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ENGINE
14
8. PRESSURE AND TEMPERATURE (P&T)
SENSOR
Function:
P & T Sensor is used to sense the pressure and
temperature of the gas in the gas rail coming from
the LP filter.
Working Principle:
Pressure Sensor:
A DC signal volt is produced by this sensor when
varying CNG pressure acts on the semiconductor
diaphragm. To produce this output the
semiconductor device has to be excited. This signal
output varies with change in the CNG rail pressure.
Temperature Sensor:
Semiconductor material changes it’s resistance
when exposed to variable temperature source (i.e.
gas temperature).
Type:
Pressure sensor: Piezoelectric.
Temperature sensor: NTC.
Location of Component:
This sensor is fitted on gas rail.
System Integration:
This sensor provides gas rail pressure &
temperature input to CNG ECU. The sensor is
activated by excitation voltage supplied by CNG
ECU.
Wiring details (CNG ECU & Sensor):
1: ECU pin 208 : PIN1
2: ECU pin 137 : PIN4
3: ECU pin 226 : PIN3
4: ECU pin 225 : PIN2