The first thing to do is to be sure the computer is awake. Turn the key on and check reference voltage to the tps, cam and crank sensors. If there is full reference voltage, check to be sure the ASD relay is engaging when trying to start the engine and that there is power to the injectors and coil/coils when cranking. IF there is no power to the injectors or coil when cranking and the ASD relay is not engaging, then we might have a bad cam or crank sensor (or a valve timing issue).

If there is no reference voltage to these sensors with the key on, then the computer might not be waking up. We will need to check all powers and grounds going into the computer with the key on. This includes, all powers through the computer fuses, fusible links and even the ignition switch.

Hint: Sometimes the cam and crank sensors can short out and pull the computer down temporarily. If all powers and grounds check out and we still do not have any reference voltage to the cam, crank or the tps, then disconnect them one by one with the key on to see if the reference voltage comes back. If so, then one of the sensors is bad and will need to be replaced.

This is because the computers on your vehicle are not communicating with each other over the BUS circuit. Any sensor or module on board your vehicle can short out causing this problem. You will need to track it down.

Can you check for reference voltage going to the TPS voltage on the throttle body for me with the key on and let me know? This will help out big time.

This is what electrical parts do when they go bad. They short out intermittently.