2008 INFINITI QX56 E125

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

C1156 ST ANG SEN COM CIRBRC-67
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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C1156 ST ANG SEN COM CIR
DescriptionINFOID:0000000001686326
The steering angle sensor is connected to the ABS actuat or and electric unit (control unit) in addition to CAN
lines. CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle
multiplex communication line with high data communication speed and excellent error detection ability. Many
electronic control units are equipped onto a vehicle, and each control unit shares information and links with
other control units during operation (not independent). In CAN communication, control units are connected
with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less
wiring. Each control unit transmits/receives data but selectively reads required data only.
DTC LogicINFOID:0000000001686327
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-67, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686328
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn ignition switch OFF and disconnect ABS actuat or and electric unit (control unit) connector E125,
check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or
replace terminal.
2. Reconnect connector and perform self-diagnosis.
Is above displayed on the self-diagnosis display?
YES >> Refer to LAN-14, "Trouble Diagnosis Flow Chart".
NO >> Inspection End
DTC Display item Malfunction detected condition Possible cause
C1156 ST ANG SEN COM CIR When steering angle sensor is not transmitting CAN
communication signal to th
e ABS actuator and electric
unit (control unit). • Harness or connector
• CAN communication line
• Steering angle sensor
• ABS actuator and electric unit
(control unit)
Self-diagnosis results
ST ANG SEN COM CIR
Self-diagnosis results
CAN COMM CIRCUIT
ST ANG SEN COM CIR
Revision: March 2010 2008 QX56

C1164, C1165, C1166, C1167 CV/SV SYSTEM
BRC-71
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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2.CHECK SOLENOID, VDC SWITCH-OVER VALVE A ND ACTUATOR RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ABS actuator and electric unit (control unit) connec- tor.
3. Check voltage between ABS actuator and electric unit (control unit) harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace malfunctioning components.
3.CHECK SOLENOID, VDC SWITCH-OVER VA LVE AND ACUATOR RELAY GROUND CIRCUIT
Check continuity between ABS act uator and electric unit (control
unit) harness connector terminals and ground.
Is the inspection result normal?
YES >> Replace ABS actuator and electric unit (control unit). Refer to BRC-116, "
Removal and Installation".
NO >> Repair or replace malfunctioning components.
Component InspectionINFOID:0000000001691160
1.CHECK ACTIVE TEST
1. Select each test menu item on ”ACTIVE TEST“.
2. On the display, touch “UP”, “KEEP”, and “DOWN”, and check that the system operates as shown in the
table below.
*: ON for 1 to 2 seconds after the touch, and then OFF
ABS actuator and electric unit (control unit)
—Volt a ge
Connector Terminal
E125 32Ground Battery voltage
AWFIA0018ZZ
ABS actuator and electric unit (control unit)
—Contin u it y
Connector Terminal
E125 16, 47GroundYes
AWFIA0016ZZ
Operation ABS solenoid valve
ABS solenoid valve (ACT)
UP KEEP DOWN UP ACTUA-
TOR UP ACTUA-
TOR KEEP
FR RH SOL
FR RH ABS SOLE-
NOID (ACT) FR RH IN SOL
OFF ON ON OFF OFF OFF
FR RH OUT SOL OFF OFF ON* OFF OFF OFF
FR LH SOL
FR LH ABS SOLE-
NOID (ACT) FR LH IN SOL
OFF ON ON OFF OFF OFF
FR LH OUT SOL OFF OFF ON* OFF OFF OFF
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
Revision: March 2010 2008 QX56

C1178, C1181, C1184, C1189 ABS ACTIVE BOOSTER
BRC-73
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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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-74
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1178, C1181, C1184, C1
189 ABS ACTIVE BOOSTER
1. Measure the continuity between ABS actuator and electric unit
(control unit) harness connector E125 (A) and active booster
harness connector E49 (B).
2. Measure the continuity between ABS actuator and el ectric unit (control unit) harness connector E125 (A)
and body ground.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace harness or connector.
3.ACTIVE BOOSTER INSPECTION
1. Reconnect the active booster and ABS actuator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if the status of “RELEASE SWITCH NO” and “RELEASE SWITCH NC” is
normal.
Is the inspection result normal?
YES >> Replace the ABS actuator and electric unit (control unit). Refer to BRC-116, "Removal and Instal-
lation".
NO >> Replace the active booster. Refer to BR-26, "
Removal and Installation".
Component InspectionINFOID:0000000001686343
1.CHECK DATA MONITOR
Use “DATA MONITOR” to check if the status of “RELEASE SWITCH NO” and “RELEASE SWITCH NC” is nor-
mal.
ABS actuator and electric unit (control unit) Active booster
Continuity
Connector Terminal Connector Terminal
A: E125 17
B: E49 3
Ye s
27
1
28 5
30 2
31 4
ABS actuator and electric unit (control unit) —Contin u it y
Connector Terminal
A: E125 17
Ground No
27
28
30
31
AWFIA0028ZZ
Condition
RELEASE SWITCH NO
(DATA MONITOR) RELEASE SWITCH NC
(DATA MONITOR)
When brake pedal is depressed. ONOFF
When brake pedal is released. OFFON
ConditionRELEASE SWITCH NO
(DATA MONITOR) RELEASE SWITCH NC
(DATA MONITOR)
When brake pedal is depressed. ONOFF
When brake pedal is released. OFFON
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

C1179 ABS DELTA S SEN NGBRC-77
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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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:0000000001686348
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:0000000001691163
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: March 2010 2008 QX56

C1185 ICC UNITBRC-79
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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1. Measure the continuity between ABS actuator and electric unit
(control unit) connector E125 and ICC unit connector B13.
2. Measure the continuity between ABS actuator and electric unit
(control unit) connector E125 and body ground.
Is the inspection result normal?
YES >> Replace ABS actuator and electric unit (control unit). Refer to BRC-116, "Removal and Installa-
tion".
NO >> Repair or replace harness or connector.
Special Repair RequirementINFOID:0000000001691167
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".
>> 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) ICC unit
Continuity
Connector Terminal Connector Terminal
A: E125 7B: B13 10Yes
ABS actuator and electric unit (control unit) —Con tin uit y
Connector Terminal
A: E125 7Ground No
AWFIA0067ZZ
Revision: March 2010 2008 QX56