T42

[camaro68]

How do you change the OS of a t42 module. Or is it even possible and if so where do you find the files at?

[Taz]

Starting multiple threads with the same issue often leads to confusion.

In your other thread GMPX answered your question - EFILive is able to completely flash T42 controllers (i.e. no Tech 2 type device required - generally).

Your 2005 Corvette was the one and only year that the Corvette used a T42 TCM. The OS is very old - as T42 TCMs were used in Trucks until 2013.

It has been awhile since I tested the limits of the T42, but if memory serves, when attempting to fully program a T42 using EFILive software, these seemed to fall into 2 camps - older vs newer. As an example, a T42 that had a 2007 OS could not be programmed with a 2013 OS using EFILive.

In your case, where you wish to fully program a 2005 T42 OS using EFILive, I would suggest sourcing a T42 from a 2005 to 2008 vehicle from your local salvage yard. I am guessing (because you never posted any tune or OS numbers), that the T42 that you were unsuccessful in flashing likely had a 2010 or newer OS in it.

[camaro68]

Thanks for the help. After installing the new T42 in the car I cannot get the speedometer to work in the Corvette. I can see the speed on the dashboard of EFILive but not in the car. Is this because of the mismatch in the VIN in the new T42 Module?

[joecar]

Taz, thanks.

[Taz]

Thanks for the help. After installing the new T42 in the car I cannot get the speedometer to work in the Corvette. I can see the speed on the dashboard of EFILive but not in the car. Is this because of the mismatch in the VIN in the new T42 Module?

Post your ECM and TCM tunes when you have a chance - will take a look.

If I recall - I think I used the V7 ScanTool to change the VIN in the T42s.

[camaro68]

Here are both the ecm and tcm files.

[Taz]

The T42 TCM tune that you posted is running OS 24232637 - that was used in 2006 Holden models, and I believe was paired with an E38 ECM.

You need to flash the T42 with a 2005 Corvette TCM tune (OS 24231674) - to match your 2005 Corvette E40 ECM.