P2401

2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P043E,P043F,P2401,P2402,P2419: Evaporative Emission System Leak Detection Reference Orifice Low Flow


DTC SUMMARY





DESCRIPTION

Refer to the EVAP System EVAP System.

MONITOR DESCRIPTION

In Sequence B and E, the leak detection pump creates negative pressure (vacuum) through the reference orifice. The EVAP system pressure is then measured by the ECM, using the canister pressure sensor, to determine the reference pressure. If the pressure is one of the following conditions, the ECM illuminates the MIL and sets the DTC (2 trip detection logic).

- Canister pressure is lower than the malfunction criterion (ex. 724 mmHg).

- Canister pressure is higher than the malfunction criterion (ex. 752 mmHg).

- Canister pressure is not saturated within 60 seconds.

- Canister pressure difference of sequence B and sequence E is large.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





Key-off monitor sequence 1 to 15

1. Atmospheric pressure measurement





2. First reference pressure measurement





3. Vent valve stuck closed check





4. Vacuum introduction for canister





5. Purge VSV stuck closed check





6. Second reference pressure measurement





7. Canister leak





8. Fuel vapor-containment valve (FVCV stuck closed check)





9. Vacuum introduction for fuel tank





10. FVCV stuck closed check





11. FTP sensor stuck check





12 Third reference pressure measurement





13. Fuel tank leak check





14. FTP sensor stuck check





15. Atmospheric pressure measurement





HINT
"Saturated" indicates that the EVAP pressure change in less than 0.12 kPa (0.9 mmHg) in 30 seconds.

TYPICAL MALFUNCTION THRESHOLDS





MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.

WIRING DIAGRAM

Refer to EVAP System EVAP System.

INSPECTION PROCEDURE

Refer to EVAP System EVAP System.