Page 1545 of 2896

EC-376Revision: June 2006
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
2007 Versa
DTC P0448 EVAP CANISTER VENT CONTROL VALVEPFP:16935
Component DescriptionUBS00QIN
The EVAP canister vent control valve (3) is located on the EVAP
canister (2) 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 evapo-
rative emission control system is depressurized and allows EVAP
control system diagnoses.
EVAP control system pressure sensor (1)
(This illustration is a view from under vehicle)
CONSULT-II Reference Value in Data Monitor ModeUBS00QIO
Specification data are reference values.
On Board Diagnosis LogicUBS00QIP
PBIB1263E
BBIA0693E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V
Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0448
0448EVAP canister vent con-
trol valve closeEVAP canister vent control valve remains
closed under specified driving conditions.
EVAP canister vent control valve
EVAP control system pressure sensor
and the circuit
Blocked rubber tube to EVAP canister
vent control valve
EVAP canister is saturated with water
Page 1546 of 2896

DTC P0448 EVAP CANISTER VENT CONTROL VALVE
EC-377
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: June 20062007 Versa
DTC Confirmation ProcedureUBS00QIQ
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
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 MONITOR” mode with
CONSULT-II.
4. Start engine and let it idle for at least 1 minute.
5. Repeat next procedures three 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. If 1st trip DTC is detected, go to EC-379, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the next step.
7. 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.
8. If 1st trip DTC is detected, go to EC-379, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF 0 58 Y
PBIB0972E
Page 1547 of 2896
EC-378Revision: June 2006
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
2007 Versa
Wiring DiagramUBS00QIR
BBWA2641E
Page 1548 of 2896

DTC P0448 EVAP CANISTER VENT CONTROL VALVE
EC-379
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: June 20062007 Versa
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00QIS
1. CHECK RUBBER TUBE
1. Turn ignition switch OFF.
2. Disconnect rubber tube connected to EVAP canister vent control valve (3).
3. Check the rubber tube for clogging.
–EVAP control system pressure sensor (1)
(This illustration is a view from under vehicle)
–EVAP canister (2)
OK or NG
OK >> GO TO 2.
NG >> Clean rubber tube using an air blower.
2. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-380, "
Component Inspection" .
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 attached.
2. Does water drain from the EVAP canister.
Ye s o r N o
Yes >> GO TO 4.
No >> GO TO 6.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
28 WEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
32 PECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
For a few seconds after turning ignition
switch OFF0 - 1.0V
[Ignition switch: OFF]
More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
105 G Power supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
BBIA0693E
PBIB1213E
Page 1549 of 2896

EC-380Revision: June 2006
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
2007 Versa
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 1.9 kg (4.2 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 (1) harness
connector.
–This illustration is a view from under vehicle
–EVAP canister (2)
–EVAP canister vent control valve (3)
2. Check connectors for water.
OK or NG
OK >> GO TO 7.
NG >> Replace EVAP control system pressure sensor.
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-397, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-143, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00QIT
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-II
1. Remove EVAP canister vent control valve from EVAP canister.Water should not exist.
BBIA0693E
Page 1550 of 2896

DTC P0448 EVAP CANISTER VENT CONTROL VALVE
EC-381
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: June 20062007 Versa
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.
Operation takes less than 1 second.
Make sure 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 5 again.
Without CONSULT-II
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.
Operation takes less than 1 second.
Make sure 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.
PBIB1033E
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
PBIB1787E
PBIB1033E
Condition Air passage continuity between A and B
12V direct current supply between
terminals 1 and 2No
OFF Yes
PBIB1034E
Page 1551 of 2896

EC-382Revision: June 2006
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
2007 Versa
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSORPFP:22365
Component DescriptionUBS00QIU
The EVAP control system pressure sensor (1) detects pressure in
the purge line. The sensor output voltage to the ECM increases as
pressure increases.
This illustration is a view from under vehicle
EVAP canister (2)
EVAP canister vent control valve (3)
CONSULT-II Reference Value in Data Monitor ModeUBS00QIV
Specification data are reference values.
On Board Diagnosis LogicUBS00QIW
NOTE:
If DTC P0451 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-430, "
DTC P0643 SENSOR POWER SUPPLY" .
BBIA0693E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES
Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0451
0451EVAP control system
pressure sensor perfor-
manceECM detects a sloshing signal from the EVAP
control system pressure sensor
Harness or connectors
EVAP control system pressure sensor
Page 1552 of 2896

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-383
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: June 20062007 Versa
DTC Confirmation ProcedureUBS00QIX
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
3. Start engine and wait at least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
If 1st trip DTC is detected, go to EC-383, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00QIY
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
SEF 1 94 Y
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. engine ground F16
4. Body ground E15
BBIA0698E