Tundra 2005 V8 P0335 code

I have installed a new sensor and have traced the wires most of the way back to the engine control module. I have disconnected plugs 1 and 3 so far but feel like I am probably going the wrong direction. Can a mobile auto electric service test ecm or how can I tell what position the crankshaft position sensor circuit wires plug in to the ecm?
I just don't want to spend a bunch of money for a failed diagnosis.
Thanks! Skaut