2008 INFINITI QX56 brake sensor

BRC-28
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
*: ON for 1 to 2 seconds after the touch, and then OFF
ABS MOTOR• Touch “ON” and “OFF” on screen. Make sure motor relay and actuator relay operates as shown in table
below.
BOOSTER DRIVE
• Touch “UP” and “DOWN” on the screen. Check that booster drive operates as shown in table below.
CAUTION:
Perform active test subject to the conditions below.
• Do not operate brake pedal during active test.
• Make sure the engine revo lution is over 500 rpm.
• Make sure the vehicle is not moving.
RR RH SOL
RR RH ABS SOLE-
NOID (ACT) RR RH IN SOL
OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH SOL
RR LH ABS SOLE-
NOID (ACT) RR LH IN SOL
OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
REAR SOL RR RH IN SOL
OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
Operation ONOFF
MOTOR RELAY ONOFF
ACTUATOR RLY ONON
Operation UPDOWN
STOP LAMP SW ONOFF
BST OPER SIG ONOFF
PRESS SENSOR 50 ± 5 bar 0 bar
PRESS SEN 2 50 ± 5 bar 0 bar
STP OFF RLY OFFOFF
Operation
ABS solenoid valve
ABS solenoid valve (ACT)
UP KEEP DOWN UP ACTUA-
TOR UP ACTUA-
TOR KEEP
Revision: March 2010 2008 QX56

BRC-58
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1142 PRESS SENSOR
C1142 PRESS SENSOR
DescriptionINFOID:0000000001686311
The front and rear pressure sensors convert the brake flui
d pressure to an electric signal and transmit it to the
ABS actuator and electric unit (control unit).
DTC LogicINFOID:0000000001686312
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-58, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686313
FRONT PRESSURE SENSOR INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the front pressure sensor connector E31 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.FRONT PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity betw een the ABS actuator and electric
unit (control unit) harness connector E125 (A) and front pres-
sure sensor harness connector E31 (B).
2. Measure the continuity between the ABS actuator and electric unit (control unit) harness connector E125
(A) and body ground.
DTC Display item Malfunction detected condition Possible cause
C1142 PRESS SEN CIRCUIT Pressure sensor signal line is open or shorted, or pres-
sure sensor is malfunctioning. • Harness or connector
• Pressure sensor
• ABS actuator and electric unit
(control unit)
Self-diagnosis results
PRESS SEN CIRCUIT
ABS actuator and electric unit (control unit) Front pressure sensor
Continuity
Connector Terminal Connector Terminal
A: E125 18
B: E31 3
Ye s
19 1
20 2
AWFIA0021ZZ
Revision: March 2010 2008 QX56

C1142 PRESS SENSORBRC-59
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
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.FRONT PRESSURE SENSOR INSPECTION
1. Reconnect the front pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if the status of “PRESS SENSOR” is normal.
Is the inspection result normal?
YES >> Inspection End.
NO >> Replace the front pressure sensor.
REAR PRESSURE SENSOR INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the rear pressure sensor connector E32 and ABS actuator and electric unit (control unit) con-
nector E125 and inspect the terminals for defo rmation, disconnection, looseness, or damage.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair connector.
2.REAR PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity betw een the ABS actuator and electric
unit (control unit) harness connector E125 (A) and rear pressure
sensor harness connector E32 (B).
2. Measure the continuity between t he ABS actuator and electric unit (control unit) harness connector E125
(A) and body ground.
ABS actuator and electric unit (control
unit) —Continuity
Connector Terminal
A: E125 18
Ground No
19
20
Condition PRESS SENSOR
(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
ABS actuator and electric unit (control unit) Rear pressure sensor
Continuity
Connector Terminal Connector Terminal
A: E125 21
B: E32 1
Ye s
22 3
23 2
ABS actuator and electric unit (control unit) —Con tin uit y
Connector Terminal
A: E125 21
Ground No
22
23
AWFIA0022ZZ
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

C1155 BRAKE FLUID LEVEL SWITCHBRC-65
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
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:0000000001686324
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:0000000001691158
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: March 2010
2008 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: March 2010 2008 QX56

C1178, C1181, C1184, C1189 ABS ACTIVE BOOSTER
BRC-73
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
C1178, C1181, C1184, C1189 ABS ACTIVE BOOSTER
DescriptionINFOID:0000000001686340
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:0000000001686341
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:0000000001686342
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: March 2010 2008 QX56

BRC-76
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1179 ABS DELTA S SEN NG
C1179 ABS DELTA S SEN NG
DescriptionINFOID:0000000001686345
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:0000000001686346
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:0000000001686347
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: March 2010 2008 QX56