Two-week honeymoon with Auto Start-Stop

[[DELETED MEMBER 27901]]

I'm not inclined to install the ASS eliminator. ASS is annoying but not the end of the world on a daily commuter. I do hate when you are stopping behind a car and that car is juuuuuuuust getting ready to inch along again.

This exact scenario stalled my bronco in an intersection on Thursday. I always turn off ASS as soon as I get in the vehicle but forgot. Just feathering the brake must have been enough to trip up the system.

So I’m sitting there stalled in an intersection and my dash is flashing “SHIFT VEHICLE INTO PARK AND RESTART”.

I wasn’t inclined to buy an eliminator but now I view it as a necessary safety feature.

Sponsored

 

[Snakk Attakk]

This exact scenario stalled my bronco in an intersection on Thursday. I always turn off ASS as soon as I get in the vehicle but forgot. Just feathering the brake must have been enough to trip up the system.

So I’m sitting there stalled in an intersection and my dash is flashing “SHIFT VEHICLE INTO PARK AND RESTART”.

I wasn’t inclined to buy an eliminator but now I view it as a necessary safety feature.

What was the root cause of the stall though? I think ASS can certainly exacerbate the problem if your engine is stalling, that's the point of the defeat switch. But that's different from causing stalls anomalously.

 

[Snakk Attakk]

I hate it. It is just propaganda, that it does not impact starter and battery life. Maybe if you live in the Midwest where there is no traffic and traffic lights. But here in New jersey and New York that's all we have. My friend had a new GMC pickup and he has gone through a starter in less than 2 years. Thank god not over 3 years.

I guess I'm a bit more optimistic here. This isn't your granddad's starter that goes k-k-k-k-k-k-shhhhVRRROOOOOOOOM!!!! They've really optimized the engine startup and it is like any other engineering problem, they have to determine the MTTF and mitigate the risk of premature failures. But they are mechanical devices and there will be mechanical failures. But this technology has been around a while.

 

[Squatch]

Have you heard about our Ford and starter savior, Forscan?

Also, as a bona fide champion of the manual transmission, I hate that it makes it look like I stalled it at a light, haha.

I will say that I have seen the mpg benefits long-term in other vehicles but I don't think the Broncos benefit as much as a sedan or any non-motorized brick with aerodynamics.

 

[Dunning Kruger]

I just disengage the auto stop/start feature.

I find it incredibly annoying. Besides, it's my gas, and I can burn it when I want to....

 

[Dunning Kruger]

Interesting timing on this thread. My daughter's Bronco (a sport) died last week after 2.5 years. Came to a complete stop, with a number of system warnings. Turns out it was the battery. Kind of a short life for the battery.

I wonder if the auto stop/start stresses the battery unnecessarily? It's a fair amount of power to draw to keep the fan and electronics running at a stoplight...

Anyway, I've always disengaged the auto stop/start when driving her car, and I do the same for mine. It's just a button push.

 

[Snakk Attakk]

I had every intention of leaving SS alone. My beef is how quickly it shuts off. I mean I could hardly stop at a light for a right turn into traffic without it killing the engine.

$50 part and a 5 minute install and have not missed it one bit. Sort of jealous they remove that feature during the chip shortage for some of their vehicles.

I like the fact that the eliminator doesn't disable the functionality, it just persists the setting across system restarts. It really should work that way, I mean why persist the defogger setting but not this? It doesn't appear to violate EPA standards to persist the setting.

I have found similar threads for various makes and models, and every single one of them is a shitshow of speculation, redirection, and confusion . So, I have to believe this is a risk mitigation strategy. The risk is in the driver exiting the vehicle in park with ASS engaged and leaving the car on, and having it restart automatically. It would require a failure of the hardware/software to detect that the brake was released at that moment. This is low but non-zero. So, there is an additional hardware/software failsafe to restart the engine in park.

Really the risk of running the engine in a closed garage is higher with the AutoPass remote start. That risk is mitigated by limiting the runtime to 15 minutes. So why wouldn't that same mitigation work in this case? Limit the runtime to 15 minutes in park at all times. Or, never restart automatically in park. If you want the engine back on, go to drive or reverse. There are better options here.

 

[Snakk Attakk]

Interesting timing on this thread. My daughter's Bronco (a sport) died last week after 2.5 years. Came to a complete stop, with a number of system warnings. Turns out it was the battery. Kind of a short life for the battery.

I wonder if the auto stop/start stresses the battery unnecessarily? It's a fair amount of power to draw to keep the fan and electronics running at a stoplight...

Anyway, I've always disengaged the auto stop/start when driving her car, and I do the same for mine. It's just a button push.

I think batteries are still 3-5 years regardless of whether you have ASS or not.

 

[RBF 1401]

What was the root cause of the stall though? I think ASS can certainly exacerbate the problem if your engine is stalling, that's the point of the defeat switch. But that's different from causing stalls anomalously.

Have you heard about our Ford and starter savior, Forscan?

Also, as a bona fide champion of the manual transmission, I hate that it makes it look like I stalled it at a light, haha.

I will say that I have seen the mpg benefits long-term in other vehicles but I don't think the Broncos benefit as much as a sedan or any non-motorized brick with aerodynamics.

And here I was just thinking that this was one of the ways the manual tranny is far superior...

The ASS in the manual seems to me a much simpler system than the automatic. It only stops the engine if your foot is off the clutch and you have shifted into neutral. And it starts back up when you press in the clutch. If the truck is "on" and the engine is "off" you only need to press the clutch to restart.


•Don't want to have the engine shut off when you do a California stop at a stop sign? Don't let off the clutch.

•Stall the engine on an off-road obstacle? Just press in the clutch and it restarts.

•Stall the engine in the middle of an intersection because you got distracted while shifting gears by the homeless guy running into traffic? Just press the clutch and it restarts.


But unlike a previous comment, I do think it is calculating a lot of different things when it decides to start back up on its own. I have a 22-mile daily commute and have had plenty of time to notice that the ASS behavior is definitely not random.

•I know everyone on the forum knows that it doesn't shut the engine off if you have the A/C to MAX, but it also NEVER shuts off when the outside air is over 90°.

•It will also start back up much quicker if it is under 90° but your cabin temperature is quickly rising, regardless of what you have the A/C set to.

•It turns back on quicker when you first start your trip than it does 30 minutes into your trip after the battery has had time to get more juice.

•It can stay off for a long time if the conditions are right.

I can't say what the behavior will be when it's cold outside since it is still getting into the 90s and 100s everyday, but I would guess that ASS will not let your engine get too cold and may turn back on when your engine temp reaches a certain low point, just like how it doesn't let me cook my passengers.

 

[Snakk Attakk]

I was a bit perplexed as I said by how briefly the ASS remained switched off with the AC on, but I accept that it is by design. It has been over 90 on the commute home, and it doesn't switch off then.

I can live with all that, I just can't abide this parking thing. Maybe I can get in the habit of defeating it prior to parking.

I wonder how many people defeated ASS due to this one obnoxious behavior? The law of unintended consequences could be at work here.

 

[Ducati1098]

I was a bit perplexed as I said by how briefly the ASS remained switched off with the AC on, but I accept that it is by design. It has been over 90 on the commute home, and it doesn't switch off then.

I can live with all that, I just can't abide this parking thing. Maybe I can get in the habit of defeating it prior to parking.

I wonder how many people defeated ASS due to this one obnoxious behavior? The law of unintended consequences could be at work here.

You could always turn the ignition off before shifting to park if this really bothers you. That way it wouldn’t restart Same thing just reverse operation. Just obviously don’t forget to shift to park as that could be dangerous.

 

[MNBigfoot]

Interesting timing on this thread. My daughter's Bronco (a sport) died last week after 2.5 years. Came to a complete stop, with a number of system warnings. Turns out it was the battery. Kind of a short life for the battery.

I wonder if the auto stop/start stresses the battery unnecessarily? It's a fair amount of power to draw to keep the fan and electronics running at a stoplight...

Anyway, I've always disengaged the auto stop/start when driving her car, and I do the same for mine. It's just a button push.

Yes, it stresses the battery unnecessarily, that's why Ford put an AGM battery in it.

 

[mpeugeot]

I've perused the manual and the documented conditions for ASS to restart the engine don't include shifting into park. And, I haven't heard a plausible use case of why you would want that. But the threads go back over a year, and it functions the same way to this day. Why??

I'm not inclined to install the ASS eliminator. ASS is annoying but not the end of the world on a daily commuter. I do hate when you are stopping behind a car and that car is juuuuuuuust getting ready to inch along again.

Back in the day I had a 6-speed manual transmission with the 2nd gear skip-shift feature. That HAD to go, holy crap. But this is not that.

Do yourself a favor, get the Ford Performance Tune which is warrantied by Ford and includes auto start/stop setting permanence. If you turn it off, it stays off... Turn it on and it stays on.

 

[Snakk Attakk]

Do yourself a favor, get the Ford Performance Tune which is warrantied by Ford and includes auto start/stop setting permanence. If you turn it off, it stays off... Turn it on and it stays on.

Interesting, thanks. The premium fuel requirement gives me pause, but it is something to consider.

 

[mpeugeot]

Interesting, thanks. The premium fuel requirement gives me pause, but it is something to consider.

It will run on 87, but you won't get the extra power. Mind you, it's not "recommended", but it's an option.

Another option is 12 gallons of 87 with 4-5 gallons of E-85, which won't get great mileage, but is cheap (91.5-92.3 octane). 4 gallons of E-85 and 12 gallons of 93 makes a ton of power.

I have done all the above and have 80k miles on my 2021 Bronco.

Sponsored