Last few months I have noticed that the Auto start/stop feature has not been functioning even after drives of several hundred miles. Several times the truck has given me the battery saver mode message and twice has gone into deep sleep. The latest one being this morning. Volt meter on battery showed 12.2v. The first time,I did put on a battery tender and reset the BMS after a full charge. This worked for a short time. My warranty expires in 250 miles, so I took it to the dealer two days ago. They tested the battery and said it was good. But they were showing a small parasitic draw somewhere. They want me to bring it back after the holidays. The only thing that has been done to the truck lately was a new APIM in December. All threads I found on parasitic draw had to do with area lighting, I don't have that. Another thread suggested to check that all fuses are fully seated. I did that. Any Ideas?
I did have to plead my case with the dealer. They first wanted me to leave the truck with them for two weeks before they could even look at it. They said it would be a problem if I went over the 36K miles. I argued that they are aware of the issue now, it should not matter if I drive another 250 miles, the problem is there and registered with Ford. They finally agreed to have me bring it back next Wednesday to be looked at.

 

Then they'll find nothing and send you on your way then you'll return with more than 36,000 miles and they'll be like, "Nope, nope, nope...."

 

I would not bet money against that.

 

If you don't drive it often enough, it needs to simply stay on the Battery Tender.

 

My 2023 had a "start/stop" removal/deletion. Glad I don't have to worry with that feature.

 

a battery that tested good, should not go into sleep mode a day and a half later

 

I've been on this forum for 10 years. People argue this all the time. If you charged it full, and it 1.5 days it is low (forget sleep mode), then I agree. But, if you just tested it and it said "good", and then 1.5 days later it went into sleep mode (and still tested good), no so much.

My 2013 did this starting in 2nd winter. Service Manager said drive it or put it on a tender (drive meaning 30 minutes or longer). Battery lasted 8 years on a tender, never saw message again.

Or complain about it. It's your time.

 

How about drove 400+ mile over the weekend then sleep mode Friday?

 

That would exactly qualify for the issue. 5 days later, yes. Did you test the battery? Sleep mode is not the same as the battery is unacceptably low. It is PROTECTING the battery.

 

It showed 12.2 on my multi meter. Excuse my ignorance, but I thought sleep mode meant unacceptable low.