We've been having a discussion on the rolls of the fuel pump relay and the oil pressure switch near the dizzy. I know the ECM turns on the FP relay for a couple seconds with KOEO to prime the system. Then, I think it turns on the FP when cranking (when sensing ignition pulses from the ICM). Then the OP switch sends voltage to the pump when it sees pressure.
The question is, does the ECM turn off the relay after a while so the OP switch can shut off fuel if it loses pressure to save the engine from catastrophic failure due to no/low oil pressure or does it use them both for redundancy? I've seen articles claiming both, maybe someone here has hacked the code, or something like that, and can give us a definitive answer? TIA
Edit: This is on a 88-91 C/K 5.7L if it matters?
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