Part 1

2UR-FSE 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 purge VSV is opened by the ECM 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 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 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 (95°F) or more, 5 hours after the power switch has been turned off, the ECM will begin performing a monitor check after another 2 hours. If the engine coolant temperature is still 35°C (95°F) 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.

* 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)

* 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

The purge flow monitor consists of 2 step monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary.





* The 1st monitor

While the engine is running and the purge VSV (Vacuum Switching Valve) is ON (open), the ECM monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd monitor.

* The 2nd monitor

The vent valve is turned ON (closed) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.5 kPa-g (3.75 mmHg-g), the ECM interprets this as the Purge VSV being stuck closed. The ECM illuminates the MIL and sets DTC P0441 (2 trip detection logic).

Atmospheric pressure check:

In order to ensure reliable malfunction detection, the variation between the atmospheric pressure, before and after conduction of the purge flow monitor is measured by the ECM.





RELATED DTCS





MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.

CONFIRMATION DRIVING PATTERN

1. KEY-OFF MONITOR DRIVE PATTERN

(a) Connect the Techstream to the DLC3.

(b) Confirm the following conditions are satisfied:

* The fuel level is less than 90%.

* The altitude is less than 2400 m (8000 ft.).

* 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 power switch off and wait 6 hours.

(d) Check the monitor status with the Techstream.

2. PURGE FLOW MONITOR DRIVE PATTERN (P0441)

(a) Connect the 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) Put the engine in inspection mode Inspection Mode Procedure.

(3) Warm the engine until the ECT reaches 75°C (167°F) or more.

(4) Run the engine at 2500 rpm once.

(5) 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 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 ON.

(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(g) Confirm the DTCs.

DTC and Malfunction Cross-Reference





NEXT -- Continue to next step.

2. PERFORM EVAPORATIVE SYSTEM CHECK (AUTOMATIC MODE)

NOTICE:
* In the Evaporative System Check (Automatic Mode), a series of 9 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 DTC 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 EVAP System Check is completed, check the DTC.

Result





B -- PERFORM EVAPORATIVE SYSTEM CHECK (MANUAL MODE)

C -- END
A -- Continue to next step.

3. IDENTIFICATION OF TROUBLE AREAS USING DTC

(a) 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 USING DTC

(a) Refer to the table below to determine the next procedure according to the output DTCs.

Result





B -- LOCATE EVAP LEAK PART (PURGE VSV - CANISTER)

C -- LOCATE EVAP LEAK PART (FUEL VAPOR-CONTAINMENT VALVE - FUEL TANK)

D -- CHECK FUEL VAPOR-CONTAINMENT VALVE ASSEMBLY (POWER SOURCE CIRCUIT)
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 Inspection Mode Procedure.

(c) Use your finger to confirm that the hose 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 Inspection Mode Procedure.

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VSV for EVAP Control.

(d) Turn the Purge VSV OFF (Purge VSV: OFF).

(e) Use your finger to 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 -- CHECK PURGE VSV

7. CHECK PURGE VSV

(a) Remove the purge VSV Removal.





(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 FUSE)

(a) Disconnect the E44 purge VSV connector.





(b) Turn the power switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Result





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (PURGE VSV - ECM)

(a) Disconnect the E1 ECM connector and the E44 purge VSV connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

10. REPLACE ECM

(a) Replace the ECM Removal.

NEXT -- PERFORM EVAPORATIVE SYSTEM CHECK AGAIN (AUTOMATIC MODE)

11. PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)

(a) Connect the Techstream to DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Vacuum Pump.

(d) Turn the leak detection pump ON with the Techstream.

(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 Removal.

(b) Connect the Techstream to DLC3.

(c) Turn the power switch on (IG).

(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VSV for Vent Valve.

(e) Touch the canister pump module, use the Techstream to turn the vent valve ON and OFF, and check if the vent valve is moving.

OK:

Vent valve vibration can be felt.

OK -- REPLACE CANISTER ASSEMBLY

NG -- INSPECT CANISTER PUMP MODULE (VENT VALVE OPERATION)

13. PERFORM ACTIVE TEST USING TECHSTREAM (VACUUM PUMP)

(a) Turn the power switch off.





(b) Remove the canister lower cover Removal.

(c) Disconnect the canister pump module connector.

(d) Connect the Techstream to 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 leak detection pump ON with the Techstream.

(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 Techstream.

Standard voltage:

10 to 14 V

NG -- CHECK HARNESS AND CONNECTOR (ECM - CANISTER PUMP MODULE)
OK -- Continue to next step.

14. CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - BODY GROUND)

(a) Remove the canister lower cover Removal.

(b) Disconnect the canister pump module connector.





(c) Measure the resistance between MGND terminal of the canister pump module and the body ground.

Standard resistance:

Below 1 Ohms

OK -- REPLACE CANISTER ASSEMBLY

NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR