Start Stop is not working

[Chrome_Pony]

I remember reading about an update pushed out that changed Auto Start Stop parameters.
Mine used to cut the engine frequently, during a wide range of 20F to 75F temps, and it has only cut it maybe 8 times since that update, which was some months ago.

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[Swallace]

I remember reading about an update pushed out that changed Auto Start Stop parameters.
Mine used to cut the engine frequently, during a wide range of 20F to 75F temps, and it has only cut it maybe 8 times since that update, which was some months ago.

Do you recall the version number for the update ?

 

[Big Boss]

Several things listed in the owners manual will prevent it from working normally. The most likely cause is a low battery

This was my initial guess as well. All of my preivous Ford's started acting quirky with electronics when the battery was on it's way out.

Based on what GJPTennis mentioned it appears to be because the doors are off.
Does anybody else have the doors removed and experiencing the same issue with the Auto Stop not working?

This happened to me last year. Had the doors off for about 2.5 weeks. little more than 10 days or so with them off the auto start stop just didn't engage. Doors back on and it started working again

 

[BroncosBikesBeersandBuds]

Hello All,
My apologies if this was already covered. I have 2022 Outer banks non SAS 2.7 with high package.
MY start stop has not been working for 2 days. I did not press the button to deactivate it. I am not using the Head or AC.
While I like that it is not working any more, I am concerned that this may affect something else in the Bronco.
Has this happened to anybody else??

Is your front defrost on? Having the front defrost on, and only the front defrost on with no a/c, will disable the auto-start-stop.

 

[Swallace]

Front defrost is not on. I shut off the heat/air. checked and it shows Start/stop is on, but the area is greyed out with a slash through it. The Voltage at rest was 13.2V

 

[Swallace]

I checked the battery and while running it was showing 14.2V and 12.7V when at rest.
I put the trickle charger on last night and this morning it was 13.2v and while driving it switched between 14.7 and 13.5 V while driving. The start stop was still greyed out and did not shut off. when I checked the status, it said it was on? I will trickle charge it again tonight, if it continues I will take it to the dealer to see if one or more of the battery cells are dead.

 

[Brian_B]

I checked the battery and while running it was showing 14.2V and 12.7V when at rest.
I put the trickle charger on last night and this morning it was 13.2v and while driving it switched between 14.7 and 13.5 V while driving. The start stop was still greyed out and did not shut off. when I checked the status, it said it was on? I will trickle charge it again tonight, if it continues I will take it to the dealer to see if one or more of the battery cells are dead.

The big thing is the BMS system. It looks at voltage, but it also counts the amps in and out of the battery, and temperature, and maybe a couple of other things and determines a battery "age" and "state of charge" depending on that.

It also controls the alternator to run the voltage at different levels while you are driving. "Normal" voltage is anywhere from about 12.7V all the way up to about 15.3V or so, and it depends on driving conditions, temperature, the battery "age" and "state of charge", and some other stuff.

So it's really hard to just go by voltage alone on these things - your voltages sound completely normal, but especially while the Bronco is running, the BMS can mask a lot with the alternator output and isn't very transparent about what it's doing.

Usually the first sign that the BMS thinks your battery is too old is that ASS stops working. Sometimes trickle charging it will fix it, sometimes the battery is just getting to old after all (or something else has ASS worked up). The next sign after that is that it starts putting your Bronco into "Deep Sleep". Once you have seen deep sleep a handful of times, it's probably time to get a new battery before that one leaves you stranded.

 

[Swallace]

Thank you for the update Brian. It is a 2022. I will try trickle charging it again tonight. If start stop continues not working, I will swing by the dealership for a battery test while it is still under warranty...

 

[Tricky Mike]

You can always just change the right side of the gauge cluster and go to Trip/Fuel -> Auto Start Stop, and it will show you if it is on, or why it's disabled. Ambient Air temp, charging, or heating/cooling requirements is what I have seen on mine.

I didn't know that, I'll have to check it out.

Over the last couple years I would estimate it's only worked on 10-20% of stops. I'm in no rush to disable it because it does a great job of disabling itself.

 

[Wathoff24]

Hello All,
My apologies if this was already covered. I have 2022 Outer banks non SAS 2.7 with high package.
MY start stop has not been working for 2 days. I did not press the button to deactivate it. I am not using the Head or AC.
While I like that it is not working any more, I am concerned that this may affect something else in the Bronco.
Has this happened to anybody else??

Out of curiosity, does the light on the start/stop button illuminate (even though you did not press it) or is it off, but the vehicle remains running at a stop?

 

[Swallace]

No. It is not on. It is off and the vehicle stays running at stop.

 

[Chrome_Pony]

Do you recall the version number for the update ?

I don't, offhand. Remember thinking about it in this thread.

https://www.bronco6g.com/forum/threads/auto-start-stop-only-functions-intermittently.90346/

Remember saving this to figure out why mine was misbehaving.

 

[XirallicBolts]

Also: when you're trickle charging, you can't put the charger directly on the negative post. You have to go to body metal.

There's a current sensor on the negative battery terminal that's used to judge the state-of-charge. Going directly to the post bypasses that, so the BMS doesn't realize the battery has been charged back up.

Either fully charge it and perform a BMS reset in Forscan, or let it sit for a full 12 hours without locking/unlocking/charging/starting/opening doors so it can relearn.

 

[Swallace]

I read a post from another member listed below.
Start/Stop will not work with the doors off.
Makes sense since it stopped working after I removed my doors.
The system does not stop if:
The driver door is open
The vehicle is at high altitude
The heated windshield is on
The engine is warming up
The outside temperature is too high or too low
The battery charge is low
Etc!!!

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