[Nimair.ZL1]

Hi folks,

Quick question for all you Zl1 folks. My car has a T87 TCM. When the car was originally read it had the T87 TCM in it. It was found that the TCM was defective so it was sent back and replaced. My question is that will I have a problem uploading a tune that was modified with the old TCM data into my car which has the new TCM. Since both TCM were synced, the same VIN will it create a problem?

[2018ZL1]

TCM's need to be unlocked in order for you to flash it... I could be wrong but that's what it looks like.

[Joshinator99]

Originally Posted by Nimair.ZL1

Hi folks,

Quick question for all you Zl1 folks. My car has a T87 TCM. When the car was originally read it had the T87 TCM in it. It was found that the TCM was defective so it was sent back and replaced. My question is that will I have a problem uploading a tune that was modified with the old TCM data into my car which has the new TCM. Since both TCM were synced, the same VIN will it create a problem?

SO... the '23 ZL1 has a T93 TCM, not a T87/T87A. Unless you bought a T87 from HHP or so and did that conversion back when HP Tuners did not support the T93...?

You cannot read anything other than a stock tune in the T87 (and I'm assuming the new T93 is the same way). Even if you have a modified file UPLOADED, when you read it, it will read as a stock file.

All that said... when you say "It was found that the TCM was defective"...who are we talking about... dealership? HP Tuners? Local tuner? And as @2018ZL1 said, any new TCM will need to be "unlocked" by HP Tuners before you can upload a new tune.

[Kerry]

vin is not stored in tcm but linked to hp tuners in someway hence the reason u can not flash without internet connection.

You can not read a tcm period. U get a stock flash read from hp tuners when u try to read it. You or they will not transfer credits or flash to another tcm. They hp tuners say that the dealer can read and write to the tcm after they unlock it but my dealer could not. t87a

I personaly am stuck as the dealer says my tcm is bad, but i think maybe my valve body as i can write to my tcm and change it. I will know in a few days what is bad.

I stuck 2 solenoid's in the valve body. Then all i had was reverse and 3rd gear. Got them unstuck by dealer but now real hard shift from 1 to 2 sometimes barking the tires, 5 to 6 is hard but not as bad as 1 to 2.

This is what happens when u make the mistake of having the down shift higher than the upshift

[Nimair.ZL1]

Originally Posted by Joshinator99

SO... the '23 ZL1 has a T93 TCM, not a T87/T87A. Unless you bought a T87 from HHP or so and did that conversion back when HP Tuners did not support the T93...?

You cannot read anything other than a stock tune in the T87 (and I'm assuming the new T93 is the same way). Even if you have a modified file UPLOADED, when you read it, it will read as a stock file.

All that said... when you say "It was found that the TCM was defective"...who are we talking about... dealership? HP Tuners? Local tuner? And as @2018ZL1 said, any new TCM will need to be "unlocked" by HP Tuners before you can upload a new tune.

Hey boss,

Yeah at the time the T93 TCM unlock wasn’t available so I had to go with the HHP TCM. By defective I mean the car wouldn’t shift gears or anything but that TCM was licensed with Hp tuners. When the stock ECM was pulled the stock TCM file was pulled. After that it was sent back to HHP to replace and then the new TCM was put in and licensed. My question is that if the file that is being modified is from the old TCM, will I have a problem uploading that file to this TCM? Both TCM are licensed through my mpvi3

[Kerry]

u can put any file tcm, into any licensed tcm dont matter so i think the answer to ur question is yes. And no u can not read the tcm it does not work that way. if u had a tune on the laptop from ur tuner ect u can for sure put that tune into an unlocked tcm with the 4 credits.

If u read the tcm u had in the car it will be a stock file that is downloaded from hp tuners during the read process. The tcm is not readable from ur laptop using hp tuners.

ecm yes tcm no,,,,,,, so sounds like u will be putting a stock file in the new tcm.

It tells you that when u try to read the tcm

[Nimair.ZL1]

Originally Posted by Kerry

u can put any file tcm, into any licensed tcm dont matter so i think the answer to ur question is yes. And no u can not read the tcm it does not work that way. if u had a tune on the laptop from ur tuner ect u can for sure put that tune into an unlocked tcm with the 4 credits.

If u read the tcm u had in the car it will be a stock file that is downloaded from hp tuners during the read process. The tcm is not readable from ur laptop using hp tuners.

ecm yes tcm no,,,,,,, so sounds like u will be putting a stock file in the new tcm.

It tells you that when u try to read the tcm

What I mean to say is that I sent that file to my tuner to modify. The stock tune I sent him was from the old TCM. I’m wondering if my tuner modifies that file will I be able to write it to my TCM, no problem. The current TCM in my car is licensed already

[Kerry]

Originally Posted by Nimair.ZL1

What I mean to say is that I sent that file to my tuner to modify. The stock tune I sent him was from the old TCM. I’m wondering if my tuner modifies that file will I be able to write it to my TCM, no problem. The current TCM in my car is licensed already

YES!! you can no problem

[Nimair.ZL1]

Originally Posted by Kerry

YES!! you can no problem

Perfect! Have you tried to do this before?

[Kerry]

Originally Posted by Nimair.ZL1

Perfect! Have you tried to do this before?

yes i could send u a file and u can write it to the tcm with hp tuners. any tcm file from anyone unless they lock it somehow but unlikely