The smart charge system is designed to only charge the battery to 80% in order to save the fuel that would be used to drive the alternator to give it a full charge.

The only time that the battery gets above 80% is if you are going downhill as the alternator is switched on to provide a bit more engine braking and get a bit of free charge into the battery. 

The stop/start system needs the battery to be near 80% in order to work. So one piece of fuel saving technology prevents the other piece of fuel saving technology from working.

As you don't care for the function just be grateful that the system is disabling it for you automatically.

I thought the Mk4 was fitted with a non braking engine ? 

13 hours ago, Wino said:

I thought the Mk4 was fitted with a non braking engine ? 

I haven't seen that, do you have a source?

I believe that the Mk4 still activates the alternator when going downhill to give some braking effect and get a bit of charge into the battery without using any extra fuel. 

Not necessarily IMO, wouldn't the board computer report some consumption then? Mine varies running downhill between 0,0 - 1,1 litres/100 km (measurements taken in summer with aux fuel heater off, note)

Not another one...."they all do that sir!!" Seriously, they all do!

Bought my Focus in July, stop/start didn't work. Charged the battery and after that it worked every time I stopped. 

As I do a lot of short journeys by the end of the week it was back to not working.

Sometimes mine works and sometimes mine doesn’t, but usually it does when I’ve done a trip from Brighton to Bristol, but I have found out that if I lightly press the brake I can keep the engine running, very handy if I know I’m going to be at a junction for a short while.

Like everyone else’s mines pretty hit and miss - my fiestas worked pretty much all the time unless I had full air con or heat on.

Got the focus around July so with lockdown I’ve hardly done many miles so it’s no real surprise - that said after about a 40 min drive yesterday it did start working today which was a bit of a surprise at first! 

Mine is the same. Had a recall job done last week mentioned that the start stop not working so the dealer put in on charge for the time they had it. Start stop worked fine for two days then back to normal. Not going to worry about it to be honest. 

I found this on ford.co.uk

"it ant 'arf fussy mum"

 

AUTO START-STOP: LIMITATIONS OF USE

On both manual and automatic transmissions, the engine may not stop under certain conditions, for example:

• Low engine operating temperature.
• To maintain the interior climate.
• The battery charge level is low.
• The outside temperature is too low or too high.
• Opening the driver door when in motion.
• The heated windshield is on.
• During regeneration of the diesel particulate filter.

On automatic transmissions only:

• When the driver seatbelt is unfastened.
• The steering angle is greater than 90 degrees.
• Transmission is in sport (S) or manual (M).

 

On both manual and automatic transmissions, the engine may restart under certain conditions, for example:

• To maintain the interior climate, for example air conditioning.
• The battery charge level is low.
• The heated windshield is turned on.
• Your vehicle starts to roll downhill in neutral.

On automatic transmissions only:

• When the driver seatbelt is unfastened.
• The driver door is opened when in drive.
• Transmission is shifted to sport (S) or manual (M)

 

Note: If the system detects a malfunction, it turns off. If it remains inactive after an ignition cycle, have your vehicle checked by an authorized dealer.

Note: The system may not function if you leave electrical loads connected with the ignition off as these will drain the battery.

Note: For vehicles with auto-start-stop, the battery requirement is different. Replace it with one of exactly the same specification as the original.

With all those limitations listed above its anyones guess why they bothered to fit it in the first place. 

Complete waste of time on the mk4. 

 

28 minutes ago, Wino said:

With all those limitations listed above its anyones guess why they bothered to fit it in the first place. 

Complete waste of time on the mk4. 

 

To blag emmisions regs on test cars...

 

Interesting to note the engine will start if the door is opened when in Drive on autos...that seems like a terrible idea!  People are going to run themselves over!

 

39 minutes ago, TomsFocus said:

To blag emmisions regs on test cars...

 

Interesting to note the engine will start if the door is opened when in Drive on autos...that seems like a terrible idea!  People are going to run themselves over!

 

Can you claim on your own insurance for driving over yourself ? 🤣

That fella from E17 (the 90s boy band)..he ran himself over. Fkn idiot

About SS , I only do short journeys. Works pretty much every time . Heated windscreen stops it but that’s about it . 

19 hours ago, kingfisher1967 said:

On automatic transmissions only:

• When the driver seatbelt is unfastened.
• The driver door is opened when in drive.

What cretin thought that starting the engine under either of these condtions would be a good idea. Morons!!! Surely anyone with a grain of common sense would want to prevent the engine from restarting in those situations - wouldn't they?

6 minutes ago, mjt said:

What cretin thought that starting the engine under either of these condtions would be a good idea. Morons!!! Surely anyone with a grain of common sense would want to prevent the engine from restarting in those situations - wouldn't they?

Probably the same cretin that opted to put the heated wing mirrors on the rear heated window button instead of the front screen or better still on its own. 

 

It’s just reminding you you’ve not turned the engine off. 

4 minutes ago, Wino said:

instead of the front screen or better still on its own. 

Most manufacturers use the rear screen. On its own seems like a good idea. Front screens a non starter. 

45 minutes ago, Alex.S said:

It’s just reminding you you’ve not turned the engine off. 

Why not another beep/bong though?  Ford seem to love those things...

I got in the Golf this afternoon and realised I'd left the lights on since yesterday's fog.  They're automatic so on the rare occasion I manually switch them on, always forget to switch them off!  There's no beep or bong for the lights as it switches all the lights off when you switch the ignition off.  Still annoys me though as I sometimes drive around for days with the lights on in broad daylight!

Never thought I'd miss all the bongs from the MK3 but here we are...

1 hour ago, mjt said:

What cretin thought that starting the engine under either of these condtions would be a good idea. Morons!!! Surely anyone with a grain of common sense would want to prevent the engine from restarting in those situations - wouldn't they?

If they didn't restart the car for these reasons and it restarted later for one of the many other reasons listed then it could be moving with no-one inside it. That might be a bit dangerous!

28 minutes ago, TomsFocus said:

Why not another beep/bong though?  Ford seem to love those things...

I’m pretty sure there is a beep/bong as well ! 
What I’ve realised about these mk4 focus (changing up from a 2010 astra ) all the tech I’ve had to learn to use, I’ve questioned most of it , there’s always method behind the madness. S/S may be unpopular on here but I like it with auto hold too. Both can be controlled with light breaking ...on the automatic anyway.