2005 INFINITI QX4 wheel

DTC P0441 EVAP CONTROL SYSTEM
EC-305
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Revision: October 20052005 QX56
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. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE SYSTEM” in “DTC CONFIRMATION” mode with CON-
SULT-II.
5. Touch “START”.
If “COMPLETED” is displayed, go to step 7.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-II screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
306, "Diagnostic Procedure" .
Overall Function CheckUBS00H4M
Use this procedure to check the overall monitoring function of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system
pressure sensor signal) and ground.
6. Check EVAP control system pressure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1
minute.
8. Verify that EVAP control system pressure sensor value stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 12.0 msec
COOLAN TEMP/S 70 - 100°C (158 - 212°F)
PBIB0826E
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB11 09 E

EC-318Revision: October 2005
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
2005 QX56
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VA LV E
PFP:14920
DescriptionUBS00H4R
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 ModeUBS00H4S
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-372Revision: October 2005
DTC P0500 VSS
2005 QX56
DTC P0500 VSSPFP:32702
DescriptionUBS00H6C
NOTE:
If DTC P0500 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control
unit)” by CAN communication line. The c combination meter then sends a signal to the ECM by CAN commu-
nication line.
On Board Diagnosis LogicUBS00H6D
DTC Confirmation ProcedureUBS00H6E
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.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Read “VHCL SPEED SE” in “DATA MONITOR” mode with CONSULT-II. The vehicle speed on CONSULT-
II should exceed 10 km/h (6 MPH) when rotating wheels with suitable gear position.
If NG, go to EC-373, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Warm engine up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-373, "
Diagnostic Procedure"
.
Overall Function CheckUBS00H6F
Use this procedure to check the overall function of the vehicle speed sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0500
0500Vehicle speed sensorThe almost 0 km/h (0 MPH) signal from
vehicle speed sensor is sent to ECM
even when vehicle is being driven.

Harness or connectors
(The CAN communication line is open or
shorted)

Harness or connectors
(The vehicle speed signal circuit is open or
shorted)

Wheel sensor

Combination meter

ABS actuator and electric unit (control unit)
ENG SPEED More than 1,600 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL More than 6.9 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
SEF 1 96 Y

DTC P0500 VSS
EC-373
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Revision: October 20052005 QX56
2. Start engine.
3. Read vehicle speed sensor signal in Service $01 with GST.
The vehicle speed sensor on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
4. If NG, go to EC-373, "
Diagnostic Procedure" .
Diagnostic ProcedureUBS00H6G
1. CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
>>INSPECTION END

EC-378Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
DTC P0550 PSP SENSORPFP:49763
Component DescriptionUBS00H6P
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeUBS00H6Q
Specification data are reference values.
On Board Diagnosis LogicUBS00H6R
The MIL will not light up for this diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureUBS00H6S
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
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-380, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0365E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL

Engine: After warming up, idle
the engineSteering wheel: Not being turned
(Forward direction)OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550Power steering pressure
sensor circuitAn excessively low or high voltage from the
sensor is sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted)

Power steering pressure sensor
SEF 0 58 Y

EC-380Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
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.
Diagnostic ProcedureUBS00H6U
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
12 RPower steering pressure
sensor[Engine is running]

Steering wheel: Being turned.0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned.0.4 - 0.8V
67 B Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
68 W/LSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
BBIA0354E

EC-382Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H6V
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Removal and Installation UBS00H6W
POWER STEERING PRESSURE SENSOR
Refer to PS-31, "HYDRAULIC LINE" .
Condition Voltage
Steering wheel: Being turned. 0.5 - 4.5V
Steering wheel: Not being turned. 0.4 - 0.8V
MBIB0126E

EC-440Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
DTC P1217 ENGINE OVER TEMPERATUREPFP:00000
DescriptionUBS00H8T
SYSTEM DESCRIPTION
NOTE:
If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 2-step control [HI/OFF].
Cooling Fan Operation
CONSULT-II Reference Value in Data Monitor ModeUBS00H8U
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
1
Cooling fan
controlIPDM E/R
(Cooling fan relay) Battery
Battery voltage*
1
Wheel sensor*2Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch
Air conditioner ON signal*
2
Refrigerant pressure sensor Refrigerant pressure
PBIB2060E
MONITOR ITEM CONDITION SPECIFICATION
COOLING FAN

Engine: After warming up, idle
the engineEngine coolant temperature: 99°C
(210°F) or lessOFF
Engine coolant temperature: 100°C
(212°F) or moreHI