P0448

P0448 EVAP CANISTER VENT CONTROL VALVE





Component Description





The EVAP canister vent control valve is located on the EVAP canister and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains opened.
When the vent is closed, under normal purge conditions, the evaporative emission control system is depressurized and allows EVAP
Control System diagnosis.






On Board Diagnosis Logic






DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 5 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and let it idle for at least 1 minute.
5. Repeat next procedures 3 times.
a. Increase the engine speed up to 3,000 to 3,500 rpm and keep it for 2 minutes and 50 seconds to 3 minutes.
Never exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for about 5 seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to P0448.
If 1st trip DTC is not detected, go to the next step.
8. Repeat next procedure 20 times.
a. Quickly increase the engine speed up to 4,000 to 4,500 rpm or more and keep it for 25 to 30 seconds.
b. Fully released accelerator pedal and keep engine idle for at least 35 seconds.





9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to P0448.

Diagnosis Procedure
1.CHECK RUBBER TUBE
1. Turn ignition switch OFF.
2. Disconnect rubber tube connected to EVAP canister vent control valve.





3. Check the rubber tube for clogging.
OK or NG
OK - GO TO 2.
NG - Clean rubber tube using an air blower.
2.CHECK EVAP CANISTER VENT CONTROL VALVE
P0448.
OK or NG
OK - GO TO 3.
NG - Replace EVAP canister vent control valve.
3.CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor attached.





2. Check if water will drain from the EVAP canister.
Yes or No
Yes - GO TO 4.
No - GO TO 6.
4.CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor attached.
The weight should be less than 3.2 kg (7.1 lb).
OK or NG
OK - GO TO 6.
NG - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
- EVAP canister for damage
- EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
- Repair hose or replace EVAP canister.
6.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.

Water should not exist.

OK or NG
OK - GO TO 7.
NG - Replace EVAP control system pressure sensor.
7.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
P0451.
OK or NG
OK - GO TO 8.
NG - Replace EVAP control system pressure sensor.
8.CHECK INTERMITTENT INCIDENT
How to Check Terminal and Intermittent Incident.
- INSPECTION END

Component Inspection

EVAP CANISTER VENT CONTROL VALVE

With CONSULT-III
1. Remove EVAP canister vent control valve from EVAP canister.





2. Check portion B of EVAP canister vent control valve for being rusted.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
3. Reconnect harness connectors disconnected.
4. Turn ignition switch ON.
5. Perform "VENT CONTROL/V" in "ACTIVE TEST" mode.
6. Check air passage continuity and operation delay time.
Make sure that new O-ring is installed properly.






If NG, replace EVAP canister vent control valve.
If OK, go to next step.
7. Clean the air passage (Portion A to B) of EVAP canister vent control valve using an air blower.
8. Perform step 6 again.

Without CONSULT-III
1. Remove EVAP canister vent control valve from EVAP canister.





2. Check portion B of EVAP canister vent control valve for being rusted.





3. Check air passage continuity and operation delay time under the following conditions.
Make sure that new O-ring is installed properly.






If NG, replace EVAP canister vent control valve.
If OK, go to next step.
4. Clean the air passage (Portion A to B) of EVAP canister vent control valve using an air blower.
5. Perform step 3 again.