25 minutes ago, Rob2016 said:

Still no stop / start. Car going back to the garage

Sounds like you need to go to Bob's garage, pity it is a very long way! (Just seen Bobs reply, I think he would agree!)

The basic problem seems to be a massive lack of understanding at the dealers of how these systems work, and how to properly test them. And if it is not just the odd duff garage, then the fault must lie with Ford. The modern corporate principles of information only on a "need to know (1)" basis, and treating staff and customers like mushrooms (2), are badly wrong!

1) Need to Know system: Those who need to know, don't, & those who don't need to know, do.

2) Growing Mushrooms: Keep them in the dark, dump manure on them at  frequent intervals.

If anyone has a spare Ford BMS unit (the sensor on the -ve battery terminal), preferably working ?!, I would be interested to do some tests on it. Vishay make something sounding very similar: http://www.vishay.com/search?query=wbp&searchChoice=part

Different package, but similar spec.

28 minutes ago, Bobr said:

Get them to check the battery sensor.

Cheers, I'll ask them on Tuesday if they tested that as they did state that they tested all sensors and that the there was no issue with the battery.

Just discovered that the S/S system does, in fact, work when the air conditioning is on.   Boiling here today and went out with the air con on.   First set of lights I stopped at the S/S didn't work.   20 seconds later, still at the same set of lights, and the engine cut out.   I must admit to being rather surprised.   It continued to work throughout the journey with the air con on.

it works with a/c on if at temperature if the temperature starts to rise it will restart the engine. to recool the interior.

Had my car back for a day and stop start is now working perfectly. 

The garage say that the battery although fine was sitting at 25% and wouldn't charge beyond that. They charged the battery fully overnight and all seems to be ok now.

3 hours ago, Rob2016 said:

The garage say that the battery although fine was sitting at 25% and wouldn't charge beyond that.

June 17 to July 29, and they do not seem to have really isolated the problem yet

It is possible that as the battery charges goes back to the 25%, from its overnight charge, the system will stop working again. 

A calibration error (a partial fault) in the BMS (Battery Sensor) might cause the failure to keep the battery up to the needed 80%. I guess they did not change it, and had no means to fully test it?

Anyway, see how it goes, hopefully it will work now, otherwise regular overnight charges may be needed until the fault is properly fixed. Seems to have been the BMS in Bob's car.

21 hours ago, Tdci-Peter said:

Anyway, see how it goes, hopefully it will work now, otherwise regular overnight charges may be needed until the fault is properly fixed. Seems to have been the BMS in Bob's car.

No doubt about it Peter.   Since the BMS was changed in my car I've had no further problems.

At what voltage does stop start stop working. After a week of short journeys in heavy traffic. my battery voltage is sitting at 12.2 volts 30 minutes after engine switch off. Stop start is now refusing to work because of i assume low voltage.

4 hours ago, cjay1 said:

12.2 volts 30 minutes after engine switch off. Stop start is now refusing to work because of i assume low voltage.

Unfortunately, it may not that simple. The Stop-Start system seems to try to maintain the battery at about 80% charge, as I understand it. Battery voltage depends (rather weakly) on charge level (state of charge), but also on temperature, type & age of battery, and past history (how long since last charge or discharge, and if any low level loads are connected.

When cars kept the battery at 100% charge, it was simpler. There is a distinct increase in terminal voltage at this point, so in many cases, a simple fixed charge voltage of about 14.5 volts would do the job.

I think your 12.2v figure is within normal limits for 80% charge, but does not mean that is is at 80%, my guess is it could be anything from under 50% to over 90%.

The Ford system actively charges and discharges the battery, while monitoring current, temperature and voltage (via the BMS). Then complex algorithms are used to convert this to a "state of charge". A bit like the battery tester meters you can buy, that perform discharge pulses to estimate charge state.

It means that the calibration and correct operation of the BMS is vital to both enable stop-start (when the system thinks the charge state is ok), and to maintain the battery (when the charge state actually is ok). The state, type & age of the battery also matters. Minor faults (one cell dropping off a tine bit, perhaps) that would have no effect previously, now will prevent start-stop. They could also result in the battery being under charged by the system.

I think you are doing the right thing to monitor your battery voltage. If the unloaded (without internal lights, alarm & lock/unlock loads) terminal voltage drops more, to say, 12v, then that would show either a poor battery, or the system not charging it properly.

Battery voltage can be displayed on the dash of some cars. Check this is the same as the actual terminal voltage. Also is there a way to make it show "State of Charge", or SOC? This is a critical parameter for start stop to work.

 

 

put the car on charge this afternoon took around 4 hours with a 4 amp charger voltage is now 12.71 after the surface charge dissipated now stop start is once again working. will see how it goes. not sure if it is a fault or the fact i've only done multiple short trips in heavy traffic 1-3 miles each with no long runs. dont think i can get soc reading on the dash. does anybody no if torque pro app can display this info with the odb data?

On 29 July 2016 at 1:38 PM, Tdci-Peter said:

June 17 to July 29, and they do not seem to have really isolated the problem yet

It is possible that as the battery charges goes back to the 25%, from its overnight charge, the system will stop working again. 

A calibration error (a partial fault) in the BMS (Battery Sensor) might cause the failure to keep the battery up to the needed 80%. I guess they did not change it, and had no means to fully test it?

Anyway, see how it goes, hopefully it will work now, otherwise regular overnight charges may be needed until the fault is properly fixed. Seems to have been the BMS in Bob's car.

They have said to get back in touch should the problem occur again, so far all is working though.

On 7/14/2016 at 2:34 PM, Tdci-Peter said:

Assuming the design department won, it makes sense to use the system while it works, but if it starts playing up just because the battery is approaching what would normally be 50% of its lifespan, then ignore it or turn it off. That 1mpg is no way worth chucking out a very expensive battery when 50% life remains.

 

Stop start only needs to work long enough for a car to go through the government's fuel CO2/consumption test. If it means the owner pays less tax than otherwise, its job is done. After that, it seems pointless worrying about it. Surely it uses more fuel to travel back and forth to the dealer to try and fix it than it will ever save?

I thought it would be good to provide an update:

Since the car went to the garage to have its battery tested and fully charged the stop / start has worked perfectly ever since without fail. 

You are not the only one that has issues with Ford. My Edge stop start works when it feels like along with the heated front screen. Its not a battery charge issue as I have installed a battery charge indicator and and external charging point for a specialist battery charger/ conditioner. Battery at 97% heated screen does not defrost and stop start does not work even when car is at working tempeture when stuck in traffic ( heated seats off heated steering wheel off driving lights only on). So these facilities are as useful as a chocolate tea pot. Ford has tried to blame it on my accident camera. This has been checked by a professional electrical engineer ( diffrent one to who installed it) and nothing found wrong with the instillation. Have also tried unplugging it no difference. Something is wrong at Ford as they are looking to blame the customer rather than look at what’s is the true issue we can’t all be wrong

If the battery is fully charged and in good condition try a battery monitor reset 

Acc on 10 seconds 

Press fog lights switch 5 times

Press hazard switch 3 times.

Battery light flashes 

Job done, switch off. stop start should start working again.

18 hours ago, cjay1 said:

If the battery is fully charged and in good condition try a battery monitor reset 

Acc on 10 seconds 

Press fog lights switch 5 times

Press hazard switch 3 times.

Battery light flashes 

Job done, switch off. stop start should start working again.

Doesn't seem to work on my car.

3 hours ago, Bobr said:

Doesn't seem to work on my car.

Doesn't work for me either. 

video of the process

 

The video is from a later model than mine. I found this old post from Iantt and found that it did work. its essentially the same procedure but explained a bit better (no offence).

 

"Ron, if you want to have a go at reseting battery monitoring, just do as follows

Ign on for 10 secs, press rear foglight switch 5 times, press hazzard switch 3 times, wait 10 secs. Battery light flashes. Ign off

use car, and see if that fixes"

 

 

 

11 hours ago, Vendee said:

The video is from a later model than mine. I found this old post from Iantt and found that it did work. its essentially the same procedure but explained a bit better (no offence).

 

"Ron, if you want to have a go at reseting battery monitoring, just do as follows

Ign on for 10 secs, press rear foglight switch 5 times, press hazzard switch 3 times, wait 10 secs. Battery light flashes. Ign off

use car, and see if that fixes"

 

 

 

I'll try that this morning.

Tried it and it worked.   The stop / start system, which hadn't worked for several months, now works every time.   Exactly what I did is as follows:  Ignition on for 10 secs, lights off, pressed rear fog light switch 5 times, press hazard switch 3 times, waited 10 seconds and the battery light flashed several times.   It didn't work with the light on.

None of the previous posts have mentioned putting the lights on.lol 

2 hours ago, iantt said:

None of the previous posts have mentioned putting the lights on.lol 

I saw these instructions on YouTube and it said to switch the lights on first.   I tried it and it simply doesn't work with the lights on.   Have driven just over 40 miles today and stop / start has never failed.

 

The BMS reset works on mine and the stop/start system is fine for a couple of days, then it stops working again and I have to do the BMS reset again. I'm not really bothered but it would be interesting to know what module is causing the BMS to fail all the time. 

18 minutes ago, Vendee said:

The BMS reset works on mine and the stop/start system is fine for a couple of days, then it stops working again and I have to do the BMS reset again. I'm not really bothered but it would be interesting to know what module is causing the BMS to fail all the time. 

Mines exactly the same.   Only takes a few seconds to do the reset but it is a nuisance.