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I have a 2006 GTO that I have a rather confusing no crank no start condition with. It's not throwing any codes, vehicle anti-theft system has been disabled with HP tuners and it has a brand new key fob, new battery, new starter,AND new ignition switch. I have been through all of the relays and fuses and had to replace a couple of relays due to corrosion on them, specifically the engine controls relay and a starter relay under the hood, and on the inside fuse panel I replaced the ECM TCM control relay 1 and ECM TCM control relay 2 just because. I am not a pro, but I have been doing most of my own work on my cars and I can pretty easily find my way around on a vehicle and I am familiar with all the common issues and problems and I really don't know what I could be missing. I have found and cleaned every ground, I think, and I have replaced the positive battery cable to the alternator. I am getting voltage that reads battery voltage when I turn the key to the start position and everything looks great up to the starter relay. At the relay I have battery voltage on pin 30 which is constant I have good ground at the starter on pin 87 and with the ignition in the on position I have battery voltage on 85. Pin 86 I believe is a ground control that is supposed to receive a ground from the computer, but it's not. As far as I know, the BCM and ECM are both communicating because that is the way I programmed my key fob just by leaving it in the Run position. Help?
With multiple new components, a non-stock tune and evidence of corrosion in the power distribution block, there could be a number of things going on.
I would firstly start by looking through anti theft and starter relay request/command data PIDs to ensure that the car is not seeing or lacking a critical input that would inhibit starter operation.
A couple quick checks I like to make for a no crank is the park input (does the car know it's in park?), and the block ground (cleaning the grounds is not the same as checking the grounds).
when you ground the start relay, it is starting, correct? make sure the car is in neutral or park so you dont run yourself over. Also, like Noah said, make sure the car is is being recognized that it is in park or neutral. You can try holding the key in start and moving the gear selector back and forth if you do not have a proper scanner as a quick test.
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