Ins INFINITI QX56 2004 Factory Service Manual

PRECAUTIONS
BRC-3
[VDC/TCS/ABS]
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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.

BRC-6
[VDC/TCS/ABS]
PREPARATION
Revision: August 20072004 QX56
PREPARATIONPFP:00002
Special Service ToolEFS003QG
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEFS003QH
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

TROUBLE DIAGNOSIS
BRC-11
[VDC/TCS/ABS]
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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

TROUBLE DIAGNOSIS
BRC-23
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Basic InspectionEFS003QU
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 2 seconds 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 2 seconds 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)" .

BRC-24
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Warning Lamp and Indicator TimingEFS003QV
X: ON
—: OFF
Control Unit Input/Output Signal StandardEFS003QW
REFERENCE VALUE FROM CONSULT-II
CAUTION:
The display shows the control unit calculation data, so a normal value might be displayed even in the
event the output circuit (harness) is open or short circuited.
ConditionABS
warning lampVDC OFF
indicator lampSLIP
indicator lampRemarks
When the ignition switch is OFF — — — —
After the ignition switch is turned
ON for approx. 1 second×××—
After the ignition switch is turned
ON for approx. 2 seconds———Lamp goes off approx. 2 seconds
after the engine is started.
When the VDC OFF switch is
pressed (VDC function OFF)—×——
ABS/TCS/VDC malfunction×××—
××—When the ABS actuator and elec-
tric unit (control unit) is malfunc-
tioning (power supply or ground
malfunction).
When the VDC is malfunctioning —××—
Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation
N POSI SIGPNP switch signal ON/
OFF conditionA/T shift position = N position ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"A/T shift position = other than
N positionsOFF
P POSI SIGPNP switch signal ON/
OFF conditionA/T shift position P position ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"A/T shift position = other than
P positionsOFF
GEAR A/T gear position1st gear 1
— 2nd gear 2
3rd gear 3
4th gear 4
5th gear 5
FR RH SENSOR
FR LH SENSOR
RR RH SENSOR
RR LH SENSORWheel speedVehicle stopped 0 [km/h (MPH)]
BRC-38, "
Wheel Sensor
System Inspection"Vehicle running (Note 1)Almost in accor-
dance with speed-
ometer display
(within ±10%)
ACCEL POS SIG Open/close condition
of throttle valve (linked
with accelerator pedal).Accelerator pedal not
depressed (ignition switch is
ON)0%
BRC-54, "
CAN Commu-
nication System Inspec-
tion"Depress accelerator pedal
(ignition switch is ON)0 to 100%
ENGINE SPEED With engine runningWith engine stopped 0 rpm
BRC-39, "
Engine System
Inspection"Engine runningAlmost in accor-
dance with
tachometer display

TROUBLE DIAGNOSIS
BRC-25
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
STR ANGLE SIGSteering angle
detected by steering
angle sensorStraight-ahead Approx. 0 deg
BRC-40, "Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW R AT E S E NYaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/sBRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running –100 to 100 d/s
SIDE G SENSORTransverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-41, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running
–16.7 to 16.7 m/s2
BATTERY VOLTBattery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON 10 to 16VBRC-46, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SWStop lamp switch oper-
ationBrake pedal depressed ONBRC-45, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SWVDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)ON
BRC-56, "
VDC OFF
SWITCH"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF)OFF
ABS WARN LAMPABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF
MOTOR RELAYOperation status of
motor and motor relayIgnition switch ON or running
(ABS not activated)OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Ignition switch ON or engine
running (ABS activated)ON
ACTUATOR RLYActuator relay opera-
tion statusVehicle stopped (Ignition
switch ON)OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Vehicle stopped (Engine run-
ning)ON
OFF LAMPVDC OFF indicator
lamp status (Note 3) When VDC OFF indicator
lamp is ONON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When VDC OFF indicator
lamp is OFFOFF
SLIP LAMPSLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ONON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When SLIP indicator lamp is
OFFOFF Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation

BRC-26
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Note 1: Confirm tire pressure is normal.
Note 2: ON/OFF timing of ABS warning lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation) and TCS/VDC function is not
activated.
Note 3: ON/OFF timing of VDC OFF indicator lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and VDC OFF switch is ON.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation.) And when VDC OFF switch is
OFF.
Note 4: SLIP indicator lamp ON/OFF timing
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and TCS/VDC function is acti-
vated while driving.FR LH IN SOL
FR LH OUT SOL
FR RH IN SOL
FR RH OUT SOL
RR RH IN SOL
RR RH OUT SOL
RR LH IN SOL
RR LH OUT SOLSolenoid valve opera-
tionActuator (solenoid) is active
(“ACTIVE TEST” with CON-
SULT-II) or actuator relay is
inactive (in fail-safe mode).ON
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
When actuator (solenoid) is
not active and actuator relay is
active (ignition switch ON).OFF
CV1
CV2
SV1
SV2VDC switch-over valve
statusWhen actuator (switch-over
valve) is active (“ACTIVE
TEST” with CONSULT-II) or
actuator relay is inactive (when
in fail-safe mode).ON
When actuator (switch-over
valve) is not active and actua-
tor relay is active (ignition
switch ON).OFF
DECEL G-SENLongitudinal accelera-
tion detected by Decel
G-SensorVehicle stopped Approx. 0 GBRC-41, "
Ya w R a te / S i d e /
Decel G Sensor System
Inspection"Vehicle running -1.7 to 1.7 G
PRESS SENSORBrake fluid pressure
detected by pressure
sensorDo not step on the Brake pedal
(When ignition switch is ON)Approx. 0 bar
—
Step on the Brake pedal
(When ignition switch is ON)-40 to 300 bar
FLUID LEV SWON/OFF status of
brake fluid level switchWhen brake fluid level switch
ONON
DI-31, "
WAR NIN G
LAMPS"When brake fluid level switch
OFF OFF
VDC SIGNAL
TCS SIGNAL
ABS SIGNAL
EBD SIGNALSignal statusVDC active
TCS active
ABS active
EBD activeON
VDC system
TCS system
ABS system
EBD system VDC not active
TCS not active
ABS not active
EBD not activeOFF
VDC FAIL SIG
TCS FAIL SIG
ABS FAIL SIG
EBD FAIL SIGFail signal statusVDC fail
TCS fail
ABS fail
EBD failON
VDC system
TCS system
ABS system
EBD system VDC normal
TCS normal
ABS normal
EBD normalOFF Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation

BRC-28
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
CONSULT-II Function (ABS)EFS003QX
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II BASIC OPERATION PROCEDURE
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the
data link connector.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II
CONVERTER, malfunctions might be detected in self-diag-
nosis depending on control unit which carries out CAN
communication.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ABS” in the “SELECT SYSTEM” screen.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link
Connector (DLC) Circuit" .
ABS diagnostic mode Description
WORK SUPPORTSupports inspection and adjustments. Commands are transmitted to the ABS actuator and electric
unit (control unit) for setting the status suitable for required operation, input/output signals are
received from the ABS actuator and electric unit (control unit) and received data is displayed.
SELF-DIAG RESULTS Displays ABS actuator and electric unit (control unit) self-diagnosis results.
DATA MONITOR Displays ABS actuator and electric unit (control unit) input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
FUNCTION TESTConducted by CONSULT-II instead of a technician to determine whether each system is "OK" or
"NG".
ECU PART NUMBER ABS actuator and electric unit (control unit) part number can be read.
BBIA0369E
BCIA0029E
BCIA0030E

TROUBLE DIAGNOSIS
BRC-29
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Revision: August 20072004 QX56
6. Select the required diagnostic location from the “SELECT DIAG
MODE” screen.
For further information, see the CONSULT-II Operation Manual.
SELF-DIAGNOSIS
Description
If an error is detected in the system, the ABS warning lamp will turn on. In this case, perform self-diagnosis as
follows:
Operation Procedure
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the data link connector.
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.
3. Turn ignition switch ON.
4. Start engine and drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute.
5. After stopping the vehicle, with the engine running, touch “START (NISSAN BASED VHCL)”, “ABS”,
“SELF-DIAG RESULTS” in order on the CONSULT-II screen.
CAUTION:
If “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning on
the ignition switch, “ABS” might not be displayed in the Select System screen. In this case, repeat
the operation from step 1.
6. The self-diagnostic results are displayed. (If necessary, the self-diagnostic results can be printed out by
touching “PRINT”.)

When “NO DTC IS DETECTED” is displayed, check the ABS warning lamp, SLIP indicator lamp and
VDC OFF indicator lamp.
7. Conduct the appropriate inspection from the display item list, and repair or replace the malfunctioning
component.
8. Start engine and drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute.
CAUTION:

When a wheel sensor “short-circuit” is detected, if the vehicle is not driven at 30 km/h (19 MPH)
for at least 1 minute, the ABS warning lamp will not turn off even if the malfunction is repaired.
9. Turn ignition switch OFF to prepare for erasing the memory.
10. Start the engine and touch “START (NISSAN BASED VHCL)”, “ABS”, “SELF-DIAG RESULTS”, “ERASE”
in order on the CONSULT-II screen to erase the error memory.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
If the error memory is not erased, re-conduct the operation from step 5.
11. For the final inspection, drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute and
confirm that the ABS warning lamp, SLIP indicator lamp, and VDC OFF indicator lamp are off.
BCIA0031E