2005 INFINITI QX4 relay

EC-4Revision: October 20052005 QX56 Diagnostic Procedure ...........................................338
Component Inspection ..........................................340
DTC P0453 EVAP CONTROL SYSTEM PRESSURE
SENSOR ..................................................................341
Component Description ........................................341
CONSULT-II Reference Value in Data Monitor Mode
.341
On Board Diagnosis Logic ....................................341
DTC Confirmation Procedure ...............................342
Wiring Diagram .....................................................343
Diagnostic Procedure ...........................................344
Component Inspection ..........................................348
DTC P0455 EVAP CONTROL SYSTEM .................349
On Board Diagnosis Logic ....................................349
DTC Confirmation Procedure ...............................350
Diagnostic Procedure ...........................................351
DTC P0456 EVAP CONTROL SYSTEM .................357
On Board Diagnosis Logic ....................................357
DTC Confirmation Procedure ...............................358
Overall Function Check ........................................359
Diagnostic Procedure ...........................................360
DTC P0460 FUEL LEVEL SENSOR .......................366
Component Description ........................................366
On Board Diagnosis Logic ....................................366
DTC Confirmation Procedure ...............................366
Diagnostic Procedure ...........................................367
Removal and Installation ......................................367
DTC P0461 FUEL LEVEL SENSOR .......................368
Component Description ........................................368
On Board Diagnosis Logic ....................................368
Overall Function Check ........................................368
Diagnostic Procedure ...........................................369
Removal and Installation ......................................369
DTC P0462, P0463 FUEL LEVEL SENSOR CIR-
CUIT ........................................................................370
Component Description ........................................370
On Board Diagnosis Logic ....................................370
DTC Confirmation Procedure ...............................370
Diagnostic Procedure ...........................................371
Removal and Installation ......................................371
DTC P0500 VSS ......................................................372
Description ............................................................372
On Board Diagnosis Logic ....................................372
DTC Confirmation Procedure ...............................372
Overall Function Check ........................................372
Diagnostic Procedure ...........................................373
DTC P0506 ISC SYSTEM .......................................374
Description ............................................................374
On Board Diagnosis Logic ....................................374
DTC Confirmation Procedure ...............................374
Diagnostic Procedure ...........................................375
DTC P0507 ISC SYSTEM .......................................376
Description ............................................................376
On Board Diagnosis Logic ....................................376
DTC Confirmation Procedure ...............................376
Diagnostic Procedure ...........................................377
DTC P0550 PSP SENSOR ......................................378
Component Description ........................................378
CONSULT-II Reference Value in Data Monitor Mode . 378
On Board Diagnosis Logic .................................... 378
DTC Confirmation Procedure ................................ 378
Wiring Diagram ..................................................... 379
Diagnostic Procedure ............................................ 380
Component Inspection .......................................... 382
Removal and Installation ....................................... 382
DTC P0605 ECM ..................................................... 383
Component Description ........................................ 383
On Board Diagnosis Logic .................................... 383
DTC Confirmation Procedure ................................ 383
Diagnostic Procedure ............................................ 384
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1
HEATER ................................................................... 386
Description ............................................................ 386
CONSULT-II Reference Value in Data Monitor Mode
. 386
On Board Diagnosis Logic .................................... 386
DTC Confirmation Procedure ................................ 386
Wiring Diagram ..................................................... 387
Diagnostic Procedure ............................................ 390
Component Inspection .......................................... 392
Removal and Installation ....................................... 392
DTC P1065 ECM POWER SUPPLY ........................ 393
Component Description ........................................ 393
On Board Diagnosis Logic .................................... 393
DTC Confirmation Procedure ................................ 393
Wiring Diagram ..................................................... 394
Diagnostic Procedure ............................................ 395
DTC P1121 ELECTRIC THROTTLE CONTROL
ACTUATOR ............................................................. 397
Component Description ........................................ 397
On Board Diagnosis Logic .................................... 397
DTC Confirmation Procedure ................................ 397
Diagnostic Procedure ............................................ 398
DTC P1122 ELECTRIC THROTTLE CONTROL
FUNCTION .............................................................. 399
Description ............................................................ 399
On Board Diagnosis Logic .................................... 399
DTC Confirmation Procedure ................................ 399
Wiring Diagram ..................................................... 400
Diagnostic Procedure ............................................ 401
Component Inspection .......................................... 404
Removal and Installation ....................................... 404
DTC P1124, P1126 THROTTLE CONTROL MOTOR
RELAY ..................................................................... 405
Component Description ........................................ 405
CONSULT-II Reference Value in Data Monitor Mode
. 405
On Board Diagnosis Logic .................................... 405
DTC Confirmation Procedure ................................ 405
Wiring Diagram ..................................................... 407
Diagnostic Procedure ............................................ 408
DTC P1128 THROTTLE CONTROL MOTOR ......... 410
Component Description ........................................ 410
On Board Diagnosis Logic .................................... 410
DTC Confirmation Procedure ................................ 410
Wiring Diagram .....................................................411
Diagnostic Procedure ............................................ 412

EC-28Revision: October 2005
AIR CONDITIONING CUT CONTROL
2005 QX56
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartUBS00KZA
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionUBS00KZB
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed

ON BOARD REFUELING VAPOR RECOVERY (ORVR)
EC-43
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Revision: October 20052005 QX56
Component InspectionUBS00KZL
REFUELING EVAP VAPOR CUT VALVE
With CONSULT-II
1. Remove fuel tank. Refer to FL-9, "FUEL TANK" .
2. Drain fuel from the tank as follows:
a. Remove fuel feed hose located on the fuel gauge retainer.
b. Connect a spare fuel hose, one side to fuel gauge retainer where the hose was removed and the other
side to a fuel container.
c. Drain fuel using “FUEL PUMP RELAY” in “ACTIVE TEST” mode with CONSULT-II.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that
the air flows freely into the tank.
4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.
c. Put fuel tank upside down.
d. Apply vacuum pressure to hose end [−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer
remaining open and check that the pressure is applicable.
Without CONSULT-II
1. Remove fuel tank. Refer to FL-9, "FUEL TANK" .
2. Drain fuel from the tank as follows:
a. Remove fuel gauge retainer.
b. Drain fuel from the tank using a handy pump into a fuel container.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that
the air flows freely into the tank.
4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.
c. Put fuel tank upside down.
BBIA0401E

TROUBLE DIAGNOSIS
EC-103
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EC
Revision: October 20052005 QX56
Fail-safe ChartUBS00L04
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P1121 Electric throttle control
actuator(When electric throttle control actuator does not function properly due to the return spring
malfunction:)
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.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While 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.
P1122 Electric throttle control
functionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2122
P2123
P2127
P2128
P2138Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
6GRHeated oxygen sensor 2
heater (bank 1)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
12 RPower steering pressure sen-
sor[Engine is running]

Steering wheel: Being turned0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned0.4 - 0.8V
13 OCrankshaft position sensor
(POS)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleApproximately 10V
[Engine is running]

Engine speed: 2,000 rpmApproximately 10V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E

EC-124Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
101 R/W Stop lamp switch[Ignition switch: OFF]
Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
102 GR/R PNP switch[Ignition switch: ON]

Selector lever: P or NApproximately 0V
[Ignition switch: ON]

Except the above gear positionBATTERY VOLTAGE
(11 - 14V)
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
106 BR/WAccelerator pedal position
sensor 1[Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully released0.5 - 1.0V
[Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully depressed4.2 - 4.8V
107 V/R Fuel tank temperature sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with fuel
tank temperature.
108 BR/WICC brake switch
(Models with ICC system)
ASCD brake switch
(Models with ASCD system)[Ignition switch: ON]

Brake pedal: Slightly depressedApproximately 0V
[Ignition switch: ON]

Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)
109 L/W Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
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)
113 GR Fuel pump relay[Ignition switch: ON]

For 1 second after turning ignition switch
ON
[Engine is running]0 - 1.5V
[Ignition switch: ON]

More than 1 second after turning ignition
switch ONBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
B/WECM ground[Engine is running]

Idle speedBody ground
11 7 L / YEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
121 WPower supply for ECM
(Back-up)[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V) TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)

EC-128Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-130, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
INSPECTION PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
1. Turn ignition switch OFF.
2. Connect “CONSULT-II” and “CONSULT-II CONVERTER” to
data link connector, which is located under LH dash panel near
the hood opener handle.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector×× ×
Power transistor (Ignition timing)×× ×
Throttle control motor relay×××
Throttle control motor×
EVAP canister purge volume con-
trol solenoid valve×××××
Air conditioner relay××
Fuel pump relay××××
Cooling fan relay××××
Air fuel ratio (A/F) sensor 1 heater××××
Heated oxygen sensor 2 heater××××
EVAP canister vent control valve×× ×××
Calculated load value××× ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
BBIA0369E
BCIA0029E

EC-132Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
FUEL LEVEL SE
[V]×
The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF]××

Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.

After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF]××

Indicates idle position [ON/OFF] com-
puted by ECM according to the acceler-
ator pedal position sensor signal.
AIR COND SIG
[ON/OFF]××

Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF]××

Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF]××

[ON/OFF] condition of the power steer-
ing system (determined by the signal
voltage of the power steering pressure
sensor signal) is indicated.
LOAD SIGNAL
[ON/OFF]××

Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF]×

Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF]×

Indicates [ON/OFF] condition from
heater fan switch signal.
BRAKE SW
[ON/OFF]×

Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec]×

Indicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.
When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC]×

Indicates the ignition timing computed
by ECM according to the input signals.
When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]

“Calculated load value” indicates the
value of the current air flow divided by
peak air flow.
MASS AIRFLOW
[g·m/s]

Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.

The opening becomes larger as the
value increases.
AIR COND RLY
[ON/OFF]×

The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF]×

Indicates the fuel pump relay control
condition determined by ECM according
to the input signals. Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIGNALSDescription Remarks