My green / blue gen 3 PCM is not commanding TCC lockup on my 4L80e. Car isn't throwing any codes, it isn't misfiring. I turned off DTCs for EVAP and rear o2 sensors.
I am able to trigger the PWM TCC solenoid as well as other solenoids both manually providing ground and power at the correct pins on the trans harness, as well as through an Autel scan tool from OBDII port.
I segment swapped the transmission diagnostic and calibration tunes 4L80e tune from another 2007 express 3500 van with 4L80 using Universal Patcher, and still no changed. I ran a filter for TCC comparing both my bin and the express van bin. The only thing that I saw that I am not sure applies to the 4L80 is that the TCC_Enable_Solenoid_Present is not checked, however I believe the 4L80 doesn't have this solenoid and only the PWM solenoid for TCC, or are they one in the same and this should be checked?




Is there anything else I should be looking at in the tune to get the computer to command TCC lockup?

 

With the 4L80E the TCC PWM Solenoid is one in the same. You need to check the tables for what Vehicle Speed & TPS % it commands Lockup. That's how it works, those are the two values used.

This is the Tune Settings for my 2001 2500HD that has a 4L80E in it. It'll never lockup in 2nd Gear but will in 3 & 4.

 

Very informative.

 

This might add, if you are getting misfire codes, PO300 for example I think that can result in the ecu not locking up as well?