OBD Code P0441

Good afternoon,

I attached the flow chart below for the code. It is not an easy code to resolve. It appears the dealer has no experience techs to do this repair. You will need an advanced scan tool to follow this flow chart.

Roy

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 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.
Purge VSV
Connector/wire harness (Purge VSV - ECM)
ECM
Canister pump module
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 measured at start and at end of check.
If pressure does not return to near atmospheric pressure, ECM determines that purge VSV stuck closed.
Purge VSV
Connector/wire harness (Purge VSV - ECM)
ECM
Canister pump module
Leak from EVAP system
While ignition switch off 2 trip
Purge flow While engine running, following conditions successively met:
Negative pressure not created in EVAP system when purge VSV turned ON (open)
EVAP system pressure change less than 0.4 kPa-g (3.0 mmHg-g) when vent valve turned ON (closed)
Atmospheric pressure change before and after purge flow monitor less than 0.1 kPa-g (0.75 mmHg-g)
Purge VSV
Connector/wire harness (Purge VSV - ECM)
Leak from EVAP line (Purge VSV - Intake manifold)
ECM
While engine running 2 trip

DESCRIPTION
The description can be found in EVAP (Evaporative Emission) System. [ 2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System+ ]

INSPECTION PROCEDURE
Refer to EVAP System. [ 2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System+ ]

HINT:

Unit expressions

[kPa-a (mmHg-a)] is the absolute pressure.
[kPa-g (mmHg-g)] is the gauge pressure (relative pressure).
On the Techstream, convert the unit of measurement according to the inspection procedure.
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 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 turned OFF (vent) and EVAP system pressure measured by ECM in order to register atmospheric pressure.
If pressure in EVAP system not between 70 kPa-a and 110 kPa-a (525 mmHg-a and 825 mmHg-a), 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 turned ON (closed) to shut EVAP system.
Negative pressure (vacuum) created in EVAP system, and EVAP system pressure 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 opened and then EVAP system pressure measured by ECM.
Large increase indicates normality. 10 seconds
E Second reference pressure measurement After second reference pressure measurement, leak check performed by comparing first and second reference pressure.
If stabilized system pressure higher than second reference pressure, ECM determines that EVAP system leaking. 60 seconds- Final check Atmospheric pressure measured and then monitoring result recorded by ECM. -

: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
Image
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).
Image
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-g (2.25 mmHg-g) 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).
Image
PURGE FLOW MONITOR
image
The purge flow monitor consists of two 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-g (3.0 mmHg-g), the ECM interprets this as the purge VSV being stuck closed, 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.

OBD II MONITOR SPECIFICATIONS
Key-off Monitor
Monitor Strategy

Required Sensors/Components Purge VSV
Canister pump module
Frequency of Operation Once per driving cycle
Duration Within 15 minutes (varies with amount of fuel in tank)
MIL Operation 2 driving cycles
Sequence of Operation None

Typical Enabling Conditions

Monitor runs whenever following DTCs not stored P0451, P0452, P0453 (EVAP System)
EVAP key-off monitor runs when all of following conditions met -
Atmospheric pressure 70 to 110 kPa-a (525 to 825 mmHg-a)
Battery voltage 10.5 V or higher
Vehicle speed Less than 4 km/h (2.5 mph)
Ignition switch off
Time after key-off 5, 7 or 9.5 hours
Purge VSV Not operated by scan tool
Vent valve Not operated by scan tool
Leak detection pump Not operated by scan tool
Both of 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
ECT 4.4 to 35°C (40 to 95°F)
IAT 4.4 to 35°C (40 to 95°F)

Typical Malfunction Thresholds

Purge VSV stuck open: -
EVAP pressure when vacuum introduction complete Higher than reference pressure x 0.2

Purge VSV stuck closed: -
EVAP pressure change after purge VSV open Below 0.3 kPa-g (2.25 mmHg-g)

OBD II MONITOR SPECIFICATIONS
Purge Flow Monitor
Monitor Strategy

Required Sensors/Components Purge VSV
Canister pump module
Frequency of Operation Once per driving cycle
Duration Within 10 minutes
MIL Operation 2 driving cycles
Sequence of Operation None

Typical Enabling Conditions

Monitor runs whenever following DTCs not stored P0451, P0452, P0453 (EVAP System)
Engine Running
ECT 4.4°C (40°F) or higher
IAT 4.4°C (40°F) or higher
Purge VSV Not operated by scan tool
EVAP system check Not operated by scan tool
Battery voltage 10 V or higher
Purge duty-cycle 8% or more

Typical Malfunction Thresholds

Both of following conditions met Conditions 1 and 2
1. EVAP pressure change when purge operation started Below 0.1 kPa-g (0.75 mmHg-g)
2. EVAP pressure change during purge operation when vent valve closed Below 0.4 kPa-g (3.0 mmHg-g)

MONITOR RESULT
Refer to Checking Monitor Status. [ 2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: CHECKING MONITOR STATUS ]

CONFIRMATION DRIVING PATTERN

image
Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation) [A].
Start the engine and wait 15 minutes or more [B].
Enter the following menus: Powertrain / Engine and ECT / Utility / All readiness.
Input the DTC: P0441.
Check the DTC judgment result [C].
Tester Display Description
NORMAL
DTC judgment completed
System normal
ABNORMAL
DTC judgment completed
System abnormal
INCOMPLETE
DTC judgment not completed
You should perform driving pattern after confirming DTC enabling conditions
UNKNOWN
Unable to perform DTC judgment
Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

NOTICE:

The Evaporative System Check (Automatic Mode) consists of 5 steps performed automatically by Techstream. It takes a maximum of approximately 18 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).
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation) [D].
Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
After the "Evaporative System Check" is completed, check for All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0441.
Check the DTC judgment result [E].
Tester Display Description
NORMAL
DTC judgment completed
System normal
ABNORMAL
DTC judgment completed
System abnormal
INCOMPLETE
DTC judgment not completed
Perform driving pattern after confirming DTC enabling conditions
UNKNOWN
Unable to perform DTC judgment
Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows ABNORMAL, the system has a malfunction.

If the test result is UNKNOWN, enter the following menus: Powertrain / Engine and ECT / Trouble Code / Pending.
Read Pending DTCs.
HINT:

If a pending DTC is output, the system is malfunctioning.

If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs. [ 2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: DTC CHECK / CLEAR ]
HINT:

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