5.0 MPI Fuel Pump Relay fault code

[skibumnh]

I have a 2003 5.0 MPI that is sounding the alarm every minute. I got the TechMate to read the codes, and in additional to the 4 code for sensors that are not installed, I get a 151 Fuel Pump Relay code. I can clear the code, but it comes back after a few minutes. The boat seems to be running normally, and all gauges are within normal ranges. I tried changing the relay, but that had no effect. Does anyone have suggestions as to what could be causing this?

 

[skibumnh]

I also have what looks like a ground wire that is not attached. Could that be the cause? I assume that if something isn't grounded properly, there would be something not working, but I'm no expert.

 

[achris]

That loose ground wire is normal.

 

[achris]

Have a read of this thread, it may help..

https://www.justanswer.com/boat/ak4ud-mercruiser-techs-available-speak-with-getting-fuel.html

 

[skibumnh]

Thanks for that link. I'll start tracing wires.

 

[skibumnh]

Following up here in case anyone finds this in a search. My wiring was all good, but the process of pulling out the relays and the ECU connectors seems to have fixed it. I've had the boat out a few times without the code returning.