Trans relearn lost communication

[dieseladdiction23]

Hey guys, I have a question, I took my truck to the dealer today to have the fast learn procedure done on my newly built transmission and they weren't able to do it. Here is what they wrote "attempt to perform quick learn process, keeps loosing communication with vehicle, attempt with other scan tool, same result, Preset taps 0.60 Possibly due to aftermarket programming on pcm". Should I have put my truck back to stock before doing this? They kept saying they were trying to program it, does that sound right? im not to familiar with how you do the relearn with the tech 2. Thanks for any info

 

[blue8135]

I've been told that any time you take it to dealership, return all programming to stock calibration.

 

[ceide4489]

X2

 

[Cougar281]

I HIGHLY doubt your tune caused it. from the pespective of the fastlearn processes, the TCM doesn't care about the ECM's tune. The main reason people put trucks back to stock before going to the dealer is if it's under warranty, so the dealer doesn't see the aftermarket tune (pointless with LMM & Newer and the CVN History). Do you have any aftermarket electronics that interface with the Class2 databus? Some kind of Radio interface maybe? I've never done a fast learn on my truck with a stock tune. Always been modified, both when it was still a LLY and after I converted to over to LBZ.

Returning the truck to stock for a built transmission's relearn processes would be counter productive... you'd go through the processes, at which point the transmission has learned the stock power level and a lot of cells have transitioned over to slow adapt, so now when you put your modded tune back in, now the TCM has to relearn the shifts for the higher power level with the cells in slow adapt, which will take longer.

 

[dieseladdiction23]

Yea I was thinking the tune shouldn't cause that but wasn't sure, but yes I have a aftermarket head unit, and a aftermarket alarm, so maybe that was causing it?

 

[Max Attitude]

Idk if you figured it out yet but with my aftermarket deck/alarm dinger...I have to unplug it to get the Predator programmer to work.

 

[Cougar281]

If something aftermarket connects to the Class2 databus, such as some of the adapter harnesses that include a relay for ignition power that allow you to use an aftermarket stereo without adding a power wire (There is only a B+ wire there, the stock HU uses Class2 to turn on and off), then yes, that can interfere. It's not uncommon for aftermarket devices to not listen to the 'Silence' command sent out on the busses that's meant to keep chatter down while doing programming and diagnostics.

 

[blk smoke lb7]

Never go to the dealer they can mess up a tuned truck in a hurry,the trans will learn on its own just by slowly breaking it in and figuring out where it wants to be.
You wouldn't want to set it back to stock if your doing a relearn .......it will relearn stock tuning until you turn it up and then it has to relearn again.

 

[blk smoke lb7]

If something aftermarket connects to the Class2 databus, such as some of the adapter harnesses that include a relay for ignition power that allow you to use an aftermarket stereo without adding a power wire (There is only a B+ wire there, the stock HU uses Class2 to turn on and off), then yes, that can interfere. It's not uncommon for aftermarket devices to not listen to the 'Silence' command sent out on the busses that's meant to keep chatter down while doing programming and diagnostics.

X2 that's why they say to pull the stereo and on star fuss before programing.