P0448
P0448 EVAP Canister Vent Control ValveComponent 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)
- White arrow indicates Vehicle front
On Board Diagnosis Logic
P0448:
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 [P0448 EVAP Canister Vent Control Valve]. 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 [P0448 EVAP Canister Vent Control Valve].
WITH GST
Follow the procedure "WITH SDT" above.
Diagnosis Procedure
Step 1-4:
Step 5-9:
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
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.
Check new O-ring is installed properly.
Operation takes less than 1 second.
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.
6. 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.