P0451

DTC P0451 Evaporative Emission Control System Pressure Sensor/Switch Range/Performance

CIRCUIT DESCRIPTION

Dtc Detecting Condition:

The vapor pressure sensor, VSV for canister closed valve (CCV) and VSV for pressure switching valve are used to detect abnormalities in the evaporative emission control system.

The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal.

DTC P0450 or P0451 is recorded by the ECM when the vapor pressure sensor malfunction.

Wiring Diagram:

Step 1:

Step 2 - 3:

INSPECTION PROCEDURE

HINT:
- If DTC P0441 (Purge flow), P0446 (VSV for CCV for pressure switching valve), P0451 (Evaporative pressure sensor), P0452 (Evaporative pressure sensor low input), or P0453 (Evaporative pressure sensor low input) is output after DTC P0442 or P0456, first troubleshoot DTC P0441, P0446, P0451, P0452 or P0453. If no malfunction is detected, troubleshoot DTC P0442 or P0456 next.
- Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful to determine whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
- When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the VSV for EVAP. charcoal canister and vapor pressure sensor.