brake fluid INFINITI QX56 2007 Factory Manual PDF

TROUBLE DIAGNOSIS
BRC-11
< SERVICE INFORMATION >[VDC/TCS/ABS]
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TROUBLE DIAGNOSIS
How to Perform Trouble Diagnosis for Quick and Accurate RepairINFOID:0000000003532776
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 malfunctions such as air leaks in the booster or lines, lack
of brake fluid, or other malfunctions with the brake system.
It is much more difficult to diagnose a malfunction that occurs inter-
mittently rather than continuously. Most intermittent malfunctions are
caused by poor electrical connections or wiring. In this case, careful
checking of suspicious circuits may help prevent the replacement of
good parts.
A visual check only may not find the cause of the malfunction, 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, especially for inter-
mittent malfunctions. 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” malfunctions first.
This is one of the best ways to troubleshoot brake malfunctions on
an ABS/TCS/VDC equipped vehicle. Also check related Service Bul-
letins for information.
SEF233G
SEF234G

BRC-22
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Basic Inspection
INFOID:0000000003532780
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.
WFWA0320E

TROUBLE DIAGNOSIS
BRC-23
< SERVICE INFORMATION >[VDC/TCS/ABS]
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• 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-53, "
Component Inspection". Check
CAN communications. If there are no errors with the VDC OFF switch or CAN communication system,
replace combination meter. Refer to DI-5
.
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 of ABS actuator and electric unit (control unit). If no malfunctions
are detected in self-diagnosis, replace combination meter. Refer to DI-5
.
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-53, "
Component Inspection".
4. After conducting the self-diagnosis, be sure to erase the error memory. Refer to BRC-26, "
CONSULT-II
Function (ABS)".
Warning Lamp and Indicator TimingINFOID:0000000003532781
×: ON
—: OFF
Control Unit Input/Output Signal StandardINFOID:0000000003532782
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——— —
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 —××—

TROUBLE DIAGNOSIS
BRC-25
< SERVICE INFORMATION >[VDC/TCS/ABS]
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MOTOR RELAYOperation status of mo-
tor and motor relayIgnition switch ON or running
(ABS not activated)OFF
BRC-39, "
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-39, "
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
LAN-7
When VDC OFF indicator
lamp is OFFOFF
SLIP LAMPSLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ONON
LAN-7
When SLIP indicator lamp is
OFFOFF
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 in-
active (in fail-safe mode).ON
BRC-38, "
Solenoid and
VDC Change-Over Valve
System Inspection"
When actuator (solenoid) is not
active and actuator relay is ac-
tive (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-37, "
Yaw Rate/Side/
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-26
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 Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation

TROUBLE DIAGNOSIS
BRC-29
< SERVICE INFORMATION >[VDC/TCS/ABS]
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Note 1: If wheel sensor 2 for each wheel is indicated, check ABS actuator and electric unit (control unit) power supply voltage in addition
to wheel sensor circuit check.
Note 2: If multiple malfunctions are detected including CAN communication line [U1000], perform diagnosis for CAN communication line
first.
DATA MONITOR
Display Item List
CONTROLLER FAILURE
[ C 111 0 ]Internal malfunction of ABS actuator and electric unit (control
unit).BRC-35, "ABS/TCS/VDC
Control Unit Inspection"
CAN COMM CIRCUIT
[U1000]• CAN communication line is open or shorted.
• ABS actuator and electric unit (control unit) internal malfunction
• Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.LAN-7 (Note 2)
SIDE G-SEN CIRCUIT
[C1146]Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted.BRC-37, "
Yaw Rate/
Side/Decel G Sensor
System Inspection"
BR FLUID LEVEL LOW
[C1155]Brake fluid level drops or circuit between ABS actuator and elec-
tric unit (control unit) and brake fluid level switch is open or
shorted.BRC-42, "Brake Fluid
Level Switch System In-
spection"
ENGINE SIGNAL 1
[C1130]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
BRC-35, "
Engine System
Inspection"
ENGINE SIGNAL 2
[C1131]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 3
[C1132]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 4
[C1133]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ENGINE SIGNAL 6
[C1136]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunctioning.
ACTUATOR RLY
[C1140]ABS actuator relay or circuit malfunction.BRC-39, "
Actuator Mo-
tor, Motor Relay, and Cir-
cuit Inspection"
PRESS SEN CIRCUIT
[C1142]ABS pressure sensor circuit malfunction.BRC-45, "Pressure Sen-
sor System Inspection"
VARIANT CODING
[C1170]V coding is not malfunctioning.BRC-35, "ABS/TCS/VDC
Control Unit Inspection"
ABS ACTIVE BOOSTER SV NG
[C1178]Active booster solenoid is malfunctioning, or signal line of active
booster servo is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS DELTA S SEN NG
[C1179]Delta stroke sensor malfunctioning, or signal line of delta stroke
sensor is open or shorted.BRC-44, "Delta Stroke
Sensor System Inspec-
tion"
ABS ACTIVE BOOSTER RE-
SPONSE NG
[C1181]Active booster response is malfunctioning, or signal line of active
booster response is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS BRAKE RELEASE SW NG
[C1184]Brake release switch is malfunctioning, or signal line of brake re-
lease switch is open or shorted.BRC-43, "Active Booster
System Inspection"
ABS ACC CU INTERNAL NG
[C1185]ICC control unit internal malfunction.BRC-48, "ICC System In-
spection"
ABS BRAKE BOOSTER DEFECT
[C1189]Brake booster is defective or malfunctioning.BRC-43, "Active Booster
System Inspection"
Self-diagnostic item Malfunction detecting condition Check system

TROUBLE DIAGNOSIS
BRC-31
< SERVICE INFORMATION >[VDC/TCS/ABS]
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RR LH IN SOL
(ON/OFF)–××Rear LH IN ABS solenoid (ON/OFF)
status is displayed.
RR LH OUT SOL
(ON/OFF)–××Rear LH OUT ABS solenoid (ON/
OFF) status is displayed.
OFF LAMP
(ON/OFF)–××OFF Lamp (ON/OFF) status is dis-
played.
MOTOR RELAY
(ON/OFF)–××ABS motor relay signal (ON/OFF)
status is displayed.
ACTUATOR RLY
(ON/OFF)– ××ABS actuator relay signal (ON/OFF)
status is displayed.
CV1
(ON/OFF)––×Front side switch-over solenoid
valve (cut valve) (ON/OFF) status is
displayed.
CV2
(ON/OFF)––×Rear side switch-over solenoid
valve (cut-valve) (ON/OFF) status is
displayed.
SV1
(ON/OFF)––×Front side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
SV2
(ON/OFF)––×Rear side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
VDC FAIL SIG
(ON/OFF)––×VDC fail signal (ON/OFF) status is
displayed.
TCS FAIL SIG
(ON/OFF)––×TCS fail signal (ON/OFF) status is
displayed.
ABS FAIL SIG
(ON/OFF)––×ABS fail signal (ON/OFF) status is
displayed.
EBD FAIL SIG
(ON/OFF)––×EBD fail signal (ON/OFF) status is
displayed.
FLUID LEV SW
(ON/OFF)×–×Brake fluid level switch (ON/OFF)
status is displayed.
EBD SIGNAL
(ON/OFF)––×EBD operation (ON/OFF) status is
displayed.
ABS SIGNAL
(ON/OFF)––×ABS operation (ON/OFF) status is
displayed.
TCS SIGNAL
(ON/OFF)––×TCS operation (ON/OFF) status is
displayed.
VDC SIGNAL
(ON/OFF)––×VDC operation (ON/OFF) status is
displayed.
EBD WARN LAMP – –×Brake warning lamp (ON/OFF) sta-
tus is displayed.
SLCT LVR POSI×××Shift position judged by PNP switch
signal.
R POSI SIG – –×Shift position judged by PNP switch
signal.
4WD FAIL REQ – –×The state of 4WD controller is dis-
played by CAN communication sig-
nal.
2WD/4WD – –×It recognizes on software whether it
is 2WD and whether it is in 4WD
state. Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU

BRC-42
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
OK or NG
OK >> Check the battery for loose terminals, low voltage, etc. Repair as necessary.
NG >> Repair the circuit.
Brake Fluid Level Switch System InspectionINFOID:0000000003532793
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
1. Check the brake reservoir tank fluid level. If the level is low, add brake fluid.
2. Erase the self-diagnosis results and check the self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2.CONNECTOR INSPECTION
1. Disconnect the ABS actuator and electric unit (control unit) connector E125 and brake fluid level switch
connector E21.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3.CHECK THE HARNESS BETWEEN THE BRAKE FLUID LEVEL SWITCH AND THE ABS ACTUATOR AND
ELECTRIC UNIT (CONTROL UNIT)
Check the continuity between the brake fluid level switch harness connector E21 and the ABS actuator and
electric unit (control unit) harness connector E125.
OK or NG
OK >> GO TO 4.
NG >> Repair the circuit.
4.CHECK BRAKE FLUID LEVEL SWITCH
Check continuity between brake fluid level switch terminals 1 and 2.
OK or NG
OK >> Perform self-diagnosis again. If the same results appear, replace ABS actuator and electric unit
(control unit). Refer to BRC-58, "
Removal and Installation".
NG >> Replace brake fluid level switch.Ground16
— Continuity should exist.
47
Self-diagnosis results
BR FLUID LEVEL LOW
ABS actuator and electric unit
(control unit) harness connector
E125Brake fluid level switch harness
connector E21Continuity
81Yes
8GroundNo
Ground 2 Yes
Continuity should not exist.

BRC-50
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
TROUBLE DIAGNOSES FOR SYMPTOMS
ABS Works FrequentlyINFOID:0000000003532802
INSPECTION PROCEDURE
1.CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-26, "
CONSULT-II Function (ABS)".
2.CHECK WHEEL SENSORS
Check the following.
• Wheel sensor mounting for looseness
• Wheel sensors for physical damage
• Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3.CHECK FRONT AND REAR AXLES
Check wheel bearing axial end play. Refer to FAX-5, "
On-Vehicle Inspection and Service" (front) or RAX-5,
"On-Vehicle Inspection and Service" (rear).
OK or NG
OK >> GO TO 4.
NG >> Repair as necessary.
4.CHECK BRAKE FLUID PRESSURE
Check brake fluid pressure distribution.
Refer to BRC-22, "
Basic Inspection".
Is brake fluid pressure distribution normal?
YES >> Inspection End.
NO >> Perform Basic Inspection. Refer to BRC-22, "
Basic Inspection".
Unexpected Pedal ActionINFOID:0000000003532803
INSPECTION PROCEDURE
1.CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-26, "
CONSULT-II Function (ABS)".
2.CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
Is pedal stroke excessive?
YES >> Perform Basic Inspection. Refer to BRC-22, "Basic
Inspection".
NO >> GO TO 3.
SBR540A

BRC-58
< SERVICE INFORMATION >[VDC/TCS/ABS]
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
Removal and InstallationINFOID:0000000003532813
REMOVAL
1. Disconnect the negative battery terminal.
2. Remove the cowl top extension. Refer to EI-17, "
Removal and Installation" .
3. Drain the brake fluid. Refer to BR-8, "
Drain and Refill".
4. Disconnect the actuator harness from the ABS actuator and electric unit (control unit).
CAUTION:
• To remove the brake tubes, use a flare nut wrench to prevent the flare nuts and brake tubes from
being damaged.
• 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.
5. Disconnect the brake tubes.
6. Remove the three bolts and remove the ABS actuator and electric unit (control unit).
INSTALLATION
Installation is in the reverse order of removal.
NOTE:
To install, use a flare nut wrench (commercial service tool). Tighten brake tubes to specification when install-
ing. Refer to BR-10, "
Hydraulic Circuit" .
1. To left front 2. To rear right 3. To rear left
4. To front right 5. From the master cylinder secondary
side6. From the master cylinder primary
side
7. ABS actuator and electric unit (con-
trol unit)8. Harness connector
WFIA0375E

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
BRC-59
< SERVICE INFORMATION >[VDC/TCS/ABS]
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• After installation of the ABS actuator and electric unit (control unit), refill the brake system with new brake
fluid. Refer to MA-10
. Then bleed the air from the system. Refer to BR-8, "Bleeding Brake System" .
CAUTION:
• Never reuse drained brake fluid.
• Adjust the steering angle sensor. Refer to BRC-54, "
Adjustment of Steering Angle Sensor Neutral
Position" .
• Calibrate the yaw rate/side/decel G sensor. Refer to BRC-54, "
Calibration of Decel G Sensor" .