2001 INFINITI QX4 IDX

6 CHECK IGNITION SPARK
1. Turn ignition switch ªOFFº.
2. Disconnect ignition coil assembly from rocker cover.
3. Connect a known good spark plug to the ignition coil assembly.
4. Place end of spark plug against a suitable ground and crank engine.
5. Check for spark.
SEF575Q
OK or NG
OK©GO TO 7.
NG©Check ignition coil with power transistor and their circuit. Refer to EC-499.
7 CHECK INJECTOR
1. Turn ignition switch ªOFFº.
2. Remove injector assembly.
Refer to EC-41.
Keep fuel hose and all injectors connected to injector gallery.
3. Disconnect all ignition coil harness connectors.
4. Turn ignition switch ªONº.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)©GO TO 8.
NG (Drips.)©Replace the injector(s) from which fuel is dripping.
8 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
Trouble is fixed.©INSPECTION END
Trouble is not fixed.©Replace warm-up three way catalyst.
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DTC P0420 (RIGHT BANK, -B1), P0430 (LEFT BANK, -B2) THREE WAY
CATALYST FUNCTION
Diagnostic Procedure (Cont'd)
EC-351

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.
IWater separator
IEVAP canister is saturated with water.
IEVAP control system pressure sensor
IFuel level sensor and the circuit
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Possible Cause (Cont'd)
EC-353

IIf 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 ProcedureNBEC0220
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.
3 CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
DTC Confirmation Procedure (Cont'd)
EC-355

5 INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pressure pump to EVAP service port securely.
SEF983Y
SEF916U
NOTE:
Improper installation of the EVAP service port adapter to the EVAP service port may cause leaking.
Models with CONSULT-II©GO TO 6.
Models without CON-
SULT-II©GO TO 7.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-357

7 CHECK FOR EVAP LEAK
Without CONSULT-II
1. Turn ignition switch ªOFFº.
2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts until the end of
test.)
SEF598U
3. Apply 12 volts DC to vacuum cut valve bypass valve. The valve will open. (Continue to apply 12V until the end of test.)
SEF599U
4. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg), then remove
pump and EVAP service port adapter.
NOTE:
INever use compressed air or a high pressure pump.
IDo not exceed 4.12 kPa (0.042 kg/cm
2, 0.6 psi) of pressure in the system.
5. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details.
Refer to ªEVAPORATIVE EMISSION LINE DRAWINGº, EC-36.
SEF200U
OK or NG
OK©GO TO 8.
NG©Repair or replace.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-359

11 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 (With CONSULT-II)©GO TO 13.
OK (Without CONSULT-
II)©GO TO 14.
NG©GO TO 12.
12 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.
13 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform ªPURG VOL CONT/Vº in ªACTIVE TESTº mode.
4. Touch ªQuº on CONSULT-II screen to increase ªPURG VOL CONT/Vº opening to 100.0%.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
SEF984Y
OK or NG
OK©GO TO 16.
NG©GO TO 15.
14 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
Vacuum should exist.
OK or NG
OK©GO TO 17.
NG©GO TO 15.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-361

17 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.
SEF986Y
SEF334X
Without CONSULT-II
Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions.
SEF986Y
SEF335X
OK or NG
OK©GO TO 18.
NG©Replace EVAP canister purge volume control solenoid valve.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-363

20 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 0.5m
(19.7in) onto a hard surface such as a concrete floor; use a new one.
OK or NG
OK©GO TO 21.
NG©Replace EVAP control system pressure sensor.
21 CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to ªEvaporative Emission Systemº, EC-32.
OK or NG
OK©GO TO 22.
NG©Repair or reconnect the hose.
22 CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
©GO TO 23.
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DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-365