EVAP System

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System

EVAP System

DESCRIPTION

While the engine is running, if a predetermined condition (closed loop, etc.) is met, the EVAP VSV is opened by the ECM (Included in HV 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 EVAP VSV to control purge flow volume.
Purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed 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.

Key-off monitor

This monitoring system checks for 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 ignition switch has been turned off, the ECM (Included in HV 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 ignition 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 EVAP VSV and pump module. (Method A)
2 If the fuel tank pressure is almost the same as the atmospheric pressure, vacuum pressure will 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 EVAP VSV is turned ON (closed), the ECM (Included in HV control ECU) determines that the purge flow is insufficient.

RELATED DTCS

MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.
The test value and test limit information are described as shown in the following table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").

- MID (Monitor Identification Data) is assigned to each emissions-related component.
- TID (Test Identification Data) is assigned to each test value.
- Scaling is used to calculate the test value indicated on generic OBD II scan tools.

CONFIRMATION DRIVING PATTERN

1. KEY-OFF MONITOR DRIVE PATTERN
(a) Connect Techstream to the DLC3.
(b) Confirm the following conditions are satisfied:
- The fuel level is less than 90%.
- The altitude is less than 8,000 ft. (2,400 m).
- The vehicle is stopped (the vehicle speed is less than 2 mph).
- The ECT is 4.4 to 35°C (40 to 95°F)
- The IAT is 4.4 to 35°C (40 to 95°F)

(c) Perform the drive pattern:
(1) Allow the engine to idle for 5 minutes or more.
(2) Turn the ignition switch OFF and wait 6 hours.
(d) Check the monitor status with the Techstream.
2. PURGE FLOW MONITOR DRIVE PATTERN (P0441)
(a) Connect Techstream to the DLC3.
(b) Confirm that the following conditions are satisfied:
- The Engine Coolant Temperature (ECT) is more than 4.4°C (40°F).
- The Intake Air Temperature (IAT) is more than 4.4°C (40°F).

(c) Perform the drive pattern:
(1) Remove and reinstall the fuel cap to release the fuel tank pressure.
(2) Warm the engine until the ECT reaches 75°C (167°F) or more.
(3) Run the engine at 3,000 rpm once.
(4) Allow the engine to idle and turn on the air conditioning (A/C) for 1 minute.
(d) Check the monitor status with the Techstream.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CONFIRM DTC
(a) Turn the ignition switch OFF and wait 10 seconds.
(b) Turn the ignition switch to the ON position.
(c) Turn the ignition switch off and wait 10 seconds.
(d) Connect Techstream to the DLC3.
(e) Turn the ignition switch to the ON position and press the Techstream switch on.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(g) Confirm the DTCs.

EVAP Related DTCs

DTC and Malfunction Cross-Reference

NEXT -- Continue to next step.
2. PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
NOTICE:
- In the 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 the 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 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. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Result:

C -- END
B -- PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION)
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 BY TECHSTREAM (EVAP VSV)
C -- CHECK PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
B -- CHECK 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 PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
A -- Continue to next step.
5. CHECK VACUUM HOSE (EVAP VSV - THROTTLE BODY)

(a) Disconnect the hose (to throttle body) from the EVAP VSV.
(b) Start the engine.
(c) Use your finger and confirm that the EVAP VSV has suction.
Result:

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

(a) Disconnect the hose (to canister) from the EVAP VSV.
(b) Start the engine.
(c) Enter the following menus on the Techstream: Powertrain / Engine and ECT / Active Test / Activate the VSV for Evap Control.
(d) Turn the EVAP VSV OFF (EVAP VSV: OFF).
(e) Use your finger and confirm that the EVAP VSV has no suction.
(f) Turn the EVAP VSV ON (EVAP VSV: ON).
(g) Turn the EVAP VSV ON (EVAP VSV: ON).
OK:
EVAP VSV functions normally
OK -- CHECK HOSES (EVAP VSV - CANISTER)
NG -- Continue to next step.
7. CHECK EVAP VSV

(a) Remove the EVAP VSV.
(b) Apply compressed air to the EVAP VSV, and confirm that no air flows from A to B as shown in the illustration.
(c) Apply battery voltage to the EVAP VSV.
(d) While applying compressed air, confirm that air flows from A to B as shown in the illustration.
Result:

NG -- REPLACE EVAP VSV
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (EVAP VSV - IGCT NO. 4 FUSE)

(a) Disconnect the V3 VSV for EVAP connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage between terminal 1 of the V3 connector and body ground.
Result:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (EVAP VSV - HV CONTROL ECU)

(a) Disconnect the H32 HV control ECU connector and the V3 VSV for EVAP 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 HV CONTROL ECU
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
11. CHECK PUMP MODULE (VACUUM PUMP POWER SOURCE CIRCUIT)

(a) Turn the ignition switch off.
(b) Remove the canister lower cover.
(c) Disconnect the L5 canister pump module connector.
(d) Connect Techstream to the DLC3.
(e) Turn the ignition switch to the ON position.
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.
(g) Turn the vacuum pump on using the tester.
(h) Measure the voltage between terminals 1 and 6 of the L5 connector.
Standard voltage:
10 to 14 V
OK -- CHECK PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
NG -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (VACUUM PUMP - BODY GROUND)

(a) Turn the ignition switch off.
(b) Measure the resistance between terminal L5-6 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 - HV CONTROL ECU)

(a) Disconnect the H30 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.
14. REPLACE HV CONTROL ECU
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
15. CHECK PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)

(a) Turn the ignition switch off.
(b) Remove the canister lower cover.
(c) Disconnect the L5 canister pump module connector.
(d) Connect Techstream to the DLC3.
(e) Turn the ignition switch to the ON position.
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.
(g) Turn the vacuum pump on using the tester.
(h) Measure the voltage between terminals 8 and 9 of the L5 connector and body ground.
Standard voltage:
10 to 14 V
OK -- REPLACE CANISTER ASSEMBLY
NG -- Continue to next step.
16. CHECK HARNESS AND CONNECTOR (VENT VALVE - BODY GROUND)

(a) Turn the ignition switch off.
(b) Measure the resistance between terminal L5-9 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 - HV CONTROL ECU)

(a) Disconnect the H30 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.
18. REPLACE HV CONTROL ECU
NEXT -- Continue to next step.
19. CHECK HOSES (EVAP 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 24 and 28 mmHg.
NOTE: More than 35 mmHg of pressure will damage the EVAP system. Pay attention to the pressure.
(d) Apply soapy water to the piping and connecting parts 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 (AUTO OPERATION)
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 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 15 mmHg.
OK:
Higher than 15 mmHg
NG -- REPLACE FUEL TANK CAP ASSY
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 Techstream to the DLC3.
(d) Turn the ignition switch to the ON position.
(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 tester.
(g) Pressurize the EVAP system to between 24 and 28 mmHg.
NOTE: More than 35 mmHg of pressure will damage the EVAP system. Pay attention to the pressure.
(h) Apply soapy water to the piping and connecting parts 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 ignition switch off.
(b) Disconnect the BL1 wire harness to wire harness connector.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch to the ON position.
(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 tester.
(g) Measure the voltage between terminals 3 and 7 of the BL1 connector.
Standard voltage:
10 to 14 V
OK -- CHECK HARNESS AND CONNECTOR (TANK WIRE HARNESS)
NG -- Continue to next step.
24. CHECK HARNESS AND CONNECTOR (TANK CLOSE VALVE - IGCT NO. 4 FUSE)

(a) Turn the ignition switch to the ON position.
(b) Measure the voltage between terminal BL1-3 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 - HV CONTROL ECU)

(a) Disconnect the H30 HV control ECU 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.
26. REPLACE HV CONTROL ECU
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
27. REPLACE EVAP VSV
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
28. REPLACE CANISTER ASSEMBLY
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
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 fuel tank assembly. Installation

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
30. REPLACE FUEL VAPOR-CONTAINMENT VALVE
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
31. REPLACE FUEL TANK CAP ASSY
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
32. REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
33. REPAIR OR REPLACE VACUUM HOSE (EVAP VSV - THROTTLE BODY)
NEXT -- PERFORM EVAP SYSTEM CHECK AGAIN (AUTO OPERATION)
34. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION)
HINT: In the manual operation check, the EVAP system can be checked in signal 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 cap.
(c) Select the following menu items: Powertrain / Engine and ECT / Utility / Evaporative System Check / Manual Mode.
NOTICE:
- Do not perform the Evaporative System Check (Manual Mode) 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 unavailable.
- 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 (Manual Mode), keep the temperature below 35°C (95°F).

Tester Display

Manual Operation Step

- Timing Chart

NEXT -- Continue to next step.
35. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION STEP 1)
(a) Select step 1 and wait 10 seconds.
NEXT -- Continue to next step.
36. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION 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 CANISTER ASSEMBLY
B -- CHECK PUMP MODULE (VACUUM PUMP POWER SOURCE CIRCUIT)
A -- Continue to next step.
37. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION 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 BY TECHSTREAM (EVAP VSV)
C -- CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)
B -- CHECK PUMP MODULE (VENT VALVE POWER SOURCE CIRCUIT)
A -- Continue to next step.
38. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION STEP 4)
(a) Perform step 4.
(b) Check the EVAP pressure change in step 3.

Result:

B -- CHECK VACUUM HOSE (EVAP VSV - THROTTLE BODY)
A -- Continue to next step.
39. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION 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 OPERATION STEP 6)
(a) Perform step 6 and wait 5 seconds.
NEXT -- Continue to next step.
41. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION 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 OPERATION 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 Techstream to the DLC3.
(2) Confirm the following conditions are satisfied:

- The fuel level is less than 90%.
- The altitude is less than 8,000 ft. (2,400 m).
- The vehicle is stopped (the vehicle speed is less than 2 mph).
- The ECT is 4.4 to 35°C (40 to 95°F)
- The IAT 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 ignition switch off and wait 6 hours.

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

- The Engine Coolant Temperature (ECT) is more than 4.4°C (40°F).
- The Intake Air Temperature (IAT) 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 ECT reaches 75°C (167°F) or more.
3 Run the engine at 3,000 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 (AUTO OPERATION)