Write TCM Failure 08 Pontiac G8 GT

[cadams]

When I write the calibration it goes through the VCM with no problem, when it gets to step 5 on write to TCM is gives me a failure. I close the program, turn the key off and wait the 10 seconds. Turn the key back on and everything seems fine.
It appears that everything is good, I want to know how to keep it from giving me the failure. The first time it did it the transmission was stuck in third gear, it cleared it self up after leaving the car off for a while. Since then I have not had any driveability problems but am still getting the failure on step 5.

[lakemg]

Before you do write the calibration, are you waiting the 10 to 15 seconds? I was having a similar issue with my friends g8 and I think it was because of not waiting. We also later noticed that some of our files were getting corrupted and only have about half the file size that they should have. Check the file size of the tune that you're trying to write to your VCM/TCM. If it's considerably less than 3.4 MB (3,400 KB) then something is wrong with your tune file.

[cadams]

Thanks for replying, I was not waiting long before writing the cal. I will try that tomorrow. The files are in the 3.4 range so that should not be a problem, but I will keep an eye on that. I will reply back tomorrow after I try waiting the 10 to 15 seconds before writing the file. Thanks again.

[cadams]

I waited about 20 seconds before writing and it did the same thing, fail at step 5. I will call tech support in the morning to see if they have any answers.

[jakebdb56]

Make sure you're not doing it in high speed

Also, doing a write entire is the "best" way to make sure everything writes correctly. Just goto flash>write entire>uncheck "high speed mode" and you should be good to go

[cadams]

Thanks jakebdb I have been trying it in high speed, I was just leery of doing the write entire. I will try these changes and see if it works. I have been trying to ge a response from HP Tuners but am having no luck. I hope that is not normal.

[jakebdb56]

Support is usually quick to reply, but a lot depends on how backlogged they are and if possibly one of them is out of the office. Backlogged being the likely issue.

High Speed writing is almost always the problem I have writing to Gen IV PCMs. For some reason there's some PCMs that do it just fine, and others are picky.

[DSteck]

Disconnect your battery for a couple minutes and try again without high speed mode enabled.

[cadams]

I did disconnect the battery but did not try slow speed, I will do that. Thanks for the info.

[Chris@HPTuners]

high/low speed makes no difference for CAN based ECM's.

What exact error message are you getting?

Chris...

[cadams]

Chris,

Ther error message pops up in step 5 of the write TCM. It gives me failure error 22.
It writes all the information to the VCM with no problem, just nothing to the TCM. I am able to pull all the information from VCM,TCM.

[Chris@HPTuners]

if you can please email me (chris@hptuners) the file you are trying to write and also a screenshot of the error.

[jah81592]

I had this issue and the problem was I had the gear selector in N instead of P. Always make sure you put the vehicle in Park and the issue will go away. I have seen this with G8's and Camaro's. I always use high speed write.-j

[Chris@HPTuners]

The problem in this case was a modified (or poorly constructed by GM) calibration. A very strange one that i have never seen before. Anyway, all fixed now

Chris...

[GMRACIN]

The problem in this case was a modified (or poorly constructed by GM) calibration. A very strange one that i have never seen before. Anyway, all fixed now

Chris...

I am having the same problem with a 08 G8. I have emailed you the file!

[wreckwriter]

Oftentimes if you pull the TCM fuse, leave it out for a few minutes then replace it, it will then work.

[jakebdb56]

Oftentimes if you pull the TCM fuse, leave it out for a few minutes then replace it, it will then work.

Yeah, had the same issue last night with a '08 3500 HD with the 6 speed auto. After a read entire the TCM didn't reboot, mph and gear selection indicator didn't work. Had to disconnect power cable to get it to reboot so we could reflash. It was a brain frying experience, but learned a lot after doing so.

[GMRACIN]

Oftentimes if you pull the TCM fuse, leave it out for a few minutes then replace it, it will then work.

Thanks, Tried pulling fuse and even tried disconnecting power for a few minutes but still no luck. Hopefully Chris will be able to help me out shortly!

[wreckwriter]

Did the car have a previous tune with other software, like LS2Edit? If so, could be locked?

[GMRACIN]

Did the car have a previous tune with other software, like LS2Edit? If so, could be locked?

No, It just left the GM dealer with a brand new GM computer.