P0451

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

CIRCUIT DESCRIPTION

DTC Detecting Condition:

The vapor pressure sensor, the VSV for the canister closed valve (CCV) and the VSV for the 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 P0451 is recorded by the ECM when the vapor pressure sensor malfunctions.

Wiring Diagram:

Step 1 - 3:

INSPECTION PROCEDURE

HINT:
- If different DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may be open.
- If DTC P0441, P0446, or P0451 is output after DTC P0442 or P0456, first troubleshoot DTC P0441, P0446 or P0451. If no malfunction is detected, troubleshoot DTC P0442 or P0456 next.
- Read freeze frame data using hand-held tester or OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining 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 vapor pressure sensor.