Part 1

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2420: Evaporative Emission System Switching Valve Control Circuit High

DTC P2420 - Evaporative Emission System Switching Valve Control Circuit High

DTC SUMMARY

DESCRIPTION

While the engine is running, if 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 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.

Key-off monitor

This monitoring system checks for canister pump module malfunctions and leaks from the EVAP and closed tank systems. Be sure to leave the vehicle for at least 5 hours to sufficiently cool the fuel and stabilize fuel tank pressure. This makes EVAP system monitoring more accurate.
HINT: If the engine coolant temperature is 35°C or more, 5 hours after the power switch has been turned off, the ECM (included in the hybrid vehicle control ECU) will begin performing a monitor check after another 2 hours. If the engine coolant temperature is still 35°C or more, 7 hours after the power switch has been turned off, the ECM will begin performing a monitor check after another 2.5 hours.

There are two methods for monitoring the EVAP system.
1. If the fuel tank pressure is higher or lower than the atmospheric pressure, the system determines that there are no leaks in the closed tank system and the system will check for leaks from the piping and canister between the purge VSV and canister pump module. (Method A)
2. If the fuel tank pressure is almost the same as the atmospheric pressure, vacuum will be allowed to enter the fuel tank and the system will check for leaks from the fuel tank after checking for leaks from the canister. (Method B)

HINT: *: If there is only a small amount of fuel in the fuel tank, stabilizing the EVAP pressure takes longer than usual.

Purge flow monitor

If EVAP system pressure change is less than 7.5 mmHg (1 kPa) when the engine is running and the purge VSV is turned ON (closed), the ECM (included in the hybrid vehicle control ECU) determines that the purge flow is insufficient.

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 Techstream switch on.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(g) Confirm the DTCs and freeze frame data.

EVAP Related DTCs

DTC and Malfunction Cross-Reference

NEXT -- Continue to next step.
2. PERFORM EVAP SYSTEM CHECK (AUTOMATIC MODE)
NOTICE:
- In the Evaporative System Check (Automatic Mode), a series of 6 EVAP SYSTEM CHECK steps are performed automatically. A maximum of 15 minutes is required.
- Do not perform the EVAP 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 impossible.
- 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 and ECT / Utility / Evaporative System Check / Automatic Mode.
(d) After the Evaporative System Check is completed, check for pending DTCs.
Result:

C -- END
B -- PERFORM EVAP SYSTEM CHECK (MANUAL MODE)
A -- Continue to next step.
3. IDENTIFY TROUBLE AREAS USING DTC
(a) Refer to the table below to determine the next procedure according to the output DTCs.
Result:

D -- PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
C -- CHECK CANISTER PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
B -- CHECK CANISTER PUMP MODULE (VACUUM PUMP POWER SOURCE CIRCUIT)
A -- Continue to next step.
4. IDENTIFY TROUBLE AREAS USING DTC
(a) 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 -- CHECK FUEL TANK CAP ASSEMBLY
B -- CHECK CANISTER PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
A -- Continue to next step.
5. CHECK VACUUM HOSE (PURGE VSV - THROTTLE BODY)

(a) Disconnect the hose (to the intake air connector) from the purge VSV.
(b) Start the engine.
(c) Use your finger and confirm that the purge VSV has suction.
Result:

NG -- REPAIR OR REPLACE VACUUM HOSE (PURGE VSV - THROTTLE BODY)
OK -- Continue to next step.
6. PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)

(a) Disconnect the hose (to canister) from the purge VSV.
(b) Start the engine.
(c) Enter the following menus on the Techstream: Powertrain / Engine and ECT / Active Test / Active the VSV for EVAP Control.
(d) Turn the purge VSV OFF.
(e) Use your finger and confirm that the purge VSV has no suction.
(f) Turn the Purge VSV ON.
(g) Use your finger and confirm that the purge VSV has suction.
OK:
Purge VSV functions normally
Result:

B -- CHECK HOSES (PURGE VSV - CANISTER)
A -- Continue to next step.
7. CHECK PURGE VSV

(a) Remove the purge VSV.
(b) Apply compressed air to the purge VSV, and 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 purge VSV connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage between terminal 1 of the B29 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 hybrid vehicle control ECU connector and the B29 purge VSV connector.
(b) Measure the resistance according to the value(s) in the table below.
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 Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
11. CHECK CANISTER PUMP MODULE (VACUUM PUMP POWER SOURCE CIRCUIT)

(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 and ECT / Active Test / Activate the Vacuum Pump.
(g) Turn the vacuum pump on using the Techstream.
(h) Measure the voltage between terminals 1 and 6 of the O42 connector.
Standard voltage:
10 to 14 V
Result:

B -- CHECK CANISTER PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
A -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (VACUUM PUMP - BODY GROUND)

(a) Turn the power switch off.
(b) Measure the resistance between terminal O42-6 and body ground.
Standard resistance:
Below 10 Ohms
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
13. CHECK HARNESS AND CONNECTOR (VACUUM PUMP - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the hybrid vehicle control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(c) Connect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
14. REPLACE HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
15. CHECK CANISTER PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)

(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 and ECT / Active Test / Activate the Vacuum Pump.
(g) Turn the vacuum pump on using the Techstream.
(h) Measure the voltage between terminals 8 and 9 of the O42 connector and body ground.
Standard voltage:
10 to 14 V
Result:

B -- REPLACE CANISTER ASSEMBLY
A -- Continue to next step.
16. CHECK HARNESS AND CONNECTOR (VENT VALVE - BODY GROUND)

(a) Turn the power switch off.
(b) Measure the resistance between terminal O42-9 and body ground.
Standard resistance:
Below 10 Ohms
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
17. CHECK HARNESS AND CONNECTOR (VENT VALVE - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the hybrid vehicle control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(c) Connect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
18. REPLACE HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Components.
NEXT -- Continue to next step.
19. CHECK HOSES (PURGE VSV - CANISTER)
(a) Remove the canister cover.

(b) Connect the pressure gauge (SST) to the canister pump module with the adapter.
(c) Pressurize the EVAP system to between 3.2 and 3.7 kPa (24 and 28 mmHg).
NOTE: More than 4.7 kPa (35 mmHg) of pressure will damage the EVAP system. Pay attention to the pressure.
(d) Apply soapy water to the piping and connections of the EVAP system. Look for the area where bubbles appear.
HINT:
- If the system has leaks, a whistling sound will be heard.
- Disconnect the hose between the canister and fuel tank from the canister. Close the canister on the area where the hose was connected and perform an inspection. The fuel tank can be eliminated from the suspected areas for leak checks.

NEXT -- Continue to next step.
20. REPLACE MALFUNCTIONING PART
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
21. CHECK FUEL TANK CAP ASSEMBLY
(a) Check if the fuel cap is tightened until a few "click" sounds are heard.
(b) If you have the EVAP tester, check the fuel cap using the fuel cap adaptor.
(1) Install the fuel cap to the fuel cap adaptor, and connect the hose from the EVAP tester's pump.
(2) Pressurize the fuel cap adaptor to between 3.2 and 3.7 kPa (24 and 28 mmHg) or for 45 seconds.
(3) Stop the pump and seal the fuel cap adaptor.
(4) Wait 2 minutes.
(5) Confirm that the pressure is higher than 2.0 kPa (15 mmHg).
OK:
Higher than 2.0 kPa (15 mmHg)
NG -- REPLACE FUEL TANK CAP ASSEMBLY
OK -- Continue to next step.
22. CHECK HOSES (FUEL VAPOR-CONTAINMENT VALVE - FUEL TANK)
(a) Remove the canister cover.

(b) Connect the pressure gauge (SST) to the canister pump module with the adapter.
(c) Connect the Techstream to the DLC3.
(d) Turn the power switch on (IG).
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Fuel Vapor-Containment Valve.
(f) Turn the fuel vapor-containment valve ON using the Techstream.
(g) Pressurize the EVAP system to between 3.2 and 3.7 kPa (24 and 28 mmHg).
NOTE: More than 4.7 kPa (35 mmHg) of pressure will damage the EVAP system. Pay attention to the pressure.
(h) Apply soapy water to the piping and connections of the EVAP system. Look for the area where bubbles appear.
HINT:
- If the system has leaks, a whistling sound will be heard.
- Disconnect the hose between the canister and fuel tank from the canister. Close the canister on the area where the hose was connected and perform an inspection. The fuel tank can be eliminated from the suspected areas for leak checks.

NEXT -- Continue to next step.
23. CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)

(a) Turn the power switch off.
(b) Disconnect the Ok1 connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the power switch on (IG).
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Fuel Vapor-Containment Valve.
(f) Turn the fuel vapor-containment valve ON using the Techstream.
(g) Measure the voltage between terminals 3 and 7 of the Ok1 connector.
Standard voltage:
10 to 14 V
Result:

B -- CHECK HARNESS AND CONNECTOR (TANK WIRE HARNESS)
A -- Continue to next step.
24. CHECK HARNESS AND CONNECTOR (TANK CLOSE VALVE - IGCT NO. 4 FUSE)

(a) Turn the power switch on (IG).
(b) Measure the voltage between terminal Ok1-3 and body ground.
Standard voltage:
10 to 14 V
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

25. CHECK HARNESS AND CONNECTOR (TANK CLOSE VALVE - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the hybrid vehicle control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(c) Connect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
26. REPLACE HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
27. REPLACE PURGE VSV
(a) Replace the purge VSV Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
28. REPLACE CANISTER ASSEMBLY
(a) Replace the canister assembly Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
29. CHECK HARNESS AND CONNECTOR (TANK WIRE HARNESS)
(a) Remove the fuel tank assembly. Removal

(b) Disconnect the fuel vapor-containment valve connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(d) Reinstall the fuel tank assembly. Installation

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
30. REPLACE FUEL VAPOR-CONTAINMENT VALVE
(a) Replace the fuel vapor-containment valve Components.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
31. REPLACE FUEL TANK CAP ASSEMBLY
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
32. REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
33. REPAIR OR REPLACE VACUUM HOSE (PURGE VSV - THROTTLE BODY)
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
34. PERFORM EVAP SYSTEM CHECK (MANUAL MODE)
HINT: In the manual operation check, the EVAP system can be checked in several steps. Valve operation and pressure in each step can also be checked.
(a) Clear the DTCs DTC Check / Clear.
(b) Remove the fuel tank cap and reinstall the fuel tank cap.
(c) Select the following menu items: Powertrain / Engine and ECT / Utility / Evaporative System Check / Manual Mode.
NOTICE:
- In the Evaporative System Check (Manual Mode), the series of 9 EVAP SYSTEM CHECK steps is performed automatically. 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 leak check of the fuel tank impossible.
- Do not run the engine in this step.
- 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 temperature below 35°C (95°F).

Tester Display

Manual Operation Step

NEXT -- Continue to next step.
35. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 1)
(a) Select step 1 and wait 10 seconds.
NEXT -- Continue to next step.
36. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 2)
(a) Perform step 2.
(b) Check the EVAP pressure 2 seconds after the vacuum pump is activated*.
*: The vacuum pump begins to operate at the start of step 2.

Result:

C -- REPLACE CHARCOAL CANISTER ASSEMBLY
B -- CHECK CANISTER PUMP MODULE (VACUUM PUMP POWER SOURCE CIRCUIT)
A -- Continue to next step.
37. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 3)
(a) Perform step 3.
(b) Check the EVAP pressure change in step 3.

Result:

(d) Check the EVAP pressure again when it has stabilized. This pressure is the canister leak pressure standard.
(e) Compare the first reference pressure with the canister leak pressure.

Result:

D -- PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
C -- CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)
B -- CHECK CANISTER PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
A -- Continue to next step.
38. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 4)
(a) Perform step 4.
(b) Check the EVAP pressure change in step 3.

Result:

B -- CHECK VACUUM HOSE (PURGE VSV - THROTTLE BODY)
A -- Continue to next step.
39. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 5)
(a) Perform step 5 and wait 60 seconds.
(b) Check the EVAP pressure. This pressure is the second reference pressure standard.
NEXT -- Continue to next step.
40. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 6)
(a) Perform step 6 and wait 5 seconds.
NEXT -- Continue to next step.
41. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 7)
(a) Perform step 7.
(b) Check that the tank pressure and EVAP pressure change.
(c) Check the tank pressure again when it has stabilized. This pressure is the fuel tank leak pressure standard.

Result:

B -- CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)
A -- Continue to next step.
42. PERFORM EVAP SYSTEM CHECK (MANUAL MODE STEP 8)
(a) Perform step 8 and wait 60 seconds.
(b) Check the EVAP pressure. This pressure is the third reference pressure standard.
(c) Compare the tank pressure checked in step 41 with the third reference pressure.

Result:

B -- REPLACE FUEL VAPOR-CONTAINMENT VALVE
A -- Continue to next step.
43. PERFORM CONFIRMATION DRIVING PATTERN
(a) KEY-OFF MONITOR DRIVE PATTERN
(1) Connect the Techstream to the DLC3.
(2) Confirm the following conditions are satisfied:

- The fuel level is less than 90%.
- The altitude is less than 8000 ft. (2400 m).
- The vehicle is stopped (the vehicle speed is less than 2 mph).
- The engine coolant temperature is 4.4 to 35°C (40 to 95°F)
- The intake air temperature is 4.4 to 35°C (40 to 95°F)

(3) Perform the drive pattern:
1. Allow the engine to idle for 5 minutes or more.
2. Turn the power switch off and wait 6 hours.

(4) Check the monitor status with the Techstream.
(b) PURGE FLOW MONITOR DRIVE PATTERN (P0441)
(1) Connect the Techstream to the DLC3.
(2) Confirm that the following conditions are satisfied:

- The engine coolant temperature is more than 4.4°C (40°F).
- The intake air temperature is more than 4.4°C (40°F).

(3) Perform the drive pattern:
1. Remove and reinstall the fuel cap to release the fuel tank pressure.
2. Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or more.
3. Run the engine at 3000 rpm once.
4. Allow the engine to idle and turn on the air conditioning (A/C) for 1 minute.

(4) Check the monitor status with the Techstream.
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTOMATIC MODE)
44. CHECK VACUUM HOSE (PURGE VSV - THROTTLE BODY)

(a) Disconnect the hose (to intake air connector) from the purge VSV.
(b) Start the engine.
(c) Use your finger and confirm that the purge VSV has suction.
Result:

NG -- REPAIR OR REPLACE VACUUM HOSE (PURGE VSV - THROTTLE BODY)
OK -- Continue to next step.