Newest Ford special service message on Hybrid 12v Volt Battery Drain Problem

[HeyBales]

I know they were in contact with Ford and were told what to do and in what order.

Makes me think there is a better process discovered since the 24MY manual.

Appears 15 to 30 min drive after BMS reset, and then park, lock, and don't touchy for 8 hrs.

After my next trickle charge up to 100% going to do that, see if any improvement over the last disappointing result.

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[Darnon]

Yes, so. Even Forscan Lite can do it.

But the point - Should their process be followed of a decent drive and then park - or the manual instructions which give that process you stated.

They were specifically evaluating how much the quiescent draw discharged the battery.

 

[Hoagus]

They were specifically evaluating how much the quiescent draw discharged the battery.

”Quiescent” good word of the day.

 

[HeyBales]

They were specifically evaluating how much the quiescent draw discharged the battery.

I reread the routine.
I don't think so. That's the investigation they had to do AFTER proving it wasn't the battery.
Each time they did the normal BMS reset and sit overnight (24 hrs in their case), it was after a total recharge in 1st case, and then with new battery topped off in the 2nd case.
Times when you are supposed to do a reset so the system knows how to handle this new battery and deciding what you have as one.

Starting off with totally charged and then new totally charged batteries merely allowed them to start from a baseline if it was not the battery. (less time just replacing a bad battery if that was it)

And part of doing that is the routine with BMS reset and sit. They just added to it a 15-30 min drive after the reset.

The draw test was done the next day, with already reduced battery from overnight proving it wasn't the battery.

If they were doing the drive to see if there was a system problem after a BMS reset - then invalid test - unless you happen to do a BMS reset every night with a short drive before parking as part of your normal routine.

Their process seems to indicate there is probably a SMS for getting an accurate reset after a battery charge or new battery.

Considering how many threads I've read (not that many compared to all of them) where the dealership said they just replaced the battery and did a reset, or charged it up and did a reset, and gave the truck back later that day (totally invalid routine according to manual), I would not be shocked if there are special instructions to handle a new/recharged battery to get the point across, and would not surprise me if it had an enhanced routine compared to the manual.

 

[Darnon]

All of that wouldn't be necessary to evaluate that the BMS was reset. You can literally just see the PID of battery SoC resets to 100%.

A tech isn't going to sit there monitoring for parasitic draw for hours. So if nothing immediately presents itself, you leave it sit overnight to make sure there isn't something activating after a prolonged period that is putting on an unusual draw that drains the battery. Notice it went down 26% overnight the first time after replacing the battery. Then they replaced the telemetry module and after charging and sitting for ~2 days it was only down 14%.

 

[CurtisB]

I had all the same issues, always started though for 18 months. Battery was replaced twice, but this time they did module bypassing to figure out the draw over a 3 week span and they finally determined it was the TCU. I've had it back for a couple weeks now and all seems good. I had/have a voltage meter in the cig lighter, so visually I can see things seem to be in order now. I'm attaching the work order to maybe help others out. If you have questions, keep it simple because I don't know what anything means on the work order. Lol.

I wonder if this "TCU" issue is the final resolve for the parasitic draw causing the "deep sleep" issue?

 

[HeyBales]

All of that wouldn't be necessary to evaluate that the BMS was reset. You can literally just see the PID of battery SoC resets to 100%.

A tech isn't going to sit there monitoring for parasitic draw for hours. So if nothing immediately presents itself, you leave it sit overnight to make sure there isn't something activating after a prolonged period that is putting on an unusual draw that drains the battery. Notice it went down 26% overnight the first time after replacing the battery. Then they replaced the telemetry module and after charging and sitting for ~2 days it was only down 14%.

Your BECM SOC reads 100% after a BMS reset? I've just reviewed several threads of people measuring battery stats and the trucks report of it - never did I see a correct 100% reported. Some didn't report what the truck said, so perhaps correct or unable to see it.

3 resets - mine never has (and yes I get the 3 flashes saying it was done). The device charging the battery reports 100%, the truck system never has.

And the techs were never evaluating that the BMS was actually reset - that wasn't the question.
They assumed the battery replacement process was working - except they added a 15-30 min drive to the process.
BMS reset - drive - park over 8 hrs for BMS relearn. That's the process for them.

They never did a draw test right after the BMS reset - reread the procedure they followed.
Sitting overnight is part of the new/charged battery process - they measured AFTER that was done.
You don't measure right after the BMS reset, as the battery was having problems under NORMAL circumstances, normal driving, normal routine. BMS reset & relearn is not a normal routine, any draw happening then or for hours is part of the process - NOT normal, and not valid to find an issue.

Yes it is obvious they did a draw test one day and found within spec despite the drop.
Next day probably would have been the same with about same drop.

The only thing I'm pointing out is that both test cases started with a full battery and system that knows it's a full battery, the full process for them included a drive before the park and relearn.
While that relearn may indeed include the time of the parasitic draw, the drive was not to induce that, I'm convinced it's part of the new battery process now.

Frankly it makes sense - part of the relearn is what does the battery drain look like with known draw on it. Well the drive also adds the info only available during a drive - what is the charge to it with known amps. Maybe it's part of the relearn only available after a recall update - several comments in threads they saw a difference after the taillight recall update was done.

 

[HeyBales]

I wonder if this "TCU" issue is the final resolve for the parasitic draw causing the "deep sleep" issue?

It was in this case.
Doesn't mean it is in all cases of deep sleep, which may not even be the result of abnormal parasitic draw but just normal ones over extended time.

You'll notice in the process the draw was within expected range for 6 hrs. (bummer they didn't give the full spec range, but at least some values given to compare)
There is an expected draw - there has to be as the ATT modem has to be on to see if you want to remote start, and the radio to hear the key fob pressed to unlock doors, or for keyless systems the radio sending to see if a key nearby. There will be a draw.

Then again the battery was already at 74% prior to drive and that test, so some systems were likely already disabled that would have caused higher draw to be discovered.
Hence the TCU being found later after pulling it's power just in the process of testing what it might be. It's interesting that's the only one pulled & then left extended period to see if that was it. The other modules that had power pulled didn't get the same extended test it appears.
That tells me they sort of expected it in the process.

I'm also curious if the new SIM card in the TCU (unless they moved the old one) was programmed to connect to the ATT network yet. If programming was left out, then it wasn't trying to connect, so less battery usage. For now.

 

[Ozarkbeard]

I wonder if this "TCU" issue is the final resolve for the parasitic draw causing the "deep sleep" issue?

I don't know.

Purely anecdotal, but I have never had any 12v battery issues at all on my Hybrid XL, which I've had for 11 months and 17K miles.

For battery care, I trickle charged the truck the first day/night I got it.

Disconnected the telematics fuse 11, not long after I got the truck.

Double-lock the truck with the fob when I park it.

Put it on a battery maintainer whenever I won't be driving it for a few days. After work, I reset the BMS with the brights+brake pedal procedure.

It's ridiculous we have to resort to trying things like this, and there's absolutely no way to tell if this would work for anyone else. But it has worked for me.

For lead acid batteries, I've always been a strong believer in keeping them fully charged with a battery maintainer, when possible. Most of my vehicle batteries, including lawn mower battery, have lasted much longer than what seems to be the norm.

 

[Ryom]

Reading up on this does anyone else see a cheap ‘fix’ like I do to solve this for themselves…. Not going to post that but I can’t be the only one to see something very obvious.

No, fuses are there for a reason. Don't hardwire a plate in between, car fires are no joke. This isn't something to yee-haw.

 

[Tuch]

@HeyBales
"I'm also curious if the new SIM card in the TCU (unless they moved the old one) was programmed to connect to the ATT network yet. If programming was left out, then it wasn't trying to connect, so less battery usage. For now."

Hey, thanks for all the schooling regarding my work order. Any way to see if the sim was programmed on my end?

 

[MavTime]

I wonder if this "TCU" issue is the final resolve for the parasitic draw causing the "deep sleep" issue?

I don't think that person is giving it enough time to reach Deep Sleep again. It seems to come back eventually no matter what has been done. If you are discussing Deep Sleep conditions it helps to tell people how long in time (not miles) you drive it each day and how many days per week it gets driven. I really think there is no "fix" aside from having a long commute and driving often, as I think it comes down to drive time to put as much back in the battery as you take out by driving it for a longer time since it is DC-to-DC charging. Having it sit parked while on a trip shouldn't be much of a problem if the battery is topped off which seems to only be possible with a trickle charger. Those of us with short 15-20 minute commutes, 30-40 round trip and not much driving on weekends will always have the Deep Sleep problem and always need a monthly trickle charge back to full.

 

[MakinDoForNow]

Your BECM SOC reads 100% after a BMS reset? I've just reviewed several threads of people measuring battery stats and the trucks report of it - never did I see a correct 100% reported. Some didn't report what the truck said, so perhaps correct or unable to see it.

3 resets - mine never has (and yes I get the 3 flashes saying it was done). The device charging the battery reports 100%, the truck system never has.

And the techs were never evaluating that the BMS was actually reset - that wasn't the question.
They assumed the battery replacement process was working - except they added a 15-30 min drive to the process.
BMS reset - drive - park over 8 hrs for BMS relearn. That's the process for them.

They never did a draw test right after the BMS reset - reread the procedure they followed.
Sitting overnight is part of the new/charged battery process - they measured AFTER that was done.
You don't measure right after the BMS reset, as the battery was having problems under NORMAL circumstances, normal driving, normal routine. BMS reset & relearn is not a normal routine, any draw happening then or for hours is part of the process - NOT normal, and not valid to find an issue.

Yes it is obvious they did a draw test one day and found within spec despite the drop.
Next day probably would have been the same with about same drop.

The only thing I'm pointing out is that both test cases started with a full battery and system that knows it's a full battery, the full process for them included a drive before the park and relearn.
While that relearn may indeed include the time of the parasitic draw, the drive was not to induce that, I'm convinced it's part of the new battery process now.

Frankly it makes sense - part of the relearn is what does the battery drain look like with known draw on it. Well the drive also adds the info only available during a drive - what is the charge to it with known amps. Maybe it's part of the relearn only available after a recall update - several comments in threads they saw a difference after the taillight recall update was done.

I take the procedure described in his work order as one proposed by an engineer at Ford to try to determine his exact problem over several days. The results of this test will likely cause it to be repeated exactly the same way for a number of trucks which people are agreeable to leave their truck for a week or so. Then depending on what is found Ford will decide if this is a proper way to handle. This procedure was stated to be arranged by dealers tech as I read his post. They may create a program update with new codes for finding what's using current above expected amounts.

 

[HeyBales]

@HeyBales
"I'm also curious if the new SIM card in the TCU (unless they moved the old one) was programmed to connect to the ATT network yet. If programming was left out, then it wasn't trying to connect, so less battery usage. For now."

Hey, thanks for all the schooling regarding my work order. Any way to see if the sim was programmed on my end?

Sorry never saw this.

For the modem in truck, programmed SIM would connect to ATT network and be sending up data.
To confirm programmed - you'd have to do the process of connecting a FordPass account to it and see the info from the truck.
If truck complains it can't reach the network - that could be why.

 

[Tuch]

If an update helps at all, been about a month and still going strong. In the past I could not even clean the interior with doors open without getting a deep sleep, not the case currently. I had to remove dash cam (usb c armrest) and hud display(obd ) as well. Since that work order I've put those 2 devices back in play. I will add I know for a fact I do not hear all that clicking I used to hear. Still get some, but at least 75% less.

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