Infiniti QX4 (R50). Manual - part 271

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

Yes or No

Yes

GO TO 14.

GO TO 17.

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

GO TO 16.

GO TO 15.

DETECT MALFUNCTIONING PART

Check the following.

EVAP canister for damage

EVAP hose between EVAP canister and water separater for clogging or poor connection

Repair hose or replace EVAP canister.

IDX

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE

Diagnostic Procedure (Cont’d)

EC-551

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 that A and C are not clogged by blowing air into B with A, and then C plugged.

SEF829T

5. In case of NG in items 2 - 4, replace the parts.
NOTE:

Do not disassemble water separator.

OK or NG

GO TO 17.

Clean or replace water separator.

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-140.

INSPECTION END

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE

Diagnostic Procedure (Cont’d)

EC-552

SEF032W

SEF143S

Component Description

NBEC0326

The 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
“EVAP Control System (Small Leak)” diagnosis.

CONSULT-II Reference Value in Data Monitor
Mode

NBEC0327

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

VENT CONT/V

Ignition switch: ON

OFF

ECM Terminals and Reference Value

NBEC0679

Specification 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

COLOR

ITEM

CONDITION

DATA (DC Voltage)

G/Y

EVAP canister vent
control valve

[Ignition switch “ON”]

BATTERY VOLTAGE
(11 - 14V)

On Board Diagnosis Logic

NBEC0329

Malfunction is detected when EVAP canister vent control valve
remains closed under specified driving conditions.

IDX

DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL

VALVE (CLOSE)

Component Description

EC-553

Possible Cause

NBEC0589

EVAP canister vent control valve

EVAP control system pressure sensor and the circuit

Blocked rubber tube to EVAP canister vent control valve

Water separator

EVAP canister is saturated with water.

SEF201Y

DTC Confirmation Procedure

NBEC0330

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted,
always turn ignition switch “OFF” and wait at least 10 seconds
before conducting the next test.

WITH CONSULT-II

NBEC0330S01

Turn ignition switch “ON”.

Select “DATA MONITOR” mode with CONSULT-II.

Start engine.

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 “Diagnostic Procedure”,
EC-556.

WITH GST

NBEC0330S02

Follow the procedure “WITH CONSULT-II” above.

DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL

VALVE (CLOSE)

Possible Cause

EC-554

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