rough shift 1st to 2nd: fast service learn

[persistent]

i've recently done a dod delete, and i also did a transmission fluid flush and filter change. the vehicle had the battery disconnected for long periods of time, and i experienced battery problems to the point i had to replace the battery a few days ago. i am experiencing missed/rough shifts from 1st to 2nd when driving now.

when i did the trans fluid flush, i followed the instructions about getting trans fluid temp up to 167-175 F then filling via the fill plug until it was dripping out. this process is no fun.

i've done some reading and watched some videos that suggest when you're having issues with rough shifting, you should do a "transmission fast service learn". afaict, this entails doing torque converter stalls to get trans fluid temp up to the same range you use for filling - 167-175 F - and then using a scan tool to initiate a fast service learn. this sounds relatively straighforward, but i've found very little information about how to properly execute the fast service learn. i have 4 scan tools that may support the service fast learn.

i suspect the battery being unplugged for so long or the battery problems led to the tcm losing its programming, so it's trying to do a slow adaptive relearn, which is going poorly.

i'm looking for advice on executing the fast service learn or similar procedures that would help fix the rough shift from 1st to 2nd.

 

[swathdiver]

@NickTransmissions

What do you think Nick?

 

[NickTransmissions]

i've recently done a dod delete, and i also did a transmission fluid flush and filter change. the vehicle had the battery disconnected for long periods of time, and i experienced battery problems to the point i had to replace the battery a few days ago. i am experiencing missed/rough shifts from 1st to 2nd when driving now.

when i did the trans fluid flush, i followed the instructions about getting trans fluid temp up to 167-175 F then filling via the fill plug until it was dripping out. this process is no fun.

i've done some reading and watched some videos that suggest when you're having issues with rough shifting, you should do a "transmission fast service learn". afaict, this entails doing torque converter stalls to get trans fluid temp up to the same range you use for filling - 167-175 F - and then using a scan tool to initiate a fast service learn. this sounds relatively straighforward, but i've found very little information about how to properly execute the fast service learn. i have 4 scan tools that may support the service fast learn.

i suspect the battery being unplugged for so long or the battery problems led to the tcm losing its programming, so it's trying to do a slow adaptive relearn, which is going poorly.

i'm looking for advice on executing the fast service learn or similar procedures that would help fix the rough shift from 1st to 2nd.

Check out my 6L80 Information thread, link is in my signature line...There's a link to fast-adapt relearn instructions you can download and follow....I believe the link is called 'Installation Procedures' - this all assumes you have a 6L80/90.

 

[persistent]

i used the cgsulit sc530, my cheapest scan tool, to do the fast service learn.

the shifting issue is substantially improved from earlier, but it still misses every so often. i will update after another few 100 miles of driving if it sorts itself out.

if the problem persists post-fast-learn, i will try a clutch learn for that shift in particular.