Need help on a mercruiser alarm code issue. My 350 mag mpi has mercruiser VesselView mobile connected to it so I can view data on my phone or any Bluetooth device. It runs great with no problems, no overheating, good oil pressure, everything seems to be normal but once I hit 3500 RPM the 2 beeps every minute alarm sounds. If I open the throttle to wide open for about 10 seconds it goes into guardian mode with a constant horn but does not limit power only beeps until I put it back in neutral and then returns to 2 beeps every minute. So what I assume it is is seawater pressure sensor because my motor is raw water cooled. I can view the sensor PSI output on the VesselView. It was reading 41.3 and would not move. I figured this was wrong and the sensor was bad causing the issue. I ordered a new one and installed. The sensor now read 0 PSI at all times, and it threw a code for “BLOCK COOLANT PRESSURE, INPUT CIRCUT BELOW THE VALID LIMIT”. Figured bad sensor, brought it back to the dealer and got a replacement, now it reads 36.2 all the time and doesn’t change. still has the 2 beeps over 3500 RPM but doesn’t throw a code to tell me what it’s for. Can’t figure out what is going on here, I’m assuming the actual pressure is good because my temps are always good and in check. I can touch the risers no problem while running they do not get too hot. Anyone have any issues or tips to look into? Thanks!
