Cylinder Head Temperature Sensor; Air Temperature Sensor - Mercury 150 EFI Service Manual

IGNITION

Cylinder Head Temperature Sensor

Two (2) temperature sensors are used to provide temperature information to the ECM.
One sensor is mounted in each cylinder head.
The ECM uses this information to increase injector pulse width for cold starts and to retard
timing in the event of an over-heat condition. Should a temperature sensor fail, the ECM
will default to a temperature value of 32 F (0 C).
a
a -
b -

Air Temperature Sensor

The air temperature sensor is mounted on top of the air plenum. The ECM regulates fuel
flow, in part, based on manifold air temperature. As air temperature increases, the ECM
decreases fuel flow. Should the air temperature sensor fail, the ECM will default to a tem-
perature value of 32 F (0 C).
a -
Page 2A-18
Cylinder Temperature Sensor (PORT)
Cylinder Temperature Sensor (STARBOARD)
Air Temperature Sensor
b
a
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90-883728 JULY 2001
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