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).





CONFIRMATION DRIVING PATTERN

NOTICE:
- The Evaporative System Check (Automatic Mode) consists of 9 steps performed automatically by the Techstream. It takes a maximum of approximately 18 minutes.
- Do not perform the Evaporative System Check when the fuel tank is more than 90% full because the cut-off valve may be closed, making the fuel tank leak check unavailable.
- Do not run the engine during this operation.
- When the temperature of the fuel is 35°C (95°F) or more, a large amount of vapor forms and any check results become inaccurate. When performing the Evaporative System Check, keep the fuel temperature below 35°C (95°F).

1. Connect the Techstream to the DLC3.

2. Turn the power switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the power switch off and wait for 30 seconds.

5. Turn the power switch on (IG) and turn the Techstream on.

6. Enter the following menus: Powertrain / Engine and ECT / Utility / Evaporative System Check / Automatic Mode [A].

7. After the Evaporative System Check is completed, check for DTCs by entering the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

8. Read the Pending DTC.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine and ECT / Utility / All readiness.

10. Input the DTC: P1420 or P1421.

11. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform step [A] again.

12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

13. Check the judgment result.

HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.

14. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

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.