Looking for 06 Holden T42 Trans Tune

[vette5797]

Apparently, from the research I've been doing, the '06 Holden Commodore and HSV use E38 ECM and T42 TCM. Earlier and later Holdens use a different combination. There are a number of posts on this board and others that have various trans problems using this ECM/TCM combo, and there have been suggestions that this file may be the answer to our problems. There is no TCM file on HoldenCrazy. If some kind person would post a TCM file on HoldenCrazy or here I think there would be a number of us that would be greatly appreciative.
Also, for my own problem, does anyone know for sure if the 06 Holden transmissions have an ISS (input speed sensor).
Thanks, Gary

[Taz]

Hello Gary,

Checked the T42 TCM tune I have from a 2006 Holden VZ - equipped with a 6.0 L (L76) and 4L65 / 4L70 transmission. It uses an ISS …… FYI.


Regards,
Taz

[vette5797]

Thanks Taz. Appreciate the quick response and all your previous help. Not the answer I was hopeing for though. Still working on my TCC P0741 unlocking problem that you've been trying to help me with. I'll keep digging. Thanks again, Gary

[ScarabEpic22]

Gary, do you know for sure the that ISS is causing the problem? I ask because I know of someone online who swapped a built 4L60E into his TrailBlazer SS (factory 4L70E w/ISS) and didnt touch the TCM tune and hasnt had any glitches at all.

[vette5797]

Hi Eric. Thanks for the help. No, I don't know for sure that it's the the lack of ISS or what's causing the problem. Apparently the ECM or TCM in my configuration runs tests on the TCC. My combination is failing the tests and shuts off the TCC lockup after a few miles on each drive. I can see this by scanning the TCC PWM and TCC pressures. After the 2 drive cycles I get the P0741 DTC - TCC unlocked code. Everything is brand new over the counter from GM. In the TCM, D7026 is set to NO ISS. P0716 and P0717 are set to NOT REPORTED. It's not missfires, I changed those settings as directed by other helpful people on this site and it didn't change anything. Maybe I need to look in an entirely different direction, but I don't know where. This project, 62 Corvette/ LS3/4l65e has been otherwise finished for about 2 years, but I can't seem to get it all quite together. There's been discussions regarding the brake switch, but I've disconnected it completely and have the same results. I may have been focused on the ISS (lack of) from other research on these forums.
So, new focus. Does anybody have a list of parameters that will give code P0741?
Again, Eric, Taz, and others, I really appreciate your help. I'll eventually figure this out. Thanks again, Gary

[Taz]

Hello Gary,

Took another look at your tune files from your previous post - made some changes to both ECM / TCM files. Give them a try - may not make any difference.


Regards,
Taz

[vette5797]

Taz, that's exactly what I was going to try next, not reporting P0741 and see what happens. The brake switch changes may help too 'cause from what I can tell so far I'm not sure that these newer controllers need the brake switch for TCC. I don't have cruise, so don't need it for that. I'll probably get a chance to flash your changes in within the next few days and get back to you here with the results. Thanks again for all your help. Gary

[joecar]

Also try this: for the DTC's you set to Not-Reported, also set them to MIL (yes MIL) to see if there's any difference.

I know that for some DTC's that are set to Not-Reported, also setting them to MIL makes the test complete immediately.

[Taz]

Hello Gary,

A brake switch should be used for proper TCC function.

Brake switch function:

a fused 12 volt power supply to the PCM when the vehicle’s brakes are NOT being applied
applying the vehicle’s brakes interrupts this 12 volt circuit (turns it off)
similar to a cruise control type switch mounted on the brake pedal assembly - that “turns off” the cruise control when the vehicle’s brakes are applied
the PCM uses this signal to control torque converter lockup function
if not connected, DTC P0719 will be stored (this DTC should not illuminate the MIL)
if connected to a power source (but without the brake switch - ie. constant power), DTC P0724 will be stored (this DTC should not illuminate the MIL)

DTC P0719 and P0724 are still active in your TCM tune, but they shouldn’t turn on the MIL.

Your question about P0741 sent to into a stack of manuals - so if the changes to the tunes work, you in a way led me to the answer !


Regards,
Taz

[CV8IIM6]

Good luck, hope this helps.:)

[vette5797]

CV8, thanks for posting the tune. As Taz reported, it does show it uses an ISS so won't help my problem. Thanks for taking the time to help. Hopefully by the end of the week I'll be able to try Taz and Joecars ideas. Thanks to all of you. Gary

[vette5797]

Hey guys. Just wanted to let you know that I flashed in Taz's changes and no longer have the TCC unlock problem and the associated P0741 code. Basically he turned off the P0741 reporting and that apparently eliminated the tests that were causing the TCC to unlock. Thanks Taz, Joecar, Eric and all of you for the help. You guys are the greatest for all the help you give to not so smart guys like me. Thanks again, Gary

[ScarabEpic22]

Great to hear Gary!

Must be nice to have the car behaving on long highway trips, I know how frustrating it is watching the RPMs (and exhaust note!) fluctuate while cruising because the TCC is locking/unlocking/locking all the time.