Dtc P0441 Evaporative Emission Control System Incorrect Purge Flow

Engine Hybrid System. Corolla. Zre142 Aze141
2Zr-Fe Engine Control. Corolla. Zre142 Aze141

DTC SUMMARY

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

MONITOR RESULT

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

DTC P0441 Evaporative Emission Control System Incorrect Purge Flow


DTC SUMMARY


DTC No.
Monitoring Item
Malfunction Detection Condition
Trouble Area
Detection Timing
Detection Logic
P0441
Purge VSV (Vacuum Switching Valve) stuck open
Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. Reference pressure is measured at start and at end of leak check.
If stabilized pressure higher than [second reference pressure x 0.2], ECM determines that purge VSV stuck open.
  1. Purge VSV
  2. Connector/wire harness (Purge VSV - ECM)
  3. ECM
  4. Canister pump module
  5. Leak from EVAP system
While ignition switch off
2 trip
Purge VSV stuck closed
After EVAP leak check performed, purge VSV turned on (open), and atmospheric air introduced into EVAP system. Reference pressure is measured at start and at end of check.
If pressure does not return to near atmospheric pressure, ECM determines that purge VSV stuck closed.
  1. Purge VSV
  2. Purge line
  3. Connector/wire harness (Purge VSV - ECM)
  4. ECM
  5. Canister pump module
  6. Canister (filter inside canister clogged)
  7. Leak from EVAP system
While ignition switch off
2 trip
Purge flow
While engine running, following conditions successively met:
  1. Negative pressure not created in EVAP system when purge VSV turned on (open)
  2. EVAP system pressure change less than 0.4 kPa(gauge) [3.0 mmHg(gauge)] when vent valve turned on (closed)
  3. Atmospheric pressure change before and after purge flow monitor less than 0.154 kPa(gauge) [1.155 mmHg(gauge)]
  1. Purge VSV
  2. Purge line
  3. Connector/wire harness (Purge VSV - ECM)
  4. ECM
  5. Canister pump module
  6. Canister (filter inside canister clogged)
  7. Leak from EVAP system
While engine running
2 trip

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System (COROLLA_ZRE142 RM0000011IO03FX_07.html).

MONITOR DESCRIPTION

The two 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 off. The purge flow monitor runs while the engine is running.

KEY-OFF MONITOR
5 hours* after the ignition switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) 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 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 off, the monitor check starts 2.5 hours later.

Sequence
Operation
Description
Duration
-
ECM activation
Activated by soak timer, 5, 7 or 9.5 hours after ignition switch turned off.
-
A
Atmospheric pressure measurement
Vent valve is turned off (vent) and EVAP system pressure is measured by ECM in order to register atmospheric pressure.
If pressure in EVAP system is not between 70 kPa(abs) and 110 kPa(abs) [525 mmHg(abs) and 825 mmHg(abs)], ECM cancels EVAP system monitor.
60 seconds
B
First reference pressure measurement
In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally.
60 seconds
C
EVAP system pressure measurement
Vent valve is turned on (closed) to shut EVAP system.
Negative pressure (vacuum) is created in EVAP system, and EVAP system pressure is then measured.
Write down measured value as it will be used in leak check
If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.
15 minutes*
D
Purge VSV monitor
Purge VSV is opened and then EVAP system pressure is measured by ECM.
Large increase indicates normal.
10 seconds
E
Second reference pressure measurement
After second reference pressure measurement, leak check is performed by comparing first and second reference pressure measurements.
If stabilized system pressure is higher than second reference pressure, ECM determines that EVAP system is leaking.
60 seconds
-
Final check
Atmospheric pressure is measured and then monitoring result is recorded by ECM.
-
HINT:
*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

Corolla. Zre142 Aze141.2Zr-Fe Engine Control.Sfi System. Dtc P0441 Evaporative Emission Control System Incorrect Purge Flow



  1. Purge VSV stuck open
    In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) 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 sets the DTC (2 trip detection logic).


    Corolla. Zre142 Aze141.2Zr-Fe Engine Control.Sfi System. Dtc P0441 Evaporative Emission Control System Incorrect Purge Flow



  2. Purge VSV stuck closed
    In operation D, the canister pressure sensor measures the EVAP (Evaporative Emission) system pressure. The pressure measurement for the purge VSV monitor begins 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 sets the DTC (2 trip detection logic).


    Corolla. Zre142 Aze141.2Zr-Fe Engine Control.Sfi System. Dtc P0441 Evaporative Emission Control System Incorrect Purge Flow


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

Corolla. Zre142 Aze141.2Zr-Fe Engine Control.Sfi System. Dtc P0441 Evaporative Emission Control System Incorrect Purge Flow

  1. The 1st monitor
    While the engine is running and the purge VSV (Vacuum Switching Valve) 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.
  2. 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 mmHg(gauge)), the ECM interprets this as the purge VSV being stuck closed, and illuminates the MIL and sets DTC P0441 (2 trip detection logic).
  1. Atmospheric pressure check:
    1. In order to ensure reliable malfunction detection, the variation between the atmospheric pressure, before and after conduction of the purge flow monitor, is measured by the ECM.

MONITOR STRATEGY


Required Sensors/Components
Purge VSV
Canister pump module
Frequency of Operation
Once per driving cycle
Duration
Within 20 minutes: Purge VSV stuck open/close
Within 30 seconds: Purge flow
MIL Operation
2 driving cycles
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


All
Monitor runs whenever following DTCs are not present
None

Key-off Monitor
Monitor runs whenever the following DTCs are not stored
None
Atmospheric pressure
70 kPa(abs) [525 mmHg(abs)] or more, and less than 110 kPa(abs) [825 mmHg(abs)]
Battery voltage
10.5 V or more
Vehicle speed
Less than 4 km/h (2.5 mph)
Ignition switch
Off
Time after key-off
5, 7 or 9.5 hours
Canister pressure sensor malfunction (P0452, P0453)
Not detected
Purge VSV
Not operated by scan tool
Vent valve
Not operated by scan tool
Leak detection pump
Not operated by scan tool
Both of the following conditions met before key-off
Conditions 1 and 2
1. Duration that vehicle is driven
5 minutes or more
2. EVAP purge operation
Performed
Engine coolant temperature
4.4°C (40°F) or more, and less than 35°C (95°F)
Intake air temperature
4.4°C (40°F) or more, and less than 35°C (95°F)

Purge Flow Monitor
Engine
Running
Engine coolant temperature
4.4°C (40°F) or more
Intake air temperature
4.4°C (40°F) or more
Canister pressure sensor malfunction
Not detected
Purge VSV
Not operated by scan tool
EVAP system check
Not operated by scan tool
Battery voltage
10 V or more
Purge duty cycle
8% or more

TYPICAL MALFUNCTION THRESHOLDS


Purge VSV Stuck Open
EVAP pressure when vacuum introduction is complete
Higher than [reference pressure x 0.2]

Purge VSV Stuck Closed
EVAP pressure change after purge VSV is open
Less than 0.3 kPa(gauge) [2.25 mmHg(gauge)]

Purge Flow
Both of the following conditions are met:
Conditions 1 and 2
1. EVAP pressure change when purge flow is started
Less than 0.154 kPa(gauge) [1.155 mmHg(gauge)]
2. EVAP pressure change during purge flow when vent valve is on (closed)
Less than 0.4 kPa(gauge) [3.0 mmHg(gauge)]

MONITOR RESULT

Refer to Checking Monitor Status (Link).

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation) (COROLLA_ZRE142 RM000000PDK0ZAX.html).
  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 the pending DTCs.
    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. 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.

    Techstream Display
    		Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
    3. If the judgment result shows INCOMPLETE or N/A, perform the following procedure.
    NOTICE:
    1. The Evaporative System Check (Automatic Mode) consists of 6 steps performed automatically by the Techstream. It takes a maximum of approximately 18 minutes.
    2. 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.
    3. Do not run the engine during this operation.
    4. 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 the DTCs (even if no DTCs are stored, perform the clear DTC operation) (COROLLA_ZRE142 RM000000PDK0ZAX.html).
  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 "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.

    Techstream Display
    		Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
  20. If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).
    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.

INSPECTION PROCEDURE

Refer to the EVAP System (COROLLA_ZRE142 RM0000011IO03FX_09.html).