2001 INFINITI QX4 IDX

SEF194Y
SEF340X
WITH CONSULT-IINBEC0239S011) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 10 seconds.
3) Turn ignition switch ªONº.
4) Select ªDATA MONITORº mode with CONSULT-II.
5) Make sure that ªFUEL T/TEMP SEº is more than 0ÉC (32ÉF).
6) Start engine and wait at least 20 seconds.
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-385.
WITH GSTNBEC0239S021) Start engine and warm it up to normal operating temperature.
2) Check that voltage between ECM terminal 92 (Fuel tank tem-
perature sensor signal) and ground is less than 4.2V.
3) Turn ignition switch ªOFFº and wait at least 10 seconds.
4) Start engine and wait at least 20 seconds.
5) Select ªMODE 7º with GST.
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-385.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
DTC Confirmation Procedure (Cont'd)
EC-383

Diagnostic ProcedureNBEC0241
1 CHECK RUBBER TUBE
1. Turn ignition switch ªOFFº.
2. Check rubber tube connected to the EVAP control system pressure sensor for clogging, vent, kink, disconnection or
improper connection.
SEF495R
OK or NG
OK©GO TO 2.
NG©Reconnect, repair or replace.
2 RETIGHTEN GROUND SCREWS
Loosen and retighten engine ground screws.
SEF959Y
©GO TO 3.
3 CHECK CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check sensor harness connector for water.
Water should not exist.
OK or NG
OK©GO TO 4.
NG©Repair or replace harness connector.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
Diagnostic Procedure
EC-385

8 CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 84 and EVAP control system pressure sensor terminal 2.
Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)©GO TO 10.
OK (Without CONSULT-
II)©GO TO 11.
NG©GO TO 9.
9 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors B101, B43
IHarness connectors B1, M2 and M94, F27
IHarness for open or short between ECM and EVAP control system pressure sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
10 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Start engine.
2. 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 12.
NG©GO TO 11.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
Diagnostic Procedure (Cont'd)
EC-387

12 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 13.
NG©Clean the rubber tube using an air blower.
13 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 14.
NG©Replace EVAP canister vent control valve.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
Diagnostic Procedure (Cont'd)
EC-389

16 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 17.
NG©Replace EVAP control system pressure sensor.
17 CHECK RUBBER TUBE
Check obstructed rubber tube connected to EVAP canister vent control valve.
OK or NG
OK©GO TO 18.
NG©Clean rubber tube using an air blower, repair or replace rubber tube.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
Diagnostic Procedure (Cont'd)
EC-391

21 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.
22 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0450 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PRESSURE
SENSOR
Diagnostic Procedure (Cont'd)
EC-393

IEVAP purge line rubber tube bent.
IBlocked or bent rubber tube to EVAP control system pressure
sensor
ILoose or disconnected rubber tube
IEVAP canister vent control valve and the circuit
IEVAP canister purge volume control solenoid valve and the
circuit
IAbsolute pressure sensor
IFuel tank temperature sensor
IO-ring of EVAP canister vent control valve is missing or dam-
aged.
IEVAP control system pressure sensor
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0455 EVAP CONTROL SYSTEM (GROSS LEAK)
Possible Cause (Cont'd)
EC-395

8) Stop vehicle.
9) Select ªMODE 3º with GST.
IIf P0455 is displayed on the screen, go to ªDiagnostic
Procedureº, EC-397.
IIf P0440 or P1440 is displayed on the screen, go to ªDiagnos-
tic Procedureº, for DTC P0440, EC-355.
IIf P1447 is displayed on the screen, go to ªDiagnostic Proce-
dureº for DTC P1447, EC-564.
IIf P0455, P0440, P1440 and P1447 are not displayed on the
screen, go to the following step.
10) Select ªMODE 1º with GST.
IIf SRT of EVAP system is set, the result will be OK.
IIf SRT of EVAP system is not set, go to step 6.
Diagnostic ProcedureNBEC0647
1 CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch ªOFFº.
2. Check for genuine NISSAN fuel filler cap design.
SEF915U
OK or NG
OK©GO TO 2.
NG©Replace with genuine NISSAN fuel filler cap.
2 CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK©GO TO 3.
NG©IOpen fuel filler cap, then clean cap and fuel filler neck threads using air blower.
IRetighten until ratcheting sound is heard.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0455 EVAP CONTROL SYSTEM (GROSS LEAK)
DTC Confirmation Procedure (Cont'd)
EC-397