2010 INFINITI QX56 cooling

COOLING FANEC-393
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Cooling fan motor should operate.
If NG, replace cooling fan motor.
SEF888V
Revision: April 20092010 QX56

REFRIGERANT PRESSURE SENSOREC-419
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
REFRIGERANT PRESSURE SENSOR
Component DescriptionINFOID:0000000005149490
The refrigerant pressure sensor is installed at the condenser of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.
Diagnosis ProcedureINFOID:0000000005149491
1.CHECK REFRIGERANT PRESSURE
SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check voltage between ECM terminal 70 and ground with CON- SULT-III or tester.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower fan switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
BBIA0445E
PBIB2657E
Voltage: 1.0 - 4.0 V
PBIB1188E
Revision: April 20092010 QX56

ECM
EC-423
< ECU DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
LOAD SIGNAL • Ignition switch: ON
Rear 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 —
INT/V TIM (B1)
INT/V TIM (B2) • Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load Idle
−5° - 5 °CA
2,000 rpm Approx. 0° - 20°CA
INT/V SOL (B1)
INT/V SOL (B2) • Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
• No load Idle
0% - 2%
2,000 rpm Approx. 25% - 50%
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
•
E

ngine 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
MONITOR ITEM
CONDITION SPECIFICATION
Revision: April 20092010 QX56

ECM
EC-457
< ECU DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
• When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt 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
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 following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-IIl display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting. 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 th rottle 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 thro ttle control ac-
tuator (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
Revision: April 20092010 QX56

EC-480
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-33
,
LU-
14 , LU-11 ,
LU-12
Oil level (Low)/Filthy oil LU-8, "In-
spection"
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-15
Thermostat
5CO-22
Water pump CO-20
Water galleryCO-6
Cooling fan5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-9
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
Revision: April 20092010 QX56

DRIVE BELTSEM-13
< ON-VEHICLE MAINTENANCE >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
ON-VEHICLE MAINTENANCE
DRIVE BELTS
Exploded ViewINFOID:0000000005148974
Checking Drive BeltsINFOID:0000000005148975
WARNING:
Be sure to perform when the engine is stopped.
1. Remove air duct and resonator assembly when inspecting drive belt.
2. Make sure that indicator (single line notch) of eac
h auto tensioner is within the allowable working range
(between three line notches).
NOTE:
• Check the drive belt auto tensioner indication when the engine is cold.
• The indicator notch is located on the moving side of the drive belt auto tensioner.
3. Visually check entire belt for wear, damage or cracks.
4. If the indicator is out of allowable working range or belt is damaged, replace the belt. Refer to EM-13
.
DRIVE BELT TENSION
There is no manual drive belt tension adjustment. The driv e belt tension is automatically adjusted by the drive
belt auto tensioner.
Removal and InstallationINFOID:0000000005148976
REMOVAL
1. Remove the air duct and resonator assembly. Refer to EM-25, "Removal and Installation".
1. Drive belt2. Power steering pump pulley 3. Generator pulley
4. Crankshaft pulley 5. A/C compressor6. Idler pulley
7. Cooling fan pulley 8. Water pump pulley9. Drive belt auto tensioner
A. Allowable working range
LBIA0391E
Revision: April 20092010 QX56

EM-30
< ON-VEHICLE REPAIR >
EXHAUST MANIFOLD AND THREE WAY CATALYST
EXHAUST MANIFOLD AND THREE WAY CATALYST
Exploded ViewINFOID:0000000005148989
Removal and InstallationINFOID:0000000005148990
REMOVAL
WARNING:
Perform the work when the exhaust and cooling system have cooled sufficiently.
1. Remove the engine undercover (rear) using power tool (4WD models).
2. Remove front final drive assembly (4WD models). Refer to DLN-215, "
Removal and Installation".
3. Remove the main muffler assembly and center exhaust tube. Refer to EX-6, "
Removal and Installation".
4. Remove the front exhaust tubes. Refer to EX-6, "
Removal and Installation".
5. Remove front tires. Refer to WT-49, "
Rotation".
6. Remove fender protectors. Refer to EXT-23, "
Removal and Installation".
7. Remove the LH and RH air fuel ratio A/F sensors. • Follow steps below to remove each air fuel ratio A/F sensor.
a. Remove the harness connector of each air fuel ra tio A/F sensor, and harness from bracket and middle
clamp.
1. Air fuel ratio A/F sensor 1 (bank 2) 2. Exhaust manifold cover (bank 2) 3. Exhaust manifold (bank 2)
4. Gaskets 5. Exhaust manifold (bank 1) 6. Exhaust manifold cover (bank 1)
7. Air fuel ratio A/F sensor 1 (bank 1) A. Up B. Coated face
C. Manifold side D. Up mark Front
AWBIA0453GB
Revision: April 20092010 QX56

EM-52
< ON-VEHICLE REPAIR >
TIMING CHAIN
b. Select the one most visible notch of the four on the bolt flange.Corresponding to the selected notch, put a alignment mark
(such as paint) on the crankshaft pulley.
14. Rotate the crankshaft pulley in normal direction (clockwise when viewed from engine front) to check for parts interference.
15. Installation of the remaining components is in the reverse of order of removal.
INSPECTION AFTER INSTALLATION
• Before starting the engine, check oil/fluid levels in cluding engine coolant and engine oil. If the levels are
lower than required quantity, fill to the specified level. Refer to MA-13, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to the fuel piping, check for fuel leakage at the connection points.
• Start engine. With engine speed increased, che ck again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration. NOTE:
If hydraulic pressure inside timing chain tensioner drops after removal and installation, slack in the guide
may generate a pounding noise during and just after engine start. However, this is normal. Noise will stop
after hydraulic pressure rises.
• Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids including engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to
specified level if necessary.
• Summary of the inspection items:
*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.
Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90 ° (angle tightening)
KBIA2519E
Item Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakageLeakage
Exhaust gas —Leakage —
Revision: April 20092010 QX56