Guardian Protection System; Guardian System Activation - Mercury 150 EFI Service Manual

Guardian Protection System

The guardian protection system monitors critical engine functions and will reduce engine
power accordingly in an attempt to keep the engine running within safe operating parameters.
IMPORTANT: The Guardian System cannot guarantee that powerhead damage will
not occur when adverse operating conditions are encountered. The Guardian Sys-
tem is designed to (1) warn the boat operator that the engine is operating under ad-
verse conditions and (2) reduce power by limiting maximum rpm in an attempt to
avoid or reduce the possibility of engine damage. The boat operator is ultimately
responsible for proper engine operation.
Guardian System Operation with Gauges
Smartcraft Gauge/Monitor

Guardian System Activation

Function
Cooling System Problem
Oil Level Is Critically Low
Oil Pump Failure
90-883728 JULY 2001
System will sound warning horn and display the
warning message.
Warning Horn
Sound
Continuous Engine Guardian System is activated. Power
limit will very with level of overheat. Shift out-
board into neutral and check for a steady stream
of water coming out of the water pump indicator
hole. If no water is coming out of the water pump
indicator hole or flow is intermittent, stop engine
and check water intake holes for obstruction. The
Guardian system must be RESET before engine
will operate at higher speeds. Moving throttle
Continuous Engine Guardian System is activated. Power
limit will limit engine speed. The oil level is criti-
cally low in the engine mounted oil reservoir
tank. Refill the engine mounted oil reservoir tank
Continuous Engine Guardian System is activated. Power
limit will limit engine speed. The warning horn is
activated if the oil pump should ever stop func-
tioning electrically. No lubricating oil is being
WIRING DIAGRAMS
Description
lever back to idle resets the system.
along with the remote oil tank.
supplied to the engine.
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