2005 INFINITI QX4 light

DTC P0327, P0328, P0332, P0333 KS
EC-279
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Revision: October 20052005 QX56
DTC P0327, P0328, P0332, P0333 KSPFP:22060
Component DescriptionUBS00H3T
The knock sensor is attached to the cylinder block. It senses engine
knocking using a piezoelectric element. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
On Board Diagnosis LogicUBS00H3U
The MIL will not light up for these diagnoses.
DTC Confirmation ProcedureUBS00H3V
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 that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and run it for at least 5 seconds at idle speed.
3. If 1st trip DTC is detected, go to EC-281, "
Diagnostic Procedure"
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0021E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0327
0327
(bank 1)Knock sensor circuit low
inputAn excessively low voltage from the sensor
is sent to ECM.

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

Knock sensor P0332
0332
(bank 2)
P0328
0328
(bank 1)Knock sensor circuit high
inputAn excessively high voltage from the sensor
is sent to ECM.
P0333
0333
(bank 2)
SEF 0 58 Y

EC-306Revision: October 2005
DTC P0441 EVAP CONTROL SYSTEM
2005 QX56
9. If NG, go to EC-306, "Diagnostic Procedure" .
Diagnostic ProcedureUBS00H4N
1. CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-II)>>GO TO 2.
OK (Without CONSULT-II)>>GO TO 3.
NG >> Replace EVAP canister.
2. CHECK PURGE FLOW
With CONSULT-II
1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-33, "
EVAPORATIVE
EMISSION LINE DRAWING" .
2. Start engine and let it idle.
3. Select “PURG VOL CONT/V” in “ACTIVE TEST” mode with CONSULT-II.
4. Rev engine up to 2,000 rpm.
5. Touch “Qd” and “Qu” on CONSULT-II screen to adjust “PURG
VOL CONT/V” opening and check vacuum existence.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
3. CHECK PURGE FLOW
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-33, "
EVAPORATIVE
EMISSION LINE DRAWING" .
4. Start engine and let it idle.
Do not depress accelerator pedal even slightly.
5. Check vacuum gauge indication before 60 seconds passed after starting engine.
6. Revving engine up to 2,000 rpm after 100 seconds passed after starting engine.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
PURG VOL CONT/V Vacuum
100% Should exist.
0% Should not exist.
PBIB1678E
Vacuum should not exist.
Vacuum should exist.

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 —

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-321
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EC
Revision: October 20052005 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 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

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-333
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00H59
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 OFF and wait at least 10 seconds.
2. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
3. Start engine and wait at least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
If 1st trip DTC is detected, go to EC-333, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H5A
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.
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BBIA0354E

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
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DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR
EC-397
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Revision: October 20052005 QX56
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATORPFP:16119
Component DescriptionUBS00H7E
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-
tle valve and feeds the voltage signals to the ECM. The ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagnosis LogicUBS00H7F
This self-diagnosis has one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7G
NOTE:

Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A AND B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to P position.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Turn ignition switch ON and wait at least 1 second.
7. Shift selector lever to D position and wait at least 3 seconds.
8. Shift selector lever to P position.
9. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
10. If DTC is detected, go to EC-398, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1121
11 2 1Electric throttle control
actuatorA)Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.

Electric throttle control actuator
B)Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction AThe ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction CWhile the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
SEF 0 58 Y

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-399
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Revision: October 20052005 QX56
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTIONPFP:16119
DescriptionUBS00H7I
NOTE:
If DTC P1122 is displayed with DTC P1121 or 1126, first perform the trouble diagnosis for DTC P1121 or
P1126. Refer to EC-397, "
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR" or EC-405, "DTC
P1124, P1126 THROTTLE CONTROL MOTOR RELAY" .
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicUBS00H7J
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7K
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 that battery voltage is more than 11V when engine
is running.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-401, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1122
11 2 2Electric throttle control
performance problemElectric throttle control function does not oper-
ate properly.

Harness or connectors
(Throttle control motor circuit is open or
shorted)

Electric throttle control actuator
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
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