Fault Information; Guardian Protection System; Guardian Warning System Control Matrix - Mercury 25 EFI Service Manual

Fault Information

CDS Screen
Fault Status ‑ Active Faults
CDS Screen
Engine Speed
Baro Pressure
Manifold Pressure
Throttle Position
Ignition Timing
Data List IAC Duty Cycle
Engine Coolant Temperature Cylinder block water temperature.
Fuel Flow Rate
INJ Pulse Width
Low Oil Pressure Switch

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 Protection System cannot guarantee that powerhead damage will not occur when adverse
operating conditions are encountered. The Guardian Protection System is designed to 1) warn the boat operator that the
engine is operating under adverse 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 Warning System Control Matrix

The warning horn will emit either a continuous beep or intermittent short beeps and the engine speed will be limited. This will
alert the operator and help identify the following listed situations.
90-8M0105568 eng MARCH 2016
Display
ACG Coil 1, 2, 3
IGN 1, 2, 3
INJ 1, 2, 3
Fuel Pump Circuit
ISC
Throttle Position Sensor
Intake Temperature Sensor Intake temperature sensor fault code #13.
Water Temperature Sensor Water temperature sensor fault code #14.
Pressure Sensor
Oil Pressure Sensor
Display
ACG Stator voltage driving the engine operating systems
Engine RPM
The amount of voltage the ECM is receiving through the engine stator or
Driver Power
diagnostic cable.
Ambient air pressure.
May be referred to as MAP (Manifold Absolute Pressure).
Percentage of throttle angle.
Ignition timing displayed in degrees BTDC.
ISC (Idle Speed Control) activation percentage 0 ‑ 100%.
Amount of calculated fuel consumption.
Fuel injector activation duration ms (milliseconds).
Low oil pressure displayed in the CDS as:
•
•
Ignition key is OFF, lanyard stop switch active: displayed in the CDS as ON.
Stop Switch
Ignition key is ON, lanyard stop switch is open: displayed in the CDS as OFF.
Fault Information
ACG Coil faults #1 through #3
Ignition coil fault code #4 through #6.
Fuel injector fault code #7 through #9.
High pressure fuel pump fault code #10
(Idle Speed Control) Fault code #11. May be referred to as IAC (Idle
Air Control).
Throttle position sensor fault code #12.
Pressure sensor fault code #15. May be referred to as MAP
(Manifold Absolute Pressure).
Oil pressure sensor fault code #16.
Data Stream Information
Engine running ON (adequate oil pressure)
Engine not running OFF (low oil pressure)
© 2016 Mercury Marine
Troubleshooting and Diagnostics
Description
Description
Page 3B-5