T42 4L60e TCC tuning

[jpgmtech]

Hi all,

Got a 2007 new-style truck, 4.8 turbo. TCC seems to lock at 130kms/hr no matter what I do with the tables. Any secrets?

Joel

[Taz]

Hello Joel,

I take it you don’t want the TCC to lock at all ?

D2201 (TCC Apply Speeds - Second Gear)

• all shift patterns set to 511 Km/h
• TCC won’t be locking

D3201 (TCC Apply Speeds - Third Gear)

• shift pattern B set to 511 Km/h
• other shift patterns set between 62 Km/h and 148 Km/h
• TCC will lock under some conditions
• these shift patterns should be modified (i.e. 511 Km/h) to prevent TCC for locking

D4201 (TCC Apply Speeds - Fourth Gear)

• shift pattern B set to 511 Km/h
• other shift patterns set between 99 Km/h and 150 Km/h
• TCC will lock under some conditions
• these shift patterns should be modified (i.e. 511 Km/h) to prevent TCC for locking

Regards,
Taz

[jpgmtech]

Thanks Taz,

I've put these tables both up and down and it doesn't seem to change WOT lockup at all. It always locks around 130kms/hr, period.

Joel

[Taz]

Hello Joel,

Just took a quick look … you will need to go through table by table to catch everything ..


Set D2201 / D3201 / D4201 to 511 Km/h in all patterns.

Set D2202 / D3202 / D4202 to 506 Km/h in all patterns.

Set D7013 to “TCC Off”.

D7014 is part of the trans slipping test protocol – not sure if this test will lock the TCC, or just set a DTC. D7014 is currently set to 48 Km/h. Depending on if you want the slip diagnostic to run – this could also be set to 506 Km/h to determine TCC effect – if any.


Regards,
Taz

[jpgmtech]

I'll give it a try, see what happens. The way it's acting there would seem to be a separate WOT TCC table/parameters hiding somewhere we can't get at them.

Thanks again!

Joel

[jpgmtech]

This just prompted me to check back and look at a T42 file I have from 2007 with xxTuners software, they do show separate WOT TCC tables from the standard TCC tables. Hmmm....

[Taz]

D7013 mentioned previously - is from the general parameters (not WOT). You will have to go through your tune table by table. In the WOT parameters some shifts are set to vehicle speed only, other shifts are set to speed and RPM.

Might be helpful to also post the ECM portion of this TCM tune - they need to function together in the vehicle.

Regards,
Taz