Merc 5.0 mpi alarm out of the blue?

2005 5.0 MPI Bravo alarm beeps twice every minute

I've seen a few older posts about the same problem I'm having and was hoping there was some newer insight other than limping it back to the shop.

I started to get two loud beeps about a minute apart... (after a weekend of smooth running), and on the way back I stopped to put up some canvas and saw the one engine died when I slowed to neutral. Finally I was able to start the S. engine and keep it running in neutral (1000 rpms)? so I had power steering for the port engine and get back across the Bay before nightfall. I see a lot about an idle sensor(?) that folks seems to think is the problem ($80) and wanted to ask you all if you've heard about this and is correct and my first step.. Fluids and temps were fine on both engines..... Just can't keep it (S. engine) running at an idle and then shift into gear before it stalls.

Thanks for any help.
Bill and Carrie Baker
"Carrie Me Away"

Re: Merc 5.0 mpi alarm out of the blue?

That double beep about a minute apart is your engine telling you it has a problem. Like your oil pressure is too low. Your oil level is too low. Read your owners manual. It tells you all the different reasons you get a double beep at one minute intervals. It's an alert system that is built into the Merc. ECMs. An audio version of the check engine lightThat will give a place to start looking.
Or, swing it by the local merc. dealer and ask them to hook it up to their diagnostic tool. That will tell you exactly what sensor triggered the signal, The temprature of the engine when it happened, the oil pressure, vacuum, map, etc, etc.
You can guess all day long and spend a fortune trying this or that you heard from us, or you can get an accurate diagnostic reading from any shop that works on mercruiser engines for $40-$80