[KansasMatthew]

I'm having a similar issue in my '23 2.0 non-hybrid.

Dome light switch is in the middle position. It's a 3-position rocker switch - Left - ON, Right - OFF, Middle - auto.

Tonight was the first time I got into the car in a very dark parking space. As long as I've had this car, it's either been light outside, my lit garage, or a well-lit parking lot. So I noticed this for the first time tonight.

1) car is off, I'm not in it. Walk up to it, open the door, and the dome lights do not come on. I can manually turn them on and off. If I open and close the door, the lights stay off.

2) start the car, or put it into on/acc mode. Shut it off and the lights will come on. They stay on until I open the door, exit, close the door. Or, if I stay in the car, they stay on for a set time and then turn off. (I think this is what happens, I didn't pay very close attention. I was really trying to figure out why they didn't come on when I open the door.)

As long as the vehicle is off, and the dome lights are off, they don't come on automatically.

I honestly don't know if this has worked properly in the past and has just started acting this way, or if this has always been.

It's also been double digits below zero (F), so I'm going to give it the benefit of the doubt and hope that this is just a temporary cold weather behavior.

 

[KansasMatthew]

You might be in battery saver mode. If you have a voltmeter or multimeter, check the 12v battery voltage at the posts under the hood. If you're somewhere near 11.7 that would explain it. Or, anyway... that is how it was for my PHEV.

Another test is to have the radio playing, and turn off the car. See how long it stays playing. If you pretty quickly get a gray screen saying something like "Shutting system down to save battery" that's battery saver mode for sure.

Another symptom we had of battery save mode was fob didn't unlock the passenger side door.

Plugger

I don’t get any indication of battery saver mode. The interior lights and radio stay on until I open the door or there’s a timeout value that’s exceeded.

I’ll connect a voltmeter but the last time I did that, last month, it was 12.6V. Min voltage during start was 10.8V and then rose to 14.9V when it began charging.

 

[KansasMatthew]

Ok. Keep us posted about what you learn.

I’ll check voltage again in a little while. I put the car in the garage where it’s a little warmer, it was 6F outside where the car had been soaking for several hours.

 

[KansasMatthew]

I checked just now. The battery is sitting at 11.8V with no lights on. I think some parts of the displays may have been activate because I had to open the door to unlatch the hood.

11.8 seems way too low.

 

[KansasMatthew]

I checked my Ford app and saw this message from earlier today.

That was from this morning. I did drive for about 40 minutes this afternoon, but it was like 15+20+5.

I didn’t drive it yesterday.

Should be much warmer tomorrow and I know I’ll be driving it.

 

[KansasMatthew]

I’ll leave the hood open and my fob inside the house, then let the vehicle sit for a while to get into a “rest” condition before I check the battery again.

I re-read the manual again, the section on the battery management system. It needs 8 hrs of uninterrupted off time to calibrate, but it specifically says the doors need to be locked. I keep it garaged overnight but unlocked.

The battery is in the engine compartment in a conventional gas version. I haven’t verified yet, but the manual says the part number is BAGM-48H6-760, a 760 amp battery.

 

[KansasMatthew]

45 deg in the garage. Opened the hood and let the car sit for about 10-15 minutes so anything triggered when I opened and closed the doors would reset. I left the fob in the house and saw 12.1V.

That still seems low, I think it should be closer to 12.6V. I have enough of a warranty punch list now that it’s probably time to call the dealer and let them take a look.

 

[KansasMatthew]

Just drove over to the dealer to have them test the battery. They said it’s good, and that a lot of people have been coming in for the same thing. I’m going to let them have it for a day next week and dig into a few other items. And I will have them retest the battery and the battery saver mode.

As of now: battery is 12.4v. Battery saver mode is still on. I’m going to get some highway driving tonight, not much, but some. If it doesn’t clear up on its own then I’ll let it sit, locked, overnight and check again in the morning. If that doesn’t do it then I’ll reset the battery monitoring system manually. And if that doesn’t work then the dealer will be seeing it next week anyway.

Also - now my Ford Pass app won’t connect and the exterior door lock/unlock function is disabled. I think this is battery saver related.

 

[KansasMatthew]

Hey Kansas Matthew.... did you ever get this resolved? I'm struggling with this battery saver crap now. (2023 ST line hybrid) Even replaced the battery with a group 48 AGM.... still happens, it just took longer to start showing up. I know the battery is good, I had it tested at three different parts stores. I did some testing, found out that for the first 15 minutes after shutting down, the car draws 6 amps from the battery, then drops down to 3.5 amps for another 20 minutes. It eventually drops down to 100mA.

I reset the battery monitor once or twice - There's a procedure in the manual. I can't remember the exact sequence of how many times to press the brake pedal after pressing "start: without your foot on the brake.

Another way to recalibrate the battery monitor is to leave the vehicle locked for >8 hrs (also noted in the manual somewhere). That is something I hadn't been doing, I normally leave it unlocked when it's parked in the garage.

None of those things seemed to have any effect.

Eventually, I simply drove an hour or so and the weather warmed up. I opened the door and noticed the dome lights were working again. Everything seems normal.