Up to 08/2009
2GR-FXE ENGINE CONTROL: SFI SYSTEM: P1420,P1421: Evaporative Emission Canister Small Leak
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
- 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).
- P1421: 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 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. Fuel tank pressure sensor stuck check
12 Third reference pressure measurement
13. Fuel tank leak check
14. Fuel tank pressure sensor stuck check
15. Atmospheric pressure measurement
TYPICAL MALFUNCTION THRESHOLDS
P1420: EVAP small leak
P1421: EVAP gross leak
MONITOR RESULT
Refer to Checking Monitor Status Mode 6 Data.