2008 INFINITI QX56 4 wheel drive

BRC-24
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
CONSULT-III Function (ABS)INFOID:0000000001686255
FUNCTION
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
SELF-DIAG RESULTS MODE
Operation Procedure
1. Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for
approximately 1 minute.
How to Erase Self-d iagnosis Results
1. After erasing DTC memory, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately
1 minute as the final inspection, and make sure that the ABS warning lamp, VDC OFF indicator lamp,
SLIP indicator lamp and brake warning lamp turn OFF.
CAUTION:
If memory cannot be erased, pe rform applicable diagnosis.
NOTE:
• When the wheel sensor malfunctions, after inspecting the wheel sensor system, the ABS warning lamp,
VDC OFF indicator lamp, SLIP indicator lamp and brake warning lamp will not turn OFF even when the
system is normal unless the vehicle is driving at approximately 30 km/h (19 MPH) or more for approxi-
mately 1 minute.
• Brake warning lamp will turn ON in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient).
• VDC OFF switch should not stay “ON” position.
Display Item List
Refer to BRC-100, "DTC No. Index".
DATA MONITOR MODE
Display Item List
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following
the indications on CONSULT-III.
Self-diagnostic results Self-diagnostic results can be read and erased quickly.
Data monitor Input/Output data in the ABS actuator and electric unit (control unit) can be read.
Active test Diagnostic test mode is which CONSULT-III drives some actuators apart from the ABS actuator
and electric unit (control unit) and also shifts some parameters in a specified range.
ECU part number ABS actuator and electric unit (control unit) part number can be read.
CAN diagnostic support monitor The results of transmit/receive diagnosis of CAN communication can be read.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
GEAR ××× Gear position judged by transmis-
sion range switch signal is dis-
played.
FR RH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front RH
wheel sensor signal is displayed.
FR LH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH) ×××
Wheel speed calculated by rear RH
wheel sensor signal is displayed.
Revision: March 2010
2008 QX56

NORMAL OPERATING CONDITIONBRC-109
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001686381
Symptom Result
Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC, TCS or ABS is acti-
vated. This is a normal condi-
tion due to the VDC,
TCS or ABS activation.
Stopping distance is longer than that of vehicles without ABS when the vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
The brake pedal moves and generates noises, when TCS or VDC is activated due to rapid acceleration or
sharp turn.
The brake pedal vibrates and motor operation noises occur from the engine room, after the engine starts and
just after the vehicle starts. This is normal, and it is
caused by the ABS op-
eration check.
Depending on the road conditions, the driver may experience a sluggish feel. This is normal, because
TCS places the highest
priority on the optimum
traction (stability).
TCS may activate momentarily if wheel speed changes when driving over location where friction coefficient
varies, when downshifting, or when fully depressing accelerator pedal.
The ABS warning lamp, VDC OFF indicato
r lamp and SLIP indicator lamp may turn ON when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is rotating on a turntable or located on
a ship while the engine is running. In this case, restart the
engine on a normal
road. If the normal con-
dition is restored, there
is no malfunction. At
that time, erase the self-
diagnosis memory.
VDC may not operate normally or the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp
may illuminate, when running on a special road that is extremely slanted (e.g. bank in a circuit course).
A malfunction may occur in the yaw rate/side/decel G sensor system, when the vehicle turns sharply, such
as during a spin turn, axle turn, or drift driving, while the VDC function is off (VDC OFF indicator lamp illumi-
nated).
The vehicle speed will not increase even though the accelerator pedal is depressed, when inspecting the
speedometer on a 2-wheel chassis dynamometer.
Normal (Deactivate the
VDC/TCS function be-
fore performing an in-
spection on a chassis
dynamometer.)
VDC OFF indicator lamp and SLIP indicator lamp may simultaneously turn on when low tire pressure warn-
ing lamp turns on. This is not a VDC sys-
tem error but results
from characteristic
change of tire.
Revision: March 2010
2008 QX56

BRC-110
< PRECAUTION >[VDC/TCS/ABS]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004873045
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004873055
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

PRECAUTIONSBRC-111
< PRECAUTION > [VDC/TCS/ABS]
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5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Brake SystemINFOID:0000000001604543
CAUTION:
• Always use recommended brake fluid. Refer to MA-12, "
Fluids and Lubricants".
• Never reuse drained brake fluid.
• Be careful not to splash brake fluid on painted areas; it may cause paint damage. If brake fluid is
splashed on painted areas, wash it away with water immediately.
• To clean or wash all parts of master cylin der and disc brake caliper, use clean brake fluid.
• Never use mineral oils such as gasoline or kerosen e. They will ruin rubber parts of the hydraulic sys-
tem.
• Use flare nut wrench when removing and installing brake
tube.
• If a brake fluid leak is found, the part must be disassembled
without fail. Then it has to be replaced with a new one if a
defect exists.
• Turn the ignition switch OFF and remove the connector of the ABS actuator and electric unit (con trol unit) or the battery ter-
minal before performing the work.
• Always torque brake lines when installing.
• Burnish the brake contact surf aces after refinishing or replac-
ing rotors, after replacing pads, or if a soft pedal occurs at
very low mileage.
Refer to BR-30, "
Brake Burnishing Procedure" (front disc brake) or BR-35, "Brake Burnishing Proce-
dure" (rear disc brake).
WARNING:
• Clean brake pads and shoes with a waste cl oth, then wipe with a dust collector.
Precaution for Brake ControlINFOID:0000000001604544
• During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting vehicle, the brake pedal may vibrate or a motor operating noise may be heard from engine
compartment. This is a normal status of operation check.
• Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or snow-covered (fresh, deep snow) roads.
• When an error is indicated by ABS or another warning lamp, collect all necessary information from customer (what symptoms are present under what conditions) and check for simple causes before starting diagnosis.
Besides electrical system inspection, check boos ter operation, brake fluid level, and fluid leaks.
• If incorrect tire sizes or types are installed on the vehicle or brake pads are not Genuine NISSAN parts, stop-
ping distance or steering stability may deteriorate.
• If there is a radio, antenna or related wiring near control module, ABS function may have a malfunction or
error.
• If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness pinches, open circuits or improper wiring.
• If the following components are replaced with non-genuine components or modified, the VDC OFF indicator lamp and SLIP indicator lamp may turn on or the VDC system may not operate properly. Components
related to suspension (shock absorbers, struts, springs , bushings, etc.), tires, wheels (exclude specified
size), components related to brake system (pads, roto rs, calipers, etc.), components related to engine (muf-
fler, ECM, etc.), components related to body reinforcement (roll bar, tower bar, etc.).
• Driving with broken or excessively worn suspensi on components, tires or brake system components may
cause the VDC OFF indicator lamp and the SLIP indicator lamp to turn on, and the VDC system may not
operate properly.
• When the TCS or VDC is activated by sudden acceleration or sudden turn, some noise may occur. The noise is a result of the normal operation of the TCS and VDC.
• When driving on roads which have extreme slopes (such as mountainous roads) or high banks (such as sharp curves on a freeway), the VDC may not operate no rmally, or the VDC warning lamp and the SLIP indi-
cator lamp may turn on. This is not a problem if normal operation can be resumed after restarting the engine.
SBR686C
Revision: March 2010 2008 QX56

CCS-66
< SYMPTOM DIAGNOSIS >
NORMAL OPERATING CONDITION
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001731913
PRECAUTIONS FOR VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
• Intelligent Cruise Control is functionally limited. This never support careless driving and low visibility (rain,fog, etc.). Drive the vehicle safely. Keep a safe di stance between vehicles by decreasing the vehicle speed
according to the driving condition etc.
• Intelligent Cruise Control never stop the vehicle autom atically. Intelligent Cruise Control is automatically
released, and the buzzer sounds if any vehicle ahead is not detected when the vehicle speed is approxi-
mately 35 km (21.5 MPH) or less.
• Use this system when the vehicle speed does not extr emely change. This system may not properly function
when any vehicle cuts in, or when the vehicle ahead s uddenly applies the brake. Then, the warning (buzzer
and indication) activates.
• Never use Intelligent Cruise Control in the following conditions.
- A well-trafficed road, and a tight turn. It may cause any accident because the dr iving does not fit to the road condition.
- A slippery road (e.g., freezing, or snowy road) The vehicle may lose the control by wheelspin.
- The vehicle drives in bad whet her (rain, fog, snow etc.).
The distance from the vehicle ahead is not detected pr ecisely if the whether condition is bad. Intelligent
Cruise Control is released automatically if the wiper activates in low or high speed.
- The vehicle receives bright light (sunshine etc.). The distance from the vehicle ahead is not detected pr ecisely if bright light enters in the vehicle.
- Raindrop or snow is on the sensor.
The distance from the vehicle ahead is not detected prec isely if raindrop or snow attaches on the sensor.
- A steep downhill The setting vehicle speed may exceed if Intelligent Cruise Control does not detect the vehicle ahead. The
brake may heat up in the vehicle- to-vehicle distance control mode.
- A repeated uphill and downhill Intelligent Cruise Control may not detect the vehicl e ahead precisely. An accident may occur by tailgating.
- Maintaining proper vehicle distance is difficult due to frequent acceleration/deceleration. It may cause any accident because the driving does not fit to the road condition if keeping a proper vehicle-
to-vehicle distance is difficult.
- When entering in the highway interchange (swerving off the main line),
Unexpected accident may cause if the vehicle ahead drives slower
than the preset vehicle speed. T he vehicle-to-vehicle distance con-
trol mode accelerates automatically because the vehicle ahead is
not detected on the lane if the own vehicle or the vehicle ahead
changes the lane.
• Intelligent Cruise Control does not activate to the parking vehicles, and vehicles driving extremely slow er than the own vehicle. Never
hit the vehicle stopping at a tollgate, or the tail end of traffic jam.
• Intelligent Cruise Control does not activate to the vehicle edging way, and non-vehicle objects (passengers etc.).
• This function detects the reflector of the vehicle ahead. Intelligent Cruise Control may not detect the vehicle
ahead, and keep a proper vehicle-to-vehicle distance in t he following conditions. Drive the vehicle according
to the driving condition.
- The vehicle ahead installs the reflector higher (trailer etc.).
- The rear of the vehicle ahead is extremely dirt.
- The vehicle ahead or vehicle on other lanes splashes water or snow on the road.
- The vehicle ahead provides dark exhaust gas. Smoke blocks the visibility.
- The vehicle ahead attaches film on the reflector. The v ehicle ahead does not install the reflector. The reflec-
tor is broken.
- Extremely heavy load is on the rear seat or in the cargo area.
- The vehicle drives on a repeated uphill and downhill
EL-2980D
Revision: March 2010 2008 QX56

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NORMAL OPERATING CONDITIONCCS-67
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• The sensor detection distance is limited if the vehicle-to-vehicle distance is close. The vehicle distance may not maintain properly
because the motorcycle (A) driving on the lane edge is not
detected or detecting the vehicle ahead (cutting in the own vehicle)
delays.
• The sensor dirt is detected automat ically. But it is not perfect. Dirt
is not judged despite the sensor is dirt. Dirt is not detected if snow
or ice is on the sensor.
Keeping the vehicle-to-vehicle distance is difficult. Drive the vehi-
cle safely. Always clean the sensor.
Intelligent Cruise Control is released automatically if dirt is
detected.
• The vehicle ahead may not be detected temporarily, the vehicle or object on the neighboring lane may be
detected or the warning buzzer may sound according to the road shape (curve and narrow road) and the
own vehicle condition (steering, driving lane position, accident , malfunction etc.).
The vehicle ahead is not detected temporarily. The vehicle approaches too close.
PRECAUTIONS FOR CONVENTIONAL (F IXED SPEED) CRUISE CONTROL MODE
• Conventional cruise control mode does neither control the brake nor activate the warning.
Drive the vehicle safely. Keep a safe distance between vehicles by decreasing the vehicle speed according
to the driving condition etc.
• Never use the conventional cruise control mode in the following conditions.
- A well-trafficed road, and a tight turn. It may cause any accident because the driving does not fit to the road condition.
- A slippery road (e.g., freezing, or snowy road) The vehicle may lose the control by wheelspin.
- A steep downhill The engine brake does not activate effectively on a steep downhill. The preset vehicle speed may exceed.
JSOIA0050ZZ
Revision: March 2010 2008 QX56

CHG-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004857596
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004857595
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

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CONTENTS
ENGINE COOLING SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Liquid Gasket .....................................3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tool ........................................... ......4
Commercial Service Tool ..........................................5
FUNCTION DIAGNOSIS ...............................6
COOLING SYSTEM ....................................... .....6
Cooling Circuit ..................................................... ......6
Schematic .................................................................7
OVERHEATING CAUSE ANALYSIS ..................8
Troubleshooting Chart ...............................................8
ON-VEHICLE MAINTENA NCE ....................10
ENGINE COOLANT ....................................... ....10
Inspection ............................................................ ....10
Changing Engine Coolant ........................................11
RADIATOR ........................................................14
Checking Radiator ............................................... ....14
ON-VEHICLE REPAIR .................................15
RADIATOR ....... .................................................15
Removal and Installation ..................................... ....15
ENGINE COOLING FAN ...................................18
Removal and Installation (Crankshaft Driven
Type) .......................................................................
18
Removal and Installation (Motor Driven Type) ........19
WATER PUMP ..................................................20
Removal and Installation .........................................20
THERMOSTAT AND WATER PIPING ..............22
Removal and Installation .........................................22
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
24
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
24
Standard and Limit .............................................. ....24
Revision: March 2010 2008 QX56