I have an LE5 turbo engine swapped into my 91 240sx and am having problems trying to get it started. I'm assuming the problem is related to the fuel pump circuit although I can't figure out why.
The code it's throwing is
"0x7E8: P0230 - Fuel Pump Primary Circuit (Pending, Current, Old, History)"
It has also thrown
"0x7E8: P0690 - ECM/PCM Power Relay Sense Circuit High (SES, Pending, Current, History)"
but that one hasn't come back since clearing the codes
I'm assuming P0690 is being thrown because I don't have the powertrain relay wired as stock for a Cobalt. I was under the impression it isn't needed to start the car.
Upon reading the service manual, P0230 is caused by the fuel pump relay ground signal wire to C1 Pin 13 either being open, voltage present or with high resistance. I tested the resistance on this wire from the PCM pin to the relay and I'm getting 2.9-3 ohm which seems pretty normal to me. If I apply ground to that pin with the connector removed, the fuel pump relay is switched on and the fuel pump runs as expected. So I'm at a loss as to why the PCM can't switch on the relay.
Even with the relay jumped and fuel pump running, the PCM will not fire the injectors or coils so I still am unable to start the engine. Is there a way to bypass this or will I potentially need to completely re-wire the fuel pump circuit?
Attached is my tune file and a log of a starting attempt.
Pump did not come on with the key at all. Not for a priming period or during cranking. However...
I got it started. Replacing the injectors fixed it. I never did get the fuel pump relay circuit working. I just ended up bypassing the relay altogether and now it comes on with the key.
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