Pro Power reserve limit fails

[TaxmanHog]

But, still, the 12v battery could be the problem. Research is continuing! Thanks for your thoughts.

The DC/DC converter should be maintaining the LVB {12v} normally in full run mode.

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[chl]

The DC/DC converter should be maintaining the LVB {12v} normally in full run mode.

Yes, it should, but...when the current draw is high-ish, it still needs the battery...which is basically why short-trip driving and parasitic drains kill batteries over time even in ICE vehicles - they never really get topped off.

My last experiment seems to suggest that the power down timer kicked in with the truck ON after I switched from PPOB with truck OFF to truck powered ON - the PPOB quit after 30 minutes.

Whenever I have the 240V 30A outlet in use, the power down timer always defaults to OFF without my intervention which I always confirm by looking at the truck menu screen.

I can turn the power down timer back ON from there if I want to, but that would be dumb since when using the PPOB I set a reserve limit already which defaults to 10 miles so I don't want the power down timer to kick in and override the reserve.

So my guess is that the OTA update in question 'glitched' the power down timer control.

IMHO the reserve setting should override any power down timer anyway, not the other way around.

 

[chl]

While running another test of the PPOB with the truck OFF, I accidentally touched the climate button on the FORD app screen and the whole thing shut down...PPOB shut off that is.

Went to the truck, turned it ON and restarted PPOB. No error message or ground fault.

I was not running a large load on the PPOB well under 1000W.

I am able to turn the truck ON after running PPOB with the truck OFF without any problem/shutdown.

I suppose this is another bug.

 

[K6CCC]

While running another test of the PPOB with the truck OFF, I accidentally touched the climate button on the FORD app screen and the whole thing shut down...PPOB shut off that is.

I will have to test that this afternoon. I have PPOB on with about a 50 watt load for about 16 hours. I do have the truck on L2 charge at this time. Note that I have observed one change sometime or another. A 50 watt load on PPOB is resulting in PPOB with the truck off NOT timing out. I thought in the past it took a higher continuous load to keep PPOB running.

 

[chl]

I will have to test that this afternoon. I have PPOB on with about a 50 watt load for about 16 hours. I do have the truck on L2 charge at this time. Note that I have observed one change sometime or another. A 50 watt load on PPOB is resulting in PPOB with the truck off NOT timing out. I thought in the past it took a higher continuous load to keep PPOB running.

The shut down when I accidentally touched climate with the PPOB ON and the truck OFF turned the heated seat ON full blast (all bars).
I never use it that high.
I am guessing the heated seat uses the HVB.
The HVB also powers the inverters that run PPOB.
So I guess there would be an uptick in the HVB usage.

Why that would cause the PPOB to shut off before the reserve was met is a mystery.

 

[TaxmanHog]

I am guessing the heated seat uses the HVB.

It's powered by the 12v LVB system.

 

[K6CCC]

Confirmed, PPOB on with a 50 watt load for the past 16 hours or so with truck plugged into L2 charging.

Turned on Climate and PPOB turned off.

I wish I could turn PPOB back on from the phone...

 

[chl]

It's powered by the 12v LVB system.

Thanks for the info - I had seen conflicting info about which was powering it.

That it is the 12v system lends credence to the idea that these PPOB premature shut downs are a result of the 12v system having a low SOC and off loading the PPOB.

The weird thing is it happens when the truck is ON.

I just ran another test today - started with the truck OFF and the PPOB ON.
After about 6 hours, I turned the truck ON.
About/exactly 1/2 hour later the PPOB shut OFF abruptly at 187 miles range before the 120 mile reserve was met.
No warning message about approaching the reserve this time either.

I will do a bug report on these last two premature shut downs now that Ford is monitoring the truck and hope that they can solve it.

Running the PPOB with the truck OFF might be draining the 12v battery so that when the truck is turned back ON the 30 minute power down time gets activated.

I did look to see if the power down timer was still OFF when I first turned the truck back ON after the 6 hours with the truck OFF, and the power down timer was OFF according to the truck menu screen anyway. PPOB ran another 30 minutes and then shut down.

The fact that both times it happened to me it was 30 minutes after the truck was turned back ON makes me suspect the power down timer and the 12v battery system.

Other people have had premature shut downs WITHOUT using the Truck OFF and PPOB ON, but they may have weak 12v batteries.

Anyway, this was a recent problem after one of the OTAs earlier this year.

And so far it only seems to have affected our 2023 Pro trim.

 

[chl]

Just did three bug reports for the issue using the truck voice recording method.

Two for the premature PPOB shut downs on May 29 and May 31 and one for the shut down when I touched the Climate button on the FORD app. and it shut PPOB down.

Hopefully @Ford Motor Company can get to the bottom of this and institute a fix...soon?

 

[chl]

Alas, I will have to do the test again.

I was just informed that apparently one has to report the bug by sending a recorded message in the truck IMMEDIATELY after it happens, and I waited until the next day.

Event: May 31, 2026, 8:21pm.
Report: June1, 2026, afternoon sometime.

And all the time I thought Ford had a data stream they could look at if I gave them the time and date it happened.

What can I say?

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