Part 1
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1420,P1421: Evaporative Emission Canister Small Leak
DTC P1420 - Evaporative Emission Canister Small Leak
DTC P1421 - Evaporative Emission Canister Gross Leak
DTC SUMMARY
DESCRIPTION
While the engine is running, if a predetermined conditions (closed loop, etc.) are met, the purge VSV is opened by the ECM (included in the hybrid vehicle control ECU) and stored fuel vapors in the canister are purged to the intake manifold. The ECM will change the duty cycle ratio of the purge VSV to control purge flow volume.
Purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed to enter into the canister through the vent valve to ensure that purge flow is maintained when negative pressure (vacuum) is applied to the canister.
The ECM monitors the condition of both the key-off monitor and purge flow monitor to ensure proper operation of the EVAP system.
MONITOR DESCRIPTION
1. 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).
2. 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:
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 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
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
P1420: EVAP small leak
MONITOR RESULT
Refer to EVAP System .
INSPECTION PROCEDURE
PROCEDURE
1. CONFIRM DTC
(a) Turn the power switch off and wait 10 seconds.
(b) Turn the power switch on (IG).
(c) Turn the power switch off and wait 10 seconds.
(d) Connect the Techstream to the DLC3.
(e) Turn the power switch on (IG) and turn the tester on.
(f) Enter the following menus: Powertrain / Engine / Trouble Code.
(g) Confirm the DTCs.
DTC and Malfunction Cross-Reference:
NEXT -- Continue to next step.
2. PERFORM SYSTEM CHECK (EVAPORATIVE SYSTEM CHECK (AUTOMATIC OPERATION))
NOTICE:
- In Evaporative System Check (Automatic Mode), a series of 6 Evaporative System Check steps are performed automatically. A maximum of 15 minutes is required.
- Do not perform Evaporative System Check when the fuel tank is more than 90% full because the cut-off valve may be closed and the leak check of the fuel tank is unavailable.
- Do not run the engine.
- 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 an Evaporative System Check, keep the temperature below 35°C (95°F).
(a) Clear the DTCs with the Techstream.
(b) Remove the fuel tank cap and reinstall the fuel cap.
(c) Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Automatic Mode.
(d) After Evaporative System Check is completed, check for DTCs.
Result:
C -- END
B -- PERFORM SYSTEM CHECK (EVAPORATIVE SYSTEM CHECK (MANUAL OPERATION))
A -- Continue to next step.
3. IDENTIFICATION OF TROUBLE AREAS
(a) Identification of trouble areas according to DTCs.
(b) Refer to the table below to determine the next procedure according to the output DTCs.
Result:
B -- PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)
A -- Continue to next step.
4. IDENTIFICATION OF TROUBLE AREAS
(a) Identification of trouble areas according to DTCs.
(b) Refer to the table below to determine the next procedure according to the output DTCs.
Result:
D -- CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)
C -- LOCATE EVAP LEAK PART (FUEL VAPOR-CONTAINMENT VALVE - FUEL TANK)
B -- LOCATE EVAP LEAK PART (PURGE VSV - CANISTER)
A -- Continue to next step.
5. CHECK VACUUM HOSE (PURGE VSV - INTAKE MANIFOLD)
(a) Disconnect the hose (to intake manifold) from the purge VSV.
(b) Put the engine in inspection mode Component Tests and General Diagnostics.
(c) Use your finger and confirm that the purge VSV has suction.
Result:
NG -- REPAIR OR REPLACE VACUUM HOSE
OK -- Continue to next step.
6. PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
(a) Disconnect the hose (to canister) from the purge VSV.
(b) Put the engine in inspection mode Component Tests and General Diagnostics.
(c) Enter the following menu: Powertrain / Engine / Active Test / Activate the VSV for EVAP Control.
(d) Turn the purge VSV OFF (Purge VSV: OFF).
(e) Use your finger and confirm that the purge VSV has no suction.
(f) Turn the purge VSV ON (Purge VSV: ON).
(g) Use your finger to confirm that the purge VSV has suction.
OK:
Purge VSV functions normally
OK -- REPAIR OR REPLACE VACUUM HOSE
NG -- Continue to next step.
7. CHECK PURGE VSV
(a) Remove the purge VSV.
(b) Apply compressed air to the purge VSV, confirm that no air flows from A to B as shown in the illustration.
(c) Apply battery voltage to the purge VSV.
(d) While applying compressed air, confirm that air flows from A to B as shown in the illustration.
Result:
NG -- REPLACE PURGE VSV
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (PURGE VSV - EFI NO. 3 FUSE)
(a) Disconnect the C6 purge VSV connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage between terminal 1 of the C6 connector and body ground.
Result:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (PURGE VSV - HYBRID VEHICLE CONTROL ECU)
(a) Disconnect the C64 hybrid vehicle control ECU connector and the C6 purge VSV connector.
(b) Measure the resistance.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. REPLACE HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Removal.
NEXT -- PERFORM SYSTEM CHECK (EVAPORATIVE SYSTEM CHECK AGAIN (AUTOMATIC OPERATION))
11. PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Enter the following menus: Powertrain / Engine / Active Test / Activate the Vacuum Pump.
(d) Turn the leak detection pump ON with the tester.
(e) Touch the canister pump module and check if the pump is moving.
OK:
Pump operates
NG -- PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)
OK -- Continue to next step.
12. PERFORM ACTIVE TEST USING TECHSTREAM (VENT VALVE)
(a) Remove the canister lower cover.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for Vent Valve.
(e) Touch the canister pump module, use the tester to turn the vent valve ON and OFF, and check if the vent valve is moving.
OK:
Vent valve vibration can be felt.
NG -- INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)
OK -- REPLACE CANISTER ASSEMBLY
13. PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)
(a) Turn the power switch off.
(b) Remove the canister lower cover.
(c) Disconnect the canister pump module connector.
(d) Connect the Techstream to the DLC3.
(e) Turn the power switch on (IG).
(f) Enter the following menus: Powertrain / Engine / Active Test / Activate the Vacuum Pump.
(g) Turn the leak detection pump ON with the tester.
(h) Measure the voltage between MTRB terminal 1 of the canister pump module connector and body ground when the leak detection pump is turned ON and OFF using the tester.
Standard voltage:
10 to 14 V
NG -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - CANISTER PUMP MODULE)
OK -- Continue to next step.
14. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - BODY GROUND)
(a) Remove the canister lower cover.
(b) Disconnect the canister pump module connector.
(c) Measure the resistance between the MGND terminal of the canister pump module and body ground.
Standard resistance:
Below 1 Ohms
NG -- REPAIR OR REPLACE VACUUM HOSE
OK -- REPLACE CANISTER ASSEMBLY
15. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - CANISTER PUMP MODULE)
(a) Disconnect the A61 hybrid vehicle control ECU connector.
(b) Disconnect the canister pump module connector.
(c) Measure the resistance between the MPMP terminal of the hybrid vehicle control ECU connector and the MTRB terminal of the canister pump module connector.
Standard resistance:
NG -- REPAIR OR REPLACE VACUUM HOSE
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
1 6. INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)
(a) Turn the power switch off.
(b) Remove the canister lower cover.
(c) Disconnect the canister pump module connector.
(d) Apply battery voltage to the VLVB and VGND terminals of the canister pump module.
(e) Touch the canister pump module to confirm the vent valve operation.
Result:
(f) Reconnect the canister pump module connector.
B -- REPLACE CANISTER ASSEMBLY
A -- Continue to next step.
17. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - HYBRID VEHICLE CONTROL ECU)
(a) Disconnect the A61 hybrid vehicle control ECU connector.
(b) Disconnect the canister pump module connector.
(c) Measure the resistance between the VPMP terminal of the hybrid vehicle control ECU connector and the VGND terminal of the canister pump module connector.
Standard resistance:
(d) Reconnect the hybrid vehicle control ECU connector.
(e) Reconnect the canister pump module connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
18. LOCATE EVAP LEAK PART (PURGE VSV - CANISTER)
(a) Disconnect the vent hose.
(b) Connect the EVAP tester to the vent hose with the adapter.
(c) Pressurize the EVAP system to 3.2 to 3.7 kPa (24 to 28 mmHg).
(d) Apply soapy water to the piping and connecting parts of the EVAP system.
(e) Look for areas where bubbles appear. This indicates the leak point.
(f) Repair or replace the leak point.
HINT: Disconnect the hose between the canister and the fuel tank from the canister. Block the canister side and conduct an inspection. In this way, the fuel tank can be excluded as an area suspected of causing fuel leaks.
NEXT -- Continue to next step.
19. REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA
NEXT -- PERFORM SYSTEM CHECK (EVAPORATIVE SYSTEM CHECK AGAIN (AUTOMATIC OPERATION))