I have a 2001 baja 232, 6.2 l. Made a run yesterday on the river. Running about 55 for several miles and when I would come off plane to idle, Guardian Alarm would go off for about 10 seconds. No high temp, voltages look good on the guages,, no immediate sign of trouble. After the first stop I checked the lube bottle, between fill and full. I did top it off, made the next run and stop, same result.. nothing obvious. Made a 3rd run back to the marina,, all good , no alarms. No signs of danger throught out the day. I will have my mechanic look at it this week ( he is out of town til wed)but any ideas you guys may have. Maybe someone had similiar experience. Appreciate everyones input.

could be low oil level, or oil pressure sending unit for the ECM, have it scanned

Your heat exchanger may have some crud run through it. The back pressure when letting off the throttle may be what was triggering the alarm. We ran into that a few years ago, when It picked up some weedy stuff in the spring. Cleaned it out and all was good.

+2 on having it scanned. It is ALWAYS better to know for sure.

For sure will have the engine scanned before the next trip..nail down the issue. Archived a old thread with some info. Boat has 466 hours.
Constant tone alarms are for:
1.) engine coolant temp overheat,
2.) low engine oil pressure,
3.) engine overspeed,
4.) exhaust manifold cooling temp overheat
5.) sea pump PSI low

Low drive oil