INFINITI QX4 2001 Factory Service Manual

Diagnostic ProcedureNBEC0332
1 CHECK RUBBER TUBE
1. Turn ignition switch ªOFFº.
2. Disconnect rubber tube connected to EVAP canister vent control valve.
3. Check the rubber tube for clogging.
SEF143S
OK or NG
OK©GO TO 2.
NG©Clean rubber tube using an air blower.
2 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 3.
NG©Clean or replace water separator.
DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Diagnostic Procedure
EC-556

3 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 4.
NG©Replace EVAP canister vent control valve.
4 CHECK EVAP CANISTER VENT CONTROL VALVE-II
With CONSULT-II
1. Turn ignition switch ON.
2. Perform ªVENT CONTROL/Vº in ªACTIVE TESTº mode.
3. 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 6.
NG©GO TO 5.
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DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Diagnostic Procedure (Cont'd)
EC-557

5 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 the procedure 4 again.
OK or NG
OK©GO TO 6.
NG©Replace EVAP canister vent control valve.
6 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 7.
No©GO TO 9.
7 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 9.
NG©GO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
IEVAP canister for damage
IEVAP hose between EVAP canister and water separator for clogging or poor connection
©Repair hose or replace EVAP canister.
9 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR HOSE
Check disconnection or improper connection of hose connected to EVAP control system pressure sensor.
OK or NG
OK©GO TO 10.
NG©Repair it.
DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Diagnostic Procedure (Cont'd)
EC-558

10 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
SEF495R
2. Check connectors for water.
Water should not exist.
OK or NG
OK©GO TO 11.
NG©Replace EVAP control system pressure sensor.
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DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Diagnostic Procedure (Cont'd)
EC-559

11 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©GO TO 12.
NG©Replace EVAP control system pressure sensor.
12 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Diagnostic Procedure (Cont'd)
EC-560

System DescriptionNBEC0333NOTE:
If DTC P1447 is displayed with P0510, perform trouble diagnosis for DTC P0510 first. (See EC-431.)
SEF373Z
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
On Board Diagnosis LogicNBEC0334Under normal conditions (non-closed throttle), sensor output volt-
age indicates if pressure drop and purge flow are adequate. If not,
a fault is determined.
Malfunction is detected when EVAP control system does not oper-
ate properly, EVAP control system has a leak between intake mani-
fold and EVAP control system pressure sensor.
Possible CauseNBEC0590IEVAP canister purge volume control solenoid valve stuck
closed
IEVAP control system pressure sensor and the circuit
ILoose, disconnected or improper connection of rubber tube
IBlocked rubber tube
ICracked EVAP canister
IEVAP canister purge volume control solenoid valve circuit
IClosed throttle position switch
IBlocked purge port
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DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
System Description
EC-561

IEVAP canister vent control valve
SEF207Y
SEF208Y
SEF238Y
DTC Confirmation ProcedureNBEC0335CAUTION:
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.
TESTING CONDITION:
Always perform test at a temperature of 5ÉC (41ÉF) or more.
WITH CONSULT-IINBEC0335S011) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 10 seconds.
3) Start engine and let it idle for at least 70 seconds.
4) Select ªPURG FLOW P1447º of ªEVAPORATIVE SYSTEMº in
ªDTC CONFIRMATIONº mode with CONSULT-II.
5) Touch ªSTARTº.
If ªCOMPLETEDº is displayed, go to step 7.
6) When the following conditions are met, ªTESTINGº will be dis-
played on the CONSULT-II screen. Maintain the conditions
continuously until ªTESTINGº changes to ªCOMPLETEDº. (It
will take at least 35 seconds.)
Selector lever Suitable position
Vehicle speed 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 10 msec
Engine coolant temperature More than 70ÉC (158ÉF)
If ªTESTINGº is not changed for a long time, retry from
step 2.
7) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-564.
DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
Possible Cause (Cont'd)
EC-562

SEF355X
Overall Function CheckNBEC0336Use this procedure to check the overall monitoring function of the
EVAP control system purge flow monitoring. During this check, a
1st trip DTC might not be confirmed.
WITH GSTNBEC0336S011) Lift up drive wheels.
2) Start engine (TCS switch ªOFFº) and warm it up to normal
operating temperature.
3) Turn ignition switch ªOFFº, wait at least 10 seconds.
4) Start engine and wait at least 70 seconds.
5) Set voltmeter probes to ECM terminals 84 (EVAP control sys-
tem pressure sensor signal) and ground.
6) Check EVAP control system pressure sensor value at idle
speed and note it.
7) Establish and maintain the following conditions for at least 1
minute.
Air conditioner switch ON
Steering wheel Fully turned
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than ªPº, ªNº or ªRº
8) Verify that EVAP control system pressure sensor value stays
0.1V less than the value at idle speed (measured at step 6) for
at least 1 second.
9) If NG, go to ªDiagnostic Procedureº, EC-564.
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DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
Overall Function Check
EC-563

Diagnostic Procedure=NBEC0337
1 CHECK EVAP CANISTER
1. Turn ignition switch ªOFFº.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-II)©GO TO 2.
OK (Without CONSULT-
II)©GO TO 3.
NG©Replace EVAP canister.
2 CHECK PURGE FLOW
With CONSULT-II
1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port and
install vacuum gauge.
SEF983Y
2. Start engine and let it idle.
3. Select ªPURG VOL CONT/Vº in ªACTIVE TESTº mode with CONSULT-II.
4. Rev engine up to 2,000 rpm.
5. Touch ªQdº and ªQuº on CONSULT-II screen to adjust ªPURG VOL CONT/Vº opening and check vacuum existence.
SEF012Z
OK or NG
OK©GO TO 7.
NG©GO TO 4.
DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
Diagnostic Procedure
EC-564

3 CHECK PURGE FLOW
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port and
install vacuum gauge.
SEF983Y
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum gauge indication when revving engine up to 2,000 rpm.
Vacuum should exist.
6. Release the accelerator pedal fully and let idle.
Vacuum should not exist.
OK or NG
OK©GO TO 7.
NG©GO TO 4.
4 CHECK EVAP PURGE LINE
1. Turn ignition switch ªOFFº.
2. Check EVAP purge line for improper connection or disconnection.
Refer to ªEVAPORATIVE EMISSION LINE DRAWINGº, EC-36.
OK or NG
OK (With CONSULT-II)©GO TO 5.
OK (Without CONSULT-
II)©GO TO 6.
NG©Repair it.
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DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
Diagnostic Procedure (Cont'd)
EC-565