P0448

DTC P0448 EVAP CANISTER VENT CONTROL VALVE





Component Description





The EVAP canister vent control valve (1) is located on the EVAP canister (2) and is used to seal the canister vent.
- Illustration shows the view from under the vehicle.
- : Vehicle front
- EVAP control system pressure sensor (3)





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.




CONSULT-III Reference Value in Data Monitor Mode
Specification data are reference values.









On Board Diagnosis Logic









DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
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. Rev engine between 3,000 and 3,500 rpm, then maintain that speed for 2 minutes and 50 seconds to 3 minutes.
Do not exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for approximately 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 rev engine between 4,000 and 4,500 rpm or more, then maintain that speed 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.




Wiring Diagram





Specification data are reference values and are measured between each terminal and ground.

CAUTION:
Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.









Diagnosis Procedure
1.CHECK RUBBER TUBE
1. Turn ignition switch OFF.





2. Disconnect rubber tube connected to EVAP canister vent control valve (1).
- Illustration shows the view from under the vehicle.
- : Vehicle front
- EVAP canister (2)
- EVAP control system pressure sensor (3)
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 IS 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 (1).
- EVAP canister vent control valve (2)
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 2.0 kg (4.4 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
Diagnosis Procedure.
- 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 rust.
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.
Check that new O-ring is installed properly.





If NG, 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.
If NG, replace EVAP canister vent control valve.

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





2. Check portion (B) of EVAP canister vent control valve for rust.





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





If NG, 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.
If NG, replace EVAP canister vent control valve.