P1421

2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1420,P1421: Evaporative Emission Canister Small Leak
P1421 - Evaporative Emission Canister Gross Leak

DTC SUMMARY

DESCRIPTION

Refer to the EVAP System EVAP System.

MONITOR DESCRIPTION

1. P1420: EVAP (Evaporative Emission) 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 reference pressure, the ECM determines that the EVAP system has a small leakage, illuminates the MIL and sets the DTC (2 trip detection logic).

2. P1421: EVAP very 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 reference pressure 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).

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

P1421: EVAP gross leak

P1420: EVAP small leak

MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.

WIRING DIAGRAM

Refer to the EVAP System EVAP System.

INSPECTION PROCEDURE

Refer to the EVAP System EVAP System.