2008 INFINITI QX56 Brake booster

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

BRC-78
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1185 ICC UNIT
C1185 ICC UNIT
DescriptionINFOID:0000000001691164
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:0000000001691165
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:0000000001691166
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: March 2010 2008 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-91
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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NOTE:
• 1: Confirm tire pr essure is normal.
• 2: Only 4WD models.
• 3: On and off timing for warning lamp and indicator lamp.
- ABS warning lamp: Refer to BRC-83, "
Description".
- Brake warning lamp: Refer to BRC-84, "
Description".
- VDC OFF indicator lamp: Refer to BRC-85, "
Description".
- SLIP indicator lamp: Refer to BRC-86, "
Description".
TERMINAL LAYOUT
DELTA S SEN Value detected by delta stroke sensor When brake pedal is depressed 1.05 - 1.80 mm
When brake pedal is released
0.00 mm (+0.6/-0.4)
RELEASE SWITCH
NO Active booster signal status When brake pedal is depressed
ON
When brake pedal is released OFF
RELEASE SWITCH
NC Active booster signal status When brake pedal is depressed
OFF
When brake pedal is released ON
STP OFF RLY Stop lamp relay signal When stop lamp relay is ON
ON
When stop lamp relay is OFF OFF
PRES CTRL ACC This item is not used for this model. ——
PRES FAIL ACC This item is not used for this model. ——
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
AWFIA0032ZZ
Revision: March 2010 2008 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-101
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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C1145 YAW RATE SENSOR
BRC-40, "Description"C1146SIDE G-SEN CIRCUIT
C1155 BR FLUID LEVEL LOW BRC-64, "
Description"
C1156ST ANG SEN COM CIR BRC-67, "Description"
C1160DECEL G SEN SET BRC-68, "Description"
C1163ST ANGL SEN SAFE BRC-69, "Description"
C1164CV1
BRC-70, "
Description"C1165CV2
C1166 SV1
C1167 SV2
C1170 VARIANT CORDING BRC-37, "
DTC Logic"
C1178ABS ACTIVE BOOSTER SV NG BRC-73, "Description"
C1179ABS DELTA S SEN NG BRC-76, "Description"
C1181ABS ACTIVE BOOSTER RESPONSE NG
BRC-73, "Description"C1184ABS BRAKE RELEASE SW NG
C1185 ABS ACC CU INTERNAL NG BRC-78, "
Description"
C1189ABS BRAKE BOOSTER DEFECT BRC-73, "Description"
U1000CAN COMM CIRCUIT BRC-80, "Description"
DTCItems (CONSULT screen terms) Reference
Revision: March 2010 2008 QX56

BRC-104
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
UNEXPECTED PEDAL REACTION
UNEXPECTED PEDAL REACTION
Diagnosis ProcedureINFOID:0000000001686376
1.CHECK BRAKE PEDAL STROKE
Check brake pedal stroke. Refer to BR-15, "
Inspection and Adjustment".
Is the stroke too large?
YES >> • Bleed air from brake tube and hose. Refer to BR-17, "Bleeding Brake System".
• Check brake pedal, brake booster, and master cylinder for mount play, looseness, brake system fluid leakage, etc. Refer to BR-15, "
Inspection and Adjustment" (brake pedal), BR-12, "On
Board Inspection" (master cylinder), BR-10, "Inspection" (brake booster).
NO >> GO TO 2
2.CHECK FUNCTION
Disconnect ABS actuator and electric unit (control unit) c onnector to deactivate ABS. Check if braking force is
normal in this condition. Connect connector after inspection.
Is the inspection result normal?
YES >> Normal
NO >> Check brake system.
Revision: March 2010 2008 QX56

CCS
INTELLIGENT CRUISE CONTROL SYSTEMCCS-13
< FUNCTION DIAGNOSIS >
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INTELLIGENT CRUISE CONTROL SYSTEM
System DiagramINFOID:0000000001731809
System DescriptionINFOID:0000000001731810
• The Intelligent Cruise Control (ICC) system automatic ally maintains a selected distance from the vehicle
ahead according to that vehicle's speed, or at the set speed, if the road ahead is clear.
• The ICC function has two cruise control modes and brake assist (with preview function).
• To activate or deactivate the ICC system and set the vehicle speed and vehicle-to-vehicle distance, use the
ICC steering switch.
• The operation status of the ICC system is indicated on the ICC system display of the combination meter.
VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE
• Vehicle-to-vehicle distance control mode, the vehicle can maintain the same speed as other vehicles without
the constant need to adjust the set speed as the dr iver would with a normal cruise control system.
• The system is intended to enhance the operation of the v ehicle when following the vehicle traveling in the
same lane and direction.
• If the ICC sensor integrated unit detects a slow er moving vehicle ahead, the system will reduce speed so
that the vehicle ahead can be followed at the selected distance.
• The system automatically controls the throttle and applies the brakes (up to 25% of vehicle braking power) if necessary.
• The detection range of the sensor is approximately 390 ft (120 m) ahead.
• Refer to Owner's Manual for Intelligent Cr uise Control System operating instructions.
CONVENTIONAL (FIXED SPEED) CRUISE CONTROL MODE
• Conventional (fixed speed) cruise control mode is cruising at preset speeds.
• Refer to Owner's Manual for Intelligent Cruise Control System operating instructions.
BRAKE ASSIST (WITH PREVIEW FUNCTION)
• 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 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.
• Refer to Owner's Manual for BRAKE ASSIST (WITH PREVIEW FUNCTION) operating instructions.
WKIA1976E
Revision: March 2010 2008 QX56