2011 INFINITI QX56 Eco

BRC-126
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
VDC OFF INDICATOR LAMP
VDC OFF INDICATOR LAMP
Component Function CheckINFOID:0000000006222655
1.CHECK VDC OFF INDICATO
R LAMP FUNCTION (1)
Check that VDC OFF indicator lamp in combination me ter turns ON for approx. 1 second after ignition switch
is turned ON.
CAUTION:
Never start engine.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Proceed to diagnosis procedure. Refer to BRC-126, "
Diagnosis Procedure"
2.CHECK VDC WARNING LAMP FUNCTION (2)
Check that VDC OFF indicator lamp in combination meter turns ON/OFF when VDC OFF switch is operated.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Check VDC OFF switch system. Refer to BRC-119, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006222656
1.CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) POWER SUPPLY AND GROUND CIR-
CUIT
Perform the trouble diagnosis for ABS actuator and elec tric unit (control unit) power supply and ground circuit.
Refer to BRC-113, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK VDC OFF INDICATOR LAMP SIGNAL (1)
With CONSULT-III.
1. Select “ABS”, “DATA MONITOR” and “OFF LAMP” according to this order.
2. Turn the ignition switch OFF.
3. Check that data monitor displays “On” for approx. 1 second after ignition switch is turned ON and then
changes to “Off”.
CAUTION:
Never start engine.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace ABS actuator and electric unit (control unit). Refer to BRC-137, "
Removal and Installa-
tion".
3.CHECK VDC OFF INDICATOR LAMP SIGNAL (2)
With CONSULT-III.
1. Select “ABS”, “DATA MONITOR” and “OFF LAMP” according to this order.
2. Check that data monitor displays “On” or “Off” each time when VDC OFF switch is operated.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Check VDC OFF switch system. Refer to BRC-119, "
Diagnosis Procedure".
4.CHECK COMBINATION METER
Check combination meter. Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Repair or replace combination meter. Refer to MWI-85, "
Removal and Installation".
Revision: 2010 May2011 QX56

EXCESSIVE OPERATION FREQUENCYBRC-127
< SYMPTOM DIAGNOSIS > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
SYMPTOM DIAGNOSIS
EXCESSIVE OPERATION FREQUENCY
DescriptionINFOID:0000000006222657
VDC function, TCS function, ABS functi on, EBD function, hill start assist function and brake limited slip differ-
ential (BLSD) function operates in excessive operation frequency.
Diagnosis ProcedureINFOID:0000000006222658
1.CHECK BRAKING FORCE
Check brake force using a brake tester.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Check brake system.
2.CHECK FRONT AND REAR AXLE
Check that there is no excessive looseness in front and rear axle.
 Front axle: Refer to FA X - 7 , "
Inspection" (2WD), FAX-16, "Inspection" (4WD).
 Rear axle: Refer to RAX-5, "
Inspection"
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK WHEEL SENSOR
Check wheel sensor.
 Check installation and damage of wheel sensor.
 Check connection of wheel sensor harness connector.
 Check terminal of wheel sensor harness connector.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace wheel sensor.  Front wheel sensor: Refer to BRC-134, "
FRONT WHEEL SENSOR : Removal and Installation".
 Rear wheel sensor: Refer to BRC-135, "
REAR WHEEL SENSOR : Removal and Installation".
4.CHECK WARNING LAMP TURNS OFF
Check that ABS warning lamp, brake warning lamp and VDC warning lamp turn OFF approx. 1 second after
key switch is turned ON and stay in OFF status during driving.
CAUTION:
Brake warning lamp turns ON when parking brake is operated (parking brake switch is ON) or brake
fluid is less than the specified level (brake fluid level switch is ON).
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis for “ABS” with CONSULT-III.
Revision: 2010 May2011 QX56

THE BRAKING DISTANCE IS LONGBRC-129
< SYMPTOM DIAGNOSIS > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
THE BRAKING DISTANCE IS LONG
DescriptionINFOID:0000000006222661
Brake stopping distance is long when ABS function is operated.
Diagnosis ProcedureINFOID:0000000006222662
CAUTION:
Brake stopping distance on slippery road like roug h road, gravel road or snowy road may become
longer when ABS is operated than when ABS is not operated.
1.CHECK BRAKING FORCE
Check brake force using a brake tester.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Check each component s of brake system.
2.CHECK BRAKE PERFORMANCE
Disconnect ABS actuator and electric unit (control unit) connector so that ABS does not operate. Check brake
stopping distance in this condition. Connect harness connectors after checking.
Is the inspection result normal?
YES >> Normal
NO >> Check each component s of brake system.
Revision: 2010 May2011 QX56

BRC-130
< SYMPTOM DIAGNOSIS >[WITH VDC]
DOES NOT OPERATE
DOES NOT OPERATE
DescriptionINFOID:0000000006222663
VDC function, TCS function, ABS functi
on, EBD function, hill start assist function and brake limited slip differ-
ential (BLSD) function does not operate.
Diagnosis ProcedureINFOID:0000000006222664
CAUTION:
 VDC function, ABS function and EBD function never operate when the vehicle speed is 10 km/h (6.2
MPH) or less.
 TCS function, hill start assist fu nction and brake limited slip diffe rential (BLSD) function operates
when the vehicle speed is 0 km/h (0 MPH) (the vehicle is in stop status).
 VDC function and TCS function never operate wh en VDC OFF switch is operated (when VDC OFF
indicator lamp turns ON).
1.CHECK ABS WARNING LAMP
Check that ABS warning lamp, brake warning lamp and VDC warning lamp turn ON and turn OFF approx. 1
second after key switch is turned ON. Check that ABS warning lamp, brake warning lamp and VDC warning
lamp and stay in OFF status during driving.
CAUTION:
Brake warning lamp turns ON when parking brake is operated (parking brake switch is ON) or brake
fluid is less than the specified level (brake fluid level switch is ON).
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis for “ABS” with CONSULT-III.
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-133
< SYMPTOM DIAGNOSIS > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006222669
Symptom Result
Brake pedal slightly vibrates and operation sound (motor sound and sound from suspen-
sion) occurs when VDC function, TCS function, ABS function, EBD function, hill start assist
function and brake limited slip differential (BLSD) function operates. This is not a malfunction, The symptom
occurs VDC function
, TCS function, ABS
function, EBD function, hill start assist
function and brake limited slip differential
(BLSD) function that are normally operat-
ed.
Brake stopping distance may become longer than models without ABS function depending
on the road conditions, when
ABS function is operated on slip pery road like rough road,
gravel road or snowy road.
Brake pedal vibrates and operation sound occurs during sudden acceleration and corner-
ing, when VDC function, TCS function, hill start assist function and brake limited slip differ-
ential (BLSD) function is operated.
Brake pedal vibrates and motor sound from the engine room occurs, when the engine starts
or the vehicle starts just after starting the engine This is not a malfunction. The symptom
occurs during the brake fluid accumula-
tion in the accumulator and operational
check of the ABS actuator and electric
unit (control unit).
Acceleration may be felt insufficient depending on the road conditions. This is not a malfunction. The symptom occurs TCS function that puts the highest
priority to obtain the optimum traction
(stability).
TCS may operate momentarily, while driving on a road where friction coefficient varies, or
when downshifting or fully depressing accelerator pedal
ABS warning lamp and VDC warning lamp may turn ON, when the vehicle is on a rotating
turntable or is given a strong shaking or large vibrations on a ship while the engine is run-
ning.
In this case, restart the engine on a nor-
mal road. If the normal condition is re-
stored, there is no malfunction. In that
case, erase self-diagnosis result memory
for “ABS” with CONSULT-III.
VDC warning lamp may turn ON and VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function may not normally operate, when driving
on a special road the is extremely slanted (bank in a circuit course).
A malfunction in yaw rate/side/decel G sensor system may be detected when the vehicle
sharply turns during a spin turn, acceleration turn or drift driving while VDC function and
TCS function are OFF (VDC OFF switch is pressed and VDC OFF indicator lamp is in ON
status).
The vehicle speed does not increase, when the accelerator pedal is depressed while the
vehicle is on a 2-wheel chassis dynamometer for speedometer check.
This is not malfunction. (When checking
the vehicle on a chassis dynamometer,
operate VDC OFF switch so that TCS
function is OFF.)
The VDC warning lamp, ABS warn ing lamp and brake warning lamp turn ON and DTC
“C118E” may be detected in self-diagnosis resu lt of “ABS” when the brake pedal is exces-
sively operated, such as air bleeding. This is not a system malfunction because
this occurs due to the temporary de-
crease in accumulator fluid pressure. The
system returns to no
rmal condition when
the accumulator fluid pressure reaches
the specified pressure with the ignition
switch ON and the VDC warning lamp,
ABS warning lamp, a nd brake warning
lamp turn OFF. After these steps, ABS
self-diagnosis results are erased.
VDC OFF indicator lamp turns ON and TCS function is not operate when 4WD mode is “4L”.
(Models with 4WD system) This is not a malfunction. When the 4WD
mode becomes “4L” state, the TCS func-
tion is disabled. This function is enabled
when the 4WD mode becomes “AUTO”
or “4H”.
Revision: 2010 May2011 QX56

SYSTEM
BRC-145
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
SYSTEM
BRAKE ASSIST (WITH PREVIEW FUNCTION)
BRAKE ASSIST (WITH PREVIEW F UNCTION) : System DescriptionINFOID:0000000006228293
FUNCTION DESCRIPTION
When the Preview Function identifies the need to apply emergency braking by sensing a vehicle ahead in the
same lane and the distance and relative speed from it, it applies the brake pre-pressure before the driver
depress the brake pedal and helps improve brake response by reducing pedal free play.
The Preview Function shares component parts and diagnosis with the Intelligent Cruise Control (ICC) system.
CAUTION:
This system is only an aid to assist braking oper ation and is not a collision warning or avoidance
device. It is the driver ′s responsibility to stay aler t, drive safely and be in control of the vehicle at all
times.
OPERATION DESCRIPTION
 The system detects the distance to the vehicle in fr ont with the ICC sensor of ICC and judges the necessity
of emergency braking.
 The system detects the accelerator pedal release operati on of the driver by the accelerator pedal position
sensor and estimates the driver's brake operation intention.
 If the system is judged that the emergency braking is nec essary and that the driver has the intention to oper-
ate the brake, the ABS actuator and electric unit (control unit) applies pre-pressure to reduce brake pedal
play.
NOTE:
This system will not operate under the following conditions:
 When the vehicle is moving at approx imately 32 km/h (20 MPH) or less.
 When the 4WD shift switch is in the 4H or 4L position.
END OF OPERATION
The pre-pressure function ceases when the following conditions are met:
1. When the driver depresses the acce lerator pedal or the brake pedal.
2. If the driver does not operate the accelerator pedal or brake pedal within approximately 1 second.
Revision: 2010 May2011 QX56

SWITCH DOES NOT TURN ON / SWITCH DOES NOT TURN OFF
BRC-155
< SYMPTOM DIAGNOSIS > [INTELLIGENT BRAKE ASSIST]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
SYMPTOM DIAGNOSIS
SWITCH DOES NOT TURN ON / SWITCH DOES NOT TURN OFF
Symptom TableINFOID:0000000006228301
CAUTION:
Perform the self-diagnosis with CONS ULT-III before the symptom diagnosis. Perform the trouble diag-
nosis if any DTC is detected.
DescriptionINFOID:0000000006228302
IBA system does not turn ON/OFF.
 IBA OFF indicator lamp does not illuminate even if the IBA OFF switch is depressed when IBA OFF indicator
lamp is not illuminated.
 IBA OFF indicator lamp does not turn off even if t he IBA OFF switch is depressed when IBA OFF indicator
lamp is illuminated.
NOTE:
 To turn the system OFF ⇔ON, push and hold the IBA OFF switch after starting the engine for more than 1
second.
 The system ON/OFF condition will be memoriz ed even if the ignition switch turns OFF.
Diagnosis ProcedureINFOID:0000000006228303
1.PERFORM THE SELF-DIAGNOSIS
1. Perform “All DTC Reading” with CONSULT-III.
2. Check if the DTC is detected in self-diagnosis results for “ICC/ADAS” with CONSULT-III. Refer to CCS-50,
"DTC Index".
Is any DTC detected?
YES >> GO TO 6.
NO >> GO TO 2.
2.IBA OFF SWITCH INSPECTION
1. Start the engine.
2. Check that “IBA SW” operates normally in “D ATA MONITOR” for “ICC/ADAS” with CONSULT-III.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 5.
3.CHECK IBA OFF INDICATOR CIRCUIT
1. Start the engine.
2. Select the active test item “METE R LAMP” for “ICC/ADAS” with CONSULT-III.
3. Check if the IBA OFF indicator lamp illuminates when the test item is operated.
Is the inspection result normal?
YES >> Refer to CCS-69, "Work Flow".
NO >> GO TO 4.
4.CHECK DATA MONITOR OF COMBINATION METER
Check that “BA W/L” operates normally in “DATA MO NITOR” for “METER/M&A” with CONSULT-III, when the
IBA OFF switch is pushed and hold for more than 1 second.
Is the inspection result normal?
YES >> Replace the combination meter. Refer to MWI-85, "Removal and Installation".
NO >> Replace the ADAS control unit. Refer to DAS-63, "
Removal and Installation".
Symptom Inspection item/Reference page
IBA system does not turn ON/OFF IBA OFF indicator lamp is not turned
ON
⇔OFF when operating IBA OFF switch BRC-155, "
Diagnosis Procedure"
Revision: 2010 May2011 QX56

REPAIRING HIGH STRENGTH STEELBRM-5
< PRECAUTION >
C
DE
F
G H
I
J
L
M A
B
BRM
N
O P
 The repair of reinforcements (such as side members) by heat- ing is not recommended, because it may weaken the compo-
nent. When heating is unavoidable, never heat HSS parts
above 550 °C (1,022 °F).
Verify heating temperature with a thermometer.
(Crayon-type and other similar type thermometer are appropri-
ate.)
 When straightening body panels, use caution in pul ling any HSS panel. Because HSS is very strong,
pulling may cause deformation in adjacent sections of the body. In this case, increase the number of
measuring points, and carefully pull the HSS panel.
 When cutting HSS panels, avoid gas (torch) cutting if possible.
Instead, use a saw to avoid weakening surrounding areas due
to heat. If gas (torch) cutting is unavoidable, allow a minimum
margin of 50 mm (1.97 in).
 When welding HSS panels, use spot welding whenever possi- ble in order to minimize weakening surrounding areas due to
heat.
If spot welding is impossible, use MIG. welding. Do not use
gas (torch) for welding because it is inferior in welding
strength.
 Spot welding on HSS panels is harder than that of an ordinary steel panel.
Therefore, when cutting spot welds on a HSS panel, use a low
speed high torque drill (1,000 to 1,200 rpm) to increase drill bit
durability and facilitate the operation.
PIIA0115E
PIIA0117E
PIIA0144E
PIIA0145E
Revision: 2010 May2011 QX56