Chrysler laser 1990 Technical Information Manual page 130

BAROMETRIC PRESSURE SENSOR
A barometric pressure sensor is alas mounted on
the aif flow sensor. It senses the barometric
pressure and converts it to electrical voltage which
is sent as a signal to the engine control unit.
Using this signal, the engine control unit calculates
the altitude of.the location where the vehicle is, and
corrects the fuel injection quantity for the optimum
air-fuel ratio at that altitude, and also corrects the
TEMPERATURE SENSOR
The engine coolant temperature sensor installed in
the coolant passage of the thermostat case is a
thermistor whose resistance changes with the
engine coolant temperature.
T h e annine control unit iudoes t h e e n o i n e w a r m UD
FUEL SYSTEM - Sensors
ignition timing.
This ensures improved driveability at high altitudes.
The barometric pressure sensor converts the pres-
sure to a voltage making use of the fact that the
resistance of a strain gauge changes in direct
proportion to the pressure as shown in this diagram
which
barometric pressure and output voltage.
0 (321
state based on the output voltage of this sensor and
provides optimum mixture enrichment when the
engine is cold.
The sensor characteristics are as shown above.
pressure sensor
760 (30)
Barometric pressure mmHg (in.Hg)
illustrates the relationship between
Engine control unit
Coolant
temperature
sensor
20 (68)
Engine
control unit
Coolant temperature -