Unusual Hybrid AC problem

[Uncle Ed]

Truck is a 2024 Hybrid XL , 35,000 miles. It went to the dealer for an oil leak ' gasket changed on front cover. When I picked it up a.c. failed to get cold. Service immediately took it back to be tested and an hour later bring it around as a could not duplicate. AC was working. In the couple of weeks since then and after almost 1000 miles the problem has returned. I have found when initially turning on the ignition switch the AC decides then if it is going to cool or not. Once AC works it has never failed going down the highway. But if the AC doesn't cool when first turned on it will not come on no matter what position controls are in, and remains off until ignition switch is turned off and truck is restarted. I have driven as long as a week without failure then AC fails on start up. Turn off truck restart AC may or may not cool. Any ideas ? Thanks additional info AC control lights work as intended, I have the original 12 volt battery , tested ok by dealer.

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[jfgesquire]

There was an update to the accm, AC control module, that was supposed to fix some intermittent operation that sounds like what you described.

 

[Glen Baker LLC]

These posts are mainly refer to battery drain and its relationship to the air conditioning control module whether there is a connection with what your experiencing I have no idea. It's worth a shot to investigate.

Jan 26 2026 New 2022-2025 Maverick - 2.5L Hybrid - Various Electrical Symptoms And/Or No Crank/No Start - Related To 12-Volt Battery Drain Some 2022-2025 Maverick hybrid vehicles may exhibit a no crank/no start condition due to a 12V battery drain after performing the air conditioning control module (ACCM) software update. Engineering is aware of this symptom and is currently developing a repair which is expected to be available in late Q2 of 2026. If a vehicle comes in for this condition, submit a Global Concern Report (GCR) and monitor Professional Technician System (PTS) for additional information and schedule service appointments for customers once the repair becomes available. To submit a report, click on the "Submit Global Concern Report (GCR)" link at the upper right of the PTS Vehicle ID screen (VIN required) and fill out the form. Do not use the "Report A Problem" link to submit a report for this condition. SSM 54519

Here is the older SSM that's still in effect assuming you want to try that first. If it works, it'll prevent them from having to submit a report. If not, then they need to submit the report per the present SSM

SSM 53801 2022-2025 Maverick - Hybrid - 12V Battery Drain - Built On Or Before 17-Feb-2025
Some 2022-2025 Maverick vehicles with a hybrid powertrain and built on or before 17-Feb-2025 may exhibit a 12V battery drain. This may be due to the software installed in the air conditioning control module (ACCM). To correct this condition, perform a battery condition test as outlined in Workshop Manual (WSM), Section 414-01 Battery, Mounting and Cables > Diagnosis and Testing > Pinpoint Test A. Service the battery as necessary. Connect a battery charger such as Rotunda GRX-3590 or DCA-8000 to the 12-volt battery. Download and run the "air conditioning control module (ACCM) software update" application in the Ford Diagnosis And Repair System (FDRS) scan tool. If the battery was replaced, download and run the "BCM-reset the battery monitoring sensor learned values" application in FDRS. For claiming, use causal part 19703 and applicable labor operations in Section 10 of the Service Labor Time Standards (SLTS) Manual

 

[HeyBales]

So when it fails - AC button is lit it sounds like.
Ya, not 12V battery strength related since the HVB needs to be connected to run the 3 phase compressor off the DCDC converter , and by then the 12V system is being powered by DCDC converter.

It is hard to figure out the exact sequence of events that might cause that - so they can duplicate.
Maybe it's a sequence (probably turn-off related if so), or just the electrons aligning a certain way on that day (annoying).
Always same turnoff routine if you do one - AC off, or HVAC off, or whole thing always on, ect?
Could you have times that on shutoff the AC button is not pushed - but you can tell from cool air the system is auto-engaged for humidity control? HVAC still has to be on for that to happen in our years.

At least it sounds like not charge related, since it does work well when working.
And not wiring related since you said a key cycle with no truck movement resets it finally, so not like wires finally touching, or likely have problems bouncing while driving.

Is it possible next time it's not working (and prep for this ahead of time looking when it does work), to pop the hood, and video the fact the button is pressed and then jump out and show the compressor isn't spinning?
Tight space down there, but with no ICE running you can hear and maybe see it enough in video.

That's if you can't find a sequence to cause it. At least get it on record with dealership (if not already) there is an issue.
Not sure if the tech couldn't duplicate would stick on your record as a problem logged.

 

[Uncle Ed]

So when it fails - AC button is lit it sounds like.
Ya, not 12V battery strength related since the HVB needs to be connected to run the 3 phase compressor off the DCDC converter , and by then the 12V system is being powered by DCDC converter.

It is hard to figure out the exact sequence of events that might cause that - so they can duplicate.
Maybe it's a sequence (probably turn-off related if so), or just the electrons aligning a certain way on that day (annoying).
Always same turnoff routine if you do one - AC off, or HVAC off, or whole thing always on, ect?
Could you have times that on shutoff the AC button is not pushed - but you can tell from cool air the system is auto-engaged for humidity control? HVAC still has to be on for that to happen in our years.

At least it sounds like not charge related, since it does work well when working.
And not wiring related since you said a key cycle with no truck movement resets it finally, so not like wires finally touching, or likely have problems bouncing while driving.

Is it possible next time it's not working (and prep for this ahead of time looking when it does work), to pop the hood, and video the fact the button is pressed and then jump out and show the compressor isn't spinning?
Tight space down there, but with no ICE running you can hear and maybe see it enough in video.

That's if you can't find a sequence to cause it. At least get it on record with dealership (if not already) there is an issue.
Not sure if the tech couldn't duplicate would stick on your record as a problem logged.

Thanks everyone for suggestions, I'll check with the dealer about updates. I think it's a control module/ programming problem.

 

[Darnon]

A dealership likely wouldn't have arbitrarily performed the ACCM reprogramming, though, unless you had them addressing a battery drain problem.

 

[KenE]

Thanks everyone for suggestions, I'll check with the dealer about updates. I think it's a control module/ programming problem.

I think 'HayBales' advice in post #4 is spot on, you should follow that. Intermittent problems are the hardest to resolve. Documenting your sequence of operation will be valuable in solving.

 

[Uncle Ed]

Sorry it's taken so long to update , but it took me several weeks to figure out when the a.c. would fail with any certainty. I think it fails when the outside temperature is in the high 80's and above. I noticed it never failed before noon and I would always be somewhere in the afternoon. I even waited on the first drive to be in the afternoon . Yesterday was 92 degrees by 1:45 pm so I started it up and the a.c. failed. It would start to cool for a minute then the air gradually became warmer. So it's at the dealer now, I'll post what they find.

 

[HeyBales]

Sorry it's taken so long to update , but it took me several weeks to figure out when the a.c. would fail with any certainty. I think it fails when the outside temperature is in the high 80's and above. I noticed it never failed before noon and I would always be somewhere in the afternoon. I even waited on the first drive to be in the afternoon . Yesterday was 92 degrees by 1:45 pm so I started it up and the a.c. failed. It would start to cool for a minute then the air gradually became warmer. So it's at the dealer now, I'll post what they find.

I've been going a bit OCD on watching the grill fins position during the hot weather.
I have it watching in the scanner info, but rarely look at it.

Got done with a hot 95 F drive AC going - parked and happened to notice the changing value in the fins went to 100% from wherever it was.
I recalled incorrectly and thought 100% was closed - and I thought why in the world would the system want it closed with hot engine and AC on.
Should have looked with it running to discover 100% is full open.
Anyway - next several days I'm goin a bit nuts because because on startup I'm finding 0% and closed, and 100% and closed, after looking at scanner and jumping out to look at fins.
Turns out they rotate fast. Or I'm moving slow in 85 F.

Anyway - proved out driving with no AC but using vent fan - system is willing to be at 0% total closed to 80% open - totally depending on coolant temp and 195 F and ICE running.
Click AC on - 100% open, even when parked. If moving and not so hot, down to 80% open.
Click AC off - 80% to 0% again.

I'm wondering if your fins are not moving correctly for the fact the AC is on.
Block that flow for a bit - AC won't be working so well.

 

[Uncle Ed]

I've been going a bit OCD on watching the grill fins position during the hot weather.
I have it watching in the scanner info, but rarely look at it.

Got done with a hot 95 F drive AC going - parked and happened to notice the changing value in the fins went to 100% from wherever it was.
I recalled incorrectly and thought 100% was closed - and I thought why in the world would the system want it closed with hot engine and AC on.
Should have looked with it running to discover 100% is full open.
Anyway - next several days I'm goin a bit nuts because because on startup I'm finding 0% and closed, and 100% and closed, after looking at scanner and jumping out to look at fins.
Turns out they rotate fast. Or I'm moving slow in 85 F.

Anyway - proved out driving with no AC but using vent fan - system is willing to be at 0% total closed to 80% open - totally depending on coolant temp and 195 F and ICE running.
Click AC on - 100% open, even when parked.
Click AC off - 80% to 0% again.

I'm wondering if your fins are not moving correctly for the fact the AC is on.
Block that flow for a bit - AC won't be working so well.

I brought my maverick home from the dealer today. They replaced the a.c. compresser. It had been failing in Hot weather and today was 92 degrees when I drove home. It stayed cold all the way , so only time will tell. The truck had about 34k miles when it first failed, it has 37.5k miles now. Repaired at no cost ,

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