P0441

DTC P0441 Evaporative Emission Control System Incorrect Purge Flow

CIRCUIT DESCRIPTION

DTC Detection Condition:

The vapor pressure sensor, VSV for canister closed valve (CCV), 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

DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components within the dotted line in Fig 1, or when there is a malfunction in either the VSV for EVAP, the VSV for pressure switching valve, or in the vapor pressure sensor itself.

P0441
The ECM closes the CCV and opens the VSV for pressure switching valve, causing vacuum to increase in the entire EVAP system.

The ECM continues to operate the VSV for EVAP until the vacuum is increased to a specified point at which time the ECM closes the VSV for EVAP.

If the vacuum did not increase, or if the vacuum increased beyond the specified limit, the ECM judges the VSV for EVAP and related components to be faulty.






HINT: Typical DTC output of each trouble part.

Wiring Diagram:

INSPECTION PROCEDURE

HINT:
- If DTC P0441 (Purge Flow), P0446 (VSV for CCV or VSV for Pressure switching valve) or P0451 (Evaporative Pressure Sensor) is output with 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 OBD II scan tool or hand-held tester Because freeze frame records the engine conditions when the 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.

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Hand-held tester

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OBD II scan tool (excluding hand-held tester)