T56 reverse lockout problem

[badazz81z28]

I'm not the OP, i was just asking... The LS7 and LS3 both use e67.

Based on what i see the OP should have an E38 ECU if its from a 2007 Silverado. Assuming he bought both the ECU and harness from PSI, it should be wired for reverse lockout. He could possibly have that ECU overwritten with a base tune from an LS2 Corvette with manual wich i belive had e38 also?

The E67 isn’t actually a LS3/LS7 ECU. A factory ECU for these engines was mainly the the E38. Most of the new trucks, Hummers, LS9 and some LS3s saw the E67.
Based on my limited tuning knowledge, the car being and auto or manual is not part of the tune. When you move a tune from one ECU to another, your just changing running parameters.

Its important to know what ECU the OP is running. It may not be wired correctly. The signal from the computer is a ground, you would need to run a 12v power source to make it work.