2008 INFINITI QX56 brake sensor

BR-38
< DISASSEMBLY AND ASSEMBLY >
BRAKE MASTER CYLINDER
1. Apply brake fluid or rubber grease to the new grommets, then insert the new grommets into the mastercylinder assembly.
CAUTION:
Do not reuse the grommets.
2. Install the reservoir tank onto the master cylinder assembly.
3. Install the fluid level sensor on the reservoir tank.
4. Install the new front and rear pressure sensors. CAUTION:
Do not reuse the front and rear pressure sensors.
Revision: March 2010 2008 QX56

BRC-1
BRAKES
C
DE
G H
I
J
K L
M
SECTION BRC
A
B
BRC
N
O P
CONTENTS
BRAKE CONTROL SYSTEM
VDC/TCS/ABS
BASIC INSPECTION ....... .............................
4
DIAGNOSIS AND REPAIR WORKFLOW ..... .....4
Work Flow ........................................................... ......4
Diagnostic Work Sheet ..............................................7
INSPECTION AND ADJUSTMENT .....................8
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT .................................................... ......
8
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT : Description ..................................
8
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT : Special Repair Requirement .......
8
ADJUSTMENT OF STEERING ANGLE SENSOR
NEUTRAL POSITION ............................................ ......
8
ADJUSTMENT OF STEERING ANGLE SENSOR
NEUTRAL POSITION : Description ..........................
8
ADJUSTMENT OF STEERING ANGLE SENSOR
NEUTRAL POSITION : Special Repair Require-
ment ..........................................................................
8
CALIBRATION OF DECEL G SENSOR ............... ......9
CALIBRATION OF DECEL G SENSOR : Descrip-
tion ............................................................................
9
CALIBRATION OF DECEL G SENSOR : Special
Repair Requirement ..................................................
9
FUNCTION DIAGNOSIS ..............................11
VDC ................................................................ ....11
System Diagram .................................................. ....11
Hydraulic Circuit Diagram .......................................12
System Description ............................................. ....12
Component Parts Location ......................................13
Component Description ...........................................14
TCS .....................................................................15
System Diagram .................................................. ....15
System Description .................................................15
Component Parts Location .................................. ....16
Component Description ...........................................17
ABS ...................................................................18
System Diagram ......................................................18
System Description ..................................................18
Component Parts Location ......................................19
Component Description ...........................................20
EBD ...................................................................21
System Diagram ......................................................21
System Description ..................................................21
Component Parts Location ......................................22
Component Description ...........................................23
DIAGNOSIS SYSTEM [ABS ACTUATOR
AND ELECTRIC UNIT (CONTROL UNIT)] .......
24
CONSULT-III Function (ABS) ..................................24
COMPONENT DIAGNOSIS .........................29
C1101, C1102, C1103, C1104 WHEEL SEN-
SOR-1 ................................................................
29
Description ........................................................... ....29
DTC Logic ................................................................29
Diagnosis Procedure ...............................................29
Component Inspection .............................................31
Special Repair Requirement ....................................31
C1105, C1106, C1107, C1108 WHEEL SEN-
SOR-2 ................................................................
32
Description ...............................................................32
DTC Logic ................................................................32
Diagnosis Procedure ...............................................32
Component Inspection .............................................34
Special Repair Requirement ....................................34
C1109 POWER AND GROUND SYSTEM ........35
Description ...............................................................35
DTC Logic ................................................................35
Diagnosis Procedure ...............................................35
Special Repair Requirement ....................................36
Revision: March 2010 2008 QX56

BRC-2
C1110, C1170 ABS ACTUATOR AND ELEC-
TRIC UNIT (CONTROL UNIT) ...........................
37
DTC Logic ...............................................................37
Diagnosis Procedure ..............................................37
Special Repair Requirement ...................................37
C1111 ABS MOTOR, MOTOR RELAY SYS-
TEM ................................................................. ...
38
Description ........................................................... ...38
DTC Logic ...............................................................38
Diagnosis Procedure ..............................................38
Component Inspection ............................................39
Special Repair Requirement ...................................39
C1113, C1145, C1146 YAW RATE/SIDE/DE-
CEL G SENSOR ............................................. ...
40
Description ........................................................... ...40
DTC Logic ...............................................................40
Diagnosis Procedure ..............................................40
Component Inspection ............................................41
Special Repair Requirement ...................................41
C1115 WHEEL SENSOR ................................ ...43
Description ........................................................... ...43
DTC Logic ...............................................................43
Diagnosis Procedure ..............................................43
Component Inspection ............................................44
Special Repair Requirement ...................................45
C1116 STOP LAMP SWITCH ......................... ...46
Description ........................................................... ...46
DTC Logic ...............................................................46
Diagnosis Procedure ..............................................46
Special Repair Requirement ...................................47
C1120, C1122, C1124, C1126 IN ABS SOL .....48
Description ........................................................... ...48
DTC Logic ...............................................................48
Diagnosis Procedure ..............................................48
Component Inspection ............................................49
Special Repair Requirement ...................................50
C1121, C1123, C1125, C1127 OUT ABS SOL ...51
Description ........................................................... ...51
DTC Logic ...............................................................51
Diagnosis Procedure ..............................................51
Component Inspection ............................................52
Special Repair Requirement ...................................53
C1130, C1131, C1132, C1133, C1136 EN-
GINE SIGNAL ................................................. ...
54
Description ........................................................... ...54
DTC Logic ...............................................................54
Diagnosis Procedure ..............................................54
Special Repair Requirement ...................................54
C1140 ACTUATOR RLY ................................ ...56
Description ........................................................... ...56
DTC Logic ...............................................................56
Diagnosis Procedure ..............................................56
Component Inspection ......................................... ...57
Special Repair Requirement ...................................57
C1142 PRESS SENSOR ...................................58
Description ........................................................... ...58
DTC Logic ...............................................................58
Diagnosis Procedure ...............................................58
Component Inspection ............................................60
Special Repair Requirement ...................................60
C1143, C1144 STEERING ANGLE SENSOR ...61
Description ..............................................................61
DTC Logic ...............................................................61
Diagnosis Procedure ...............................................61
Component Inspection ............................................62
Special Repair Requirement ...................................62
C1155 BRAKE FLUID LEVEL SWITCH ...........64
Description ........................................................... ...64
DTC Logic ...............................................................64
Diagnosis Procedure ...............................................64
Component Inspection ............................................65
Special Repair Requirement ...................................65
C1156 ST ANG SEN COM CIR .........................67
Description ..............................................................67
DTC Logic ...............................................................67
Diagnosis Procedure ...............................................67
C1160 DECEL G SEN SET ...............................68
Description ..............................................................68
DTC Logic ...............................................................68
Diagnosis Procedure ...............................................68
C1163 ST ANGLE SEN SAFE ..........................69
Description ........................................................... ...69
DTC Logic ...............................................................69
Diagnosis Procedure ...............................................69
C1164, C1165, C1166, C1167 CV/SV SYS-
TEM ....................................................................
70
Description ........................................................... ...70
DTC Logic ...............................................................70
Diagnosis Procedure ...............................................70
Component Inspection ............................................71
Special Repair Requirement ...................................72
C1178, C1181, C1184, C1189 ABS ACTIVE
BOOSTER .........................................................
73
Description ........................................................... ...73
DTC Logic ...............................................................73
Diagnosis Procedure ...............................................73
Component Inspection ............................................74
Special Repair Requirement ...................................75
C1179 ABS DELTA S SEN NG .........................76
Description ........................................................... ...76
DTC Logic ...............................................................76
Diagnosis Procedure ...............................................76
Component Inspection ............................................77
Special Repair Requirement ...................................77
Revision: March 2010 2008 QX56

BRC-3
C
DE
G H
I
J
K L
M A
B
BRC
N
O P
C1185 ICC UNIT .................................................78
Description .......................................................... ....78
DTC Logic ...............................................................78
Diagnosis Procedure ...............................................78
Special Repair Requirement ...................................79
U1000 CAN COMM CIRCUIT .............................80
Description .......................................................... ....80
DTC Logic ...............................................................80
Diagnosis Procedure ...............................................80
Special Repair Requirement ...................................80
VDC OFF SWITCH ......................................... ....81
Description .......................................................... ....81
Component Function Check ....................................81
Diagnosis Procedure ...............................................81
Component Inspection ............................................82
ABS WARNING LAMP ................................... ....83
Description .......................................................... ....83
Component Function Check ....................................83
Diagnosis Procedure ...............................................83
BRAKE WARNING LAMP ............................. ....84
Description .......................................................... ....84
Component Function Check ....................................84
Diagnosis Procedure ...............................................84
VDC OFF INDICATOR LAMP ............................85
Description .......................................................... ....85
Component Function Check ....................................85
Diagnosis Procedure ...............................................85
SLIP INDICATOR LAMP ....................................86
Description .......................................................... ....86
Component Function Check ....................................86
Diagnosis Procedure ...............................................86
ECU DIAGNOSIS .........................................87
ABS ACTUATOR AND ELECTRIC UNIT
(CONTROL UNIT) .......................................... ....
87
Reference Value ................................................. ....87
Wiring Diagram .......................................................92
Fail-Safe ..................................................................99
DTC No. Index ......................................................100
SYMPTOM DIAGNOSIS ............................102
VDC/TCS/ABS ................................................ ..102
Symptom Table ................................................... ..102
EXCESSIVE ABS FUNCTION OPERATION
FREQUENCY ...................................................
103
Diagnosis Procedure ........................................... ..103
UNEXPECTED PEDAL REACTION ...............104
Diagnosis Procedure ........................................... ..104
THE BRAKING DISTANCE IS LONG .............105
Diagnosis Procedure .............................................105
ABS FUNCTION DOES NOT OPERATE .......106
Diagnosis Procedure .............................................106
PEDAL VIBRATION OR ABS OPERATION
SOUND OCCURS ...........................................
107
Diagnosis Procedure ........................................... ..107
VEHICLE JERKS DURING VDC/TCS/ABS
CONTROL .......................................................
108
Diagnosis Procedure .............................................108
NORMAL OPERATING CONDITION .............109
Description .............................................................109
PRECAUTION ............................................110
PRECAUTIONS ...............................................110
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
110
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .................................
110
Precaution for Brake System .................................111
Precaution for Brake Control .................................111
Precaution for CAN System ...................................112
PREPARATION .........................................113
PREPARATION ...............................................113
Special Service Tool ............................................ ..113
Commercial Service Tool ......................................113
REMOVAL AND INSTALLATION .............114
WHEEL SENSORS .........................................114
Removal and Installation ..................................... ..114
SENSOR ROTOR ............................................115
Removal and Installation .......................................115
ACTUATOR AND ELECTRIC UNIT (ASSEM-
BLY) ................................................................
116
Removal and Installation .......................................116
STEERING ANGLE SENSOR .........................118
Removal and Installation .......................................118
G SENSOR ......................................................119
Removal and Installation .......................................119
Revision: March 2010 2008 QX56

BRC-12
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
VDC
Hydraulic Circuit Diagram
INFOID:0000000005875001
System DescriptionINFOID:0000000001686240
• Vehicle Dynamics Control system detects driver ′s steering operation amount and brake pedal travel from
steering angle sensor and pressure sensors. Using information from yaw rate/side/decel G sensor and
wheel sensor, VDC judges driving condition (conditions of under steer and over steer) to improve vehicle
driving stability by controlling brake application to 4 wheels and engine output.
• During VDC operation, it inform s driver of system operation by flashing SLIP indicator lamp.
• Electrical system diagnosis by CONSULT-III is available.
WFIA0187E
Revision: March 2010 2008 QX56

VDC
BRC-13
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
Component Parts LocationINFOID:0000000001686241
1. Front wheel sensor LH E18 Front wheel sensor RH E117 2. Delta stroke sensor E114 3. Brake fluid level switch E21
4. Active booster E49 5. Front pressure sensor E31 6. Rear pressure sensor E32
7. ABS actuator and electric unit (con- trol unit) E125 8. Stop lamp switch E38
9. Combination meter M23, M24
AWFIA0713GB
Revision: March 2010 2008 QX56

BRC-14
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
VDC
Component Description
INFOID:0000000001686242
10. Yaw rate/side/decel G sensor M108 11. Rear wheel sensor LH C11 Rear wheel sensor RH C10 12. Steering angle sensor M17
13. VDC OFF switch M253 14. Stop lamp relay E12
Component parts Reference
ABS actuator and electric unit (control unit) Pump
BRC-38, "
Description"Motor
Actuator relayBRC-56, "
Description"
Solenoid valveBRC-48, "Description"
VDC switch-over valve
(CV1, CV2, SV1, SV2)BRC-70, "Description"
Wheel sensor
BRC-29, "Description"
Yaw rate/side/decel G sensorBRC-40, "Description"
Steering angle sensorBRC-61, "Description"
VDC OFF switchBRC-81, "Description"
ABS warning lampBRC-83, "Description"
Brake warning lampBRC-84, "Description"
VDC OFF indicator lampBRC-85, "Description"
SLIP indicator lampBRC-86, "Description"
Front pressure sensor
BRC-58, "Description"Rear pressure sensor
Active boosterBRC-73, "
Description"
Delta stroke sensorBRC-76, "Description"
Revision: March 2010 2008 QX56

TCS
BRC-15
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
TCS
System DiagramINFOID:0000000001691092
System DescriptionINFOID:0000000001686244
• Traction Control System is a function that electronically controls engine torque, brake fluid pressure and A/T gear position to ensure the optimum slippage ratio at drive wheels by computing wheel speed signals from 4
wheel sensors. When ABS actuator and electric unit (control unit) detects a spin at drive wheels (rear
wheels), it compares wheel speed signals from all 4 wheel s. At this time, LH and RH rear brake fluid pres-
sure are controlled, while fuel being cut to engine and throttle valve being closed to reduce engine torque by
the control unit. Further more, throttle position is continuously controlled to ensure the optimum engine
torque at all times.
• During TCS operation, it inform s driver of system operation by flashing SLIP indicator lamp.
• Electrical system diagnosis by CONSULT-III is available.
AWFIA0065GB
Revision: March 2010 2008 QX56