Evaporative Emission Control System Pressure Sensor Malfunction
CODE NUMBERP0450 Evaporative Emission Control System Pressure Sensor Malfunction
BACKGROUND
- The fuel tank differential pressure sensor outputs the voltage in proportion to the pressure in the fuel lank. (differential pressure against the barometric pressure)
- The engine control module checks whether the output voltage of the fuel tank differential pressure sensor is within the specified range.
CHECK AREA
- Engine speed is 1600 r/min or more.
- Volume efficiency is 20 - 80%.
JUDGMENT CRITERIA
- Sensor output voltage has continued to be 4.5 V or more although the purge solenoid is operating at 100% duty when the intake air temperature is 5 - 45~C (4i~F - 1I3~F) or more.
or
- Sensor output voltage has continued to be 0.5 V or less for 10 sec. although the purge solenoid is off when the intake air temperature is 0.5° C (41° F) or more.
CHECK AREA
- Voltage deviates by 0.2 V or more 20 times.
- Closed throttle position switch: ON
JUDGMENT CRITERIA
- Voltage deviates by 0.2 V or more 20 times or more at each of consecutive 8 idling operation.
PROBABLE CAUSE
- Fuel tank differential pressure sensor failed.
- Open or shorted fuel tank differential pressure sensor circuit, or loose connector.
- Engine control module failed.
- Fuel vent valve, fuel vapor line, etc. clogged.
DIAGNOSTIC CHART