INFINITI QX56 2008 Factory Service Manual

BRC-104
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
UNEXPECTED PEDAL REACTION
UNEXPECTED PEDAL REACTION
Diagnosis ProcedureINFOID:0000000001686376
1.CHECK BRAKE PEDAL STROKE
Check brake pedal stroke. Refer to BR-15, "
Inspection and Adjustment".
Is the stroke too large?
YES >> • Bleed air from brake tube and hose. Refer to BR-17, "Bleeding Brake System".
• Check brake pedal, brake booster, and master cylinder for mount play, looseness, brake system fluid leakage, etc. Refer to BR-15, "
Inspection and Adjustment" (brake pedal), BR-12, "On
Board Inspection" (master cylinder), BR-10, "Inspection" (brake booster).
NO >> GO TO 2
2.CHECK FUNCTION
Disconnect ABS actuator and electric unit (control unit) c onnector to deactivate ABS. Check if braking force is
normal in this condition. Connect connector after inspection.
Is the inspection result normal?
YES >> Normal
NO >> Check brake system.
Revision: March 2010 2008 QX56

THE BRAKING DISTANCE IS LONGBRC-105
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
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THE BRAKING DISTANCE IS LONG
Diagnosis ProcedureINFOID:0000000001686377
CAUTION:
The stopping distance on slippery road surfaces might be longer with the ABS operating than when
the ABS is not operating.
1.CHECK FUNCTION
Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector to deactivate
ABS. In this condition, check stopping di stance. After inspection, connect connector.
Is the inspection result normal?
YES >> Normal
NO >> Check brake system.
Revision: March 2010 2008 QX56

BRC-106
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
ABS FUNCTION DOES NOT OPERATE
ABS FUNCTION DOES NOT OPERATE
Diagnosis ProcedureINFOID:0000000001686378
CAUTION:
ABS does not operate when speed
is 10 km/h (6 MPH) or lower.
1.CHECK ABS WARNING LAMP DISPLAY
Make sure that the ABS warning lamp turns OFF af ter ignition switch is turned ON or when driving.
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
Revision: March 2010 2008 QX56

PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
BRC-107
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
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PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
Diagnosis ProcedureINFOID:0000000001686379
CAUTION:
Under the following conditions, ABS is activated an d vibration is felt when brake pedal is lightly
depressed. However, this is normal.
• When shifting gears
• When driving on slippery road
• During cornering at high speed
• When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more]
• When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher]
1.SYMPTOM CHECK 1
Check that there are pedal vibrat ions when the engine is started.
Do vibrations occur?
YES >> GO TO 2
NO >> Inspect the brake pedal.
2.SYMPTOM CHECK 2
Check that there are ABS operation noises when the engine is started.
Do the operation noises occur?
YES >> GO TO 3
NO >> Perform self -diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
3.SYMPTOM CHECK 3
Check symptoms when electrical component (headlamps, etc.) switches are operated.
Do symptoms occur?
YES >> Check if there is a radio, antenna, antenna lead wire, or wiring close to the control unit. If there is,
move it farther away.
NO >> Normal
Revision: March 2010 2008 QX56

BRC-108
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VEHICLE JERKS DURING VDC/TCS/ABS CONTROL
VEHICLE JERKS DURING
VDC/TCS/ABS CONTROL
Diagnosis ProcedureINFOID:0000000001686380
1.SYMPTOM CHECK
Check if the vehicle jerks during VDC/TCS/ABS control.
Is the inspection result normal?
YES >> Normal.
NO >> GO TO 2
2.CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis of ABS actuator and electric unit (control unit). Refer to \
BRC-24, "
CONSULT-III Func-
tion (ABS)".
Are self-diagnosis results indicated?
YES >> Check corresponding items, make repairs, and perform ABS actuator and electric unit (control
unit) self-diagnosis.
NO >> GO TO 3
3.CHECK CONNECTOR
• Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector and check
terminal for deformation, disconnection, looseness, etc.
• Securely connect connectors and perform ABS actuator and electric uni t (control unit) self-diagnosis.
Are self-diagnosis results indicated?
YES >> If poor contact, damage, open or short circuit of connector terminal is found, repair or replace.
NO >> GO TO 4
4.CHECK ECM AND TCM SELF-DIAGNOSIS RESULTS
Perform ECM and TCM self-diagnosis.
Are self-diagnosis results indicated?
YES >> Check the corresponding items. • ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
• TCM: Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
NO >> Replace ABS actuator and electric unit (control unit). Refer to BRC-116, "
Removal and Installa-
tion".
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

BRC-112
< PRECAUTION >[VDC/TCS/ABS]
PRECAUTIONS
• Sudden turns (such as spin turns, acceleration turns), drifting, etc. with VDC turned off may cause the yaw
rate/side/decel G sensor to indicate a problem. This is not a problem if normal operation can be resumed
after restarting the engine.
Precaution for CAN SystemINFOID:0000000001604545
• Do not apply voltage of 7.0V or higher to terminal to be measured.
• Maximum open terminal voltage of test er in use must be less than 7.0V.
• Before checking harnesses, turn ignition sw itch OFF and disconnect battery negative cable.
• Area to be repaired must be soldered and wrapped with tape. Make sure that fraying of twisted wire is within 110 mm (4.33 in).
• Do not make a bypass connection to repaired area. (If the circuit is bypassed, characteristics of twisted wire will be lost.)
PKIA0306E
PKIA0307E
Revision: March 2010 2008 QX56

PREPARATIONBRC-113
< PREPARATION > [VDC/TCS/ABS]
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PREPARATION
PREPARATION
Special Service ToolINFOID:0000000001604546
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000001604547
Tool number
(Kent-Moore No.)
Tool name Description
KV991J0080
(J-45741)
ABS active wheel sensor tester Checking operation of ABS active wheel sen-
sors
WFIA0101E
Tool name
Description
1. Flare nut crowfoot
2. Torque wrench Removing and installing brake piping
a: 10 mm (0.39 in)/12 mm (0.47 in)
S-NT360
Revision: March 2010
2008 QX56