Printed : 8/13/01
59
P/N 951-05002032
COOLANT TEMPERATURE SENSOR
The engine temperature sensor is brown, located on the
front of the cylinder head, and is an NTC thermistor. The
ECM receives electronic signals from this thermistor and
uses them to determine the coolant temperature. This
information is used by the ECM to optimize fueling at all
engine temperatures and to calculate hot and cold start
fueling requirements.
The engine temperature sensor's resistance decreases as
the temperature increases.
AIR TEMPERATURE SENSOR
The intake air temperature sensor is green, located on the
front area of the airbox. It is a NTC thermistor that gives an
indication of the temperature of the air that will be inducted
into the engine. An intake air temperature sensor is installed
because the air temperature affects the density of the
inducted air (and therefore the amount of oxygen available
to ignite the fuel), altering the effective engine load and thus
the fuel required for proper combustion.
The ECM uses information from this sensor to compensate
for changes in air temperature by adjusting the amount of
injected fuel to a level which enables clean combustion
(reducing the risk of knock caused by high air intake
temperatures) and low emissions.
BAROMETRIC PRESSURE SENSOR
NOTE : The barometric pressure sensor is intergrated
inside the ECU.
The intake air pressure (barometric) sensor is built into the
ECM and is connected to the airbox plenum by a narrow
tube. The sensor measures the air pressure in the airbox.
Using this information the ECM determines the air density,
and when added to other inputs to the ECM, the engine load
is calculated. This information is then used to adjust the
amount of injected fuel to match the prevailing conditions.
Components have been removed for this photo.
