P0448
P0448 EVAP Canister Vent Control Valve
Component Description
The EVAP canister vent control valve (1) is located on the EVAP canister (4) 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.
- EVAP control system pressure sensor (2)
- Drain filter (3)
- : Vehicle front
On Board Diagnosis Logic
DTC Confirmation Procedure
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
1 Turn ignition switch OFF and wait at least 10 seconds.
2 Turn ignition switch ON.
3 Turn ignition switch OFF and wait at least 10 seconds.
with SDT
1) Turn ignition switch ON and wait at least 5 seconds.
2) Turn ignition switch OFF and wait at least 10 seconds.
3) Turn ignition switch ON and select "Data list" mode with SDT.
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 between 3,000 and 3,500 rpm and keep it for 2 minutes and 50 seconds to 3 minutes.
Do not 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 "Diagnosis Procedure".
If 1st trip DTC is not detected, go to the next step.
8) Repeat next procedure 20 times.
a) Quickly increase the engine speed between 4,000 and 4,500 rpm or more and 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 "Diagnosis Procedure".
with GST
Follow the procedure "WITH SDT" above.
Diagnosis Procedure
1. CHECK RUBBER TUBE
1 Turn ignition switch OFF.
2 Disconnect rubber tube connected to EVAP canister vent control valve (1).
- EVAP control system pressure sensor (2)
- Drain filter (3)
- EVAP canister (4)
- : Vehicle front
1 Check the rubber tube for clogging.
OK or NG
OK
GO TO 2.
NG
Clean rubber tube using an air blower.
2. CHECK DRAIN FILTER
Refer to [P0447 EVAP Canister Vent Control Valve] P0447.
OK or NG
OK
GO TO 3.
NG
Replace drain filter.
3. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to "Component Inspection".
OK or NG
OK
GO TO 4.
NG
Replace EVAP canister vent control valve. Refer to [EVAP Canister: Removal and Installation] Service and Repair.
4. CHECK IF EVAP CANISTER SATURATED IS 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 5.
No
GO TO 7.
5. 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 7.
NG
GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
- EVAP canister for damage
- EVAP hose between EVAP canister and drain filter for clogging or poor connection
Repair hose or replace EVAP canister.
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1 Disconnect EVAP control system pressure sensor harness connector.
2 Check connectors for water.
OK or NG
OK
GO TO 8.
NG
Replace EVAP control system pressure sensor. Refer to [EVAP Canister: Removal and Installation] Service and Repair.
8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to [P0452 EVAP Control System Pressure Sensor] P0452.
OK or NG
OK
GO TO 9.
NG
Replace EVAP control system pressure sensor. Refer to [EVAP Canister: Removal and Installation] Service and Repair.
9. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
Component Inspection
EVAP Canister Vent Control Valve
With SDT
1) Remove EVAP canister vent control valve from EVAP canister.
2) Check portion of B EVAP canister vent control valve for being rusted.
If NG, 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 new O-ring is installed properly.
Operation takes less than 1 second.
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.
9) If NG, replace EVAP canister vent control valve.
Without SDT
10) Remove EVAP canister vent control valve from EVAP canister.
11) Check portion B of EVAP canister vent control valve for being rusted.
12) Check air passage continuity and operation delay time under the following conditions.
Check new O-ring is installed properly.
Operation takes less than 1 second.
If NG, go to next step.
13) Clean the air passage (portion A to B) of EVAP canister vent control valve using an air blower.
14) Perform step 3 again.
15) If NG, replace EVAP canister vent control valve.
Drain Filter
1) Check visually for insect nests in the drain filter air inlet.
2) Check visually for cracks or flaws in the appearance.
3) Check visually for cracks or flaws in the hose.
4) Blow air into port A and check that it flows freely out of port B.
5) Block port B.
6) Blow air into port A and check that there is no leakage.
7) If NG, replace drain filter.