Part 1
1AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System
- EVAP System
RELATED DTCS
If any EVAP system DTCs are output, the malfunctioning area can be determined using the table below.
NOTICE:
If the reference pressure difference between the first and second checks is more than the specification, all the DTCs relating to the reference pressure (P043E, P043F, P0441, P0455, P0456, P2401, P2420) will be all stored.
DESCRIPTION
NOTICE:
In the EVAP system of this vehicle, turning ON the vent valve does not seal off the EVAP system. To check for leaks in the EVAP system, disconnect the air inlet vent hose and apply pressure from atmospheric side of the canister.
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 canister 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 leak detection 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 canister 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-g (3.75 mmHg-g), 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.
MONITOR RESULT
Refer to Checking Monitor Status Mode 6 Data.
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:
* The vehicle has been driven for 10 minutes or more (in a city area or on a freeway)
* The fuel tank is less than 90% full
* The altitude is less than 8000 ft. (2400 m)
* The engine coolant temperature is between 4.4 and 35°C (40 and 95°F)
* The intake air temperature is between 4.4 and 35°C (40 and 95°F)
* 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 8 or 10.5 hours depending on certain vehicle conditions.
HINT
Do not start the engine until after checking Monitor Status. If the engine is started, the steps described above must be repeated.
(c) Monitor Status
(1) Connect the Techstream to the DLC3.
(2) Turn the ignition switch to ON and turn the Techstream on.
(3) Enter the following menus: Powertrain / Engine / Monitor / Evaporative System.
(4) Check the "Status2" displayed on the Techstream.
HINT
If Incomplete is displayed, the monitor is not complete. Make sure that the preconditions have been met, and perform the Monitor Conditions procedure again.
2. PURGE FLOW MONITOR CONFIRMATION (P0441)
HINT
Perform this monitor confirmation after the Key-Off Monitor Confirmation shows 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 engine coolant temperature is between 4.4 and 35°C (40 and 95°F)
* The intake air temperature is between 4.4 and 35°C (40 and 95°F)
(b) Monitor Conditions
(1) Release the pressure from the fuel tank by removing and reinstalling the fuel cap.
(2) Warm the engine up until the engine coolant temperature reaches higher than 75°C (167°F).
(3) Increase the engine speed to 3000 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 (if it is ON or the engine is running).
(2) Connect the Techstream to the DLC3.
(3) Turn the ignition switch to ON and turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine / Monitor / Evaporative System.
(5) Check the "Status2" displayed on the Techstream.
HINT
If Incomplete is displayed, the monitor is not complete. Make sure that the preconditions have been met, and perform the Monitor Conditions procedure again.
WIRING DIAGRAM
Refer to DTC P0451 P0451.
INSPECTION PROCEDURE
NOTICE:
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
* The Techstream is required to conduct the following diagnostic troubleshooting procedure.
HINT
* Using the Techstream monitor results enables the EVAP (Evaporative Emission) system to be confirmed.
* Read freeze frame data using the Techstream. 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 ON.
(c) Turn the ignition switch off and wait for 10 seconds.
(d) Connect the Techstream to the DLC3.
(e) Turn the ignition switch to ON and turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine / Trouble 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.
NOTICE:
If the reference pressure difference between the first and second checks is more than the specification, the DTCs relating 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 (AUTOMATIC MODE)
NOTICE:
* In the Evaporative System Check (Automatic Mode) a series of 5 steps is performed automatically by the Techstream. 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 unavailable.
* Do not run the engine during this operation.
* 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).
(a) Connect the Techstream to the DLC3.
(b) Clear the DTCs DTC Check / Clear.
(c) Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Automatic Mode.
(d) After the Evaporative System Check is completed, check for pending DTCs. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
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 MODE)
NOTICE:
* In the Evaporative System Check (Manual Mode), the series of 5 Evaporative System Check steps are performed manually using the Techstream.
* 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 unavailable.
* Do not run the engine during this operation.
* 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).
(a) Connect the Techstream to the DLC3.
(b) Clear the DTCs DTC Check / Clear.
(c) Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Manual Mode.
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 Techstream 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 Techstream when checking.
HINT
The first reference pressure standard is the value determined in step 2/5.
B -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR CANISTER PUMP MODULE)
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 leak detection pump is activated*1 (Step "A").
(b) Check the EVAP pressure again when it has stabilized. This pressure is the reference pressure standard (Step "B").
*1: The leak detection pump begins to operate at the time step 2/5 starts.
Result:
*2: The DTCs related to the EVAP system are displayed on the Techstream when checking.
D -- PERFORM ACTIVE TEST USING TECHSTREAM (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 Techstream when checking.
C -- REPLACE CHARCOAL CANISTER ASSEMBLY
B -- PERFORM ACTIVE TEST USING TECHSTREAM (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-g (0.75 mmHg-g) 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 Techstream when checking.
C -- PERFORM ACTIVE TEST USING TECHSTREAM (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 reference pressure standard (step 5/5).
Result:
*: The DTCs related to the EVAP system are displayed on the Techstream when checking.
B -- PERFORM ACTIVE TEST USING TECHSTREAM (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 Techstream when checking.
HINT
The first reference pressure standard is the value determined in step 2/5.
B -- PERFORM ACTIVE TEST USING TECHSTREAM (FOR CANISTER PUMP MODULE)
A -- REPLACE CHARCOAL CANISTER ASSEMBLY
12. PERFORM ACTIVE TEST USING TECHSTREAM (PURGE VSV)
(a) Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for EVAP Control.
(b) Disconnect the hose (connected to the canister) from the purge VSV.
(c) Start the engine.
(d) Using the Techstream, turn off the purge VSV (EVAP VSV: OFF).
(e) Confirm that the purge VSV has no suction with your fingers.
(f) Using the Techstream, 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 PURGE VSV
A -- Continue to next step.