I just bought and brought home a 2020 and noticed on my drive home that when I start the truck the Auto Start/Stop is disabled, the indicator light in the center cluster shows it being off. I can push the button and enable it. I pulled the center console apart thinking it may have had a start stop eliminator but it does not. Its like the button is functioning backwards of what it should but without the eliminator.

I had a start stop eliminator on my 2019 and do not recall ever seeing the autostart disabled indicator light illuminated. Was planning to install the eliminator in this truck but not sure I need to at this point.

If the function is disabled with forscan does it reverse the function of the button or just basically render the button useless?

I have read about disabling the autostart by disconnecting a wire under the dash or disconnecting the BMS. Do either of these change the function of the button?

Could it be a battery issue?

 

It will self disable if the battery is low.
Once battery is charged it will work normally again.

 

The Auto Stop Eliminator will have the disabled button illuminated if in the off state. FORscan will also have the button illuminated unless you also disable the button light, it's a separate step. To verify the Auto Stop eliminator just disable it and turn the truck off, and see if it's still disabled when you start back up, do the same with it enabled. It will stay in whatever state you leave it in.

 

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My AS/S eliminator is plugged into obdii port.

 

i know for certain that there is no auto start eliminator, I pulled the center trim and could see the factory wiring harness was plugged into the button.

Having read through a bunch of threads and considering the vehicle history, I think more than likely the issue is battery/charge related. It is a 2020 with 27,000 miles on it, came from Illinois. I am guessing by the low miles it was never driven much and could be that it has not received a full charge for a while, plus it sat at the dealer for about a month from the time it was traded in until it was delivered to me. It has a Motorcraft battery so I will look for the date code and see if it is the original battery. If it had a history of low charges it might be best to just replace it but will have it checked first.

I intend to hook up a battery charger when I get home tomorrow and let it charge all night and then check it out Friday, might get lucky and be corrected with a charge. My drive to work is around 30-35 minutes so if the battery holds a charge I will be good to go. My previous 2019 never had an issue, had 124,000 miles on the original battery.

 

If you have a model with the instrument panel settings menu, there is an Auto Start/Stop display that will tell you exactly why it's not working. If it says "off due to vehicle charging" it's your battery, which may just need a charge. It's common for vehicles that are mostly driven short distances to have the battery slightly below the voltage necessary for battery management to allow A.S.S. to work. That doesn't mean the battery is bad.

 

*** will also not function for a little bit after fueling up.....peep the second note in the owner's manual.

 

I will check that out when I get home. Not yet familiar enough with this truck to know all of the features, definitely has more than my 2019.

My concern with the battery is if this truck has a history of short trips and marginal on battery charge, will the battery take a full charge and then continue to do so.

If I recall from looking, the truck was delivered towards the end of 2020 so the battery has been in use for 4 years and if in the end I need to replace the battery its not like that is unreasonable. In comparing to my 2019 which I took delivery in May of 2019 and had the original battery until about a month ago, when it was totaled, it was in use for about 5-1/2 years and 124,000 miles. Both trucks have the same engine and similarly equipped XLT's but the usage, mostly trip length (based upon total mileage and model tear) being considerably different.

 

Keep in mind that the *** system on these trucks has a ton of parameters that must be met before the system will activate. A lot more than most vehicles. If it sat for any length of time on the dealer lot, it’s going to take a bit for the system to reactivate on its own. My truck sat on the dealer lot for 3 months, I purchased and drove it for about another 4 months, then finally after a 10 hour roadtrip the system began to activate.

Also keep in mind that these trucks are very battery dependent and when it starts to go, it will throw up all kinds of weird errors in the truck that don’t seem to be battery related but they usually are. Sends people down rabbit holes if they aren’t aware of that.

Finally, it never hurts to preemptively replace the battery for peace of mind. Especially if there are other signs that it’s starting to go…in my case I noticed the truck taking an extra second of crank time, and I also noticed my voltage in the 11.5 range (engine off) when I was in Forscan the other day. I’m going to go ahead and swap it out.