P1421
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1420,P1421: Evaporative Emission Canister Small Leak
P1421 - Evaporative Emission Canister Gross Leak
DTC SUMMARY
DESCRIPTION
Refer to EVAP System Component Tests and General Diagnostics.
MONITOR DESCRIPTION
* P1420: EVAP (Evaporative Emission) very small leak
* In operation C, the vacuum 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 0.02 inch leak pressure standard, the ECM (included in the hybrid vehicle control ECU) determines that the EVAP system has a large leakage. The ECM illuminates the MIL and sets the DTC (2-trip detection logic).
* P1421: EVAP very gross leak
* In operation C, the vacuum 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 (included in the hybrid vehicle control ECU) determines that the EVAP system has a large leakage. The ECM illuminates the MIL and sets the DTC (2-trip detection logic).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
Example of restart time:
Example of restart time::
Key-off monitor sequence 1 to 15
1. Atmospheric pressure measurement
1. Atmospheric pressure measurement:
2. First reference pressure measurement
2. First reference pressure measurement:
3. Vent valve stuck closed check
3. Vent valve stuck closed check:
4. Vacuum introduction for canister
4. Vacuum introduction for canister:
5. Purge VSV stuck closed check
5. Purge VSV stuck closed check:
6. Second reference pressure measurement
6. Second reference pressure measurement:
7. Canister leak check
7. Canister leak check:
8. Fuel vapor-containment valve (FVCV stuck closed check)
8. Fuel vapor-containment valve (FVCV stuck closed check):
9. Vacuum introduction for fuel tank
9. Vacuum introduction for fuel tank:
10. FVCV stuck closed check
10. FVCV stuck closed check:
11. FTP sensor stuck check
11. FTP sensor stuck check:
12. Third reference pressure measurement
12. Third reference pressure measurement:
13. Fuel tank leak check
13. Fuel tank leak check:
14. FTP sensor stuck check
14. FTP sensor stuck check:
15. Atmospheric pressure measurement
15. Atmospheric pressure measurement:
TYPICAL MALFUNCTION THRESHOLDS
"Saturated" indicates that the EVAP pressure change is less than 0.75 mmHg (0.1 kPa) in 30 seconds.
P1421: EVAP gross leak
P1421: EVAP gross leak:
P1420: EVAP small leak
P1420: EVAP small leak:
MONITOR RESULT
Refer to EVAP System Component Tests and General Diagnostics.
INSPECTION PROCEDURE
Refer to EVAP System Component Tests and General Diagnostics.