104
PRESSURE
SENSOR
LTG/R
LTG/Y
BL/Y
VCC
E2
PM
26
25
34
VCC
PM
E2
ECM
5V
5V
2
1
1. ZIRCONIA ELEMENT
2. HOUSING
O
2
SENSOR
S–R
BL/Y
24
34
OX
E2
ECM
COLOR CODE
R – RED
BL – BLUE
Y – YELLOW
PRESSURE SENSOR (PM)
The pressure sensor is a sensor that is installed on the
throttle body, detects changes in the intake manifold pres-
sure.
One terminal of the pressure sensor is connected to the
”VCC” terminal of the ECM, sensor voltage (approx. 5 V)
is supplied from the ECM, and one of the remaining two ter-
minals is connected to the ”E2” terminal (sensor earth).
The other terminal is connected to the ”PM” terminal of the
ECM, and the voltage changes in conjunction with
changes in the intake manifold pressure (0~5 V). The ECM
detects the changing voltage level of the ”PM” terminal as
intake manifold pressure changes. The voltage of the ”PM”
terminal is low when the pressure is low, and high when the
pressure is high.
O
2
SENSOR (OX)
The O
2
sensor is a sensor that is installed on the exhaust
manifold and detects changes in the oxygen concentration
in the exhaust gas by means of a zirconia element (pla-
tina–coated) that changes its output voltage according to
the oxygen concentration. The sensor is connected to the
”OX” terminal of the ECM and the main body is grounded
to the engine.
When the oxygen concentration in the exhaust gas
changes, the voltage of the ”OX” element changes (0~1
V), and the detector detects this voltage level as the oxy-
gen concentration. A voltage of the ”OX” terminal
becomes lower when the oxygen concentration increases
(approx. 0 V), and becomes higher (approx. 1 V) when the
amount of oxygen decreases.
Note: The O
2
sensor is not activated unless the tempera-
ture of the main body reaches 300°C or above.
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