I have an 08 with auto trans that I put an older Edge CTS on to read temps and several other items. I just noticed that the CTS shows the trans is locking the torque converter right after shifting into 4th gear and keeps it locked when it shifts into 5th gear. I have no idea what kind of programming has been done to the truck, but I know the DPF and EGR has been deleted. Trans was replaced with a used (I'm assuming) unit before I got it. Is there any way to look at programming with an aftermarket program or am I going to have to take it to a dealer?

 

It's supposed to lock in fourth and fifth gears. It's working as designed.

 

Mark

If it's working as its supposed to, will the converter unlock in 4th if its in the tow haul mode and run up a few RPM before it locks, and the same question for 5th gear? Right now as soon as it hits 4th it locks and stays locked as it shifts into 5th gear.

 

No, it won't unlock in fourth in tow/haul. Unlocking it then would just burn more fuel.