2009 INFINITI QX56 air condition

C1156 ST ANG SEN COM CIRBRC-67
< COMPONENT DIAGNOSIS > [VDC/TCS/ABS]
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C1156 ST ANG SEN COM CIR
DescriptionINFOID:0000000003772571
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:0000000003772572
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:0000000003772573
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: December 20092009 QX56

BRC-68
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1160 DECEL G SEN SET
C1160 DECEL G SEN SET
DescriptionINFOID:0000000003772574
The yaw rate/side/decel G sensor detects the yaw rate
/side/decel G affecting the vehicle, and transmits the
data to the ABS actuator and electric uni t (control unit) as an analog voltage signal.
DTC LogicINFOID:0000000003772575
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-68, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000003772576
INSPECTION PROCEDURE
1.PERFORM SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
Do self-diagnosis results indicate anything other than shown above?
YES >> Perform repair or replacement for the item indicated.
NO >> Perform calibration of decel G sensor. Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR :
Description". GO TO 2
2.PERFORM SELF-DIAGNOSIS AGAIN
1. Turn the ignition switch to OFF and then to ON and erase self-diagnosis results.
2. Perform ABS actuator and electric unit (control unit) self-diagnosis again.
Are any self-diagnosis results displayed?
YES >> Replace yaw rate/side/decel G sensor. Refer to BRC-119, "Removal and Installation".
NO >> Inspection End
DTC Display item Malfunction detected condition Possible cause
C1160 DECEL G SEN SET ABS decel G sensor adjustment is incomplete. • Decel G sensor calibration
• Yaw rate/side/decel G sensor
• ABS actuator and electric unit
(control unit)
Self-diagnosis results
DECEL G SEN SET
Self-diagnosis resultsDECEL G SEN SET
Revision: December 20092009 QX56

BRC-70
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1164, C1165, C1166
, C1167 CV/SV SYSTEM
C1164, C1165, C1166, C1167 CV/SV SYSTEM
DescriptionINFOID:0000000003772580
CV1, CV2 (CUT VALVE)
The cut valve shuts off the normal brake fluid path from the master cylinder, when VDC/TCS is activated.
SV1, SV2 (SUCTION VALVE)
The suction valve supplies the brake fluid from the ma ster cylinder to the pump, when VDC/TCS is activated.
DTC LogicINFOID:0000000003772581
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-70, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000003772582
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, disconnection, looseness, and so on. If any malfunction is found, re\
pair 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.
DTCDisplay item Malfunction detected condition Possible cause
C1164 CV1 VDC switch-over solenoid valve (CV1) on the primary
side is open circuit or shorted, or the control line is open
or shorted to the power supply or the ground.
• Harness or connector
• ABS actuator and electric unit (control unit)
C1165 CV2
VDC switch-over solenoid valve (CV2) on the primary
side is open circuit or shorted, or the control line is open
or shorted to the power supply or the ground.
C1166 SV1 VDC switch-over solenoid valve (SV1) on the primary
side is open circuit or shorted, or the control line is open
or shorted to the power supply or the ground.
C1167 SV2 VDC switch-over solenoid valve (SV2) on the primary
side is open circuit or shorted, or the control line is open
or shorted to the power supply or the ground.
Self-diagnosis results
CV1
CV2SV1
SV2
Revision: December 20092009 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: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-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:0000000003772588
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
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30 2
31 4
ABS actuator and electric unit (control unit) —Contin u it y
Connector Terminal
A: E125 17
Ground No
27
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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: 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]
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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: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

BRC-78
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1185 ICC UNIT
C1185 ICC UNIT
DescriptionINFOID:0000000003772595
When the force applied to brake pedal exceeds a certain level, the brake assist is activated and generates a
greater braking force than that of a convent
ional brake booster, even with light pedal force.
When the ICC preview function identifies the need to apply the sudden brake by sensing the vehicle ahead in
the same lane and the distance and relative speed from it, it applies the brake pre-pressure before driver
depresses the brake pedal and improves brake response by reducing its free play.
DTC LogicINFOID:0000000003772596
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-78, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000003772597
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
Perform self-diagnosis of ICC unit.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform ICC unit self-diagnosis again.
NO >> GO TO 2
2.CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (contro l unit) connector and the ICC unit connector and check
the terminals for deformation, disconnection, looseness or damage.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace as necessary.
3.ICC UNIT CIRCUIT INSPECTION
DTC Display item Malfunction detected condition Possible cause
C1185 ABS ACC CU INTERNAL NG ICC cont rol unit internal malfunction.• Harness or connector
• ICC unit
• ABS actuator and electric unit
(control unit)
Self-diagnosis results
ABS ACC CU INTERNAL NG
Revision: December 20092009 QX56