I have a 2019 and the auto start / stop function decided this week to stop working in Normal driving mode. It still works in Economy mode. Living in Florida I do not have the heat on and it has worked fine with the A/C on. The strange thing is that it works as it always has when I am in Economy mode.

 

I have a 2020 with the 5.0. If I have an economy mode, I am not aware of how to use it. On my truck, I use it for mainly very short trips and noticed the auto shut off stopped working. I hooked up a 10 amp battery charger, and the battery was so weak, it took several hours to bring it to full charge. Afterwards the auto shut off worked as normal. I now charge it every few weeks. On my 10 amp charger, the amp gauge reads 5 amps when the battery is fully charged, so when I start running the charger, I can see how weak the battery is.

 

Select auto stop start in your instrument cluster and it should tell you why it is disabled

 

I'd be all to happy if mine quit working! I have to remember to hit the button. Sometimes I forget.

Off, should have been the default.
Realize though, it stays off until the truck has fully warmed up. If you're making short trips from a cold start, you may not see it activate at a stop.

 

Isn't this like #6 this month?

Another Covid induced low battery charge limited driving truck?

 

it says "engine on until next vehicle stop".

 

nope I drive it every day. It works in Eco mode so not the battery. It no longer works in Normal mode.

 

I don't know how it is programmed to work since I don't have it. It could still be low battery charge. Normal mode probably allows the heat and or a/c to run when stopped, while economy mode turns that off, thus requiring less battery "state of charge" to work in eco. Charge your battery and I bet A-S-S begins working again in normal mode.

 

When and if you charger your battery, make sure you include the battery monitor. Make the first connection to the positive terminal of the battery then the second connect (not directly to the negative terminal) but to the engine block. That way should include the battery monitor, it needs to monitor all of the charging that goes into the battery + any current that discharged from the battery.

 

Lucky you, I wish Ford offered a delete option for it. So useless and risky, one of the worst ideas the auto industry ever came up with.