ENGINE CONTROL SYSTEM 3-9
MAP (Manifold Absolute Pressure) SENSOR
The MAP sensor is installed on the intake manifold and used
to detect the intake manifold pressure. It also detects the baro-
metric pressure before starting the engine. This sensor inputs
the intake manifold pressure to the ECM as a voltage value.
This input signal is used as the fundamental signal to deter-
mine the fuel injection time duration, ignition timing, etc.
CYLINDER TEMPERATURE SENSOR
The cylinder temperature sensor is installed on the cylinder (top
side) and used to detect the cylinder temperature.
This is a thermistor type sensor (resistance of which changes
depending on the temperature) and inputs a signal to the ECM
as a voltage value. This input signal is used to compensate the
fuel injection time duration, ignition timing, etc.
This sensor is also used to detect engine over-heat as the ECM
detects both the temperature and temperature change gradient
(temperature rise vs time).
EXHAUST MANIFOLD TEMPERATURE SENSOR
The exhaust manifold temperature sensor is installed on the
exhaust manifold and used to detect the exhaust manifold tem-
perature. This sensor is the same type as the cylinder tempera-
ture sensor, and inputs a signal to the ECM as a voltage value.
This input signal is also used to detect engine over-heat.
IAT (Intake Air Temperature) SENSOR
The IAT sensor is installed on the bottom of the air silencer and
used to detect the intake air temperature.
This sensor is the same type as the cylinder temperature sen-
sor, and inputs a signal to the ECM as a voltage value.
This input signal is used to compensate the fuel injection time
duration.
(kΩ)
(CËš)
Temperature
Resistance
Cylinder temp. sensorCylinder temp. sensor
Exhaust manifold
temp. sensor
Exhaust manifold
temp. sensor