2023 F-150 Lightning: battery hit 419°F with zero warning, zero fault code, zero shutdown

[thorndike]

2023 F-150 Lightning: battery hit 419°F with zero warning, zero fault code, zero shutdown — 8 weeks in Ford's shop, two denied buybacks

Posting this in case anyone else has run into something similar, or if it helps someone catch it before it gets this far.

I want to say upfront: I love this truck. ProPower Onboard has been a game-changer for my work, it tows great, and until this happened it was everything I wanted from an EV. This isn't a "Ford bad" post — it's a documentation post, because what happened is serious and I think owners and Ford both should know about it.

In June, my 2023 Lightning ER Platinum started overheating during charging and wouldn't cool down while driving. Range dropped from 312 miles to about 50. When a Ford dealership finally hooked up their own diagnostic equipment, it recorded the battery cooling circuit at 399°F and 419°F — while the AC refrigerant valves were reading "no fault detected" and "output commanded off." No warning light. No DTC. No shutdown. Ford's own Vehicle Health app told me twice, during the actual event, that the truck had no issues.

The truck's been in Ford's custody for 8 weeks now. In that time:

• The dealership has deliberately reproduced the overheating condition multiple times (with photos)
• Ford has floated three different theories (a recall software update, a TSB for an air-dam warning message I never even got, and a charging port swap) — none confirmed as root cause, and the fault keeps coming back
• Charging performance has degraded badly — sessions that terminate after 1–2 minutes, or sustain a fraction of the expected rate at higher states of charge
• Ford's repurchase division has denied my buyback request twice, both times citing grounds that don't actually apply to my claim
• I've never received any battery state-of-health data despite repeated written requests — Ford's own rep confirmed in writing that none was ever provided

I'd actually found a replacement Lightning I wanted to move into — a Lariat that made more sense for my use case than my Platinum — and had it lined up. Buyback denial killed that. So now I'm out a working truck, out the replacement I'd already found, and still making rental car payments eight weeks in that FORD will not reimburse until the case is settled.

I've put together a full write-up with the timeline, the actual diagnostic photos, and all the supporting documentation, if anyone wants the details or is dealing with something similar:

www.lightningproblems.com

Not trying to start a pile-on — just documenting what's actually happened, with the receipts, in case it's useful to anyone else driving one of these.

If anyone from Ford @Ford Motor Company — engineering, EV team, customer relations, anyone — happens to see this: I'd genuinely welcome the chance to talk this through directly. I still want this to end with me back in a Lightning that works the way it's supposed to. I'm not looking for a fight, I'm looking for someone with the authority to actually look at the data and make a real decision. My email contact info is on the website above.

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[proprepper]

Good grief. How can those temps be correct? At what temp does the whole thing catch fire?

 

[Altivec]

Very interesting... Did your battery temp gauge go up to hot or was it reading normal? Just trying to figure out if the temp sensor is faulty or if something in software or some other valve that is supposed to open is faulty.

 

[K6CCC]

That's insane!
You may need to contact a "Lemon Law" lawyer...

 

[thorndike]

So the battery temp display on the dash, would go full yellow and would NOT cool down while driving. Whenever I would charge, I would watch the charging speeds and stopped when they dropped. They were dropping long before hitting 80% so I have to assume it was purely temperature related. I stopped at one Tesla charger and all the tesla cooling fans were screaming like banshees, and my cooling fans never kicked in. If you look at the webpage, Ford keeps throwing things at the wall to see if they can figure it out. I have been trying to get this escalated above the customer relations group, but that doesn't seem to be happening. I sent a full set of documents with all the evidence to four FORD executive offices and no one responded.

I love the truck. I am beginning to dislike FORD.

Very interesting... Did your battery temp gauge go up to hot or was it reading normal? Just trying to figure out if the temp sensor is faulty or if something in software or some other valve that is supposed to open is faulty.

 

[thorndike]

I am outside of Colorado's lemon law, so FORD is using that to deny my claim. Even with all my data, they refuse. There is more info on the website lightningproblems.com . I am hoping that public exposure might help. I kept quiet hoping that FORD would do the right thing, but they keep not doing it.

That's insane!
You may need to contact a "Lemon Law" lawyer...

 

[thorndike]

Good grief. How can those temps be correct? At what temp does the whole thing catch fire?

I don't know. Ford wont tell me.

The website documents in more detail, along with evidence of reduced charging capability, so I am quite confident that the battery was damaged. Unfortunately, they have turned down my requests for a buyback and just seem to be trying things to see if it fixes the issue. I can't get them to test the battery cells to give me that data either. Or, if they tested the cells, they WONT give me the data.
lightningproblems.com

 

[Newton]

Did it ever smell hot? My heat pump hot water heater has the sensors go out regularly and it reports crazy high temps like that. At 400F I‘m pretty sure stuff would smell hot, there is a unique smell to melting wire insulation or even high temperature insulation that is approaching the limit. This is over 200C, the upper end of ‘normal’ wires can handle up to 90C.

If it were truly getting that hot I’d think that they would not want to have the vehicle in the shop. I’d then suspect a short and you don’t want an improvised heater element on top of a lithium NMC battery.

 

[Newton]

I notice that the heater core temp is only 91 degrees which I think would be hard to do if the engine coolant was 400, unless they are completely separate systems on the Ford.

 

[electricpig]

First, I agree you need either a buyback, or a NEW battery pack and coolant system.

With that said, I have a hard believing that was actual temp. IMHO that hvb would be completely inoperable if not exploded. Thermo runaway would seem certain IMHO at that temp.

 

[Timeless Epoch]

I am fairly certain that is above the runaway temperature for NMC batteries. It is definitely well above the boiling temp of coolant. So it would seem the battery never actually got that hot. Something else is going on. Unless it was your truck on that recent ’StacheD’ video.

 

[Warp Asylum]

what the hell

seriously ford, wtf

 

[TaxmanHog]

 

[electricpig]

It appears if that was actual temp, then thermal runaway would have occurred. A Google search yielded the below but with a actual citation that I did not watch. So being AI, take it for what it's worth, but I would certainly be getting legal involved ASAP. if temps were real, then FORD needs to have your truck for analysis, and if not real, FORD needs your truck for analysis.

NMC (Nickel Manganese Cobalt) lithium-ion batteries typically reach their thermal runaway critical point between 150°C and 210°C (302°F–410°F). Higher-nickel content variants (such as NMC811) trend toward the lower end of that range (~150°C–180°C), while lower-nickel variants (like NMC111 or NMC532) remain stable up to roughly 200°C–210°C before entering rapid escalation. [1, 2, 3, 4, 5]

 

[Pioneer74]

2023 F-150 Lightning: battery hit 419°F with zero warning, zero fault code, zero shutdown

Is it possible that the battery never actually reached these temps and the problem could be a faulty temp sensor?

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