Page 569 of 4083
![INFINITI QX56 2008 Factory Service Manual BRC-102
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VDC/TCS/ABS
SYMPTOM DIAGNOSIS
VDC/TCS/ABS
Symptom TableINFOID:0000000001686374
If ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn ON, p INFINITI QX56 2008 Factory Service Manual BRC-102
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VDC/TCS/ABS
SYMPTOM DIAGNOSIS
VDC/TCS/ABS
Symptom TableINFOID:0000000001686374
If ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn ON, p](/manual-img/42/57030/w960_57030-568.png)
BRC-102
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VDC/TCS/ABS
SYMPTOM DIAGNOSIS
VDC/TCS/ABS
Symptom TableINFOID:0000000001686374
If ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn ON, perform self-diagnosis.
NOTE:
• 1: The ABS does not operate when the speed is 10 km/h (6 MPH) or less.
• 2: Under the following conditions, ABS is activated and vibration is felt when brake pedal is lightly depressed. However, this
is normal.
- When shifting gears
- When driving on slippery road
- During cornering at high speed
- When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more]
- When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher] Symptom
Check itemReference
Excessive ABS function operation fre-
quency Brake force distribution
BRC-103, "
Diag-
nosis Procedure"Looseness of front and rear axle
Wheel sensor and rotor system
Unexpected pedal reaction Brake pedal stroke
BRC-104, "
Diag-
nosis Procedure"Make sure the braking force is sufficient when the ABS is not operating.
The braking distance is long Check stopping distance when the ABS is not operating. BRC-105, "
Diag-
nosis Procedure"
ABS function does not operate (Note 1) ABS actuator and electric
unit (control unit)BRC-106, "Diag-
nosis Procedure"
Pedal vibration or ABS operation sound
occurs (Note 2)Brake pedal
BRC-107, "Diag-
nosis Procedure"ABS actuator and electric unit (control unit)
Vehicle jerks during VDC/TCS/ABS con-
trol ABS actuator and electric unit (control unit)
BRC-108, "
Diag-
nosis Procedure"TCM
ECM
Revision: March 2010 2008 QX56
Page 570 of 4083
![INFINITI QX56 2008 Factory Service Manual EXCESSIVE ABS FUNCTION OPERATION FREQUENCYBRC-103
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
EXCESSIVE ABS FUNCTION OPERATION FREQUENCY
Diagnosis ProcedureINFOID:0000000001 INFINITI QX56 2008 Factory Service Manual EXCESSIVE ABS FUNCTION OPERATION FREQUENCYBRC-103
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
EXCESSIVE ABS FUNCTION OPERATION FREQUENCY
Diagnosis ProcedureINFOID:0000000001](/manual-img/42/57030/w960_57030-569.png)
EXCESSIVE ABS FUNCTION OPERATION FREQUENCYBRC-103
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
EXCESSIVE ABS FUNCTION OPERATION FREQUENCY
Diagnosis ProcedureINFOID:0000000001686375
1.CHECK START
Check front and rear brake force di stribution using a brake tester.
Is the inspection result normal?
YES >> GO TO 2
NO >> Check brake system.
2.CHECK FRONT AND REAR AXLE
Make sure that there is no excessive play in the front and rear axles. Refer to front: FAX-6, "
On-Vehicle
Inspection and Service", Rear: RAX-6, "On-Vehicle Inspection and Service".
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair or replace malfunctioning components.
3.CHECK WHEEL SENSOR AND SENSOR ROTOR
Check the following.
• Wheel sensor installation for damage.
• Sensor rotor installation for damage.
• Wheel sensor connector connection.
• Wheel sensor harness inspection.
Is the inspection result normal?
YES >> GO TO 4
NO >> • Replace wheel sensor or sensor rotor. Refer to BRC-114, "
Removal and Installation".
• Repair harness.
4.CHECK ABS WARNING LAMP DISPLAY
Make sure that the ABS warning lamp is turned off af ter the ignition switch is turned ON or when driving.
Is the ABS warning lamp illuminated?
YES >> Perform self-diagnosis. Refer to BRC-24, "CONSULT-III Function (ABS)".
NO >> Normal
Revision: March 2010 2008 QX56
Page 571 of 4083
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
Page 572 of 4083
THE BRAKING DISTANCE IS LONGBRC-105
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
THE BRAKING DISTANCE IS LONG
Diagnosis ProcedureINFOID:0000000001686377
CAUTION:
The stopping distance on slippery road surfaces might be longer with the ABS operating than when
the ABS is not operating.
1.CHECK FUNCTION
Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector to deactivate
ABS. In this condition, check stopping di stance. After inspection, connect connector.
Is the inspection result normal?
YES >> Normal
NO >> Check brake system.
Revision: March 2010 2008 QX56
Page 573 of 4083
BRC-106
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
ABS FUNCTION DOES NOT OPERATE
ABS FUNCTION DOES NOT OPERATE
Diagnosis ProcedureINFOID:0000000001686378
CAUTION:
ABS does not operate when speed
is 10 km/h (6 MPH) or lower.
1.CHECK ABS WARNING LAMP DISPLAY
Make sure that the ABS warning lamp turns OFF af ter ignition switch is turned ON or when driving.
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
Revision: March 2010 2008 QX56
Page 574 of 4083
![INFINITI QX56 2008 Factory Service Manual PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
BRC-107
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
Diagnosis ProcedureINFOID:000 INFINITI QX56 2008 Factory Service Manual PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
BRC-107
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
Diagnosis ProcedureINFOID:000](/manual-img/42/57030/w960_57030-573.png)
PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
BRC-107
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
PEDAL VIBRATION OR ABS OPERATION SOUND OCCURS
Diagnosis ProcedureINFOID:0000000001686379
CAUTION:
Under the following conditions, ABS is activated an d vibration is felt when brake pedal is lightly
depressed. However, this is normal.
• When shifting gears
• When driving on slippery road
• During cornering at high speed
• When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more]
• When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher]
1.SYMPTOM CHECK 1
Check that there are pedal vibrat ions when the engine is started.
Do vibrations occur?
YES >> GO TO 2
NO >> Inspect the brake pedal.
2.SYMPTOM CHECK 2
Check that there are ABS operation noises when the engine is started.
Do the operation noises occur?
YES >> GO TO 3
NO >> Perform self -diagnosis. Refer to BRC-24, "
CONSULT-III Function (ABS)".
3.SYMPTOM CHECK 3
Check symptoms when electrical component (headlamps, etc.) switches are operated.
Do symptoms occur?
YES >> Check if there is a radio, antenna, antenna lead wire, or wiring close to the control unit. If there is,
move it farther away.
NO >> Normal
Revision: March 2010 2008 QX56
Page 575 of 4083
![INFINITI QX56 2008 Factory Service Manual BRC-108
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VEHICLE JERKS DURING VDC/TCS/ABS CONTROL
VEHICLE JERKS DURING
VDC/TCS/ABS CONTROL
Diagnosis ProcedureINFOID:0000000001686380
1.SYMPTOM CHECK
Check if the ve INFINITI QX56 2008 Factory Service Manual BRC-108
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VEHICLE JERKS DURING VDC/TCS/ABS CONTROL
VEHICLE JERKS DURING
VDC/TCS/ABS CONTROL
Diagnosis ProcedureINFOID:0000000001686380
1.SYMPTOM CHECK
Check if the ve](/manual-img/42/57030/w960_57030-574.png)
BRC-108
< SYMPTOM DIAGNOSIS >[VDC/TCS/ABS]
VEHICLE JERKS DURING VDC/TCS/ABS CONTROL
VEHICLE JERKS DURING
VDC/TCS/ABS CONTROL
Diagnosis ProcedureINFOID:0000000001686380
1.SYMPTOM CHECK
Check if the vehicle jerks during VDC/TCS/ABS control.
Is the inspection result normal?
YES >> Normal.
NO >> GO TO 2
2.CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis of ABS actuator and electric unit (control unit). Refer to \
BRC-24, "
CONSULT-III Func-
tion (ABS)".
Are self-diagnosis results indicated?
YES >> Check corresponding items, make repairs, and perform ABS actuator and electric unit (control
unit) self-diagnosis.
NO >> GO TO 3
3.CHECK CONNECTOR
• Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector and check
terminal for deformation, disconnection, looseness, etc.
• Securely connect connectors and perform ABS actuator and electric uni t (control unit) self-diagnosis.
Are self-diagnosis results indicated?
YES >> If poor contact, damage, open or short circuit of connector terminal is found, repair or replace.
NO >> GO TO 4
4.CHECK ECM AND TCM SELF-DIAGNOSIS RESULTS
Perform ECM and TCM self-diagnosis.
Are self-diagnosis results indicated?
YES >> Check the corresponding items. • ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
• TCM: Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
NO >> Replace ABS actuator and electric unit (control unit). Refer to BRC-116, "
Removal and Installa-
tion".
Revision: March 2010 2008 QX56
Page 576 of 4083
![INFINITI QX56 2008 Factory Service Manual NORMAL OPERATING CONDITIONBRC-109
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001686381
Symptom Result
Slight vibrations a INFINITI QX56 2008 Factory Service Manual NORMAL OPERATING CONDITIONBRC-109
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001686381
Symptom Result
Slight vibrations a](/manual-img/42/57030/w960_57030-575.png)
NORMAL OPERATING CONDITIONBRC-109
< SYMPTOM DIAGNOSIS > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000001686381
Symptom Result
Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC, TCS or ABS is acti-
vated. This is a normal condi-
tion due to the VDC,
TCS or ABS activation.
Stopping distance is longer than that of vehicles without ABS when the vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
The brake pedal moves and generates noises, when TCS or VDC is activated due to rapid acceleration or
sharp turn.
The brake pedal vibrates and motor operation noises occur from the engine room, after the engine starts and
just after the vehicle starts. This is normal, and it is
caused by the ABS op-
eration check.
Depending on the road conditions, the driver may experience a sluggish feel. This is normal, because
TCS places the highest
priority on the optimum
traction (stability).
TCS may activate momentarily if wheel speed changes when driving over location where friction coefficient
varies, when downshifting, or when fully depressing accelerator pedal.
The ABS warning lamp, VDC OFF indicato
r lamp and SLIP indicator lamp may turn ON when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is rotating on a turntable or located on
a ship while the engine is running. In this case, restart the
engine on a normal
road. If the normal con-
dition is restored, there
is no malfunction. At
that time, erase the self-
diagnosis memory.
VDC may not operate normally or the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp
may illuminate, when running on a special road that is extremely slanted (e.g. bank in a circuit course).
A malfunction may occur in the yaw rate/side/decel G sensor system, when the vehicle turns sharply, such
as during a spin turn, axle turn, or drift driving, while the VDC function is off (VDC OFF indicator lamp illumi-
nated).
The vehicle speed will not increase even though the accelerator pedal is depressed, when inspecting the
speedometer on a 2-wheel chassis dynamometer.
Normal (Deactivate the
VDC/TCS function be-
fore performing an in-
spection on a chassis
dynamometer.)
VDC OFF indicator lamp and SLIP indicator lamp may simultaneously turn on when low tire pressure warn-
ing lamp turns on. This is not a VDC sys-
tem error but results
from characteristic
change of tire.
Revision: March 2010
2008 QX56