Bucking while slowing down. Anybody else?

[rallyshark]

I've had this same issue of the regen letting go and charging goes to zero. I've got the scanguage 3 and have been watching to see what is triggering this. What I've come to the conclusion is every time the battery voltage exceeds 250v it triggers this event, regardless of the HVB SOC%

Interesting... I've mainly noticed the issue when braking from highway speeds to a stop down hill. I did have it do it once in some down hill sections in the mountains in the twisty bits(not cool). I've also figured out that braking harder and avoiding trying to get much regen seems to reduce the occurrence of the issue. It almost seems like the computer doesn't know what to do on these long down hill braking situations or thinks there's an issue that isn't there. Do you think it is a situation where the computer is getting confused by the charge rate and the speed not reducing as much as it thinks it should(down hill)?

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[Bandit1]

I've watched it happen on a long downhill without being on the brakes and never felt anything smooth as can be, it's only when on the brakes and it triggers that I can feel it happen.

 

[TBD]

I've had this same issue of the regen letting go and charging goes to zero. I've got the scanguage 3 and have been watching to see what is triggering this. What I've come to the conclusion is every time the battery voltage exceeds 250v it triggers this event, regardless of the HVB SOC%

Interesting note for sure. I have a Veepeak OBD with the OBD Fusion app and can see HV battery voltage so I’ll test that out to see if 250v is the upper limit for mine and triggers the issue too. The only issue with my setup is the refresh rate for my PID’s is about 1hz so it might be hard to see it happen if it surges to 250v suddenly before it has time to refresh.

I hope we can find a solution or a way to convince service to actually do something about this. It’s EXTREMELY annoying. Especially with passengers. What really concerns me is putting extra wear on other components that might fail after warranty expires when the issue could have been fixed under warranty

 

[TBD]

I've had this same issue of the regen letting go and charging goes to zero. I've got the scanguage 3 and have been watching to see what is triggering this. What I've come to the conclusion is every time the battery voltage exceeds 250v it triggers this event, regardless of the HVB SOC%

Does the Scangauge 3 have a decent refresh rate?

 

[Bandit1]

Don't know what the refresh rate is but seems decent enough

 

[TBD]

What makes you think it’s the CV axles? I know they’ve been having a lot of issues with them but I don’t see how it would relate to my specific symptoms. It seems to be something related to the HV battery system or eCVT since after the noticeable “bang”/brake release the power goes to 0.

 

[TBD]

I've had this same issue of the regen letting go and charging goes to zero. I've got the scanguage 3 and have been watching to see what is triggering this. What I've come to the conclusion is every time the battery voltage exceeds 250v it triggers this event, regardless of the HVB SOC%

I’ve been doing some testing and I can confirm that 250v is what triggers my problem too. Also like you mentioned it’s regardless of SOC. At about 245v is when the regen breaking lets go and battery power output/charge falls to zero for a bit then slowly starts to work again. Have you made any progress with your dealer getting this fixed?

 

[Bandit1]

I never took my truck to the dealer for this issue, it would be difficult to demonstrate as it only happens occasionally

 

[CometGT]

I've had this same issue of the regen letting go and charging goes to zero. I've got the scanguage 3 and have been watching to see what is triggering this. What I've come to the conclusion is every time the battery voltage exceeds 250v it triggers this event, regardless of the HVB SOC%

Interesting, that might seem to indicate a recharging current issue. If the recharging current is greater than the batteries can handle (absorb), the voltage will rise. What overvoltage protection mechanisms/routines does the Maverick have? The overvoltage protection would not care what the current state of charge is. Which leads to the component that regulates the recharging current...
Just a thought...
Does it matter if it is in TOW/Haul, Grade Assist, or transmission in Low configurations?

 

[TBD]

I suck man, I don't remember the other details of the post I wish I could find it to link here, but no luck. I remember being surprised that the dealer said replacing the HV battery was the solution, and the person that made the post said the problem seemed to be resolved. It had only been a day or two since the repair had been made. I kind of disregarded it, given the lack of time/testing after the battery was replaced. I had hoped they would post again after some proper driving had been done.

Hopefully, we'll get another post or person chiming in to confirm the solution soon. I drive a lot, and don't have time to leave my truck at the dealer for "hopeful fixes". I need to see some definite solutions to point the dealer to in order to minimize the time my truck is there. Of course, I'll have to deal with it at some point. I'd just prefer to have a high degree of confidence that the solution is known, before I go there.

@Bandit1 @rallyshark So I finally got it fixed. It was the HV battery after all. Replaced under warranty just got it back a few days ago. I couldn’t replicate it with the techs and it was driving me nuts. I ended up getting a P0B24 DTC twice in a month and they replaced my HV battery. It could be a coincidence, I’m not sure but about a week before it triggered the first time I did a PCM module reset on FORScan. So maybe do that and see if it triggers the DTC for you? Moral of the story though is I got lucky with the DTC and the HV battery replacement completely solved the issue.

 

[sanpablo]

@Bandit1 @rallyshark So I finally got it fixed. It was the HV battery after all. Replaced under warranty just got it back a few days ago. I couldn’t replicate it with the techs and it was driving me nuts. I ended up getting a P0B24 DTC twice in a month and they replaced my HV battery. It could be a coincidence, I’m not sure but about a week before it triggered the first time I did a PCM module reset on FORScan. So maybe do that and see if it triggers the DTC for you? Moral of the story though is I got lucky with the DTC and the HV battery replacement completely solved the issue.

Can I ask why you did the PCM module reset using Forscan?

 

[TBD]

Can I ask why you did the PCM module reset using Forscan?

I did it because I was absolutely fed up with the bucking and brake release issue and there’s no BECM reset option. I was essentially throwing everything I could at it and that was one of said things

 

[rallyshark]

Good to know! I'm going to try and save this thread in case mine gets worse. It needs to get worse in the next year, or my hybrid component warranty will be gone. I'm at 60k now. I tried to reproduce it for the dealer, and couldn't, and they couldn't either. It only does it every once in a while in mine...

 

[rallyshark]

@TBD I'm at 85k now, and finally got the P0B24 code this morning. The truck still drives normally, but with an engine light... I just wanted to check in to see if you had any more issues after the high voltage battery replacement(now that you've had plenty of time with it)? Oddly enough, my bucking had pretty much stopped and my only problem now is the code.

 

[TBD]

@TBD I'm at 85k now, and finally got the P0B24 code this morning. The truck still drives normally, but with an engine light... I just wanted to check in to see if you had any more issues after the high voltage battery replacement(now that you've had plenty of time with it)? Oddly enough, my bucking had pretty much stopped and my only problem now is the code.

So I traded in for a 2025 AWD hybrid back in March. However, from the time I got the hv battery replaced until I traded in there were no issues with bucking or breaking or anything. It completely fixed the problem. Hybrid system warranty lasts to 100k miles so now that you have the code, take it to the dealership and get that new battery! They’ll probably have to order it but once it arrives it took my dealer about 3 hours to finish the job. Apparently ford made it really easy to replace these batteries. Best of luck!

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