2008 INFINITI QX56 brake fluid

ABS
BRC-19
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
Component Parts LocationINFOID:0000000001691095
1. Front wheel sensor LH E18 Front wheel sensor RH E117 2. Delta stroke sensor E114 3. Brake fluid level switch E21
4. Active booster E49 5. Front pressure sensor E31 6. Rear pressure sensor E32
7. ABS actuator and electric unit (con- trol unit) E125 8. Stop lamp switch E38
9. Combination meter M23, M24
AWFIA0713GB
Revision: March 2010 2008 QX56

EBD
BRC-21
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
EBD
System DiagramINFOID:0000000001691096
System DescriptionINFOID:0000000001686252
• Electric Brake force Distribution is a following functi on. ABS actuator and electric unit (control unit) detects
subtle slippages between the front and rear wheels during braking. Then it electronically controls the rear
braking force (brake fluid pressure) to reduce rear wheel slippage. Accordingly, it improves vehicle stability.
• Electrical system diagnosis by CONSULT-III is available.
AWFIA0014GB
Revision: March 2010 2008 QX56

BRC-22
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
EBD
Component Parts Location
INFOID:0000000001691097
1. Front wheel sensor LH E18 Front wheel sensor RH E117 2. Delta stroke sensor E114
3. Brake fluid level switch E21
4. Active booster E49 5. Front pressure sensor E316. Rear pressure sensor E32
7. ABS actuator and el ectric unit (con-
trol unit) E125 8. Stop lamp switch E38
9. Combination meter M23, M24
AWFIA0713GB
Revision: March 2010 2008 QX56

BRC-24
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
CONSULT-III Function (ABS)INFOID:0000000001686255
FUNCTION
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
SELF-DIAG RESULTS MODE
Operation Procedure
1. Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for
approximately 1 minute.
How to Erase Self-d iagnosis Results
1. After erasing DTC memory, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately
1 minute as the final inspection, and make sure that the ABS warning lamp, VDC OFF indicator lamp,
SLIP indicator lamp and brake warning lamp turn OFF.
CAUTION:
If memory cannot be erased, pe rform applicable diagnosis.
NOTE:
• When the wheel sensor malfunctions, after inspecting the wheel sensor system, the ABS warning lamp,
VDC OFF indicator lamp, SLIP indicator lamp and brake warning lamp will not turn OFF even when the
system is normal unless the vehicle is driving at approximately 30 km/h (19 MPH) or more for approxi-
mately 1 minute.
• Brake warning lamp will turn ON in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient).
• VDC OFF switch should not stay “ON” position.
Display Item List
Refer to BRC-100, "DTC No. Index".
DATA MONITOR MODE
Display Item List
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following
the indications on CONSULT-III.
Self-diagnostic results Self-diagnostic results can be read and erased quickly.
Data monitor Input/Output data in the ABS actuator and electric unit (control unit) can be read.
Active test Diagnostic test mode is which CONSULT-III drives some actuators apart from the ABS actuator
and electric unit (control unit) and also shifts some parameters in a specified range.
ECU part number ABS actuator and electric unit (control unit) part number can be read.
CAN diagnostic support monitor The results of transmit/receive diagnosis of CAN communication can be read.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
GEAR ××× Gear position judged by transmis-
sion range switch signal is dis-
played.
FR RH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front RH
wheel sensor signal is displayed.
FR LH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH) ×××
Wheel speed calculated by rear RH
wheel sensor signal is displayed.
Revision: March 2010
2008 QX56

BRC-26
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
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) (O
N/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 transmis-
sion range switch signal.
R POSI SIG ––×Shift position judged by transmis-
sion range switch signal.
2WD/4WD ––×It recognizes on software whether it
is 2WD and whether it is in 4WD
state.
BST OPER SIG ––×Active booster operation (ON/OFF)
st
atus is
di

splayed.
PRESS SENSOR ×– ×Brake pressure detected by pres-
sure sensor is displayed.
CRANKING SIG ––×The input state of the key SW
START position signal is displayed.
PRESS SEN 2 ––×Brake pressure detected by pres-
sure sensor is displayed.
DELTA S SEN ––×The amount of stroke sensor move-
ments in the active booster detected
by DELTA S SEN is displayed.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
Revision: March 2010 2008 QX56

BRC-38
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1111 ABS MOTOR, MOTOR RELAY SYSTEM
C1111 ABS MOTOR, MOTOR RELAY SYSTEM
DescriptionINFOID:0000000001686273
PUMP
The pump returns the brake fluid stored in the reservoi
r to the master cylinder by reducing the pressure.
MOTOR
The motor drives the pump according to the signals trans mitted by the ABS actuator and electric unit (control
unit).
DTC LogicINFOID:0000000001686274
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK SELF-DIAGNOSIS RESULTS
Check the self-diagnosis results.
Is above displayed on the self-diagnosis display?
YES >> Proceed to diagnosis procedure. Refer to BRC-38, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686275
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect ABS actuator and electric unit (control unit) connector.
3. Check terminal for deformation, disconnect, looseness, and so on. If any malfunction is found, repair or
replace terminal.
4. Reconnect connectors and then perform the self-diagnosis. Refer to BRC-24, "
CONSULT-III Function
(ABS)".
Is any item indicated on the self-diagnosis display?
YES >> GO TO 2
NO >> Poor connection of connector term inal. Repair or replace connector.
2.CHECK ABS MOTOR AND MOTOR RELAY POWER SUPPLY CIRCUIT
DTCDisplay item Malfunction detected condition Possible cause
C 1111 P U M P M O T O R During the actuator motor operating with ON, when the
actuator motor turns OFF, or when the control line for ac-
tuator motor relay is open.
• Harness or connector
• ABS actuator and electric unit
(control unit)
During the actuator motor operating with OFF, when the
actuator motor turns ON, or when the control line for relay
is shorted to ground.
Self-diagnosis results
PUMP MOTOR
Revision: March 2010 2008 QX56

BRC-60
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1142 PRESS SENSOR
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace harness or connector.
3.REAR PRESSURE SENSOR INSPECTION
1. Reconnect the rear pressure sensor and ABS act uator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if t he status of “PRESS SEN2” is normal.
Is the inspection result normal?
YES >> Inspection End.
NO >> Replace the rear pressure sensor.
Component InspectionINFOID:0000000001686314
1.CHECK DATA MONITOR
On “DATA MONITOR”, select “PRESS SENSOR” and “PRESS SEN2” and check the brake fluid pressure.
Is the inspection result normal?
YES >> Inspection End
NO >> Go to diagnosis procedure. Refer to BRC-58, "
Diagnosis Procedure".
Special Repair RequirementINFOID:0000000001691156
1.ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Always perform neutral position adjustment for the st eering angle sensor when replacing the ABS actuator
and electric unit (control unit). Refer to BRC-8, "
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL
POSITION : Description".
>> GO TO 2
2.CALIBRATION OF DECEL G SENSOR
Always perform calibration of decel G sensor when replac ing the ABS actuator and electric unit (control unit).
Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR : Description".
>> END
Condition PRESS SEN2
(DATA MONITOR)
With ignition switch turned ON and brake pedal released. Approx. 0 bar
With ignition switch turned ON and brake pedal depressed. Positive value
Condition PRESS SENSOR
and PRESS SEN2
(DATA MONITOR)
With ignition switch turned ON and brake pedal released. Approx. 0 bar
With ignition switch turned ON and brake pedal depressed. Positive value
Revision: March 2010 2008 QX56

BRC-64
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1155 BRAKE FLUID LEVEL SWITCH
C1155 BRAKE FLUID LEVEL SWITCH
DescriptionINFOID:0000000001686321
The brake fluid level switch converts the brake fluid level to an electric signal and transmits it to the ABS actu-
ator and electric unit (control unit).
DTC LogicINFOID:0000000001686322
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK SELF-DIAGNOSIS RESULTS
Check the self-diagnosis results.
Is above displayed on the self-diagnosis display?
YES >> Proceed to diagnosis procedure. Refer to BRC-64, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686323
INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Disconnect ABS actuator and electric unit (control unit) connector E125 and brake fluid level switch con- nector E21.
2. Check the terminals for deformati on, disconnection, looseness or damage.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair or replace as necessary.
2.CHECK HARNESS BETWEEN BRAKE FLUID LEVE L SWITCH AND ABS ACTUATOR AND ELECTRIC
UNIT (CONTROL UNIT)
1. Check continuity between ABS actuator and electric unit (control
unit) harness connector E125 (A) and brake fluid level switch
harness connector E21 (B).
2. Check continuity between ABS ac tuator and electric unit (control
unit) harness connector E125 (A) and ground.
Is the inspection result normal?
DTC Display item Malfunction detected condition Possible cause
C1155 BR FLUID LEVEL LOW Brake fluid level is low or communication line between
the ABS actuator and electric unit (control unit) and brake
fluid level switch is open or shorted. • Harness or connector
• Brake fluid level switch
•Brake fluid level
Self-diagnosis results
BR FLUID LEVEL LOW
ABS actuator and electric unit (control unit) Brake fluid level switch
Continuity
Connector Terminal Connector Terminal
A: E125 8B: E21 1Yes
ABS actuator and electric unit (control unit) —Continuity
Connector Terminal
A: E125 8Ground No
AWFIA0025ZZ
Revision: March 2010 2008 QX56