No injector pulse

How did you confirm you have good fuel pressure at the rail? Did you actually check the pressure? If so, what was the PSI? I attached the process on how to test the pressure from the manual. Let's start with this and confirm the fuel pressure is good.

Next, how did you confirm the injectors are not pulsing? I see you said there is positive voltage at the injector but there is always 12 volts when testing with a volt meter. These injectors are a low side driver meaning they are ground control. The PCM provides a ground to operate the injectors.

Let's start with this info and go from there. Thanks

Thank you KASEKENNY1,

The fuel pressure was checked using a gauge at the outlet of the fuel filter. it was 55-60 psi.
Regarding the injectors, I am aware of the presence of 12 volts at one of the terminals, and the negative coming from the PCM is what pulses (was checked with NOID light.
By the way, I read something about a security feature that might prevent starting, can you provide some information about that?

Awesome. Noid light is all I needed to hear. Shows you understand how it is operating.

The security system was the next step so thanks for being on the same page as me.

Does the theft light stay on when you turn the key on or crank the engine? Is it flashing? The only reason I am hesitant about this is because you said it hesitated the day before it would not start. This would not be a security issue. This would be a fuel issue.

However, if the PCM is not firing the injectors then clearly it is due to something shutting it down. Let me know about the theft light and then we can go from there.

Here is a quick overview of possible causes.

The security light flashes every few seconds with the key out of the ignition.
With the key in the ignition and in the on position or while cranking, the security light stays continually on.

Okay. We have a security issue. Let's try a GM trick. Turn the key to the on position and leave it there for 30 minutes just to see if that light will turn off. If it does then it should start. If it doesn't then we may have an issue with the key or greater security system.

Let me know if that works. If not, we need to know if this is a new key or do you have another key that you can try?

Hello KASEKENNY1,
I have tried the GM trick, unfortunately it didn’t work and the light stayed on and no start.
Also, I have no other key for this car. The key seems like a standard key with no chip or battery.

Okay. I think we are getting closer. You are correct that you don't have a more modern key that is considered a transponder but you do have a key that is registered to the ECM. I attached the info about this and you will see that when the light stays on it is detecting an issue most likely with the key.

I would suggest we just get another key and program it to the vehicle just to see what happens as I suspect that is the issue.