2001 INFINITI QX4 ignition

6 CHECK FOR EVAP LEAK
With CONSULT-II
1. Turn ignition switch ªONº.
2. Select ªEVAP SYSTEM CLOSEº of ªWORK SUPPORTº mode with CONSULT-II.
3. Touch ªSTARTº and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
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.
PEF917U
4. 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.
DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-358

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

18 CHECK ABSOLUTE PRESSURE SENSOR
1. Remove absolute pressure sensor with its harness connector connected.
SEF961Y
2. Remove hose from absolute pressure sensor.
3. Install a vacuum pump to absolute pressure sensor.
4. Turn ignition switch ªONº and check output voltage between ECM terminal 80 and engine ground under the following
conditions.
SEF300XA
CAUTION:
IAlways calibrate the vacuum pump gauge when using it.
IDo not apply below þ93.3 kPa (±700 mmHg, ±27.56 inHg) or over 101.3 kPa (760 mmHg, 29.92 inHg) of pressure.
OK or NG
OK©GO TO 19.
NG©Replace absolute pressure sensor.
19 CHECK FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between fuel level sensor unit and fuel pump terminals 1 and 2 by heating with hot water or heat gun
as shown in the figure.
SEF974Y
OK or NG
OK©GO TO 20.
NG©Replace fuel level sensor unit.
DTC P0440 EVAP CONTROL SYSTEM (SMALL LEAK) (NEGATIVE PRESSURE)
Diagnostic Procedure (Cont'd)
EC-364

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

DescriptionNBEC0221SYSTEM DESCRIPTIONNBEC0221S01
Sensor Input Signal to ECMECM
functionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
EVAP can-
ister purge
flow controlEVAP canister purge volume
control solenoid valve Crankshaft position sensor (REF) Engine speed (REF signal)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Throttle position switch Closed throttle position
Heated oxygen sensor 1 (front)Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Vehicle speed sensor Vehicle speed
This system controls flow rate of fuel vapor from the EVAP canis-
ter. The opening of the vapor by-pass passage in the EVAP canis-
ter purge volume control solenoid valve changes to control the flow
rate. The EVAP canister purge volume control solenoid valve
repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control.
The optimum value stored in the ECM is determined by consider-
ing various engine conditions. When the engine is operating, the
flow rate of fuel vapor from the EVAP canister is regulated as the
air flow changes.
SEF337U
COMPONENT DESCRIPTIONNBEC0221S02The EVAP canister purge volume control solenoid valve uses a
ON/OFF duty to control the flow rate of fuel vapor from the EVAP
canister. The EVAP canister purge volume control solenoid valve
is moved by ON/OFF pulses from the ECM. The longer the ON
pulse, the greater the amount of fuel vapor that will flow through the
valve.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0222Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/VIEngine: After warming up
IAir conditioner switch ªOFFº
IShift lever: ªNº
INo-loadIdle (Vehicle stopped) 0%
2,000 rpm Ð
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DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
Description
EC-367

SEF058Y
DTC Confirmation ProcedureNBEC0225NOTE:
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:
Before performing the following procedure, confirm battery
voltage is more than 11V at idle.
WITH CONSULT-IINBEC0225S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and let it idle for at least 13 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-371.
WITH GSTNBEC0225S02Follow the proocedure ªWITH CONSULT-IIº above.
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DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
DTC Confirmation Procedure
EC-369

Diagnostic ProcedureNBEC0227
1 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
SEF986Y
3. Turn ignition switch ªONº.
4. Check voltage between EVAP canister purge volume control solenoid valve terminal 1 and ground with CONSULT-II or
tester.
SEF988Y
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
IFuse block (J/B) connector M10
I10A fuse
IHarness for open or short between EVAP canister purge volume control solenoid valve and fuse
©Repair harness or connectors.
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DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
Diagnostic Procedure
EC-371

3 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT
FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 1 and EVAP canister purge volume control solenoid valve terminal 2.
Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)©GO TO 4.
OK (Without CONSULT-
II)©GO TO 5.
NG©Repair open circuit or short to ground and short to power in harness or connetors.
4 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
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 6.
NG©GO TO 5.
DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-372