Part 1
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System
- EVAP System
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.
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 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 determines that the purge flow is insufficient.
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 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 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) Warm up the engine until the ECT reaches 75°C (167°F) or more.
(3) Run the engine at 2,500 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 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 / 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 Inspection Mode Procedure.
(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 Inspection Mode Procedure.
(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 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.
(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 Techstream 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 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 (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