P0441

2ZR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0441: Evaporative Emission Control System Incorrect Purge Flow
P0441 - Evaporative Emission Control System Incorrect Purge Flow

DTC SUMMARY





DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System EVAP System.

MONITOR DESCRIPTION

The 2 monitors, Key-Off and Purge Flow, are used to detect malfunctions relating to DTC P0441. The Key-Off monitor is initiated by the ECM internal timer, known as the soak timer, 5 hours* after the ignition switch is turned to off. The purge flow monitor runs while the engine is running.

1. KEY-OFF MONITOR

5 hours* after the ignition switch is turned to off, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT
*: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned to off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned to off, the monitor check starts 2.5 hours later.





*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.





Text in Illustration





a. Purge VSV stuck open

In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The EVAP system pressure is then measured by the ECM using the canister pressure sensor. If the stabilized system pressure is higher than [second reference pressure x 0.2], the ECM interprets this as the purge VSV (Vacuum Switching Valve) being stuck open. The ECM illuminates the MIL and stores the DTC (2 trip detection logic).





b. Purge VSV stuck closed

In operation D, the canister pressure sensor measures the EVAP system pressure. The pressure measurement for the purge VSV monitor is begun when the purge VSV is turned ON (open) after the EVAP leak check. When the measured pressure indicates an increase of 0.3 kPa(gauge) [2.25 mmHg(gauge)] or more, the purge VSV is functioning normally. If the pressure does not increase, the ECM interprets this as the purge VSV being stuck closed. The ECM illuminates the MIL and stores the DTC (2 trip detection logic).





2. PURGE FLOW MONITOR

The purge flow monitor consists of 2 monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary.





- The 1st monitor

While the engine is running and the purge VSV is ON (open), the ECM monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd monitor.

- The 2nd monitor

The vent valve is turned ON (closed) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.4 kPa(gauge) [3.0 mmHg(gauge)], the ECM interprets this as the purge VSV being stuck closed, and illuminates the MIL and stores DTC P0441 (2 trip detection logic).

Atmospheric pressure check:

In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before and after conduction of the purge flow monitor, is measured by the ECM.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





Key-off Monitor





Purge Flow Monitor





TYPICAL MALFUNCTION THRESHOLDS

Purge VSV Stuck Open





Purge VSV Stuck Closed





Purge Flow





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on.

6. Start the engine and wait 15 minutes or more.

7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

8. Read pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

10. Input the DTC: P0441.

11. Check the DTC judgment result.





NOTICE:
- The Evaporative System Check (Automatic Mode) consists of 6 steps performed automatically by the Techstream. It takes a maximum of approximately 19 minutes.
- Do not perform the Evaporative System Check when the fuel tank is more than 90% full because the cut-off valve may be closed, making the fuel tank leak check unavailable.
- Do not run the engine during this operation.
- When the temperature of the fuel is 35°C (95°F) or higher, a large amount of vapor forms and any check results become inaccurate. When performing the Evaporative System Check, keep the fuel temperature below 35°C (95°F).

12. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

13. Turn the ignition switch off and wait for at least 30 seconds.

14. Turn the ignition switch to ON

15. Turn the Techstream on.

16. Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.

17. After the "Evaporative System Check" is completed, check All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

18. Input the DTC: P0441.

19. Check the DTC judgment result.





HINT
- If the judgment result is NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.

20. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

INSPECTION PROCEDURE

Refer to the EVAP System EVAP System.