Mercury 225 Manual page 63

The warning horn will emit either a continuous beep or
intermittent short beeps. This will alert the operator and help
identify the following listed situations. Refer to the
Troubleshooting section for specific information. For visual
display of the specific engine functions and for additional engine
data, refer to SmartCraft product information.
ENGINE GUARDIAN SYSTEM
The Engine Guardian System monitors the critical sensors on
the engine for any early indications of problems. The system will
respond to a problem by emitting a continuous beep and/or
reducing engine power in order to provide engine protection.
If Guardian System is activated, the system must be reset before
the engine will operate at higher speeds. Moving throttle lever
back to idle, or to the required reduced throttle position, resets
the system.
Problem
Power Up/
System Check
During Engine
Break‑In
Low Oil in
Engine Oil Tank
Critically Low
Oil in Engine Oil
Tank
Oil Pump
Electrical
Failure
Throttle
Position Sensor
Failure
Overspeed
High Engine
Temperature
eng
FEATURES AND CONTROLS
Horn
Single Beep
4 Beeps... 2 Minutes
Continuous Beep
Continuous Beep
Continuous
Intermittent Beeping
Continuous Beep
Continuous Beep
Monitor
Display
Yes
No
Yes
Off
Yes
Yes
Yes
Yes
Yes
51
Guardian
Activated
N/A
No No
Yes
Yes
Yes
Yes
Yes
Yes
Percentage
of Full
Engine
Power
Available
N/A
100%
95%
5%
5%
95%
65%
From 100%
down to 4%