Enhanced Testing

P0451 - Evaporative Emission System: Pressure Sensor Range/Performance







Function
The evaporative emissions system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Canister Closing Valve (CCV) closes off the air inlet into the canister for leak detection of the evaporative emission system. The CCV also prevents fuel vapors from escaping from the canister. When the engine purges the HC vapors from the canister, the clean air comes into the canister through the canister air-filter and the CCV.

DTC Description
The ECM measures pressure in the fuel tank through the use of a fuel tank pressure sensor. DTC P0449 is set if pressure is lower than the predetermined threshold. If the fault is detected within two consecutive test cycles, the ECM illuminates the MIL.


Detecting Condition





Wiring Schematic