INFINITI QX4 2001 Factory Service Manual

4 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR HOSE
Check disconnection or improper connection of hose connected to EVAP control system pressure sensor.
SEF495R
OK or NG
OK©GO TO 5.
NG©Repair it.
5 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 6.
NG©Replace EVAP control system pressure sensor.
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-546

6 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected.
CAUTION:
INever apply force to the air hole protector of the sensor if equipped.
SEF799W
2. Remove hose from EVAP control system pressure sensor.
3. Turn ignition switch ªONº.
4. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in figure.
CAUTION:
IAlways calibrate the vacuum pump gauge when using it.
IDo not apply below þ20 kPa (þ150 mmHg, þ5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.
5. Check input voltage between ECM terminal 84 and ground.
SEF342X
CAUTION:
IDiscard and EVAP control system pressure sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
OK or NG
OK (With CONSULT-II)©GO TO 7.
OK (Without CONSULT-
II)©GO TO 8.
NG©Replace EVAP control system pressure sensor.
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DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-547

7 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Turn ignition switch ªOFFº.
2. Reconnect harness connectors disconnected.
3. Start engine.
4. Perform ªPURG VOL CONT/Vº in ªACTIVE TESTº mode with CONSULT-II. Check that engine speed varies according
to the valve opening.
SEF985Y
OK or NG
OK©GO TO 9.
NG©GO TO 8.
8 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions.
SEF334X
Without CONSULT-II
Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions.
SEF335X
OK or NG
OK©GO TO 9.
NG©Replace EVAP canister purge volume control solenoid valve.
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-548

9 CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK©GO TO 10.
NG©Clean the rubber tube using an air blower.
10 CHECK EVAP CANISTER VENT CONTROL VALVE-I
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portionBof EVAP canister vent control valve for being rusted.
SEF337X
OK or NG
OK©GO TO 11.
NG©Replace EVAP canister vent control valve.
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DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-549

11 CHECK EVAP CANISTER VENT CONTROL VALVE-II
With CONSULT-II
1. Reconnect harness connectors disconnected.
2. Turn ignition switch ªONº.
3. Perform ªVENT CONTROL/Vº in ªACTIVE TESTº mode.
4. Check air passage continuity and operation delay time.
SEF991Y
Without CONSULT-II
Check air passage continuity and operation delay time under the following conditions.
SEF339X
Make sure new O-ring is installed properly.
OK or NG
OK©GO TO 13.
NG©GO TO 12.
12 CHECK EVAP CANISTER VENT CONTROL VALVE-III
1. Clean the air passage (PortionAtoB) of EVAP canister vent control valve using an air blower.
2. Perform procedure 9 again.
OK or NG
OK©GO TO 13.
NG©Replace EVAP canister vent control valve.
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-550

13 CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve attached.
2. Check if water will drain from the EVAP canister.
SEF596U
YesorNo
Ye s©GO TO 14.
No©GO TO 17.
14 CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve attached.
The weight should be less than 1.8 kg (4.0 lb).
OK or NG
OK©GO TO 16.
NG©GO TO 15.
15 DETECT MALFUNCTIONING PART
Check the following.
IEVAP canister for damage
IEVAP hose between EVAP canister and water separater for clogging or poor connection
©Repair hose or replace EVAP canister.
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DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-551

16 CHECK WATER SEPARATOR
1. Check visually for insect nests in the water separator air inlet.
2. Check visually for cracks or flaws in the appearance.
3. Check visually for cracks or flaws in the hose.
4. Check thatAandCare not clogged by blowing air intoBwithA, and thenCplugged.
SEF829T
5. In case of NG in items2-4,replace the parts.
NOTE:
IDo not disassemble water separator.
OK or NG
OK©GO TO 17.
NG©Clean or replace water separator.
17 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-552

SEF032W
SEF143S
Component DescriptionNBEC0326The EVAP canister vent control valve is located on the EVAP can-
ister 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 ener-
gized. A plunger will then move to seal the canister vent. The abil-
ity 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
ªEVAP Control System (Small Leak)º diagnosis.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0327Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/VIIgnition switch: ON OFF
ECM Terminals and Reference ValueNBEC0679Specification 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.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
40 G/YEVAP canister vent
control valve[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0329Malfunction is detected when EVAP canister vent control valve
remains closed under specified driving conditions.
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DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Component Description
EC-553

Possible CauseNBEC0589IEVAP canister vent control valve
IEVAP control system pressure sensor and the circuit
IBlocked rubber tube to EVAP canister vent control valve
IWater separator
IEVAP canister is saturated with water.
SEF201Y
DTC Confirmation ProcedureNBEC0330CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
WITH CONSULT-IINBEC0330S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine.
4) Drive vehicle at a speed of approximately 80 km/h (50 MPH)
for a maximum of 15 minutes.
NOTE:
If a malfunction exists, NG result may be displayed quicker.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-556.
WITH GSTNBEC0330S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Possible Cause
EC-554

Wiring DiagramNBEC0331
MEC963C
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DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Wiring Diagram
EC-555