alarm 496ho
 

any one know what a steady long alarm is for .
it will reduce the power to 1000rpms for a few minutes and then the alarm will go off and all is fine for a few minutes of runing and then it will happen again
thanks
mike

Hey Mike....these things can be hard to figure out sometimes, this is a little something to start with...

Audio Warning System alerts boater of low oil pressure, high engine temperature and low drive lubricant. Standard on all MerCruiser models

Alarm
 

Mike I Used To Have A Baja342 With 496ho's And Had The SAMe Problem And As The Other Post Stated Check Oil Levels Are Water Temp And If It Is Still Happening Then Check Something Call A ( Iack Censor) I Had To Replace One In One Motor Then Two Years Later The Other One Went Out, And The Funny Thing Was I Had Taking My Boat To Three Different Baja Dealers And Not One Could Find The Problem And I Finally Took It To A Independent Machanic And He Found The Problem.


Hope This Helps

The most common cause of a hard (steady) alarm is low drive lube reservoir, but it could be something more serious, so find the source before you run the boat again. You may need to connect a scan tool to find out what the deal is. An IAC failure will not set a hard alarm, so it's not that.

thank's
i will take another look tomorow . and see what i can find . other wise thank god for waranty :)

something else......


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After almost a month of troubleshooting, here was the cause of the problem. Looking at the waring diagram, it appearred that the ECM ( as well as the oil, temp, outdrives sending units) also had an input to the warning buzzer. When my mechanic performed the diagnostics with the engine off, the buzzer stayed on but did not show a fault code, indicating there must be a short in the harness or one of the three sending units were bad. However, running the same diagnostics with the engine running indicated a "buzzer" warning, and a code indicating the IAT sending unit could be bad. He checked it, and it was shorted. Ordered another one, replaced it, and the buzzer went back to operating the way it is supposed to. Turn the key on, three short beeps for a systems check, and the buzzer turns off. Went for an offshore run this weekend and all worked as advertised. Congrats to my mechanic for his preserverance.
http://boards.trailerboats.com/cgi-b...c;f=4;t=002010

Good info, but that is a totally different system diagnostic system, and IAT failure can not cause a hard alarm on a PCM555 system.

Good to know that somebody knows what they are talking about...I glanced and saw IAT in your other post(without really reading it) and found that on another forum so I posted it.

It's really difficult finding info online relating to this problem...although, I know that I've read about it before. :(

Mike, Call Mac @ Doller. You can have other issues unbeknowest to you. You must have the computer to figure out whats going on. The engine has what they call a Gaurdian mode when something goes wrong.