DTC Description
DTC DETECTION LOGIC
DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition |
P0448 | VENT CONTROL VALVE (Evaporative emission system vent control circuit shorted) | EVAP canister vent control valve remains closed under specified driving conditions. |
POSSIBLE CAUSE
FAIL-SAFE
Not applicable
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT
Never exceed 3 minutes.
With GST
Follow the procedure “With CONSULT” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-324, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK RUBBER TUBE
Is the inspection result normal? YES >> GO TO 2.
NO >> Clean rubber tube using an air blower.
2.CHECK EVAP CANISTER VENT CONTROL VALVE
Check the EVAP canister vent control valve. Refer to EC-325, "Component Inspection".
Is the inspection result normal? YES >> GO TO 3.
NO >> Replace EVAP canister vent control valve. Refer to FL-21, "Removal and Installation".
3.CHECK IF EVAP CANISTER IS SATURATED WITH WATER
Does water drain from EVAP canister? 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 2.1 kg (4.6 lb).
Is the inspection result normal? YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
>> Repair hose or replace EVAP canister. Refer to FL-19, "Removal and Installation".
6.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
Water should not exist.
Is the inspection result normal? YES >> GO TO 7.
NO >> Replace EVAP control system pressure sensor. Refer to FL-22, "Removal and Installation".
7.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Check the EVAP control system pressure sensor. Refer to EC-330, "Component Inspection".
Is the inspection result normal? YES >> GO TO 8.
NO >> Replace EVAP control system pressure sensor. Refer to FL-22, "Removal and Installation".
8.CHECK INTERMITTENT INCIDENT
Refer to GI-41, "Intermittent Incident".
>> INSPECTION END
Component Inspection
1.CHECK EVAP CANISTER VENT CONTROL VALVE-1
Is it rusted? YES >> Replace EVAP canister vent control valve. Refer to FL- 21, "Removal and Installation".
NO >> GO TO 2.
2.CHECK EVAP CANISTER VENT CONTROL VALVE-2
With CONSULT
Make sure new O-ring is installed properly.
Condition (VENT CONT/V) | Air passage continuity between A and B |
ON | Not existed |
OFF | Existed |
Operation takes less than 1 second.
Without CONSULT
Check air passage continuity and operation delay time under the following conditions.
Make sure new O-ring is installed properly.
Condition | Air passage continuity between A and B |
12 V direct current supply between terminals 1 and 2 | Not existed |
OFF | Existed |
Operation takes less than 1 second.
Is the inspection result normal? YES >> GO TO 3.
NO >> Replace EVAP canister vent control valve. Refer to FL-21, "Removal and Installation".
3.CHECK EVAP CANISTER VENT CONTROL VALVE-3
With CONSULT
Make sure new O-ring is installed properly.
Condition (VENT CONT/V) | Air passage continuity between A and B |
ON | Not existed |
OFF | Existe |
Operation takes less than 1 second.
Without CONSULT
Make sure new O-ring is installed properly.
Condition | Air passage continuity between A and B |
12 V direct current supply between terminals 1 and 2 | Not existed |
OFF | Existed |
Operation takes less than 1 second.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace EVAP canister vent control valve. Refer to FL-21, "Removal and Installation".
Fuse inspection
How To Check
If fuse is blown, be sure to eliminate cause of malfunction before
installing new fuse.
Use fuse of specified rating. Never use fuse of more than
specified
rating.
Do not partially install fuse; always insert it into fuse holder
properly.
Remove fus ...
Additional service when replacing ECM
Description
When replacing ECM, the following procedure must be performed. (For details,
refer to EC-136, "Work Procedure".)
PROGRAMMING OPERATION
NOTE:
After replacing with a blank ECM, programming is required to write ECM
information. Be sure to follow the procedure
to perform t ...
General maintenance
During the normal day-to-day operation of the
vehicle, general maintenance should be performed
regularly as prescribed in this section. If
you detect any unusual sounds, vibrations or
smells, be sure to check for the cause or have a
NISSAN dealer do it promptly. In addition, you
should notify ...