Deep sleep messages - dealer ‘fix’

[Tyler Durden]

Started getting deep sleep messages last weekend. Truck would always start fine, but decided to take it in to get looked at anyways. Dealer diagnosed it as a bad 12 volt battery due to sulfation/degradation. Replaced battery under warranty. So far so good, haven’t received any further messages.
I have had a powered sub (hooked to said battery) that comes on via the speaker input. Is there any reason to believe that this could’ve led to the battery problem? I’ve had it hooked up in other vehicles without issue.
FYI, I’ve had the vehicle since April 2021 and this was the first time getting the messages.
Hopefully it was just a fluke with a bad battery and not leading to a harness problem.

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[DannyP]

My Ecoboost started doing that a month or so ago. I did a “hard reboot” by unhooking the positive battery cable from the battery, waiting 5-10 minutes, and reconnected. Haven’t gotten another warning since.

 

[JimParker256]

I've read elsewhere that if you connect something "directly to the battery" on the hybrid, you could be bypassing the battery management system, so it doesn't know about that load, and won't compensate correctly for it. Over time, that could slowly lower the battery's state of charge to the failing point.

I don't know if anyone has proven this to cause the "deep sleep" issue, but it sounds somewhat plausible in situations like yours. I would probably try moving the 12V connection for powered sub to one of the "spare" fuse locations, which would eliminate that potential issue.

That said, I also believe there were some "bad" batteries delivered by Ford's supplier. It's probably not as simple as a bad "batch" (where there would be a date range or serial number range affected) or one (of multiple) battery suppliers delivering sub-standard components... I suspect that would have been easy for Ford to figure out.

The other possibility is that some engineer decided to recharge the battery based primarily on the BMS's determination of the "load" placed on the battery. I'm sure they would have used some complex formula to compensate for the efficiency losses in recharging the battery, and for most vehicles that would be sufficient.

But add in a bit of higher resistance anywhere in the wiring, or a battery that is ever-so-slightly below spec, or an "unmetered" load (such as a powered amp literally wired directly to the battery), and the calculated re-charge "dose" is NOT going to fully recharge the battery.

 

[Redneck Garage]

and this was the first time getting the messages.
Hopefully it was just a fluke with a bad ba

Started getting deep sleep messages last weekend. Truck would always start fine, but decided to take it in to get looked at anyways. Dealer diagnosed it as a bad 12 volt battery due to sulfation/degradation. Replaced battery under warranty. So far so good, haven’t received any further messages.
I have had a powered sub (hooked to said battery) that comes on via the speaker input. Is there any reason to believe that this could’ve led to the battery problem? I’ve had it hooked up in other vehicles without issue.
FYI, I’ve had the vehicle since April 2021 and this was the first time getting the messages.
Hopefully it was just a fluke with a bad battery and not leading to a harness problem.

Mine did exactly the same thing - pretty sure it is a VERY marginal battery. Tends to go into deep sleep when its really cold outside - warmer temps its ok.

 

[Renho17]

I have had my Mav as long as you, and had my powered sub hooked up the same amount of time. No sleep messages, yet.

 

[Bigsarge]

Last week my Maverick Hybrid shut down. I got in the truck and tried to start it but nothing happened. Got the message that it was in deep sleep mode. It is my daily driver and had driven it the day before with no problems. I had to put my battery charger on it and it started right up instantly. Has not done it since. Can't imagine what would set it off like that.

 

[Gullzway]

Mine did exactly the same thing - pretty sure it is a VERY marginal battery. Tends to go into deep sleep when its really cold outside - warmer temps its ok.

Has yours done the Deep Sleep recently?
I'm trying to determine if resetting the BMS fixes this problem.

I reset mine on Jan 16th and have not gotten the Deep Sleep message since. Wondering if its coincidence or not.

 

[Redneck Garage]

Has yours done the Deep Sleep recently?
I'm trying to determine if resetting the BMS fixes this problem.

I reset mine on Jan 16th and have not gotten the Deep Sleep message since. Wondering if its coincidence or not.

its so damn random. It did a few days ago but hasn't since - trying to understand the deep sleep issue is somewhat like trying to understand Ford's allocation and scheduling builds ...... LOL

 

[MakinDoForNow]

Started getting deep sleep messages last weekend. Truck would always start fine, but decided to take it in to get looked at anyways. Dealer diagnosed it as a bad 12 volt battery due to sulfation/degradation. Replaced battery under warranty. So far so good, haven’t received any further messages.
I have had a powered sub (hooked to said battery) that comes on via the speaker input. Is there any reason to believe that this could’ve led to the battery problem? I’ve had it hooked up in other vehicles without issue.
FYI, I’ve had the vehicle since April 2021 and this was the first time getting the messages.
Hopefully it was just a fluke with a bad battery and not leading to a harness problem.

Where is ground for sub? According to manual nothing should be connected to the negative battery terminal as that could affect bms readings. Ground should be found elsewhere (like always). No mention of connecting or not connecting to positive so it appears to be ok to connect to positive battery terminal

 

[Tyler Durden]

its so damn random. It did a few days ago but hasn't since - trying to understand the deep sleep issue is somewhat like trying to understand Ford's allocation and scheduling builds ...... LOL

 

[Tyler Durden]

Update - still haven’t gotten any more messages since the battery replacement. Hopefully it’s fixed for good.

 

[Tyler Durden]

Where is ground for sub? According to manual nothing should be connected to the negative battery terminal as that could affect bms readings. Ground should be found elsewhere (like always). No mention of connecting or not connecting to positive so it appears to be ok to connect to positive battery terminal

I just tied the ground wire to one of the bolts behind the seat. Worked fine for me.
And I hooked into the positive battery for my powered sub. Still don’t know if that triggered the battery going bad or not. Either way, powered sub is now disconnected.

 

[MakinDoForNow]

I just tied the ground wire to one of the bolts behind the seat. Worked fine for me.
And I hooked into the positive battery for my powered sub. Still don’t know if that triggered the battery going bad or not. Either way, powered sub is now disconnected.

I do not think what you did would matter. To many are having a problem. I am just guessing but I am expecting battery production problem or an issue of bms not properly controlling charge rate and roasting battery. The battery is supposed to be able to accept a fast float charge but too fast could possibly overheat battery. I have no doubt Ford is working on a solution.

 

[Peps]

I had the message each of the last 3 days and I drove it each day, starting without problems.
It is cold here ~20F. I checked the battery and the voltage was 11.9 Volts. I have the battery connected to a a drip charging system now, to see if this addresses the problem but if I encounter the problem again I will go to the dealership.
For my understanding the warranty on the 12 Volt battery should be 3 years so it is still covered for my Mav 2022 hybrid, in case.
I have\had no lights left on in the vehicle, nor accessories connected to the battery, with the exception of a USB that I connect with a phone only when driving.

 

[CurtisB]

I had the message each of the last 3 days and I drove it each day, starting without problems.
It is cold here ~20F. I checked the battery and the voltage was 11.9 Volts. I have the battery connected to a a drip charging system now, to see if this addresses the problem but if I encounter the problem again I will go to the dealership.
For my understanding the warranty on the 12 Volt battery should be 3 years so it is still covered for my Mav 2022 hybrid, in case.
I have\had no lights left on in the vehicle, nor accessories connected to the battery, with the exception of a USB that I connect only when driving.

They will check your battery to see if it is low and if it is, replace it with a proper replacement now that they have them in stock. You should be good to go after this. Especially if it took this long to get your first sleep message.

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