I'm having a problem with my 2007 maxima, I had to change out the dashboard harness do to some wire burning up, once i changed it the car cranks but doesn't turn over, I got a code of p0603 (keep memory alive) some tell me i gotta reprogramed the ecm or it's the a ground wire, if anyone could please help and let me know where do I check for the ground for it or if I do need to reprogramed my ecm

 

You're going to have to dig through the FSM, it will be easier than telling you the two grounds to check.

The Dash harness does hold two key grounds for the ECM. All of the connections will be noted by M at the beginning (M = Main Harness aka Dash Harness)

https://www.nicoclub.com/service-man...F2008%2Fpg.pdf

I also have an 08 ECU for sale if your ecu was fried during the fire. Will work in your '07 just fine.