200 INFINITI QX56 2009 Factory Service Manual

DIAGNOSIS AND REPAIR WORKFLOWBRC-7
< BASIC INSPECTION > [VDC/TCS/ABS]
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Diagnostic Work SheetINFOID:0000000003772477
SFIA3265E
Revision: December 20092009 QX56

BRC-8
< BASIC INSPECTION >[VDC/TCS/ABS]
INSPECTION AND ADJUSTMENT
INSPECTION AND ADJUSTMENT
ADDITIONAL SERVICE WHEN
REPLACING CONTROL UNIT
ADDITIONAL SERVICE WHEN REPL ACING CONTROL UNIT : Description
INFOID:0000000003772478
After replacing the ABS actuator and electric unit (control unit), perform the following procedures:
• Neutral position adjustment for the steering angle sensor
• Calibration of the decel G sensor
ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Re-
quirement
INFOID:0000000003772479
1.PERFORM THE NEUTRAL POSITION ADJUST MENT FOR THE STEERING ANGLE SENSOR
Perform the neutral position adjustm ent for the steering angle sensor.
>> Refer to BRC-8, "
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Spe-
cial Repair Requirement", GO TO 2
2.PERFORM CALIBRATION OF THE DECEL G SENSOR
Perform calibration of the decel G sensor.
>> Refer to BRC-9, "
CALIBRATION OF DECEL G SENSOR : Special Repair Requirement".
ADJUSTMENT OF STEERING ANGL E SENSOR NEUTRAL POSITION
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Description
INFOID:0000000003772480
Refer to the table below to determine if adjustment of steering angle sensor neutral position is required.
×: Required –: Not required
ADJUSTMENT OF STEERING ANGLE SENS OR NEUTRAL POSITION : Special Re-
pair Requirement
INFOID:0000000003772481
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
CAUTION:
To adjust neutral position of steering angl e sensor, make sure to use CONSULT-III
(Adjustment cannot be done without CONSULT-III)
1.ALIGN THE VEHICLE STATUS
Stop vehicle with front wheels in straight-ahead position.
Situation Adjustment of steering angle sensor neutral position
Removing/Installing ABS actuator and electric unit (control unit) —
Replacing ABS actuator and electric unit (control unit) ×
Removing/Installing steering angle sensor ×
Replacing steering angle sensor ×
Removing/Installing steering components ×
Replacing steering components ×
Removing/Installing suspension components ×
Replacing suspension components ×
Change tires to new ones —
Tire rotation —
Adjusting wheel alignment ×
Battery disconnection ×
Revision: December 20092009 QX56

INSPECTION AND ADJUSTMENTBRC-9
< BASIC INSPECTION > [VDC/TCS/ABS]
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>> GO TO 2
2.PERFORM THE NEUTRAL POSITION ADJUST MENT FOR THE STEERING ANGLE SENSOR
1. On the CONSULT-III screen, touch “WORK SUPP ORT” and “ST ANG SEN ADJUSTMENT” in order.
2. Touch “START”. CAUTION:
Do not touch steering wheel whil e adjusting steering angle sensor.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again. CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “STR ANGLE SIG” is within 0 ±2.5 °.
Is the steering angle within the specified range?
YES >> GO TO 4
NO >> Perform the neutral position adjustment fo r the steering angle sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indica ted by the self-diagnosis.
CALIBRATION OF DECEL G SENSOR
CALIBRATION OF DECEL G SENSOR : DescriptionINFOID:0000000003772482
Refer to the table below to determine if calibration of the decel G sensor is required.
×: Required –: Not required
CALIBRATION OF DECEL G SENSOR : Special Repair RequirementINFOID:0000000003772483
CALIBRATION OF DECEL G SENSOR
CAUTION:
To calibrate the decel G sensor, make sure to use CONSULT-III
Situation Calibration of decel G sensor
Removing/Insta lling ABS actuator and electr ic unit (control unit) —
Replacing ABS actuator and elec tric unit (control unit) ×
Removing/Installing steering angle sensor ×
Replacing steering angle sensor ×
Removing/Installing steering components ×
Replacing steering components ×
Removing/Installing suspension components ×
Replacing suspension components ×
Change tires to new ones —
Tire rotation —
Adjusting wheel alignment ×
Revision: December 20092009 QX56

BRC-10
< BASIC INSPECTION >[VDC/TCS/ABS]
INSPECTION AND ADJUSTMENT
(Calibration cannot be
done without CONSULT-III)
1.ALIGN THE VEHICLE STATUS
Stop vehicle with front wheels in straight-ahead position.
>> GO TO 2
2.PERFORM CALIBRATION OF DECEL G SENSOR
1. On the CONSULT-III screen, touch “WORK SUPPORT” and “DECEL G SEN CALIBRATION” in order.
2. Touch “START”.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again.
CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “DECEL G SEN” is within ± 0.08G.
Is the inspection result normal?
YES >> GO TO 4
NO >> Perform calibration of decel G sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indicated by the self-diagnosis.
Revision: December 20092009 QX56

VDC
BRC-11
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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FUNCTION DIAGNOSIS
VDC
System DiagramINFOID:0000000003772484
AWFIA0065GB
Revision: December 20092009 QX56

BRC-12
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
VDC
Hydraulic Circuit Diagram
INFOID:0000000005874974
System DescriptionINFOID:0000000003772485
• 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: December 20092009 QX56

VDC
BRC-13
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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Component Parts LocationINFOID:0000000003772486
AWFIA0066GB
Revision: December 20092009 QX56

BRC-14
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
VDC
Component Description
INFOID:0000000003772487
1. Front wheel sensor LH E18
RH E117 2. ABS actuator and electric unit (con-
trol unit) E125 3. Combination meter M23, M24
4. Rear wheel sensor LH C11
RH C10 5. Yaw rate/side/decel G sensor M108 6. Steering angle sensor M17
7. VDC OFF switch M253 8. Active booster E499. Delta stroke sensor E114
10. Brake fluid level switch E21 11. Front pressure sensor E31 12. Rear pressure sensor E32
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: December 20092009 QX56

TCS
BRC-15
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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TCS
System DiagramINFOID:0000000003772488
System DescriptionINFOID:0000000003772489
• 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: December 20092009 QX56

BRC-16
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
TCS
Component Parts Location
INFOID:0000000004187564
AWFIA0066GB
Revision: December 20092009 QX56