P1421

2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1420: Evaporative Emission Canister Small Leak

DTC P1420 - Evaporative Emission Canister Small Leak

DTC P1421 - Evaporative Emission Canister Gross Leak

DTC SUMMARY

DESCRIPTION

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

INSPECTION PROCEDURE

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 check

8. Fuel tank closed valve (TCV) stuck closed check

9. Vacuum introduction for fuel tank

10. TCV 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

TYPICAL MALFUNCTION THRESHOLDS

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

P1421: EVAP gross leak

P1420: EVAP small leak

MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.