2004 INFINITI QX56 Body

FRONT DISC BRAKE
BR-25
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
2. Apply brake fluid to piston and piston boot, then install piston
boot in to piston groove.
CAUTION:
Do not reuse piston boot.
3. Insert into cylinder body by hand and insert piston boot piston-side lip into piston groove.
CAUTION:
Press piston evenly and vary the pressing point to prevent cylinder body inner wall from being
rubbed.
4. Install sliding pins and sliding pin boots to torque member.
CAUTION:
Trailing/upper sliding pin must be replaced at each service.
5. Install cylinder body. Tighten sliding pin bolt to the specified torque. Refer to BR-21, "
Components" .
DISC ROTOR INSPECTION
Visual Inspection
Check surface of disc rotor for uneven wear, cracks, and serious damage. If any of them is detected, replace
applicable part.
Runout Inspection
1. Using wheel nuts, fix disc rotor to wheel hub at 2 or more positions.
2. Inspect runout using a dial gauge. (Measured at 10 mm (0.39 in)
inside the disc edge.)
NOTE:
Make sure that wheel bearing axial end play is within the specifi-
cations before measuring runout. Refer to FA X -5 , "
WHEEL
BEARING INSPECTION" .
3. If runout is outside the limit, find the minimum runout point by
shifting mounting positions of disc rotor and wheel hub by one
hole.
4. If runout still out of specification, turn rotor with on-car brake
lathe.
Thickness Inspection
Using a micrometer, check thickness of disc rotor. If thickness is
either at or below the wear limit, or exceeds maximum uneven wear,
replace disc rotor.
BRAKE BURNISHING PROCEDURE
Burnish brake contact surface according to the following procedure after refinishing or replacing rotors, after
replacing pads, or if a soft pedal occurs at very low mileage.
WFIA0211E
Runout limit (on vehicle) : 0.04 mm (0.0016 in)
BRA0013D
Standard thickness : 26.0 mm (1.024 in)
Repair limit thickness : 24.5 mm (0.965 in)
Maximum uneven wear
(Measured at 8 positions): 0.015 mm (0.0006 in)
SBR0 20 B

REAR DISC BRAKE
BR-27
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
REAR DISC BRAKEPFP:44000
On-vehicle InspectionEFS003PS
PAD WEAR INSPECTION

Inspect the thickness of pad through cylinder body inspection
hole. Use a scale for inspection if necessary.
ComponentsEFS003PT
WA RN ING:
Clean dust on cylinder body and brake pad with a vacuum dust collector to minimize the hazard of air-
borne particles or other materials.Standard thickness : 12.13 mm (0.478 in)
Repair limit thickness : 1.0 mm (0.039 in)
BRA0010D
1. Union bolt 2. Brake hose 3. Copper washer
4. Cap 5. Bleed valve 6. Mounting bolt
7. Cylinder body 8. Piston seal 9. Piston
10. Piston boot 11. Knuckle slide 12. Sliding sleeve boot
13. Sliding sleeve 14. Inner pad 15. Outer pad
WFIA0422E

BR-28
REAR DISC BRAKE
Revision: August 20072004 QX56
CAUTION:

While removing cylinder body, never depress brake pedal because piston will pop out.

It is not necessary to remove bolts on torque member and brake hose except for disassembly or
replacement of cylinder body assembly. In this case, hang cylinder body with a wire so as not to
stretch brake hose.

Do not damage piston boot.

Burnish brake contact surface after refinishing or replacing rotors, after replacing pads, or it a soft
pedal occurs at very low mileage. Refer to BR-31, "
BRAKE BURNISHING PROCEDURE" .
Removal and Installation of Brake PadEFS003PU
REMOVAL
1. Remove tires from vehicle with power tool.
2. Remove mounting bolt from the top mount.
3. Swing cylinder body open, and remove pads.
INSTALLATION
1. Push piston in so that pad is firmly attached and mount cylinder body to torque member.
NOTE:
Using a disc brake piston tool (commercial service tool), makes it easier to push in the piston.
CAUTION:
By pushing in piston, brake fluid returns to master cylinder reservoir tank. Watch the level of the
surface of reservoir tank.
2. Install pads to cylinder body.
3. Install top mounting bolt and tighten to specification.
4. Check brake for drag.
5. Install tires to the vehicle. Refer to WT-6, "
Rotation"
Removal and Installation of Brake Caliper Assembly and Disc RotorEFS003PV
REMOVAL
1. Remove tires from vehicle with power tool.
2. Drain brake fluid as necessary. Refer to BR-10, "
Drain and Refill" .
NOTE:
Do not remove union bolt unless removing cylinder body from vehicle.
3. Remove mounting bolts and cylinder body.
NOTE:
Position cylinder body aside using suitable wire, as necessary.
4. Remove disc rotor.
INSTALLATION
CAUTION:

Refill with recommended brake fluid. Refer to MA-10, "RECOMMENDED FLUIDS AND LUBRI-
CANTS" .

Do not reuse drained brake fluid.
1. Install disc rotor.
2. Install cylinder body to the vehicle, and tighten mounting bolts to specification. Refer to BR-27, "
Compo-
nents" .
CAUTION:
Before installing cylinder body to the vehicle, wipe off mounting surface of cylinder body.
LFIA0211E

REAR DISC BRAKE
BR-29
C
D
E
G
H
I
J
K
L
MA
B
BR
Revision: August 20072004 QX56
3. Install brake hose to cylinder body and tighten union bolt to specification as necessary. Refer to BR-27,
"Components" .
CAUTION:

Do not reuse copper washers.

Securely attach brake hose to protrusion on cylinder body.
4. Refill with new brake fluid and bleed air as necessary. Refer to BR-11, "
Bleeding Brake System" .
5. Install tires to the vehicle. Refer to WT-6, "
Rotation"
Disassembly and Assembly of Brake Caliper AssemblyEFS003PW
DISASSEMBLY
1. Remove pads from cylinder body.
2. Remove sliding sleeve and boot from cylinder body body.
3. Place a wooden block as shown in the figure, and blow air from
union bolt mounting hole to remove piston and piston boot.
CAUTION:
Do not get your fingers caught in piston.
4. Using a flat-bladed screwdriver, remove piston seal from cylin-
der body.
CAUTION:
Be careful not to damage cylinder body inner wall.
CALIPER INSPECTION
Cylinder Body
CAUTION:

Use new brake fluid to clean. Do not use mineral oils such as gasoline or kerosene.

Check inside surface of cylinder body for score, rust wear, damage or foreign materials. If any of
the above conditions are observed, replace cylinder body.

Minor damage from rust or foreign materials may be eliminated by polishing surface with a fine
emery paper. Replace cylinder body if necessary.
Torque Member
Check for wear, cracks, and damage. If damage or deformation is present, replace the affected part.
Piston
CAUTION:

Piston sliding surface is plated, do not polish with emery paper even if rust of foreign materials
are stuck to sliding surface.

Check piston for score, rust, wear, damage or presence of foreign materials. Replace if any of the
above conditions are observed.
Sliding Pin Bolts and Sliding Pin Boots
Make sure there is no wear, damage, or cracks in sliding sleeve and sliding sleeve boots, and if there are,
replace them.
BRD0041D
PFIA0269E

BR-30
REAR DISC BRAKE
Revision: August 20072004 QX56
ASSEMBLY
CAUTION:
Do not use NISSAN Rubber Grease (KRE00 00010, KRE00 00010 01) when assembling.
1. Apply clean brake fluid to new piston seal and insert in to
groove on cylinder body.
CAUTION:
Do not reuse piston seal.
2. Apply brake fluid to piston and to piston boot, then install piston
boot in to piston groove.
CAUTION:
Do not reuse piston boot.
3. Insert into cylinder body by hand and insert piston boot piston-side lip into piston groove.
CAUTION:
Press piston evenly and vary the pressing point to prevent cylinder body inner wall from being
rubbed.
4. Install sliding boots and sleeves to cylinder body.
DISC ROTOR INSPECTION
Visual Inspection
Check surface of disc rotor for uneven wear, cracks, and serious damage. If any non-standard condition is
detected, replace applicable part.
Runout Inspection
1. Using wheel nuts, install disc rotor to wheel hub. (2 or more positions.)
2. Inspect runout using a dial gauge. [Measured at 10 mm (0.39 in)
inside disk edge.]
NOTE:
Make sure that wheel bearing axial end play is within the specifi-
cation before measuring runout. Refer to RAX-5, "
WHEEL
BEARING INSPECTION" .
3. If runout is outside the limit, find the minimum runout point by
shifting mounting positions of disc rotor and wheel hub by one
hole.
4. If runout still out of specification, turn rotor with on-car brake
lathe.
WFIA0210E
WFIA0211E
Runout limit (on vehicle) : 0.05 mm (0.0020 in)
BRA0013D

BRC-4
[VDC/TCS/ABS]
PRECAUTIONS
Revision: August 20072004 QX56

If YES, GO TO 2.

If NO, GO TO 5.
2. Is there any indication other than indications relating to CAN communication system in the self-diagnosis
results?

If YES, GO TO 3.

If NO, GO TO 4.
3. Based on self-diagnosis results unrelated to CAN communication, carry out the inspection.
4. Malfunctions may be detected in self-diagnosis depending on control units carrying out CAN communica-
tion. Therefor, erase the self-diagnosis results.
5. Diagnose CAN communication system. Refer to BRC-10, "
CAN COMMUNICATION" .
Precautions for Brake ControlEFS003QD

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 cus-
tomer (what symptoms are present under what conditions) and check for simple causes before starting
diagnosis. Besides electrical system inspection, check booster 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,
stopping 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 indica-
tor 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, rotors, calipers, etc.), components related to engine
(muffler, ECM, etc.), components related to body reinforcement (roll bar, tower bar, etc.).

Driving with broken or excessively worn suspension 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 normally, or the VDC warning lamp and the SLIP
indicator lamp may turn on. This is not a problem if normal operation can be resumed after restarting the
engine.

Sudden turns (such as spin turns, acceleration turns), drifting, etc. with VDC turned off may cause the yaw
rate/side G sensor to indicate a problem. This is not a problem if normal operation can be resumed after
restarting the engine.
Precautions for CAN SystemEFS003QE

Do not apply voltage of 7.0V or higher to terminal to be measured.

Maximum open terminal voltage of tester in use must be less than 7.0V.

Before checking harnesses, turn ignition switch OFF and disconnect battery negative cable.

BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: August 20072004 QX56
ABS FunctionEFS003QJ

The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding
obstacles.

If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.

The electrical system can be diagnosed using CONSULT-II.

During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the 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.
EBD FunctionEFS003QK

Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure
which results in reduced rear wheel slippage.

If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inoper-
ative, and the ABS warning lamp and BRAKE warning lamp are turned on.

The electrical system can be diagnosed using CONSULT-II.

During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the 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.
TCS FunctionEFS003QL

Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs
from the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure
control and engine fuel cut are activated while the throttle value is restricted to reduce the engine torque
and decrease the amount of wheel spin. In addition, the throttle opening is controlled to achieve the opti-
mum engine torque.

Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.

TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden trans-
mission shifts or when the vehicle is driven on a road with a varying surface friction coefficient.

The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionEFS003QM

In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status
(amount of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sen-
sor, wheel speed sensors, etc. and this information is used to improve vehicle stability by controlling the
braking and engine torque application to the wheels.

The SLIP indicator lamp flashes to inform the driver of VDC operation.

During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may
be heard. This is normal.

The ABS warning lamp, VDC OFF indicator 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 on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS
warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionEFS003QN
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.

BRC-44
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
3. CHECKING SOLENOID POWER AND GROUND
1. Check voltage between ABS actuator and electric unit (control
unit) harness connector E125 and body ground.
2. Check resistance between ABS actuator and electric unit (con-
trol unit) harness connector E125 and body ground.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-66, "
Removal and Installation" .
NG >> Repair the circuit.
Actuator Motor, Motor Relay, and Circuit InspectionEFS003R4
INSPECTION PROCEDURE
1. CHECKING SELF-DIAGNOSIS RESULTS
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
Yes >> GO TO 2.
No >> Inspection End.
2. CONNECTOR INSPECTION
1. Disconnect ABS actuator and electric unit (control unit) connector E125.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.ABS actuator and electric
unit (control unit)
connector E125Body
groundMeasured
value
(Approx.)
32 (B/Y) — 12V
WFIA0195E
ABS actuator and electric
unit (control unit)
connector E125Body
groundMeasured
value Ω
(Approx.)
16 (B) — 0 Ω
47 (B) — 0 Ω
WFIA0196E
Self-diagnosis results
PUMP MOTOR
ACTUATOR RLY