P0456

4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0455, P0456: Evaporative Emission Control System Leak Detected (Gross Leak)


DTC SUMMARY





DESCRIPTION

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

INSPECTION PROCEDURE

Refer to the EVAP System EVAP System.

MONITOR DESCRIPTION

5 hours*1 after the engine switch is turned off, the electric 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
*1: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the engine 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 engine switch is turned off, the monitor check starts 2.5 hours later.





HINT
*2: 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 pressure standard 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 0.02 inch 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 pressure standard, 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





1. EVAP key-off monitor sequence 1 to 8

1. Atmospheric pressure measurement





2. First reference pressure measurement





3. EVAP canister vent valve close stuck check





4. Vacuum introduction





5. EVAP canister purge valve close stuck check





6. Second reference pressure measurement





7. Leak check





8. Atmospheric pressure measurement





TYPICAL MALFUNCTION THRESHOLDS

P0455: EVAP gross leak





P0456: EVAP 0.02 inch leak





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

CONFIRMATION DRIVING PATTERN





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, 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 more, 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).

1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

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

4. Turn the engine switch off and wait for 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on.

6. Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Automatic Mode [A].

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

8. Read the pending DTC [B].

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

9. Entering the following menus: Powertrain / Engine / Utility / All Readiness.

10. Input the DTC: P0455 or P0456.

11. Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform step [A] again.

12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

13. Check the DTC judgment result.

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

14. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.

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