So we just finished up a head gasket job on my G37X and now the car won't start. We have no injector pulse. Noid tested it to get that data. We are getting high voltage codes from the throttle position sensor and the accelerator pedal position sensors. We know timing is perfect and we built oil pressure in the motor after we put it back by turning it over without spark. VVEL sensors are in spec range. The only codes we are getting are the TPP and APP high voltage codes. We have narrowed it down and have gotten to the point where we know there is either a short in the wire harness, a bad ECM, or both. I took the ECM out last night and opened it up and could not see or smell any visible damage indicating that it is bad. The car will also try to fire off of starting fluid and almost idle but will not saty started. I have all the Infiniti tech guides and have gone through part of the diagnostics procedure and we found that there is no short running to the TPS sensors but once you get to step 4 which is the parr where you test the ECM it becomes unclear because I do not know which prongs run to the throttle bodies. I also do not know a sure fire way to tell if my ECM is fried. Do you guys have any idea how I can test these things properly? Thanks.

 

You have the service manuals, yes?
https://www.nicoclub.com/FSM/G37/Sedan/2009/EC.pdf
Throttle position sensor info is on page 195
Diagram with ECU pin numbers is on page 545

https://www.nicoclub.com/FSM/G37/Sedan/2009/PG.pdf
TP info on page 8