P0455

2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0455: Evaporative Emission Control System Leak Detected (Gross Leak)

DTC P0455 - Evaporative Emission Control System Leak Detected (Gross Leak)

DTC P0456 - Evaporative Emission Control System Leak Detected (Very Small Leak)

DTC SUMMARY

DESCRIPTION

NOTE: In this vehicle's EVAP system, turning ON the vent valve does not seal off the EVAP system. To check for leaks in the EVAP system, disconnect the air inlet vent hose and apply pressure from the atmosphere side of the canister.

While the engine is running, if a predetermined condition (closed-loop etc.) is met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged to the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.
The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into the canister through the vent valve to ensure that the purge flow is maintained when the negative pressure (vacuum) is applied to the canister.
The following two monitors run to confirm appropriate EVAP system operation.

1. Key-off monitor
This monitor checks for Evaporative Emission (EVAP) system leaks and canister pump module malfunctions. The monitor starts 5 hours* after the ignition switch is turned OFF. More than 5 hours are required to allow the fuel to cool down to stabilize the Fuel Tank Pressure (FTP), thus making the EVAP system monitor more accurate.
The leak detection pump creates negative pressure (vacuum) in the EVAP system and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system and malfunctions in both the canister pump module and purge VSV, 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.

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

- The 1st monitor
While the engine is running and the purge Vacuum Switching Valve (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 turned OFF (open) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.5 kPa (3.75 mmHg), 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.

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

INSPECTION PROCEDURE

NOTE: The Techstream is required to conduct the following diagnostic troubleshooting procedure.

HINT:
- Using the Techstream monitor results enables the EVAP system to be confirmed.
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. CONFIRM DTC
(a) Turn the ignition switch OFF and wait for 10 seconds.
(b) Turn the ignition switch ON.
(c) Turn the ignition switch OFF and wait for 10 seconds.
(d) Connect the Techstream to the DLC3.
(e) Turn the ignition switch ON.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(g) Confirm DTCs and freeze frame data.
If any EVAP system DTCs are set, the malfunctioning area can be determined using the table below.

NOTE: If the 0.02 inch leak criterion difference between the first and second checks is greater than the specification, the DTCs corresponding to the 0.02 inch leak criterion (P043E, P043F, P0441, P0455, P0456, P2401 and P2420) will all be stored.

NEXT -- Continue to next step.

2. PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)

NOTICE:
- The Evaporative System Check (Automatic Mode) consists of five 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, making the leak check of the fuel tank 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 the Evaporative System Check, keep the temperature below 35°C (95°F).

(a) Clear the 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 DTC is displayed, perform the CONFIRMATION DRIVING PATTERN. After this confirmation, check for pending DTCs. If no DTC is displayed, the EVAP system is normal.

NEXT -- Continue to next step.

3. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION)

NOTICE:
- In the Evaporative System Check (Manual Mode), the series of 5 Evaporative System Check steps are performed manually by the Techstream.
- 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 leak check of the fuel tank 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 the Evaporative System Check, keep the temperature below 35°C (95°F).
(a) Clear the DTCs DTC Check / Clear.
(b) Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Manual Mode.
NEXT -- Continue to next step.

4. PERFORM EVAP SYSTEM CHECK (STEP 1/5)

(a) Check the EVAP pressure in step 1/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.
B -- REPLACE CANISTER ASSEMBLY
A -- Continue to next step.

5. PERFORM EVAP SYSTEM CHECK (STEP 1/5 TO 2/5)

(a) Check the EVAP pressure in step 1/5 and 2/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.

HINT: The first 0.02 inch leak criterion is the value determined in step 2/5.

B -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR LEAK DETECTION PUMP)
A -- Continue to next step.

6. PERFORM EVAP SYSTEM CHECK (STEP 2/5)

HINT: Make a note of the pressures checked in the steps below.

(a) Check the EVAP pressure 4 seconds after the leak detection pump is activated* [A].
(b) Check the EVAP pressure again when it has stabilized. This pressure is the 0.02 inch leak criterion [B].
*: The leak detection pump begins to operate as step 1/5 proceeds to step 2/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.
D -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR VENT VALVE)
C -- REPLACE CANISTER ASSEMBLY
B -- PERFORM EVAP SYSTEM CHECK (STEP 3/5)
A -- Continue to next step.

7. PERFORM EVAP SYSTEM CHECK (STEP 2/5 TO 3/5)

(a) Check the EVAP pressure in step 3/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.
C -- REPLACE CANISTER ASSEMBLY
B -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR VENT VALVE)
A -- Continue to next step.

8. PERFORM EVAP SYSTEM CHECK (STEP 3/5)

(a) Wait until the EVAP pressure change is less than 0.1 kPa (0.75 mmHg) for 30 seconds.
(b) Measure the EVAP pressure and record it.

HINT: A few minutes are required for the EVAP pressure to become saturated. When there is little fuel in the fuel tank, it takes up to 15 minutes (900 seconds).

NEXT -- Continue to next step.

9. PERFORM EVAP SYSTEM CHECK (STEP 4/5)

(a) Check the EVAP pressure in step 4/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.
C -- PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
B -- CHECK EVAP HOSE (PURGE VSV - INTAKE MANIFOLD)
A -- Continue to next step.

10. PERFORM EVAP SYSTEM CHECK (STEP 5/5)

(a) Check the EVAP pressure in step 5/5.
(b) Compare the EVAP pressure in step 3/5 and the second 0.02 inch leak criterion (step 5/5).
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.
B -- PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
A -- REPAIR OR REPLACE PARTS AND COMPONENTS INDICATED BY OUTPUT DTCS
11. PERFORM EVAP SYSTEM CHECK (STEP 3/5)

(a) Check the EVAP pressure in step 3/5.
Result:

*: These DTCs are already present in the ECM when the vehicle arrives and are confirmed in step 1.

HINT: The first 0.02 inch leak criterion is the value determined in step 2/5.

B -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR LEAK DETECTION PUMP)
A -- REPLACE CANISTER ASSEMBLY

12. PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)

(a) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VSV for EVAP Control.
(b) Disconnect the hose (connected to the canister) from the purge VSV.
(c) Turn the ignition switch ON.
(d) Using the tester, turn the purge VSV OFF.
(e) Use your finger to confirm that the purge VSV has no suction.
(f) Using the tester, turn the purge VSV ON.
(g) Use your finger to confirm that the purge VSV has suction.
Result:

C -- CHECK EVAP HOSE (PURGE VSV - INTAKE MANIFOLD)
B -- INSPECT PURGE VSV
A -- Continue to next step.

13. CHECK FUEL CAP
(a) Check that the fuel cap is correctly installed.
(1) Tighten the fuel cap until a few click sounds are heard.

HINT: If an EVAP tester is available, use the tester to check the fuel cap.

(b) Remove the fuel cap and install it onto the fuel cap adaptor.
(c) Connect an EVAP tester hose to the adaptor, and pressurize the cap to 3.2 to 3.7 kPa (24 to 28 mmHg) using an EVAP tester.
(d) Seal the adaptor and wait for 2 minutes.
(e) Check the pressure. If the pressure is 2 kPa (15 mmHg) or more, the fuel cap is normal.
(f) Reinstall the fuel cap.
Result:

C -- REPLACE FUEL CAP
B -- CORRECTLY REINSTALL OR REPLACE FUEL CAP
A -- LOCATE EVAP LEAK
14. INSPECT PURGE VSV

(a) Turn the ignition switch OFF.
(b) Disconnect the V2 purge VSV connector.
(c) Disconnect the hose (connected to the canister) from the purge VSV.
(d) Start the engine.
(e) Use your finger to confirm that the purge VSV has no suction.
Result:

(f) Reconnect the purge VSV connector.
B -- REPLACE PURGE VSV
A -- REPLACE ECM
15. CHECK EVAP HOSE (PURGE VSV - INTAKE MANIFOLD)

(a) Disconnect the hose (connected to the intake manifold) from the purge VSV.
(b) Start the engine.
(c) Use your finger to confirm that the hose has suction.
Result:

B -- INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
A -- Continue to next step.

16. INSPECT PURGE VSV

(a) Remove the purge VSV connector.
(b) Apply battery voltage to the terminals of the purge VSV.
(c) Using an air gun, confirm that air flows from port A to port B.
Result:

B -- REPLACE PURGE VSV
A -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF PURGE VSV)

(a) Disconnect the V2 purge VSV connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage between terminal 2 of the purge VSV connector and the body ground.
Result:

(d) Reconnect the purge VSV connector.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- Continue to next step.

18. CHECK HARNESS AND CONNECTOR (PURGE VSV - ECM)

(a) Disconnect the V2 purge VSV connector.
(b) Disconnect the E4 ECM connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:

(d) Reconnect the ECM connector.
(e) Reconnect the purge VSV connector.

NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE ECM
19. PERFORM ACTIVE TEST USING TECHSTREAM (FOR VENT VALVE)

(a) Turn the ignition switch ON.
(b) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VSV for Vent Valve.
(c) Measure the voltage between terminal VPMP of the ECM connector and the body ground when the vent valve is turned ON (close) and OFF (vent) using the tester.
Result:

B -- REPLACE ECM
A -- INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)
20. PERFORM ACTIVE TEST USING TECHSTREAM (FOR VENT VALVE)

C -- REPLACE ECM
B -- INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)
A -- Continue to next step.

21. INSPECT CANISTER PUMP MODULE (POWER SOURCE FOR VENT VALVE)

(a) Turn the ignition switch OFF.
(b) Disconnect the L4 canister connector.
(c) Turn the ignition switch ON.
(d) Measure the voltage between terminal 9 of the canister connector and the body ground.
Result:

B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- Continue to next step.

22. INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)

(a) Turn the ignition switch OFF.
(b) Disconnect the L4 canister connector.
(c) Apply the battery voltage to terminals 9 and 8 of the canister pump module.
(d) Touch the canister pump module to confirm the vent valve operation.
Result:

(e) Reconnect the canister connector.
B -- REPLACE CANISTER ASSEMBLY
A -- REPAIR OR REPLACE HARNESS AND CONNECTOR
23. PERFORM ACTIVE TEST USING TECHSTREAM (FOR LEAK DETECTION PUMP)

(a) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.
(b) Measure the voltage between MPMP terminal of the ECM connector and the body ground when the leak detection pump is turned ON and OFF using the tester.
Result:

B -- REPLACE ECM
A -- Continue to next step.

24. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)

(a) Turn the ignition switch OFF.
(b) Disconnect the L4 canister connector.
(c) Turn the ignition switch ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.
(e) Turn the leak detection pump ON.
(f) Measure the voltage between terminal 1 of the canister connector and the body ground.
Result:

(g) Reconnect the canister connector.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- Continue to next step.

25. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - GROUND)

(a) Disconnect the L4 canister connector.
(b) Turn the ignition switch OFF.
(c) Measure the resistance of the wire harness side connectors between terminal 6 of the canister connector and the body ground.
Result:

(d) Reconnect the canister connector.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- REPLACE CANISTER ASSEMBLY
26. INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
(a) Turn the ignition switch OFF.
(b) Disconnect the EVAP hose from the throttle body.
(c) Start the engine.
(d) Use your finger to confirm that the port of the throttle body has suction.
Result:

B -- INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
A -- REPLACE EVAP HOSE (INTAKE MANIFOLD - PURGE VSV)
27. CORRECTLY REINSTALL OR REPLACE FUEL CAP

HINT:
- When reinstalling the fuel cap, tighten it until a few click sounds are heard.
- When replacing the fuel cap, use a fuel cap that meets OEM specifications, and tighten it until a few click sounds are heard.

NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
28. REPLACE FUEL CAP

HINT: When installing the fuel cap, tighten it until a few click sounds are heard.

NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
29. LOCATE EVAP LEAK
(a) Reinstall the fuel cap.
(b) Disconnect the vent hose.

(d) Pressurize the EVAP system to 3.2 to 3.7 kPa (24 to 28 mmHg).
(e) Apply soapy water to the piping and connecting parts of the EVAP system.
(f) Look for areas where bubbles appear. This indicates leak point.
(g) 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)
30. REPLACE CANISTER ASSEMBLY
(a) Replace the canister assembly.

NOTE: When replacing the canister, check the canister pump module interior and related pipes for water, fuel or 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)
31. REPLACE PURGE VSV
(a) Disconnect the connector and hoses from the purge VSV.
(b) Remove the purge VSV.
(c) Install a new purge VSV.
(d) Reconnect the connector and hose.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
32. REPAIR OR REPLACE HARNESS AND CONNECTOR
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
33. REPLACE EVAP HOSE (INTAKE MANIFOLD - PURGE VSV)
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
34. INSPECT INTAKE MANIFOLD (EVAP PURGE PORT)
(a) Remove the throttle body Removal.
(b) 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)
35. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
36. 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)
37. PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)

NOTICE:
- The Evaporative System Check (Automatic Mode) consists of five 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, making the leak check of the fuel tank 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 the DTCs DTC Check / Clear.
(b) Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode.
(c) After the System Check is completed, check for pending DTCs by entering the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

HINT: If no pending DTC is found, the repair has been successfully completed.

NEXT -- COMPLETED

MONITOR DESCRIPTION

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 P0455: EVAP gross leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second 0.02 inch leak criterion x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leakage, illuminates the MIL and sets the DTC (2 trip detection logic).
2 P0456: EVAP very small leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than the second 0.02 inch leak criterion, the ECM determines that the EVAP system has a small leakage, illuminates the MIL and sets the DTC (2 trip detection logic).

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

All

P0455 (pattern 1), P0456

P0455 (pattern 2)

HINT: "Saturated" indicates that the EVAP pressure change is less than 0.1 kPa (0.75 mmHg) in 30 seconds.

TYPICAL MALFUNCTION THRESHOLDS

Small leak (0.020 inch) malfunction detection:

Gross leak detection:

MONITOR RESULT

Refer to detailed information on CHECKING MONITOR STATUS Mode 6 Data.