2008 INFINITI QX56 brake

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

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

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

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

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

BRC-114
< REMOVAL AND INSTALLATION >[VDC/TCS/ABS]
WHEEL SENSORS
REMOVAL AND INSTALLATION
WHEEL SENSORS
Removal and InstallationINFOID:0000000001604548
REMOVAL
1. Remove wheel sensor bolt.
• When removing the front wheel sensor, first remove t he disc rotor to gain access to the front wheel sen-
sor bolt. Refer to BR-31, "
Removal and Installation of Brake Caliper and Rotor" .
• When removing the rear wheel sensor, first remove the rear hub and bearing assembly to gain access to
the rear wheel sensor bolt. Refer to RAX-8, "
Removal and Installation".
2. Pull out the sensor, being careful to turn it as little as possible. CAUTION:
• Do not pull on the sensor harness.
3. Disconnect wheel sensor harness electrical connec tor, then remove harness from attaching points.
INSTALLATION
Installation is in the reverse order of removal. Tighten wheel sensor bolt to specification.
CAUTION:
• Inspect wheel sensor O-ring, replace sensor assembly if damaged.
• Before installing wheel sensor, make sure no foreign materials (such as iron fragments) are adhered
to the pick-up part of the sensor, to the inside of the sensor hole or on the rotor mating surface.
• Apply a coat of suitable grease to the wheel sensor O-ring and hole. Refer to MA-12, "
Fluids and
Lubricants" .
WFIA0376E
Revision: March 2010 2008 QX56

BRC-116
< REMOVAL AND INSTALLATION >[VDC/TCS/ABS]
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
Removal and InstallationINFOID:0000000001604550
REMOVAL
1. Disconnect the negative battery terminal.
2. Remove the air duct and resonator assembly and air cleaner case. Refer to
EM-25, "
Removal and Instal-
lation".
3. Drain the brake fluid. Refer to BR-17, "
Drain and Refill" .
4. Disconnect the actuator harness from the ABS actuator and electric unit (control unit).
5. Disconnect the brake tubes. CAUTION:
• To remove the brake tubes, use a flare nut wrench to prevent the flare nuts and brake tubes from
being damaged.
• Be careful not to splash brake fluid on painted areas.
6. Remove the three bolts and remove the ABS actuator and electric unit (control unit).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
To install, use a flare nut wr ench (commercial service tool).
1. To rear left caliper
13 N·m (1.3 kg-m, 10 ft-lb) 2. To rear right caliper
13 N·m (1.3 kg-m, 10 ft-lb) 3. To front left caliper
13 N·m (1.3 kg-m, 10 ft-lb)
4. To front right caliper 13 N·m (1.3 kg-m, 10 ft-lb) 5. From the master cylinder secondary side
18.2 N·m (1.9 kg-m, 13 ft-lb) 6. From the master cylinder primary side
18.2 N·m (1.9 kg-m, 13 ft-lb)
7. ABS actuator and electric unit (control unit) 8. Actuator harness connector
WFIA0375E
Revision: March 2010
2008 QX56

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)BRC-117
< REMOVAL AND INSTALLATION > [VDC/TCS/ABS]
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• Always tighten brake tubes to specifi cation when installing. Refer to BR-21, "Hydraulic Circuit" .
• Never reuse drained brake fluid.
• After installation of the ABS actuator and elect ric unit (control unit), perform the following.
- Refill brake system with new br ake fluid. Then bleed the air from the system. Refer to BR-17, "
Bleed-
ing Brake System" .
- Adjust the steering angle sensor. Refer to BRC-8, "
ADJUSTMENT OF STEERING ANGLE SENSOR
NEUTRAL POSITION : Speci al Repair Requirement" .
- Calibrate the decel G sensor. Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR : Special Repair
Requirement" .
Revision: March 2010 2008 QX56