2009 INFINITI QX56 brake sensor

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:0000000003772559
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:0000000003772560
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: December 20092009 QX56

C1155 BRAKE FLUID LEVEL SWITCHBRC-65
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
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J
K L
M A
B
BRC
N
O P
YES >> GO TO 3
NO >> Repair or replace malfunctioning components.
3.CHECK BRAKE FLUID LEVEL SWITCH GROUND
Check continuity between brake fluid level switch harness connector
E21 and ground.
Is the inspection result normal?
YES >> GO TO 4
NO >> Repair or replace malfunctioning components.
4.CHECK BRAKE FLUID LEVEL SWITCH
Check continuity between brake fluid level switch terminals.
Is the inspection result normal?
YES >> Perform self-diagnosis again. If the same results appear, replace ABS actuator and electric unit (control unit). Refer to BRC-116, "
Removal and
Installation".
NO >> Replace brake fluid level switch.
Component InspectionINFOID:0000000003772569
1.CHECK BRAKE FLUID LEVEL SWITCH
1. Turn ignition switch OFF.
2. Disconnect brake fluid level switch connector.
3. Check continuity between brake fluid level switch terminals.
Is the inspection result normal?
YES >> Inspection End
NO >> Replace brake fluid level switch.
Special Repair RequirementINFOID:0000000003772570
1.ADJUSTMENT OF STEERING AN GLE 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".
Brake fluid level switch
—Continuity
Connector Terminal
E21 2Ground Yes
AWFIA0026ZZ
Brake fluid level switch
ConditionContinuity
Te r m i n a l
1 − 2 When brake fluid is full in the reser-
voir tank.
No
When brake fluid is empty in the
reservoir tank. Ye s
ALFIA0026ZZ
Brake fluid level switch
ConditionContinuity
Te r m i n a l
1 − 2 When brake fluid is full in the reser-
voir tank.
No
When brake fluid is empty in the
reservoir tank. Ye s
ALFIA0026ZZ
Revision: December 20092009 QX56

BRC-66
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1155 BRAKE FLUID LEVEL SWITCH
>> 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
Revision: December 20092009 QX56

C1178, C1181, C1184, C1189 ABS ACTIVE BOOSTER
BRC-73
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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M A
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BRC
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C1178, C1181, C1184, C1189 ABS ACTIVE BOOSTER
DescriptionINFOID:0000000003772585
The active brake booster consists of a vacuum boos ter, an active booster control group and a delta stroke
sensor. If a brake booster system malfunction occurs due to loss of vacuum, the delta stroke sensor will signal
the ABS actuator and electric unit (control unit) that a booster malfunction has occurred. The active booster
then applies supplemental force to the master cylinder re lative to the amount of force exerted on the brake
pedal.
DTC LogicINFOID:0000000003772586
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-73, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000003772587
INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the active booster connector E49 and ABS ac tuator and electric unit (control unit) connector
E125 and inspect the terminals for deforma tion, disconnection, looseness, or damage.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair connector.
2.ACTIVE BOOSTER CIRCUIT INSPECTION
DTC Display item Malfunction detected condition Possible cause
C1178 ABS ACTIVE BOOSTER SV
NG Active booster solenoid is malfunctioning, or signal line of
active booster servo is open or shorted.
• Harness or connector
• Active booster
• ABS actuator and electric unit (control unit)
C1181
ABS ACTIVE BOOSTER RE-
SPONSE NG Active booster response is malfunctioning, or signal line
of active booster response is open or shorted.
C1184 ABS BRAKE RELEASE SW
NG Brake release switch is malfunctioning, or signal line of
brake release switch is open or shorted.
C1189 ABS BRAKE BOOSTER DE-
FECT Brake booster is defective or malfunctioning.
Self-diagnosis results
ABS ACTIVE BOOSTER SV NG
ABS ACTIVE BOOSTER RESPONSE NG ABS BRAKE RELEASE SW NG
ABS BRAKE BOOSTER DEFECT
Revision: December 20092009 QX56

BRC-76
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1179 ABS DELTA S SEN NG
C1179 ABS DELTA S SEN NG
DescriptionINFOID:0000000003772590
The active brake booster consists of a vacuum booster, an active booster control group and a delta stroke
sensor. If a brake booster system malfunction occurs due
to loss of vacuum, the delta stroke sensor will signal
the ABS actuator and electric unit (c ontrol unit) that a booster malfunction has occurred. The active booster
then applies supplemental force to the master cylinder re lative to the amount of force exerted on the brake
pedal.
DTC LogicINFOID:0000000003772591
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-76, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000003772592
INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the delta stroke sensor connector E114 and ABS actuator and electric unit (control unit) con- nector E125 and inspect the terminals for def ormation, disconnection, looseness, or damage.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair connector.
2.DELTA STROKE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between ABS actuator and electric unit (control unit) harness connector E125 (A) and delta stroke sen-
sor harness connector E114 (B).
2. Measure the continuity between ABS actuator and el ectric unit (control unit) harness connector E125 (A)
and body ground.
DTC Display item Malfunction detected condition Possible cause
C1179 ABS DELTA S SEN NG Delta stroke sensor is malfunctioning, or signal line of
delta stroke sensor is open or shorted. • Harness or connector
• Delta stroke sensor
• ABS actuator and electric unit
(control unit)
Self-diagnosis results
ABS DELTA S SEN NG
ABS actuator and electric unit (control unit) Delta stroke sensor
Continuity
Connector Terminal Connector Terminal
A: E125 26
B: E114 1
Ye s
39 3
40 5
AWFIA0029ZZ
Revision: December 20092009 QX56

C1179 ABS DELTA S SEN NGBRC-77
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
C
D
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G H
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J
K L
M A
B
BRC
N
O P
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace harness or connector.
3.DELTA STROKE SENSOR INSPECTION
1. Reconnect the delta stroke sensor and ABS act uator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if the status of “DELTA S SEN” is normal.
Is the inspection result normal?
YES >> Replace the ABS actuator and elec tric unit (control unit). Refer to BRC-116, "Removal and Instal-
lation".
NO >> Replace the delta stroke sensor.
Component InspectionINFOID:0000000003772593
1.CHECK DATA MONITOR
Use “DATA MONITOR” to check if the status of “DELTA S SEN” is normal.
Is the inspection result normal?
YES >> Inspection End
NO >> Go to diagnosis procedure. Refer to BRC-76, "
Diagnosis Procedure".
Special Repair RequirementINFOID:0000000003772594
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 replacing the ABS actuator and electric unit (control unit).
Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR : Description".
>> END
ABS actuator and electric unit (control unit) —Continuity
Connector Terminal
A: E125 26
Ground No
39
40
Condition DELTA S SEN
(DATA MONITOR)
When brake pedal is depressed. 1.05–1.80 mm
When brake pedal is released. 0.00 mm (+0.6/-0.4)
ConditionDELTA S SEN
(DATA MONITOR)
When brake pedal is depressed. 1.05–1.80 mm
When brake pedal is released. 0.00 mm (+0.6/-0.4)
Revision: December 20092009 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-87
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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BRC
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ECU DIAGNOSIS
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Reference ValueINFOID:0000000003772619
VALUES ON THE DIAGNOSIS TOOL
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.
CONSULT-III MONITOR ITEM
Monitor item Display content Data monitor
Condition Reference value in
normal operation
FR LH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
FR RH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
RR LH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
RR RH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
STOP LAMP SW Stop lamp switch signal status When brake pedal is depressed
ON
When brake pedal is released OFF
BATTERY VOLT Battery voltage supplied
to the ABS actuator
and electric unit (control unit) Ignition switch ON
10 – 16 V
GEAR Gear position determined by TCM 1st gear
2nd gear
3rd gear
4th gear
5th gear 1
2
3
4
5
SLCT LVR POSI A/T selector lever position P position
R position
N position
D positionP
R
N
D
OFF SW VDC OFF switch ON/OFF VDC OFF switch ON
(When VDC OFF indicator lamp is ON)
ON
VDC OFF switch OFF
(When VDC OFF indicator lamp is OFF) OFF
YAW RATE SEN Yaw rate detected by yaw rate/side/decel G
sensor When vehicle is stopped
Approx. 0 d/s
When vehicle turning −75 to 75 d/s
ACCEL POS SIG Throttle actuator opening/closing is dis-
played (linked with accelerator pedal) Accelerator pedal not depressed (ignition
switch is ON)
0 %
Accelerator pedal depressed (ignition
switch is ON) 0 - 100 %
Revision: December 20092009 QX56

BRC-88
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
SIDE G-SENSOR Transverse G detected by side G sensorVehicle stopped
Approx. 0 m/s
2
Vehicle turning rightNegative value
(m/s2)
Vehicle turning left Positive value
(m/s
2)
STR ANGLE SIG Steering angle detected by steering angle
sensor Straight-ahead
Approx. 0°
Steering wheel turned –720 to 720°
PRESS SENSOR Brake fluid pressure detected by front pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
ENGINE SPEED With engine running With engine stopped
0 rpm
Engine running Almost in accor-
dance with tachome-
ter display
FLUID LEV SW Brake fluid level switch signal status When brake fluid level switch ON
ON
When brake fluid level switch OFF OFF
FR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR RH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: December 20092009 QX56