'94 C1500 no fuel pump relay signal

[n2stc]

I have a '94 c1500 pick up with a V6. The fuel pump relay is not triggered at times for start up ( no 5 second activation). Bypassing the relay, allows it to start. I suspect a bad connection between the relay and ECM. Anyone know what pin on the ECM controls this? What the ECM needs to provide the start up signal?

Thanks for any help you can provide,
Stan