P0441

DTC P0441 EVAPORATIVE EMISSION CONTROL SYSTEM INCORRECT PURGE FLOW

CIRCUIT DESCRIPTION

DTC Detection Condition:

The vapor pressure sensor, Canister Closed Valve (CCV), pressure switching VSV are used to detect abnormalities in the Evaporative Emissions (EVAP) control system.

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

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

HINT: Typical DTC output of each trouble part.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Monitor Result (Mode 06 Data):

P0441
The ECM checks for an EVAP VSV stuck closed malfunction by commanding the EVAP VSV to open with the CCV closed. If a high negative pressure does not develop in the fuel tank, the ECM determines that the EVAP VSV remains closed. The ECM turns on the MIL and a DTC is set.

The ECM checks for an EVAP VSV stuck open fault by commanding both valves (EVAP VSV and CCV) to close at a time when the fuel tank is at atmospheric pressure. If the fuel tank develops a high negative pressure at this early stage of the test, the ECM determines that the EVAP VSV remains open.

The ECM will turn on the MIL and a DTC is set.

Wiring Diagram:

INSPECTION PROCEDURE

HINT:
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, as well as other data from the time when a malfunction occurred.
- When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.