Very Strange Transmission Issues. Hard Shifts, Slip and one very weird problem.

[ccasanova22]

Regarding the test some had suggested: mine just blinks the gear indicator when you hit “+” in sport mode unless you are above a certain speed. It won’t shift to “2” when rolling unless throttle pressure is applied. Is this normal?

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[LightningBlue]

The first time I experienced 1st to 2nd hanging and violent slam...I came a to a complete stop and it was stuck in 7th! Eventually, it went to first...things just progressively got worse from there...I'm assuming you're under warranty so have it look it ASAP...mine was way over at 95K so I had little choice but hope it'd fix itself...it will not fix itself...

Thank you for the response, I'll be sure to get a nice long paper trail for this. I'm assuming the dealer is going to just continually reset the trans learning and sending me on my way. I asked them when it was in the dealer to inspect the fluid for clutch or metal material and they said they sure would! I know they didn't lol. I'm going to take it to another dealer.

 

[LightningBlue]

Regarding the test some had suggested: mine just blinks the gear indicator when you hit “+” in sport mode unless you are above a certain speed. It won’t shift to “2” when rolling unless throttle pressure is applied. Is this normal?

Yes as far as I'm aware this is the way it is designed. If you're not moving at the minimum speed for the gear it will not allow you to shift manually into that higher gear. Someone correct me if that's wrong

 

[Shoran12]

Thank you for the response, I'll be sure to get a nice long paper trail for this. I'm assuming the dealer is going to just continually reset the trans learning and sending me on my way. I asked them when it was in the dealer to inspect the fluid for clutch or metal material and they said they sure would! I know they didn't lol. I'm going to take it to another dealer.

If the dealer gives you the runaround about checking the fluid, it may be worthwhile to go to a transmission specific shop and have them check it. One by me said they do transmission fluid checks for free, I just haven’t had time to take it to them since their only open M-F. I would even mind paying a few bucks to have a trans shop properly check it. Just a thought. Good luck and let us know if you find anything out.

 

[LightningBlue]

If the dealer gives you the runaround about checking the fluid, it may be worthwhile to go to a transmission specific shop and have them check it. One by me said they do transmission fluid checks for free, I just haven’t had time to take it to them since their only open M-F. I would even mind paying a few bucks to have a trans shop properly check it. Just a thought. Good luck and let us know if you find anything out.

Will do! I'll keep this thread updated as I get any new info.

 

[JasonTremor]

The drop in RPM in the beginning is me lifting the throttle, attempting to let the transmission figure itself out

Seems to be a common issue across the Ford line for 10speeds.

Check out this article.
https://ford.oemdtc.com/6890/10r140...mil-and-or-wrench-lamp-2020-ford-f-super-duty

 

[Dr_Strangelove]

Aside from being the 1.0 gear is anything special about gear 7 that any forum guru can think of that would make it the "chosen one?"

(I'm not trying to infer being the 1.0 gear is the cause of this, but it is a coincidental fact about the gear the computer is selecting..)

 

[RedlandRanger]

Aide from being the 1.0 gear is anything special about gear 7 that any forum guru can think of that would make it the "chosen one?"

(I'm not trying to infer being the 1.0 gear is the cause of this, but it is a coincidental fact about the gear the computer is selecting..)

I believe 7 is the first overdrive gear if I'm not mistaken. Or maybe 7 is 1:1 and 8-10 are overdrive.

 

[LightningBlue]

So I spent some time driving around today trying out different things. I put it in tow mode and it HATES 2nd gear. From first to second it will slip so bad it's like neutral except it will kill power. If I keep the throttle in the same position it'll cut fuel. It will do this every time into 2nd gear in tow mode. Shift it into sport and it no longer has it's hatred for 2nd gear.

 

[9zero1790]

Regarding the test some had suggested: mine just blinks the gear indicator when you hit “+” in sport mode unless you are above a certain speed. It won’t shift to “2” when rolling unless throttle pressure is applied. Is this normal?

yes that is normal. the computer will not allow the truck to go into a gear lower or higher than is safe. the blinking is the truck saying no. the push buttons are more of a suggestion to the truck that it shift up or down instead of a followed rule.
the test i mentioned before should be done while stopped in safe place.

 

[airline tech]

Just shooting from the hip here but when you replaced the battery, did you perform a BMS reset, to me it appears that since it all started with a low battery voltage, just maybe the BMS needs reset to tell the system that a new battery is installed.
Plus, when you have Forscan hooked up are you seeing any codes?
You may try a module reset of the BCM, PCM and TCU are any other modules that come to mind. Something appears stuck on stupid and needs a hard reset, unfortunately the modules have KAM (Keep Alive Memory) so a battery disconnect won't help, this is why the Sync Radio presets stayed intact.
If you have access to another Scanner other than Forscan, that can do a complete system scan will most likely cure your issues. (HOPEFULLY)

 

[Dr3wDrop]

The drop in RPM in the beginning is me lifting the throttle, attempting to let the transmission figure itself out

This is how mine drives when its cold outside.

 

[Dr3wDrop]

Many of our trucks do this. It’s the trans programming that wants to be in the highest gear possible for better gas mileage/emissions. My truck has done this since day 1. If I’m going up any slight incline I’ll get a rumble strip sensation if I don’t give it gas. I’d describe it as lugging since the engine rpm’s drop to 1100-1200 or so. This has gotten a bit better overtime and was better with the tank of 93 gas I ran a bit ago. You can drive in S or tow or lockout gears when in these situations. I’m told a tune helps this which may be something I consider in the future once I’ve recovered from the last set up upgrades that other 5G members were so nice to suggest ?

Great way to describe what is going on! I have the same thing happening.

 

[LightningBlue]

Just shooting from the hip here but when you replaced the battery, did you perform a BMS reset, to me it appears that since it all started with a low battery voltage, just maybe the BMS needs reset to tell the system that a new battery is installed.
Plus, when you have Forscan hooked up are you seeing any codes?
You may try a module reset of the BCM, PCM and TCU are any other modules that come to mind. Something appears stuck on stupid and needs a hard reset, unfortunately the modules have KAM (Keep Alive Memory) so a battery disconnect won't help, this is why the Sync Radio presets stayed intact.
If you have access to another Scanner other than Forscan, that can do a complete system scan will most likely cure your issues. (HOPEFULLY)

I did not perform a BMS reset, I probably should. There are no DTCs or anything showing up on forscan. I know there were a ton of them when the dealer pulled the data. I’ll try and upload the pdf they sent to me.

 

[LightningBlue]

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