Part 2
2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0441: Evaporative Emission Control System Incorrect Purge Flow - Continued
DTC P0441 - Evaporative Emission Control System Incorrect Purge Flow
20. INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)
(a) Turn the ignition switch off.
(b) Disconnect the R1 canister pump module connector.
(c) Apply the battery voltage to 9 (VLVB) and 8 (VGND) terminals of the canister pump module.
(d) Touch the canister pump module to confirm the vent valve operation.
Result
B -- REPLACE CANISTER ASSEMBLY
A -- Continue to next step.
21. CHECK HARNESS AND CONNECTOR (ECM - CANISTER PUMP MODULE)
(a) Disconnect the A24 ECM connector.
(b) Disconnect the R1 canister pump module connector.
(c) Measure the resistance between VPMP terminal of the ECM connector and VGND terminal of the canister pump module connector.
Result
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE ECM
22. PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP (ALONE))
(a) Turn the ignition switch off.
(b) Disconnect the R1 canister pump module connector.
(c) Turn the ignition switch to ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.
(e) Measure the voltage between MTRB terminal 1 of the canister pump module connector and the body ground when the leak detection pump is turned ON and OFF using the Techstream.
Result
B -- CHECK HARNESS AND CONNECTOR (ECM - CANISTER PUMP MODULE)
A -- Continue to next step.
23. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - BODY GROUND)
(a) Turn the ignition switch off.
(b) Disconnect the R1 canister pump module connector.
(c) Check the resistance between the MGND terminal of the canister pump module connector and the body ground.
Result
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE CANISTER ASSEMBLY
24. CHECK HARNESS AND CONNECTOR (ECM - CANISTER PUMP MODULE)
(a) Turn the ignition switch off.
(b) Disconnect the R1 canister pump module connector.
(c) Disconnect the A24 ECM connector.
(d) Measure the resistance between MPMP terminal of the ECM connector and MTRB terminal of the canister pump module connector.
Result
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE ECM
25. INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
(a) Stop the engine.
(b) Disconnect the purge line from the intake manifold.
(c) Start the engine.
(d) Use your finger to confirm that the port of the intake manifold has suction.
Result
(e) Reconnect the purge line.
B -- INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
A -- REPLACE PURGE LINE (INTAKE MANIFOLD - PURGE VSV)
26. CORRECTLY REINSTALL OR REPLACE FUEL TANK CAP
HINT:
- When reinstalling the fuel tank cap, tighten it until a few click sounds are heard.
- When replacing the fuel tank cap, use a fuel tank cap that meets OEM specifications, and install it until a few click sounds are heard.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
27. REPLACE FUEL TANK CAP
HINT: When replacing the fuel cap, use a fuel cap that meets OEM specifications, and install it until a few click sounds are heard.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
28. LOCATE EVAP LEAK PART
(a) Disconnect the vent hose.
(b) Connect an EVAP tester to the canister pump module with the adapter.
(c) Pressurize the EVAP system to 3.2 to 3.7 kPa (24 to 28 mmHg).
(d) Apply soapy water to the piping and connecting parts of the EVAP system.
(e) Look for areas where bubbles appear. This indicates the leak point.
(f) Repair or replace the leak point.
HINT: Disconnect the hose between the canister and the fuel tank from the canister. Block the canister side and conduct an inspection. In this way, the fuel tank can be excluded as an area suspected of causing fuel leaks.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
29. REPLACE CANISTER ASSEMBLY
(a) Replace the canister assembly Removal.
NOTE: When replacing the canister, check the canister pump module interior and related pipes for water, fuel and other liquids. If liquids are present, check for disconnections and/or cracks in the following: 1) the pipe from the air inlet port to the canister pump module; 2) the canister filter; and 3) the fuel tank vent hose.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
30. REPLACE PURGE VSV
(a) Disconnect the connector and the hoses from the purge VSV.
(b) Replace the purge VSV.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
31. REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
32. REPLACE PURGE LINE (INTAKE MANIFOLD - PURGE VSV)
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
33. INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
(a) Check that the EVAP purge port of the intake manifold is not clogged. If necessary, replace the intake manifold.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
34. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
35. REPAIR OR REPLACE PARTS AND COMPONENTS INDICATED BY OUTPUT DTCS
(a) Repair the malfunctioning areas indicated by the DTCs that had been confirmed when the vehicle was brought in.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
36. PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
NOTICE:
- The Evaporative System Check (Automatic Mode) consists of 5 steps performed automatically by the 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. If the cut-off valve is closed, the fuel tank leak check is not possible.
- Do not run the engine in this step.
- When the temperature of the fuel is 35°C (95°F) or more, a large amount of vapor forms and any check results become inaccurate. When performing an Evaporative System Check, keep the temperature below 35°C (95°F).
(a) Clear DTCs DTC Check / Clear.
(b) Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
(c) After the Evaporative System Check is completed, check for pending DTCs by entering the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
HINT: If no pending DTCs are found, the repair has been successfully completed.
NEXT -- COMPLETED
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.
1. 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.
*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
1. 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 sets the DTC (2 trip detection logic).
2. 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 sets the DTC (2 trip detection logic).
2. PURGE FLOW MONITOR
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 0.5 kPa-g (3.75 mmHg-g), the ECM interprets this as the purge VSV being stuck closed, and illuminates the MIL and sets 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
1. Key-off Monitor
Monitor Strategy
Typical Enabling Conditions
Typical Malfunction Thresholds
OBD II MONITOR SPECIFICATIONS
1. Purge Flow Monitor
Monitor Strategy
Typical Enabling Conditions
Typical Malfunction Thresholds
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.