Section 1 - Getting to Know Your Power Package
90-8M0113924 eng DECEMBER 2015 Page 23
Testing the Audio Warning System
1. Turn the key switch to the on position without cranking the engine.
2. Listen for the audio alarm. The alarm will sound if the system is functioning correctly.
Guardian Strategy
The MerCruiser Engine Guardian system reduces the potential for engine damage by restricting engine power when the PCM
detects a potential problem. Below are some examples of what Engine Guardian monitors:
• Oil pressure
• Engine overspeed
• Exhaust manifold temperature
IMPORTANT: Engine Guardian can reduce power anywhere from 100% to idle, depending on the severity of the problem. If
forced to idle, boat speed might not respond to throttle operation.
The PCM stores the fault for diagnostics. For example, if the water inlet becomes partially blocked, Engine Guardian reduces
the available power level of the engine to help prevent damage from decreased water flow to the engine. If the debris passes
through, and full water flow is restored, Engine Guardian restores engine power to normal.
Guardian Strategy
Engine Guardian reduces the potential for engine damage by restricting engine power when the PCM detects a potential
problem. Below are some examples of what Engine Guardian monitors:
• Oil pressure
• Engine overspeed
• Exhaust manifold temperature
IMPORTANT: Guardian can reduce power anywhere from 100% to idle, depending on the severity of the problem. If forced to
idle, boat speed might not respond to throttle operation.
The PCM stores the fault for diagnostics. For example, if the water inlet becomes partially blocked, Guardian reduces the
available power level of the engine to help prevent damage from decreased water flow to the engine. If the debris passes
through, and full water flow is restored, Guardian restores engine power to normal. To avoid recurrence of the problem, contact
an authorized Mercury MerCruiser dealer.