INFINITI QX4 2005 Factory Service Manual

EC-530Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
11 . CHECK PCV VALVE
Refer to EC-45, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> Repair or replace PCV valve.
12. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace.
13. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:

Discard any air fuel ratio (A/F) 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.

Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>>INSPECTION END
Removal and InstallationUBS00HAS
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-531
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
PFP:14920
DescriptionUBS00HAT
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister 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 considering 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.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. 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 ModeUBS00HAU
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2Vehicle speed
PBIB2057E
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V

Engine: After warming up

Air conditioner switch: OFF

Selector lever: P or N

No loadIdle
(Accelerator pedal: Not depressed
even slightly, after starting engine)0%
2,000 rpm —

EC-532Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
On Board Diagnosis LogicUBS00HAV
DTC Confirmation ProcedureUBS00HAW
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.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “PURG VOL CN/V P1444” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-II.
5. Touch “START”.
6. Start engine and let it idle until “TESTING” on CONSULT-II changes to “COMPLETED”. (It will take
approximately 10 seconds.)
If “TESTING” is not displayed after 5 minutes, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
535, "Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 20 seconds.
4. Select Service $07 with GST.
5. If 1st trip DTC is detected, go to EC-535, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1444
1444EVAP canister purge
volume control solenoid
valveThe canister purge flow is detected during the
specified driving conditions, even when EVAP
canister purge volume control solenoid valve is
completely closed.

EVAP control system pressure sensor

EVAP canister purge volume control
solenoid valve
(The valve is stuck open.)

EVAP canister vent control valve

EVAP canister

Hoses
(Hoses are connected incorrectly or
clogged.)
PBIB0839E

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-533
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
Wiring DiagramUBS00HAX
BBWA1687E

EC-534Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
45 L/YEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speed

Accelerator pedal: Not depressed even
slightly, after starting engineBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)11 - 1 4 V
111 W /BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
PBIB0050E
PBIB0051E

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-535
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
Diagnostic ProcedureUBS00HAY
1. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIR-
CUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve
harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister purge volume control
solenoid valve terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E2, F32

IPDM E/R harness connector E119

Harness for open or short between EVAP canister purge volume control solenoid valve and IPDM E/R

Harness for open or short between EVAP canister purge volume control solenoid valve and ECM
>> Repair harness or connectors.
3. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OUTPUT SIGNAL CIR-
CUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 45 and EVAP canister purge volume control solenoid
valve terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0366E
Voltage: Battery voltage
PBIB2245E
Continuity should exist.

EC-536Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
4. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Replace EVAP control system pressure sensor.
5. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK (With CONSULT-II)>>GO TO 6.
OK (Without CONSULT-II)>>GO TO 7.
NG >> Replace EVAP control system pressure sensor.
6. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine.
4. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-538, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP canister purge volume control solenoid valve.
8. 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 9.
NG >> Clean the rubber tube using an air blower.
9. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-543, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP canister vent control valve.Water should not exist.
PBIB1678E

DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-537
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
10. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Check if water will drain from the EVAP canister.
Ye s o r N o
Yes >> GO TO 11.
No >> GO TO 13.
11 . CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 13.
NG >> GO TO 12.
12. DETECT MALFUNCTIONING PART
Check the following.

EVAP canister for damage

EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
BBIA0351E

EC-538Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
Component InspectionUBS00HAZ
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.
Without CONSULT-II
Check air passage continuity of EVAP canister purge volume control
solenoid valve under the following conditions.
Removal and InstallationUBS00HB0
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EM-15, "INTAKE MANIFOLD" .
Condition
(PURG VOL CONT/V value)Air passage continuity
between A and B
100% Yes
0% No
PBIB2058E
ConditionAir passage continuity
between A and B
12V direct current supply between
terminals 1 and 2Ye s
No supply No
PBIB2059E

DTC P1446 EVAP CANISTER VENT CONTROL VALVE
EC-539
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
DTC P1446 EVAP CANISTER VENT CONTROL VALVEPFP:14935
Component DescriptionUBS00HB1
The EVAP canister vent control valve is located on the EVAP canis-
ter 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 energized.
A plunger will then move to seal the canister vent. The ability 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 evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
CONSULT-II Reference Value in Data Monitor ModeUBS00HB2
Specification data are reference values.
On Board Diagnosis LogicUBS00HB3
PBIB1263E
BBIA0443E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V

Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1446
1446EVAP canister vent con-
trol valve closeEVAP canister vent control valve remains
closed under specified driving conditions.

EVAP canister vent control valve

EVAP control system pressure sensor
and the circuit

Blocked rubber tube to EVAP canister
vent control valve

EVAP canister is saturated with water