Part 1
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System
EVAP System
RELATED DTCS
If any EVAP system DTCs are set, the malfunctioning area can be determined using the table below.
NOTE: If the 0.02 inch reference pressure difference between the first and second checks is greater than the specification, the DTCs corresponding to the reference pressure (P043E, P043F, P0441, P0455, P0456, P2401, P2420) will be all stored.
CONFIRMATION DRIVING PATTERN
HINT: After a repair, check Monitor Status by performing the Key-Off Monitor Confirmation and Purge Flow Monitor Confirmation described below.
1. KEY-OFF MONITOR CONFIRMATION
(a) Preconditions
The monitor will not run unless:
(1) The vehicle has been driven for 10 minutes or more (in a city area or on a freeway)
(2) The fuel tank is less than 90% full
(3) The altitude is less than 8,000 ft (2,400 m)
(4) The Engine Coolant Temperature (ECT) is between 4.4°C and 35°C (40°F and 95°F)
(5) The Intake Air Temperature (IAT) is between 4.4°C and 35°C (40°F and 95°F)
(6) The vehicle remains stationary (the vehicle speed is 0 mph [0 km/h])
(b) Monitor Conditions
(1) Allow the engine to idle for at least 5 minutes.
(2) Turn the ignition switch off and wait for 6 hours (8 or 10.5 hours).
HINT: Do not start the engine until checking MONITOR STATUS. If the engine is started, the steps described above must be repeated.
(c) Monitor Status
(1) Connect the intelligent tester to the DLC3.
(2) Turn the ignition switch to the ON position and turn the tester on.
(3) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / MONITOR STATUS.
(4) Check the "Monitor Status" displayed on the tester.
HINT: If INCMP is displayed, the monitor is not completed. Make sure that the preconditions have been met, and perform "Monitor Conditions" again.
2. PURGE FLOW MONITOR CONFIRMATION (P0441)
HINT: Perform this monitor confirmation after the Key-Off Monitor Confirmation shows COMPL (complete).
(a) Preconditions
The monitor will not run unless:
- The vehicle has been driven for 10 minutes or more (in a city area or on a freeway)
- The ECT is between 4.4°C and 35°C (40°F and 95°F)
- The IAT is between 4.4°C and 35°C (40°F and 95°F)
(b) Monitor Conditions
(1) Release the pressure from the fuel tank by removing and reinstalling the fuel tank cap.
(2) Warm the engine up until the ECT reaches more than 75°C (167°F).
(3) Increase the engine speed to 3,000 rpm once.
(4) Allow the engine to idle and turn the A/C ON for 1 minute.
(c) Monitor Status
(1) Turn the ignition switch off.
(2) Connect the intelligent tester to the DLC3.
(3) Turn the ignition switch to the ON position and turn the tester on.
(4) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / MONITOR STATUS.
(5) Check the "Monitor Status" displayed on the tester.
HINT: If INCMP is displayed, the monitor is not completed. Make sure that the preconditions have been met, and perform "Monitor Conditions" again.
MONITOR RESULT
- Refer to Checking Monitor Status for detailed information Mode 6 Data.
- The test value and test limit information are described as shown in the following table. This information is included in MONITOR RESULT of the emissions-related DTC sections:
- 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.
Thermostat
* Pressures A to G are indicated as shown in the diagram below.
DESCRIPTION
HINT: The canister is located near the fuel tank, underneath the body.
While the engine is running, if a predetermined condition (closed-loop, etc.) is met, the purge VSV is opened by the ECM and fuel vapors stored in the canister are purged to the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.
The 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 the purge flow is maintained when negative pressure (vacuum) is applied to the canister.
The following two monitors run to confirm appropriate EVAP system operation.
1. Key-off monitor
This monitor checks for EVAP (Evaporative Emission) system leaks and pump module malfunctions. The monitor starts 5 hours* after the ignition switch is turned off. More than 5 hours are required to allow the fuel to cool down to stabilize the Fuel Tank Pressure (FTP), thus making the EVAP system monitor more accurate.
The electric vacuum pump creates negative pressure (vacuum) in the EVAP system, and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system and malfunctions in both the pump module and purge VSV, based on the EVAP pressure.
HINT: *: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.
2. Purge flow monitor
The purge flow monitor consists of the two monitors. The 1st monitor is always 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 OFF (open) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.5 kPa (3.75 mmHg), the ECM interprets this as the purge VSV being stuck closed, and 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 pressures, before and after conduction of the purge flow monitor, is measured by the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTE: An intelligent tester is required to conduct the following diagnostic troubleshooting procedure.
HINT:
- Using intelligent tester monitor results enables the EVAP (Evaporative Emission) system to be confirmed.
- Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
1. CONFIRM DTC
(a) Turn the ignition switch off and wait for 10 seconds.
(b) Turn the ignition switch to the ON position.
(c) Turn the ignition switch off and wait for 10 seconds.
(d) Connect the intelligent tester to the DLC3.
(e) Turn the ignition switch to the ON position and turn the tester on.
(f) Select the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(g) Confirm DTCs and freeze frame data.
If any EVAP system DTCs are set, the malfunctioning area can be determined using the table below.
NOTE: If the 0.02 inch reference pressure difference between the first and second checks is greater than the specification, the DTCs corresponding to the reference pressure (P043E, P043F, P0441, P0455, P0456, P2401 and P2420) will all be stored.
NEXT -- Continue to next step.
2. PERFORM EVAP SYSTEM CHECK (AUTO OPERATION)
NOTICE:
- In the EVAP SYSTEM CHECK (AUTO OPERATION), the series of 5 EVAP SYSTEM CHECK steps is performed automatically by the intelligent tester. It takes a maximum of approximately 18 minutes.
- Do not perform the EVAP 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 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 EVAP SYSTEM CHECK, keep the temperature below 35°C (95°F).
(a) Connect the intelligent tester to the DLC3.
(b) Clear the DTCs DTC Check / Clear.
(c) Select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / EVAP SYS CHECK / AUTO OPERATION.
(d) After the EVAP SYSTEM CHECK is completed, check for pending DTCs by selecting the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
HINT: If no pending DTC is displayed, perform the Monitor Confirmation after this repair is completed. After this confirmation, check for pending DTCs. If no DTC is displayed, the EVAP system is normal.
NEXT -- Continue to next step.
3. PERFORM EVAP SYSTEM CHECK (MANUAL OPERATION)
NOTICE:
- In the EVAP SYSTEM CHECK (MANUAL OPERATION), the series of 5 EVAP SYSTEM CHECK steps is performed manually by the intelligent tester.
- Do not perform the EVAP 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 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 EVAP SYSTEM CHECK, keep the temperature below 35°C (95°F).
(a) Connect the intelligent tester to the DLC3.
(b) Clear the DTCs DTC Check / Clear.
(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / EVAP SYS CHECK / MANUAL OPERATION.
NEXT -- Continue to next step.
4. PERFORM EVAP SYSTEM CHECK (STEP 1/5)
(a) Check the EVAP pressure in step 1/5.
Result:
*: The DTCs relating to the EVAP system displayed on the intelligent tester when checking.
B -- REPLACE CHARCOAL CANISTER ASSEMBLY
A -- Continue to next step.
5. PERFORM EVAP SYSTEM CHECK (STEP 1/5 TO 2/5)
(a) Check the EVAP pressure in steps 1/5 and 2/5.
Result:
*: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
HINT: The first 0.02 inch leak pressure standard is the value determined in step 2/5.
B -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FOR PUMP MODULE (VACUUM PUMP))
A -- Continue to next step.
6. PERFORM EVAP SYSTEM CHECK (STEP 2/5)
HINT: Make a note of the pressures checked in steps (a) and (b) below.
(a) Check the EVAP pressure 4 seconds after the vacuum pump is activated*1 (Step (a)).
(b) Check the EVAP pressure again when it has stabilized. This pressure is the 0.02 inch leak pressure standard (Step (b)).
*1: The vacuum pump begins to operate at the time step 2/5 starts.
Result:
*2: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
D -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FOR VENT VALVE)
C -- REPLACE CHARCOAL CANISTER ASSEMBLY
B -- PERFORM EVAP SYSTEM CHECK (STEP 3/5)
A -- Continue to next step.
7. PERFORM EVAP SYSTEM CHECK (STEP 2/5 TO 3/5)
(a) Check the EVAP pressure increase in step 3/5.
Result:
*: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
C -- REPLACE CHARCOAL CANISTER ASSEMBLY
B -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FOR VENT VALVE)
A -- Continue to next step.
8. PERFORM EVAP SYSTEM CHECK (STEP 3/5)
(a) Wait until the EVAP pressure change is less than 0.1 kPa (0.75 mmHg) for 30 seconds.
(b) Measure the EVAP pressure and record it.
HINT: A few minutes are required for the EVAP pressure to become saturated. When there is little fuel in the fuel tank, it takes up to 15 minutes.
NEXT -- Continue to next step.
9. PERFORM EVAP SYSTEM CHECK (STEP 4/5)
(a) Check the EVAP pressure in step 4/5.
Result:
*: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
C -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (PURGE VSV)
B -- CHECK EVAP HOSE (PURGE VSV - THROTTLE BODY)
A -- Continue to next step.
10. PERFORM EVAP SYSTEM CHECK (STEP 5/5)
(a) Check the EVAP pressure in step 5/5.
(b) Compare the EVAP pressure in step 3/5 and the second 0.02 inch leak pressure standard (step 5/5).
Result:
*: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
B -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (PURGE VSV)
A -- REPAIR OR REPLACE PARTS AND COMPONENTS INDICATED BY OUTPUT DTCS
11. PERFORM EVAP SYSTEM CHECK (STEP 3/5)
(a) Check the EVAP pressure in step 3/5.
Result:
*: The DTCs related to the EVAP system are displayed on the intelligent tester when checking.
HINT: The first 0.02 inch leak pressure standard is the value determined in step 2/5.
B -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FOR PUMP MODULE (VACUUM PUMP))
A -- REPLACE CHARCOAL CANISTER ASSEMBLY
12. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (PURGE VSV)
(a) Select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / EVAP VSV (ALONE).
(b) Disconnect the hose (connected to the canister) from the purge VSV.
(c) Start the engine.
(d) Using the tester, turn off the purge VSV (EVAP VSV: OFF).
(e) Confirm that the purge VSV has no suction with your fingers.
(f) Using the tester, turn on the purge VSV (EVAP VSV: ON).
(g) Confirm that the purge VSV has suction with your fingers.
Result:
(h) Reconnect the hose.
C -- CHECK EVAP HOSE (PURGE VSV - THROTTLE BODY)
B -- INSPECT VACUUM SWITCHING VALVE NO. 1
A -- Continue to next step.
13. CHECK FUEL TANK CAP ASSEMBLY
(a) Check that the fuel tank cap is correctly installed and confirm the fuel tank cap meets OEM specification.
HINT: If an EVAP tester is available, check the fuel tank cap using the tester.
(1) Tighten the fuel tank cap
(2) Remove the fuel tank cap and install it onto the fuel tank cap adaptor.
(3) Connect the EVAP tester pump hose to the adaptor, and pressurize the cap to 3.2 to 3.7 kPa (24 to 28 mmHg) using an EVAP tester pump.
(4) Seal the adaptor and wait for 2 minutes.
(5) Check the pressure. If the pressure is 2 kPa (15 mmHg) or more, the fuel tank cap is normal.
Result:
C -- REPLACE FUEL TANK CAP ASSEMBLY
B -- CORRECTLY REINSTALL OR REPLACE FUEL TANK CAP
A -- LOCATE EVAP LEAK
14. INSPECT VACUUM SWITCHING VALVE NO. 1
(a) Turn the ignition switch off.
(b) Disconnect the V3 purge VSV connector.
(c) Disconnect the hose (connected to the canister) from the purge VSV.
(d) Start the engine.
(e) Confirm that the purge VSV has no suction with your fingers.
Result:
(f) Reconnect the purge VSV connector.
(g) Reconnect the hose.
B -- REPLACE VACUUM SWITCHING VALVE NO. 1 (PURGE VSV)
A -- REPLACE ECM