wiring INFINITI QX56 2004 Factory Workshop Manual

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
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D
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SECTION BRC
A
B
BRC
Revision: August 20072004 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 ............................... 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 ANGLE
SEN SIGNAL" ......................................................... 55
Inspection For Self-diagnosis Result "DECEL G
SEN SET" ............................................................... 55
VDC OFF Indicator lamp Does Not Illuminate ........ 55
Component Inspection ............................................ 56
VDC OFF SWITCH ............................................. 56

PRECAUTIONS
BRC-3
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EFS0062W
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. 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
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 EFS003QB
CAUTION:

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

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 control unit or the battery 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-25, "
BRAKE BURNISHING PROCEDURE" (front disc brake) or BR-31, "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-IIEFS003QC
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?
SBR6 86 C

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.

PRECAUTIONS
BRC-5
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 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 EF S0 03 QF
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

TROUBLE DIAGNOSIS
BRC-11
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
TROUBLE DIAGNOSISPFP:00000
How to Perform Trouble Diagnoses for Quick and Accurate RepairEFS003QQ
INTRODUCTION
The ABS/TCS/VDC system has an electronic control unit to control
major functions. The control unit accepts input signals from sensors
and controls actuator operation. It is also important to check for con-
ventional problems such as air leaks in the booster or lines, lack of
brake fluid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electrical connections or faulty wiring. In this case,
careful checking of suspicious circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the problem, so a road
test should be performed.
Before undertaking actual checks, take just a few minutes to talk with
a customer who approaches with an ABS/TCS/VDC complaint. The
customer is a very good source of information on such problems,
especially intermittent ones. Through the talks with the customer,
find out what symptoms are present and under what conditions they
occur.
Start your diagnosis by looking for “conventional” problems first. This
is one of the best ways to troubleshoot brake problems on an ABS/
TCS/VDC equipped vehicle. Also check related Service Bulletins for
information.
SEF 2 33 G
SEF 2 34 G

BRC-16
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Wiring Diagram — VDC —EFS003QT
WFWA0289E

BRC-38
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSPFP:00000
Wheel Sensor System InspectionEFS003QY
INSPECTION PROCEDURE
1. CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector E125 and wheel sensor of malfunction-
ing code.
Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.
2. CHECK WHEEL SENSOR OUTPUT SIGNAL
1. Connect ABS active wheel sensor tester (J-45741) to wheel sensor using appropriate adapter.
2. Turn on the ABS active wheel sensor tester power switch.
NOTE:
The green POWER indicator should illuminate. If the POWER indicator does not illuminate, replace the
battery in the ABS active wheel sensor tester before proceeding.
3. Spin the wheel of the vehicle by hand and observe the red SENSOR indicator on the ABS active wheel
sensor tester. The red SENSOR indicator should flash on and off to indicate an output signal.
NOTE:
If the red SENSOR indicator illuminates but does not flash, reverse the polarity of the tester leads and
retest.
Does the ABS active wheel sensor tester detect a signal?
Yes >> GO TO 3.
No >> Replace the wheel sensor. Refer to BRC-64, "
Removal and Installation" .
3. CHECK TIRES
Check for inflation pressure, wear and size of each tire.
Are tire pressure and size correct and is tire wear within specifications?
Yes >> GO TO 4.
No >> Adjust tire pressure or replace tire(s).
4. CHECK WHEEL BEARINGS
Check wheel bearing axial end play. Refer to FAX-5, "
WHEEL BEARING INSPECTION" or RAX-5, "WHEEL
BEARING INSPECTION" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace as necessary. Refer to FAX-5, "
WHEEL BEARING INSPECTION" or RAX-5,
"WHEEL BEARING INSPECTION" .
5. CHECK WIRING HARNESS FOR SHORT CIRCUIT
1. Disconnect ABS actuator and electric unit (control unit) connec-
tor and wheel sensor connector of malfunction code No.
2. Check resistance between wheel sensor harness connector ter-
minals and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair the circuit.Continuity should not exist.
WFIA0192E

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-39
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
6. CHECK WIRING HARNESS FOR OPEN CIRCUIT
1. Check continuity between ABS actuator and electric unit (control unit) harness connector E125 and the
malfunctioning wheel sensor harness connector E18, E117, C10, or C11.
OK or NG
OK >> Replace the ABS actuator and electric unit (control unit). Refer to BRC-66, "Removal and Installa-
tion" .
NG >> Repair the circuit.
Engine System InspectionEF S0 03 QZ
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
Yes >> GO TO 2.
No >> Inspection End.
2. ENGINE SYSTEM INSPECTION
1. Perform ECM self-diagnosis and repair as necessary.
2. Perform ABS actuator and electric unit (control unit) self-diagnosis again.
OK or NG
OK >> Inspection End.
NG >> Repair or replace as necessary.
Wheel sensorABS actuator and
electric unit (control unit)Wheel sensor
Continuity
Connector - terminal Wire color Connector - terminal Wire color
Front LHE125 - 45 G/O E18 - 1 G/O
Ye s E125 - 46 BR/W E18 - 2 BR/W
Front RHE125 - 34 B/R E117 - 1 B/R
E125 - 33 BR E117 - 2 BR
Rear LHE125 - 37 P C11 - DS P
E125 - 36 L C11 - DP L
Rear RHE125 - 42 V C10 - DS V
E125 - 43 G/Y C10 - DP G/Y
Continuity should exist.
Self-diagnosis results
ENGINE SIGNAL 1
ENGINE SIGNAL 2
ENGINE SIGNAL 3
ENGINE SIGNAL 4
ENGINE SIGNAL 6

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-59
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
Long Stopping DistanceEFS0044V
1. CHECK BASE BRAKING SYSTEM PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation.
NOTE:
Stopping distance may be longer than vehicles without ABS when road condition is slippery.
OK or NG
OK >> Go to BRC-57, "ABS Works Frequently" .
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
ABS Does Not WorkEFS0044W
CAUTION:
The ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or less.
1. CHECK WARNING LAMP ACTIVATION
Turn ignition switch ON and check for warning lamp activation.

Warning lamp should activate for approximately 1 second after turning the ignition switch ON.
OK or NG
OK >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NG >> Go to BRC-60, "
ABS Warning Lamp Does Not Come On When Ignition Switch Is Turned On" .
Pedal Vibration or ABS Operation NoiseEFS0044X
NOTE:
During ABS activation, pedal vibration may be felt and a noise may be heard. This is normal and does not indi-
cate a malfunction.
1. CHECK SYMPTOM
1. Apply brake.
2. Start engine.
Does the symptom occur only when engine is started?
YES >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NO >> GO TO 2.
2. RECHECK SYMPTOM
Does the symptom occur only when electrical equipment switches (such as headlamps) are turned on?
YES >> Check for radio, antenna or related wiring that is routed too close to the ABS actuator and electric
unit (control unit) and reroute as necessary.
NO >> Go to BRC-57, "
ABS Works Frequently" .

CO-2Revision: August 2007
PRECAUTIONS
2004 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EBS00I4Q
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. 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WAR NIN G:

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.