10L80 trans adapt relearn?

[15ltz6.2]

I have a 2020 silverado L87 my truck seems to be slamming super hard like breaking traction hard from 1-2 shift (only when heavy on throttle upper PE) all other shifts feel fine. I put stock tune back in today still doing it. Maybe it?s been like this for awhile but just relized how hard it shifts in that range last few days. I can post a log if need be but it has stock tune reinstalled and the tcm is locked so nothing touched there. Is there arelearn procedure for these i cant seem to locate 1 in the hptuners scanner anywhere? Thanks

[Estep40511]

Any other mods on the vehicle? You would need access to a MDI2 and GDS2 from GM to do a fast learn and reset adaptive pressure. Could be an issue internally with trans. Hate to say it, but the newer 10 spd have a problem with the bearing on the transmission front cover seizing up and causing transmission to go into max line pressure. Is it making any weird noises, almost like a bad idler pulley, etc? If so, it may need to be looked at.

[15ltz6.2]

Thanks for reply. Truck has gm cold air intake and exhaust along with the calibration that gm gave it with the intake. Didnt know these 10 speeds had any issues thats why i was surprised its doing it. Only 28k miles on truck. If it has that issues wouldnt it shift hard in all the gears or just 1st?. It only shifts hard when the tranny fluid is hot. When fluid is cold it seems to shift fine? Luckily i still have stock ecm if it needs to go in for service. I unlocked ecm to turn dfm off and stop start and if i wanted to mod in future. Sad cause these 10 speeds def seem like a step up in the stock shifting and feel vs the older 8 speed. I have a mdi2 tool but you would need gds2 also right? Funny you mention bad pulley noise cause it seems to make alil chirping noise when warm idling from the tranny area. Dealers up my way prolly havent even worked on these 10 speeds yet. Is it really that common?

[Estep40511]

Thanks for reply. Truck has gm cold air intake and exhaust along with the calibration that gm gave it with the intake. Didnt know these 10 speeds had any issues thats why i was surprised its doing it. Only 28k miles on truck. If it has that issues wouldnt it shift hard in all the gears or just 1st?. It only shifts hard when the tranny fluid is hot. When fluid is cold it seems to shift fine? Luckily i still have stock ecm if it needs to go in for service. I unlocked ecm to turn dfm off and stop start and if i wanted to mod in future. Sad cause these 10 speeds def seem like a step up in the stock shifting and feel vs the older 8 speed. I have a mdi2 tool but you would need gds2 also right? Funny you mention bad pulley noise cause it seems to make alil chirping noise when warm idling from the tranny area. Dealers up my way prolly havent even worked on these 10 speeds yet. Is it really that common?

Very common. If its making that noise in the trans area, Id take it in and have them take a look at the fluid. chances are it will have debris in it and be metallic looking. The transmission front case cover will need to be replaced more than likely. it has the gear that turns the transmission pump. good luck

[15ltz6.2]

Would it shift hard all the time in your experience? Or not necessarily? Shifts like a shift kit 1-2 when warm but only when fluid is hot. Also like I mention only shifts real hard on the upper rpms as well. Thanks again

[Estep40511]

Would it shift hard all the time in your experience? Or not necessarily? Shifts like a shift kit 1-2 when warm but only when fluid is hot. Also like I mention only shifts real hard on the upper rpms as well. Thanks again

Yes they will shift hard. When the bearing wears out on the front cover side, it causes the pump to bump up pressure....making shifts harder. And if fluid has debris in it thats metallic, it will mess with solenoids on valve body also. Just going off what you said about the pulley sounding noise coming from transmission area, Id be willing to bet its a pump/front cover issue. Also, sometimes the fluid level can be off. seen it on brand new ones, they would be off 2 plus quarts. Would cause all kinds of shifting issues. Id prob let the local dealer just take a look at it, since its covered under warranty.

[15ltz6.2]

Stupid question but should def change ecm back to stock right? Or would they only mess with tcm? Thanks

[Estep40511]

I would change it back if possible.....just so they dont see that and say your warranty is void because of it. We have to check calibrations for about any issue anymore

[15ltz6.2]

Thanks I?ll keep you posted on what they say. I?d post a video here or something if I could? Can?t figure out how to though. The fact that this is only doing it on the 1-2nd shift with heavy throttle and rpm up has me wondering though. All other gears are shifting fine. If pump had an issue think all gears would do it but maybe I?m putting to much thought into it lol.

[15ltz6.2]

Dealer reset tcm they claimed and fluid level was good. Truck seems to be shifting 1-2 alot softer now. I wonder if something could have been screwed up in my tune to do this? I'll post that maybe someone will see something.