2007 INFINITI QX56 engine

EC-370
< SERVICE INFORMATION >
DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
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
• 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 CIRCUIT
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.
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-394, "
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.Voltage: Battery voltage
PBIB2245E
Continuity should exist.
Water should not exist.

DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-371
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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-372, "
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-384, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP canister vent control valve.
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
PBIB1678E
BBIA0351E

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-373
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLE-
NOID VALVE
DescriptionINFOID:0000000003531867
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 ModeINFOID:0000000003531868
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
Vehicle speed*
2
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-374
< SERVICE INFORMATION >
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
On Board Diagnosis Logic
INFOID:0000000003531869
DTC Confirmation ProcedureINFOID:0000000003531870
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:
Before performing the following procedure, confirm battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” 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 EC-376, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0444
0444EVAP canister purge volume
control solenoid valve circuit
openAn excessively low voltage signal is sent
to ECM through the valve• Harness or connectors
(The solenoid valve circuit is open or
shorted.)
• EVAP canister purge volume control so-
lenoid valve
P0445
0445EVAP canister purge volume
control solenoid valve circuit
shortedAn excessively high voltage signal is sent
to ECM through the valve• Harness or connectors
(The solenoid valve circuit is shorted.)
• EVAP canister purge volume control so-
lenoid valve
SEF058Y

EC-376
< SERVICE INFORMATION >
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
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.)
Diagnosis ProcedureINFOID:0000000003531872
1.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve
harness connector.
3. Turn ignition switch ON.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
45 L/YEVAP canister purge volume
control solenoid valve[Engine is running]
• Idle speed
• Accelerator pedal: Not depressed even
slightly, after starting engine.BATTERY 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
BBIA0366E

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-377
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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
• 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 CIRCUIT
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 (With CONSULT-II)>>GO TO 4.
OK (Without CONSULT-II)>>GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine.
3. 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 6.
NG >> GO TO 5.
5.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-378, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace EVAP canister purge volume control solenoid valve.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-138
. Voltage: Battery voltage
PBIB2245E
Continuity should exist.
PBIB1678E

EC-380
< SERVICE INFORMATION >
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
3. Start engine and wait at least 8 seconds.
4. If 1st trip DTC is detected, go to EC-382, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

EC-382
< SERVICE INFORMATION >
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
Diagnosis Procedure
INFOID:0000000003531880
1.INSPECTION START
Do you have CONSULT-II?
Ye s o r N o
Ye s > > G O T O 2 .
No >> GO TO 3.
2.CHECK EVAP CANISTER VENT CONTROL VALVE CIRCUIT
With CONSULT-II
1. Turn ignition switch OFF and then turn ON.
2. Select “VENT CONTROL/V” in “ACTIVE TEST” mode with CONSULT-II.
3. Touch “ON/OFF” on CONSULT-II screen.
4. Check for operating sound of the valve.
Clicking noise should be heard.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK EVAP CANISTER VENT CONTROL VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister vent control valve harness connector.
3. Turn ignition switch ON.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
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 7 L / YEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
PBIB1679E
BBIA0443E