Hybrid battery drain issue / ACCM update (as of 11/8/25) -- Latest info from a tech's perspective

[Darryl]

Update on the battery drain/deep sleep issue. We’re still dealing with the ONE stubborn case. later today a FIELD SERVICE ENGINEER is scheduled to come by and assit’s with this vehicle. He says that the ACCM update has fixed the vast majority of the trucks. But they have record of 46 ACTIVE cases that seem un fixable thus far. Hopefully, we’ll find the issue with this one. I’ll share our findings. Hopefully within a few days..

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[D.W.]

Thanks Darryl.
Please keep use up to date on this issue.

 

[BLUEOVALRACER]

Update on the battery drain/deep sleep issue. We’re still dealing with the ONE stubborn case. later today a FIELD SERVICE ENGINEER is scheduled to come by and assit’s with this vehicle. He says that the ACCM update has fixed the vast majority of the trucks. But they have record of 46 ACTIVE cases that seem un fixable thus far. Hopefully, we’ll find the issue with this one. I’ll share our findings. Hopefully within a few days..

Will Ford buy the 46 Mavericks back if they can't fix them?

 

[Darryl]

Will Ford buy the 46 Mavericks back if they can't fix them?

Actually, upon further discussion with the field service engineer, it seems as if SOME of these vehicles may already be vehicles that Ford has in its possession or are under special investigation by the engineering team. Some are equipped with a "flight recorder" in an attempt to catch something in process as it happens. The problem is labeled "battery drain even after ACCM update" because the software update fixes the VAST MAJORITY of the offending vehicles if ALL instructions were followed correctly. But these have a different problem. That is particularly difficult because it's intermittent. It may happen overnight. Or it may go several days without happening. So it may appear fixed only to reoccur after several days. Even more frustrating is that preparing the vehicle for the test often makes the problem go away during testing. This far it seems as if there may be one module that's keeping other modules awake. The challenge is finding the SOURCE module. They have some suspicions . They've had records of several techs replacing this module and the problem going away. I'll reveal it if indeed it turns out to be the case with the truck in our possession. It'll take about a week before we're confident enough to say it's fixed. But don't think that Ford is just sitting there twiddling their thumbs. They have a team working on it.

 

[Msradke]

Retired dealer tech. I have a 2024 non Hybrid having the same concern . I have been to the dealer 4 times. Several conversations with my buddy over this. Being intermittent is the biggest concern. I have been attempting to diagnose. All modules have been updated , battery replaced twice second one is better. Things I have noted front camera heater turns on, fuel pump runs , throttle body clicks, transmission solenoids start clicking. Locked or unlocked make no difference. Installed amp clamp around wiring harness that goes over the battery . I have caught it doing it and draws 5.5 amps than drops to 2.6 amps then .2 amp. over about 2 -3 minutes. I have put a camera inside the truck over 2 weeks and noted nothing turning on the dash. I have monitored and logged battery voltage , key turned before start up, charging and after driving. Noted times voltage after driving 12.5 volts next time key turned on 11.2 volts . Yes there is a something going on. My thought process after this and reading wiring diagrams is the BCM is suspect. Let me know what you find.

 

[Darryl]

Retired dealer tech. I have a 2024 non Hybrid having the same concern . I have been to the dealer 4 times. Several conversations with my buddy over this. Being intermittent is the biggest concern. I have been attempting to diagnose. All modules have been updated , battery replaced twice second one is better. Things I have noted front camera heater turns on, fuel pump runs , throttle body clicks, transmission solenoids start clicking. Locked or unlocked make no difference. Installed amp clamp around wiring harness that goes over the battery . I have caught it doing it and draws 5.5 amps than drops to 2.6 amps then .2 amp. over about 2 -3 minutes. I have put a camera inside the truck over 2 weeks and noted nothing turning on the dash. I have monitored and logged battery voltage , key turned before start up, charging and after driving. Noted times voltage after driving 12.5 volts next time key turned on 11.2 volts . Yes there is a something going on. My thought process after this and reading wiring diagrams is the BCM is suspect. Let me know what you find.

I will. However, although you've been to the dealership twice, I'd insist that they use ALL resources available to them if it's still under warranty. I don't know if you've worked for Ford or not. But they need to contact the Ford hotline and request assistance. They will receive guidance. Sometimes the hotline personnel will have access to information and possible fixes that we don't have access to. And if that doesn't work, the dealership CAN and SHOULD request the assistance of a field service engineer who will actually come to the dealership and offer assistance and insight. What what often happens is that we open a contact and go back and forth with the hotline personnel using the ideas and insight they provide. They will sometimes escalate the concerns when engineering team who may offer additional insight. If that is unsuccessful, the dealership can call or and request the assistance of a field service engineer. Sometimes it would take a few days before he can come. But you can make an appointment to bring the vehicle back in on the day he'll be there. Again, if your vehicle is under warranty. I would exhaust all resources and get the dealer to access all resources available to them. Even if it's not under warranty, it would be a good thing for them to contact hotline. A lot of text don't like doing that because it takes time and is a little bit aggravating. But my view is that Ford has these hotline people available. And I'm going to use them if I really need to

 

[Msradke]

Retired Ford dealer tech. 20+ years at same dealer where I take it. My buddy has been there more than 30 years. I do understand Fords process. We have been talking about it. Have had more contact with the hotline then I care to think about over the years. Thanks

 

[Darryl]

Retired Ford dealer tech. 20+ years at same dealer where I take it. My buddy has been there more than 30 years. I do understand Fords process. We have been talking about it. Have had more contact with the hotline then I care to think about over the years. Thanks

That's good. Because at my dealership, I literally have to nag one a couple of the techs in order to get them to open a hotline contact. . And I'm just getting some of them to get in the habit of checking Oasis to see if there's an applicable TSB, or SSM that addresses their issue before just throwing up their hands or accusing the customer of making something up because it hasn't happened with them. There will literally be a publication that addresses their intermittent concern involving a 20 minute update

 

[D.W.]

They replaced my battery with a new one just like the old one and did software update. Will see how this works.

Any update?
Did the new battery fix the problem?

 

[Darryl]

Any update?
Did the new battery fix the problem?

Still testing. . I'm going to see if it still is charged after sitting over the weekend. It was still charged on Thursday

 

[How15]

Any update?
Did the new battery fix the problem?

So far no problem but it did go 2 years before the problem started happening regularly. The test will be this weekend when the cold hits the area, 0 to 10 highs for 3 days.

 

[D.W.]

Anyone know what Exactly "software-update ECG2-25.2.8.5" does?

 

[Msradke]

Darryl,
An update. I went to the dealer and had an RO opened and hotline contacted. Was informed they know about the concern and are working on it.
Being a tech had to dig deeper myself. I upgraded the sound system, story for other day. I put a camera in the truck at the amps to monitor them. What I discovered was after charging the battery and driving the truck is when the problem happens. I charged the battery drove the truck parking in my driveway and double locked it. The next day went out to the truck to get something out of it and locked doors with remote. Went out 30 to 40 minutes later to get the mail and noted they were still on. The amps are setup to come on with ACM power up. Unlocked the it and relocked it amps turned off. Appears ACM staying on. Went and check camera footage and noted were on other times. I had in the past turn the off with the disconnect switch, it looks like the ACM coming on with key off.

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