engine INFINITI QX56 2006 Factory Service Manual

BR-6
BRAKE PEDAL
Revision: November 20092006 QX56
BRAKE PEDALPFP:46501
Inspection and Adjustment EFS0068P
INSPECTION
1. Inspect the brake pedal free height "H" from the lower dash panel using tool.
2. Adjust the height referring to the following specifications.
CAUTION:
When equipped with adjustable pedal, the pedal must be in
the forwardmost (closest to the floor) position for pedal
height measurement.
Brake Pedal Specifications
Unit: mm (in)
Tool number : — (J-46532)
WFIA0160E
Free height "H" : 182.3 - 192.3 mm (7.18 - 7.57 in)
Depressed pedal height "D" [under a force of 490 N (50 kg-f, 110 lb-f) with engine
running] : More than 90.3 mm (3.55 in)
Clearance between pedal stopper and threaded end of stop lamp switch and
ASCD switch "C
1 " or “ C2 ” : 0.74 - 1.96 mm (0.029 - 0.077 in)
Pedal play "A" : 3 - 11 mm (0.12 - 0.43 in)

BRAKE PEDALBR-7
C
DE
G H
I
J
K L
M A
B
BR
Revision: November 2009 2006 QX56
ADJUSTMENT
1. Loosen the stop lamp switch and ASCD switch by turning 45° counterclockwise.
2. Loosen lock nut on the input rod, then turn input rod to adjust the pedal to specified height. When finished adjusting, tighten lock
nut.
CAUTION:
Make sure that the screw portion of the end of input rod is
located inside the clevis.
3. With the pedal pulled up and held by hand, press the stop lamp switch and the ASCD switch in until threaded ends contact pedal
arm.
4. With the threaded ends of the stop lamp switch and ASCD switch contacting the pedal arm, turn the switches 45 ° clockwise
to lock in place.
CAUTION:
Make sure that the gap (C) between the rubber stops and
switch ends are within specification.
5. Check the pedal play. CAUTION:
Make sure that the stop lamp goes off when the pedal is
released.
6. Start the engine and check the height of the brake pedal when depressing it.Lock nut : 18.6 N·m (1.9 kg-m, 14 ft-lb)
PFIA0436E

BR-14
BRAKE PIPING AND HOSE
Revision: November 20092006 QX56
Inspection After InstallationEFS004W8
CAUTION:
If a leak is detected at the connections, retighten it or, if necessary, replace the damaged part.
1. Check brake tubes and hose connections for fluid leaks, damage, twist, deformation, contact with other
parts, and loose connections. Replace any damage parts.
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check for fluid leakage from each part.

BRAKE BOOSTERBR-17
C
DE
G H
I
J
K L
M A
B
BR
Revision: November 2009 2006 QX56
BRAKE BOOSTERPFP:47200
On-Vehicle ServiceEFS004WC
OPERATING CHECK
With engine stopped, change the vacuum to the atmospheric pres-
sure by depressing brake pedal several times. Then with brake
pedal fully depressed, start engine and when the vacuum pressure
reaches the standard, make sure the clearance between brake pedal
and floor panel decreases.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
AIRTIGHT CHECK

Run engine at idle for approximately 1 minute, and stop it after
applying vacuum to booster. Depress brake pedal normally to
change the vacuum to the atmospheric pressure. Make sure dis-
tance between brake pedal and floor panel gradually increases.

Depress brake pedal while engine is running and stop engine
with pedal depressed. The pedal stroke should not change after
holding pedal down for 30 seconds.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
BRA0037D
SBR365AA

BR-18
BRAKE BOOSTER
Revision: November 20092006 QX56
Removal and InstallationEFS004WD
REMOVAL
CAUTION:

Be careful not to deform or bend brake piping while removing and installing brake booster.

Replace clevis pin if it is damaged.

Be careful not to damage brake booster stud bolt threads. If brake booster is tilted or inclined dur-
ing installation, dash panel may damage the threads.

Attach the check valve in the correct direction.
1. Remove engine room cover with power tool. Refer to EM-12, "
Removal and Installation" .
2. Remove engine air duct assembly. Refer to EM-15, "
Removal and Installation" .
3. Remove brake piping from brake master cylinder.
4. Remove brake master cylinder. Refer to BR-15, "
Removal and Installation" .
5. Remove vacuum hose from brake booster. Refer to BR-20, "
VACUUM LINES" .
6. Disconnect active boost and delta stroke sensor harness connectors from brake booster assembly.
7. Remove brake pedal attachment snap pin and clevis pin from inside the vehicle.
8. Remove nuts on brake booster and brake pedal assembly.
9. Remove brake booster assembly from dash panel.
INSTALLATION
1. Loosen lock nut to adjust input rod length so that the length B (in the figure) satisfies the specified value.
2. After adjusting “B”, temporarily tighten lock nut and install
booster assembly to the vehicle.

Install a gaskets and spacer block between booster assembly
and the dash panel.
3. Connect brake pedal with clevis of input rod.
4. Install pedal bracket mounting nuts and tighten them to the specified torque.
5. Install brake piping from brake master cylinder to ABS actuator. Refer to BR-12, "
Hydraulic Circuit" .
1. Reservoir tank 2. Brake master cylinder 3. Gasket
4. Brake pedal 5. Lock nut 6. Spacer block
7. Brake booster 8. Active booster 9. Delta stroke sensor
BFIA0003E
Length “B” : 151 mm (5.94 in)
WFIA0382E

BRAKE BOOSTERBR-19
C
DE
G H
I
J
K L
M A
B
BR
Revision: November 2009 2006 QX56
6. Connect active boost and delta stroke sensor harness connectors to brake booster assembly.
7. Connect vacuum hose to brake booster.
8. Install master cylinder to booster assembly. Refer to BR-18, "
Removal and Installation" .
9. Adjust the height and play of brake pedal.
10. Tighten lock nut of input rod to specification.
11. Install engine air duct assembly. Refer to EM-15, "
Removal and Installation" .
12. Install engine room cover with power tool. Refer to EM-12, "
Removal and Installation" .
13. Refill with new brake fluid and bleed air. Refer to BR-11, "
Bleeding Brake System" .

BR-32
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: November 20092006 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
General SpecificationsEFS004WQ
Unit: mm (in)
Brake PedalEFS004WR
Brake BoosterEFS004WS
Check ValveEFS004WT
Front Disc BrakeEFS004WU
Front brake Brake modelCLZ31VCAD41VA
Rotor outer diameter × thickness 320 × 26 (12.60 × 1.02) 350 x 30 (13.78 x 1.181)
Pad Length × width × thickness 111 . 0
× 73.5 × 11.88 (4.73 ×
2.894 × 0.468) 151.6 x 56.5 x 12 (5.968 x
2.224 x 0.47)
Cylinder bore diameter 51 (2.01)51 (2.01)
Rear brake Brake model AD14VE
Rotor outer diameter × thickness 320 × 14 (12.60 × 0.55)
Pad Length × width × thickness 83.0 × 33.0 × 8.5 (3.268 × 1.299 × 0.335)
Cylinder bore diameter 48 (1.89)
Control valve Valve model Electric brake force distribution
Brake booster Booster model
C215T
Diaphragm diameter 215 (8.46)
Recommended brake fluid Genuine NISSAN Super Heavy Duty Brake Fluid or equivalent
Brake pedal height (from dash lower panel top surface) 182.3 − 192.3 mm (7.18 − 7.57 in)
Depressed pedal height [under a force of 490 N (50 kg-f, 110 lb-f)
with engine running] More than 90.3 mm (3.55 in)
Clearance between stopper rubber and the threaded end of stop
lamp switch 0.74
− 1.96 mm (0.029 − 0.077 in)
Pedal play 3 − 11 mm (0.12 − 0.43 in)
Output rod installation standard dimension 15.6 − 15.9 mm (0.614 − 0.626 in)
Vacuum leakage
[at vacuum of – 66.7 kPa(– 500 mmHg, – 19.69 inHg)] Within 1.3 kPa (10 mmHg, 0.39 inHg) of vacuum for 15 seconds
Brake model
CLZ31VCAD41VA
Brake pad Standard thickness (new)
11.88 mm (0.468 in)12 mm (0.47 in)
Repair limit thickness 1.0 mm (0.039 in)1.0 mm (0.039 in)
Disc rotor Standard thickness (new)
26.0 mm (1.024 in) 30.0 mm (1.181 in)
Repair limit thickness 24.5 mm (0.965 in) 28.5 mm (1.122 in)
Maximum uneven wear (measured at 8 positions) 0.015 mm (0.0006 in)
Runout limit (with it attached to the vehicle) 0.03 mm (0.001 in)

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
C
DE
G H
I
J
K L
M
SECTION
A
B
BRC
Revision: November 2009 2006 QX56VDC/TCS/ABS
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 3
Precautions for Brake System ............................. ..... 3
Precautions When Using CONSULT-II ................ ..... 3
CHECK POINTS FOR USING CONSULT-II .... ..... 3
Precautions for Brake Control ............................. ..... 4
Precautions for CAN System .............................. ..... 4
PREPARATION ...................................................... ..... 6
Special Service Tool ............................................ ..... 6
Commercial Service Tools ................................... ..... 6
SYSTEM DESCRIPTION ............................................ 7 System Components ........................................... ..... 7
ABS Function ........................................................... 8
EBD Function ...................................................... ..... 8
TCS Function ...................................................... ..... 8
VDC Function ...................................................... ..... 8
Fail-Safe Function .................................................... 8 ABS/EBD SYSTEM .......................................... ..... 9
VDC/TCS SYSTEM .......................................... ..... 9
ACTIVE BOOSTER .......................................... ..... 9
Hydraulic Circuit Diagram ................................... ..... 9
CAN COMMUNICATION ....................................... ... 10
System Description ............................................. ... 10
TROUBLE DIAGNOSIS ......................................... ....11
How to Perform Trouble Diagnoses for Quick and
Accurate Repair .................................................. .... 11
INTRODUCTION .............................................. .... 11
WORK FLOW ................................................... ... 12
CLARIFY CONCERN ....................................... ... 13
EXAMPLE OF DIAGNOSIS SHEET ................ ... 13
Component Parts and Harness Connector Location ... 14
Schematic ........................................................... ... 15
Wiring Diagram — VDC — .................................. ... 16
Basic Inspection .................................................. ... 23
BRAKE FLUID LEVEL, FLUID LEAK, AND
BRAKE PAD INSPECTION .............................. ... 23
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION ..........................
... 23
ABS WARNING LAMP, SLIP INDICATOR LAMP
AND VDC OFF INDICATOR LAMP INSPECTION ... 23
Warning Lamp and Indicator Timing .................... ... 24
Control Unit Input/Output Signal Standard .......... ... 24
REFERENCE VALUE FROM CONSULT-II ...... ... 24
CONSULT-II Function (ABS) ............................... ... 28
CONSULT-II BASIC OPERATION PROCEDURE ... 28
SELF-DIAGNOSIS ........................................... ... 29
DATA MONITOR .............................................. ... 32
ACTIVE TEST ..................................................... 35
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ..................................................................... ... 38
Wheel Sensor System Inspection ........................ ... 38
Engine System Inspection ................................... ... 39
ABS/TCS/VDC Control Unit Inspection ............... ... 40
Steering Angle Sensor System ............................ ... 40
Yaw Rate/Side/Decel G Sensor System Inspection ... 41
Solenoid and VDC Change-Over Valve System
Inspection ............................................................ ... 43
Actuator Motor, Motor Relay, and Circuit Inspection ... 44
Stop Lamp Switch System Inspection ................. ... 45
ABS/TCS/VDC Control Unit Power and Ground
Systems Inspection ............................................. ... 46
Brake Fluid Level Switch System Inspection ....... ... 47
Active Booster System Inspection ....................... ... 48
Delta Stroke Sensor System Inspection .............. ... 49
Pressure Sensor System Inspection ................... ... 51
Steering Angle Sensor Safe Mode Inspection ..... ... 53
CAN Communication System Inspection ............. ... 54
ICC System Inspection ........................................ ... 54
Inspection For Self-diagnosis Result "ST ANG SEN
SIGNAL" .............................................................. ... 55
Inspection For Self-diagnosis Result "DECEL G
SEN SET" ............................................................ ... 55
VDC OFF Indicator lamp Does Not Illuminate ..... ... 56
Component Inspection ......................................... ... 56
VDC OFF SWITCH .......................................... ... 56

BRC-4
[VDC/TCS/ABS]
PRECAUTIONS
Revision: November 20092006 QX56

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 ControlEFS004X6

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 SystemEFS004X7

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: November 20092006 QX56
ABS FunctionEFS004XC

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 FunctionEFS004XD

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 FunctionEFS004XE

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 FunctionEFS004XF

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 FunctionEFS004XG
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.