cooling INFINITI QX56 2006 Factory Repair Manual

CO-18Revision: November 2009
ENGINE COOLING FAN
2006 QX56

Start and warm up the engine. Visually make sure that there are no leaks of the engine coolant.
Removal and Installation (Motor Driven Type)EBS00REE
REMOVAL
1. Remove front bumper. Refer to EI-13, "Removal and Installation" .
2. Disconnect harness connector from fan motor.
3. Remove the bolt and remove the fan grille and motor assembly.
INSTALLATION
Installation is in the reverse order of removal.

Cooling fan is controlled by ECM. For details, refer to EC-473, "DTC P1217 ENGINE OVER TEMPERA-
TURE" .
WBIA0518E

CO-20Revision: November 2009
WATER PUMP
2006 QX56

After installation bleed the air from the cooling system. Refer to CO-11, "REFILLING ENGINE COOLANT"
.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up engine. Visually check for leaks of the engine coolant.

CO-22Revision: November 2009
THERMOSTAT AND WATER PIPING
2006 QX56
CAUTION:
Perform when the engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-15, "
Removal and Installation" .
3. Remove the engine room cover using power tool.
4. Disconnect the heater hose (heater core side).
5. Remove the heater hose bracket.
6. Disconnect the water cut valve connector.
7. Remove the water cut valve.
INSPECTION AFTER REMOVAL

Place a thread so that it is caught in the valve of the thermostat.
Immerse fully in a container filled with water. Heat while stirring.

The valve opening temperature is the temperature at which the
valve opens and falls from the thread.

Continue heating. Check the full-open lift amount.

After checking the full-open lift amount, lower the water temper-
ature and check the valve closing temperature.
Standard values:
INSTALLATION
Installation is in the reverse order of removal.
Installation of Thermostat

Install the thermostat with the whole circumference of each
flange part fit securely inside the rubber ring as shown.

Install the thermostat with the jiggle valve facing upwards.
Installation of Water Outlet Pipe and Heater Pipe
First apply a neutral detergent to the O-rings, then quickly insert the insertion parts of the water outlet pipe and
heater pipe into the installation holes.
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually check for leaks of the engine coolant.
SLC252B
Thermostat
Valve opening temperature 80 - 84°C (176 - 183° F)
Full-open lift amount More than 10 mm/ 95°C (0.39 in/ 203°F)
Valve closing temperature 77°C (171°F) or higher
KBIA2502E

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Revision: November 2009 2006 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 itemsEngine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine 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.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START 40
°C (104 °F)
More than approx. 4 minutes after
ignition ON or START 80
°C (176 °F)
Except as shown above 40 - 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
P2135 Throttle 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.
P0643 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.
P2100
P2103 Throttle 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.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 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.
P2119 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.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal 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.
Engine operating condition in fail-safe mode
Engine speed will not rise more than 2,500 rpm due to the fuel cut

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Revision: November 2009 2006 QX56
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5 EM-21
,
EX-
3Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-24
,
LU-
13 , LU-10 ,
LU-11
Oil level (Low)/Filthy oil LU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-14
Thermostat
5CO-21
Water pump CO-19
Water galleryCO-8
Cooling fan5CO-17
Coolant level (Low)/Contami-
nated coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
BL-137
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA

EC-116Revision: November 2009
TROUBLE DIAGNOSIS
2006 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-118, "
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 ×××
Item
DIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR DATA
MONI-
TOR
(SPEC) ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
BBIA0369E
BCIA0029E

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Revision: November 2009 2006 QX56VENT CONT/V
[ON/OFF]

The control condition of the EVAP canis-
ter vent control valve (determined by
ECM according to the input signals) is
indicated.
ON: Closed
OFF: Open
THRTL RELAY
[ON/OFF] ×

Indicates the throttle control motor relay
control condition determined by the
ECM according to the input signals.
COOLING FAN
[HI/OFF] ×

The control condition of the cooling fan
(determined by ECM according to the
input signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF]

Indicates [ON/OFF] condition of heated
oxygen sensor 2 heater determined by
ECM according to the input signals.
HO2S2 HTR (B2)
[ON/OFF]
I/P PULLY SPD
[rpm]

Indicates the engine speed computed
from the turbine revolution sensor sig-
nal.
VEHICLE SPEED
[km/h] or [MPH]

Indicates the vehicle speed computed
from the revolution sensor signal.
IDL A/V LEARN
[YET/CMPLT]

Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has
already been performed successfully.
TRVL AFTER MIL
[km] or [mile]

Distance traveled while MIL is activated.
A/F S1 HTR (B1)
[%]

A/F sensor 1 heater control value com-
puted by ECM according to the input sig-
nals.

The current flow to the heater becomes
larger as the value increases.
A/F S1 HTR (B2)
[%]
AC PRESS SEN [V]

The signal voltage from the refrigerant
pressure sensor is displayed.
VHCL SPEED SE
[km/h] or [mph]

The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
SET VHCL SPD*
1
[km/h] or [mph]
The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]

Indicates [ON/OFF] condition from MAIN
switch signal.
CANCEL SW
[ON/OFF]

Indicates [ON/OFF] condition from CAN-
CEL switch signal.
RESUME/ACC SW
[ON/OFF]

Indicates [ON/OFF] condition from
RESUME/ACCELERATE switch signal.
SET SW
[ON/OFF]

Indicates [ON/OFF] condition from SET/
COAST switch signal.
BRAKE SW1
[ON/OFF]

Indicates [ON/OFF] condition from
ASCD brake switch signal.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description Remarks

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Revision: November 2009 2006 QX56
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
B/FUEL SCHDL
[msec]×

Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.

When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]
A/F ALPHA-B2 [%] ×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When engine is running specification
range is indicated.

This data also includes the data for
the air-fuel ratio learning control.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description
Remarks
TEST ITEMCONDITION JUDGEMENTCHECK ITEM (REMEDY)
FUEL INJEC-
TION

Engine: Return to the original
trouble condition

Change the amount of fuel injec-
tion using CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Fuel injector

Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING

Engine: Return to the original
trouble condition

Timing light: Set

Retard the ignition timing using
CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Perform Idle Air Volume Learning.
POWER BAL-
ANCE

Engine: After warming up, idle
the engine.

A/C switch: OFF

Selector lever: P or N

Cut off each injector signal one at
a time using CONSULT-II. Engine runs rough or dies.

Harness and connectors

Compression

Fuel injector

Power transistor

Spark plug

Ignition coil
COOLING FAN*

Ignition switch: ON

Turn the cooling fan HI and OFF
using CONSULT-II. Cooling fan moves and stops.

Harness and connectors

Cooling fan motor

IPDM E/R
ENG COOLANT
TEMP

Engine: Return to the original
trouble condition

Change the engine coolant tem-
perature using CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Engine coolant temperature sen-
sor

Fuel injector
FUEL PUMP
RELAY

Ignition switch: ON
(Engine stopped)

Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
Harness and connectors

Fuel pump relay
PURG VOL
CONT/V

Engine: After warming up, run
engine at 1,500 rpm.

Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II. Engine speed changes according to
the opening percent.
Harness and connectors

Solenoid valve

EC-124Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-54, "SYSTEM READINESS TEST (SRT) CODE" .
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.FUEL/T TEMP
SEN

Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V

Ignition switch: ON
(Engine stopped)

Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound. Solenoid valve makes an operating
sound.
Harness and connectors

Solenoid valve
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode
Test itemCorresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441
P0441EC-360
EVP SML LEAK P0442/P1442* P0442
EC-365P0455EC-419
EVP V/S LEAK P0456/P1456* P0456EC-427
PURG VOL CN/V P1444 P0443EC-373
A/F SEN1 A/F SEN1 (B1) P1276
P0130EC-213A/F SEN1 (B1) P1278/P1279 P0133EC-241
A/F SEN1 (B2) P1286 P0150EC-213
A/F SEN1 (B2) P1288/P1289 P0153EC-241
HO2S2 HO2S2 (B1) P0139
P0139EC-277
HO2S2 (B1) P1146 P0138EC-264
HO2S2 (B1) P1147 P0137EC-253
HO2S2 (B2) P0159 P0159EC-277
HO2S2 (B2) P1166 P0158EC-264
HO2S2 (B2) P1167 P0157EC-253

EC-130Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
LOAD SIGNAL
Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF. OFF
IGNITION SW

Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW

Engine: After warming up, idle
the engine Heater fan control switch: ON
ON
Heater fan control switch: OFF OFF
BRAKE SW

Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle
2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle
10° - 20 ° BTDC
2,000 rpm 25° - 45 ° BTDC
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle
14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle
3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)
0%
2,000 rpm —
AIR COND RLY

Engine: After warming up, idle
the engine Air conditioner switch: OFF
OFF
Air conditioner switch: ON
(Compressor: Operates) ON
FUEL PUMP RLY

For 1 second after turning ignition switch ON

Engine running or cranking ON

Except above conditions
OFF
VENT CONT/V

Ignition switch: ON OFF
THRTL RELAY

Ignition switch: ON ON
COOLING FAN

Engine: After warming up, idle
the engine

Air conditioner switch: OFF Engine coolant temperature: 99
°C
(210 °F) or less OFF
Engine coolant temperature: 100 °C
(212 °F) or more HI
HO2S2 HTR (B1)
HO2S2 HTR (B2)

Engine speed: Below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load ON

Engine speed: Above 3,600 rpm
OFF
I/P PULLY SPD

Vehicle speed: More than 20 km/h (12 MPH) Almost the same speed as the
tachometer indication
MONITOR ITEM CONDITION SPECIFICATION