INFINITI QX4 2005 Factory Service Manual
Page 1011 of 3419
BR-32
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: October 20052005 QX56
Rear Disc BrakeEFS004WV
Brake modelAD14VE
Brake padStandard thickness (new) 12.13 mm (0.478 in)
Repair limit thickness 1.0 mm (0.039 in)
Disc rotorStandard thickness (new) 14.0 mm (0.551 in)
Repair limit thickness 12.0 mm (0.472 in)
Maximum uneven wear (measured at 8 positions) 0.015 mm (0.0006 in)
Runout limit (with it attached to the vehicle) 0.05 mm (0.0020 in)
Page 1012 of 3419
BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
C
D
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G
H
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J
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M
SECTION BRC
A
B
BRC
Revision: October 20052005 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
Wiring Diagrams and Trouble Diagnosis .................. 5
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 ................................. 23POWER 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 ..................................................... 36
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 ............................... 41
Yaw Rate/Side/Decel G Sensor System Inspection ... 42
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 Sensor System Inspection ......... 47
Active Booster System Inspection .......................... 49
Delta Stroke Sensor System Inspection ................. 50
Pressure Sensor System Inspection ...................... 51
Steering Angle Sensor Safe Mode Inspection ........ 54
CAN Communication System Inspection ................ 55
Inspection For Self-diagnosis Result "ST ANGLE
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
Page 1013 of 3419
BRC-2Revision: October 20052005 QX56 TROUBLE DIAGNOSES FOR SYMPTOMS ............. 57
ABS Works Frequently ........................................... 57
Unexpected Pedal Action ....................................... 58
Long Stopping Distance .......................................... 59
ABS Does Not Work ............................................... 59
Pedal Vibration or ABS Operation Noise ................ 59
ABS Warning Lamp Does Not Come On When Igni-
tion Switch Is Turned On ........................................ 60
ABS Warning Lamp Stays On When Ignition Switch
Is Turned On ........................................................... 60
Vehicle Jerks During TCS/VDC Activation .............. 61
ON-VEHICLE SERVICE ............................................ 62
Adjustment of Steering Angle Sensor Neutral Posi-
tion .......................................................................... 62
Calibration of Decel G Sensor ................................ 62WHEEL SENSORS ...................................................64
Removal and Installation .........................................64
REMOVAL ............................................................64
INSTALLATION ....................................................64
SENSOR ROTOR ......................................................65
Removal and Installation .........................................65
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY) ... 66
Removal and Installation .........................................66
REMOVAL ............................................................66
INSTALLATION ....................................................67
STEERING ANGLE SENSOR ...................................68
Removal and Installation .........................................68
G SENSOR ................................................................69
Removal and Installation .........................................69
REMOVAL ............................................................69
INSTALLATION ....................................................69
Page 1014 of 3419
PRECAUTIONS
BRC-3
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: October 20052005 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EFS004X3
The Supplemental Restraint System such as “AIR 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. Information necessary to service the system safely is included in the SRS and SB section of
this Service Manual.
WA RN ING:
To avoid rendering the SRS inoperative, 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 per-
formed by an authorized NISSAN/INFINITI dealer.
Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for Brake System EFS004X4
CAUTION:
Refer to MA-11, "RECOMMENDED FLUIDS AND LUBRICANTS" for recommended brake fluid.
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 cylinder and disc brake caliper, use clean brake fluid.
Never use mineral oils such as gasoline or kerosene. They will ruin rubber parts of the hydraulic
system.
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 (control unit) or the bat-
tery terminal before performing the work.
Always torque brake lines when installing.
Burnish the brake contact surfaces after refinishing or
replacing rotors, after replacing pads, or if a soft pedal
occurs at very low mileage.
Refer to BR-24, "
BRAKE BURNISHING PROCEDURE" (front disc brake) or BR-30, "BRAKE BUR-
NISHING PROCEDURE" (rear disc brake).
WA RN ING:
Clean brake pads and shoes with a waste cloth, then wipe with a dust collector.
Precautions When Using CONSULT-IIEFS004X5
When connecting CONSULT-II to data link connector, connect them through CONSULT-II CONVERTER.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
CHECK POINTS FOR USING CONSULT-II
1. Has CONSULT-II been used without connecting CONSULT-II CONVERTER on this vehicle?
If YES, GO TO 2.
If NO, GO TO 5.
SBR6 86 C
Page 1015 of 3419
BRC-4
[VDC/TCS/ABS]
PRECAUTIONS
Revision: October 20052005 QX56
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.
Page 1016 of 3419
PRECAUTIONS
BRC-5
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: October 20052005 QX56
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.)
Wiring Diagrams and Trouble Diagnosis EFS004X8
When you read wiring diagrams, refer to the following:
GI-15, "How to Read Wiring Diagrams".
PG-4, "POWER SUPPLY ROUTING CIRCUIT".
When you perform trouble diagnosis, refer to the following:
GI-11, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES".
GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident".
PKIA0306E
PKIA0307E
Page 1017 of 3419
BRC-6
[VDC/TCS/ABS]
PREPARATION
Revision: October 20052005 QX56
PREPARATIONPFP:00002
Special Service ToolEFS005G1
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEFS005G2
Tool number
(Kent-Moore No.)
Tool nameDescription
(J-45741)
ABS active wheel sensor testerChecking operation of ABS active wheel sen-
sors
WFIA0101E
Tool nameDescription
1. Flare nut crowfoot
2. Torque wrenchRemoving and installing brake piping
a: 10mm (0.39 in)/12mm (0.47 in)
S-NT360
Page 1018 of 3419
SYSTEM DESCRIPTION
BRC-7
[VDC/TCS/ABS]
C
D
E
G
H
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K
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MA
B
BRC
Revision: October 20052005 QX56
SYSTEM DESCRIPTIONPFP:00000
System ComponentsEFS004XB
WFIA0468E
Page 1019 of 3419
BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: October 20052005 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.
Page 1020 of 3419
SYSTEM DESCRIPTION
BRC-9
[VDC/TCS/ABS]
C
D
E
G
H
I
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K
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MA
B
BRC
Revision: October 20052005 QX56
ABS/EBD SYSTEM
In case of an electrical malfunction with the ABS, the ABS warning lamp, VDC OFF indicator lamp and SLIP
indicator lamp will turn on. In case of an electrical malfunction with the EBD system, the BRAKE warning lamp,
ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp will turn on.
The system will revert to one of the following conditions of the Fail-Safe function.
1. For ABS malfunction, only the EBD is operative and the condition of the vehicle is the same condition of
vehicles without ABS/TCS/VDC system.
2. For EBD malfunction, the EBD and ABS become inoperative, and the condition of the vehicle is the same
as the condition of vehicles without ABS/TCS/VDC or EBD system.
VDC/TCS SYSTEM
In case of TCS/VDC system malfunction, the VDC OFF indicator lamp and SLIP indicator lamp are turned on
and the condition of the vehicle is the same as the condition of vehicles without TCS/VDC system. In case of
an electrical malfunction with the TCS/VDC system, the ABS control continues to operate normally without
TCS/VDC control.
ACTIVE BOOSTER
The active brake booster consists of a vacuum booster, an active booster control group and a delta stroke
sensor. In case of brake booster system malfunction due to loss of vacuum, the delta stroke sensor will signal
the ABS actuator and electric unit (control unit) that a booster failure has occurred. The active booster then
applies supplemental force to the master cylinder relative to the amount of force exerted on the brake pedal.
Hydraulic Circuit DiagramEFS004XH
WFIA0187E