Mercury 150 EFI Service Manual page 197

WIRING DIAGRAMS
BATTERY (a)
When the electrical system is not charging, or the battery charge is low, the warning message
is designed to come on and the Engine Guardian System will start limiting engine power. If the
message appears immediately after starting, it is possible that the engine alternator can re-
charge the battery after operating awhile. If this message appears while driving or comes on
after starting and continues to be displayed, check engine to determine the cause of the prob-
lem and to avoid being stranded with a dead battery. To help the alternator recharge the battery
quickly, reduce the load on the electrical system by turning off any unneeded accessories.
NOTE: The throttle will have to be returned to idle to reset the system.
ENGINE DATA BUS (b)
This message tells you that the data communication link between the tachometer and engine
is not connected.
LOW FUEL LEVEL (c)
This message serves as a warning that the fuel level in the fuel tank is critically low. You
should stop for fuel immediately to avoid running out.
LOW OIL LEVEL – OUTBOARD 2 STROKE ONLY (d)
This message serves as a warning that the oil level in the remote oil tank is low. You should
stop and refill the oil tank immediately to avoid running out.
FAULT-SENSOR (e)
This message informs you if one of the sensors is not functioning correctly
If the throttle sensor has failed, the warning horn will sound a continuous beeping and the
engine will not reach its full power.
If the throttle sensor and manifold pressure sensor both fail, the warning horn will sound a con-
tinuous beeping and the engine speed will stay at idle.
If the temperature or block pressure sensor should fail, the Engine Guardian System will limit
the maximum engine power to 75 percent.
FAULT-WATER TEMP (f)
This message informs you that the sensor for measuring outside lake/sea water temperature
is not functioning correctly.
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a
b
c
F
3
4
2
5
1 6
0 7
d
E F
e
f
90-883728 JULY 2001