06 Tow/Haul with O/D off

[Tinman]

D/C saw fit to give us the option of O/D off and Tow/Haul on the 06. That's good, but when in O/D off mode, the T/C won't stay locked like in the T/H. Why in the world won't you want the T/C to stay locked in O/D off?? (Sometimes I really wonder what is going on at D/C). Anyway, I drive a lot in O/D off and I need to keep the T/C locked. There are two wires on the shifter to the select switch. I figured one wire was to theT/H and the other to O/D off and I could put a toggle in the O/D off circuit. But the same wire has current in both modes??? Any suggestions??

 

[cerberusiam]

The button on the shifter just signals the ECU to do its thing. You need to wire a switch and resistor inline to the wire that controls TC lockup in the bundle that connects to the trans. On the 05's it was pin 7 that was lockup control. Not sure if that has changed for 06 and what the results might be. Theoretically it should work the same way but... .....