2005 INFINITI QX4 warning

BODY REPAIR
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Revision: October 20052005 QX56
Replacement OperationsEIS008SO
DESCRIPTION
This section is prepared for technicians who have attained a high level of skill and experience in repairing col-
lision-damaged vehicles and also use modern service tools and equipment. Persons unfamiliar with body
repair techniques should not attempt to repair collision-damaged vehicles by using this section.
Technicians are also encouraged to read Body Repair Manual (Fundamentals) in order to ensure that the orig-
inal functions and quality of the vehicle can be maintained. The Body Repair Manual (Fundamentals) contains
additional information, including cautions and warnings, that are not including in this manual. Technicians
should refer to both manuals to ensure proper repairs.
Please note that this information is prepared for worldwide usage, and as such, certain procedures may not
apply in some regions or countries.

BRAKE FLUID
BR-9
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Revision: October 20052005 QX56
BRAKE FLUIDPFP:KN100
On-board InspectionEFS004W2
LEVEL CHECK

Make sure the fluid level in reservoir tank is within the standard
(between MAX and MIN lines).

Visually check around reservoir tank for fluid leaks.

If fluid level is excessively low, check brake system for leaks.

If brake warning lamp remains illuminated after parking lever is
released, check brake system for fluid leakage.
Drain and RefillEFS004W3
CAUTION:

Refill with new brake fluid. Refer to MA-11, "RECOMMENDED FLUIDS AND LUBRICANTS" .

Do not reuse drained brake fluid.

Do not let brake fluid splash on the painted surfaces of the body. This might damage the paint, so
when splashing it, immediately wipe off the area and wash away with water.

Before servicing, disconnect actuator connector or battery negative cable.
1. Connect a vinyl tube to each bleed valve.
2. Depress brake pedal, loosen each bleed valve, and gradually
remove brake fluid.
3. Make sure there is no foreign material in reservoir tank, and refill
with new brake fluid.
4. Rest foot on brake pedal. Loosen bleed valve. Slowly depress
pedal until it stops. Tighten bleed valve. Release brake pedal.
Repeat this process a few times, then pause to add new brake
fluid to master cylinder. Continue until new brake fluid flows out.
Bleed air from brake system. Refer to BR-10, "
Bleeding Brake
System" .
LFIA0225E
SBR4 19 C
SBR9 95

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
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SECTION BRC
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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

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

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.

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.

SYSTEM DESCRIPTION
BRC-9
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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

TROUBLE DIAGNOSIS
BRC-23
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Basic InspectionEFS004XN
BRAKE FLUID LEVEL, FLUID LEAK, AND BRAKE PAD INSPECTION
1. Check fluid level in the brake fluid reservoir. If fluid level is low, add fluid.
2. Check the brake piping and around the ABS actuator and electric unit (control unit) for leaks. If there is
leaking or seeping fluid, check the following items.

If ABS actuator and electric unit (control unit) connection is loose, tighten the piping to the specified
torque and recheck for leaks.

If there is damage to the connection flare nut or ABS actuator and electric unit (control unit) threads,
replace the damaged part and recheck for leaks.

When there is fluid leaking or seeping from a fluid connection, use a clean cloth to wipe off the fluid and
recheck for leaks. If fluid is still seeping out, replace the damaged part. If the fluid is leaking at the ABS
actuator and electric unit (control unit), replace the ABS actuator and electric unit (control unit) assem-
bly.
CAUTION:
The ABS actuator and electric unit (control unit) cannot be disassembled and must be replaced
as an assembly.
3. Check the brake pads for excessive wear.
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure the battery positive cable, negative cable and ground connection are not loose. In addition, make
sure the battery is sufficiently charged.
ABS WARNING LAMP, SLIP INDICATOR LAMP AND VDC OFF INDICATOR LAMP INSPECTION
1. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp (when VDC OFF switch
is off), turn on for approximately 1 second when the ignition switch is turned ON. If they do not, check the
VDC OFF indicator lamp and the VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" . Check CAN
communications. If there are no errors with the VDC OFF switch or CAN communication system, check
combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamps turn off approximately 1 second after the ignition switch is turned ON. If the lamp
does not turn off, conduct self-diagnosis.
3. With the engine running, make sure the VDC OFF indicator lamp turns on and off when the VDC OFF
switch is turned on and off. If the indicator lamp status does not correspond to switch operation, check the
VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" .
4. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp turn off approximately 2
seconds after the engine is started. If ABS warning lamp, SLIP indicator lamp or VDC OFF indicator lamp
have not turned off 10 seconds after the engine has been started, conduct self-diagnosis of the ABS actu-
ator and electric unit (control unit).
5. After conducting the self-diagnosis, be sure to erase the error memory. Refer to BRC-28, "
CONSULT-II
Function (ABS)" .