brake INFINITI QX56 2006 Factory Service Manual

BRC-52
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: November 20092006 QX56
4. FRONT PRESSURE SENSOR INSPECTION
1. Reconnect the front pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "PRESS SENSOR" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace pressure sensor.
REAR PRESSURE INSPECTION PROCEDURE
1. DISPLAY SELF DIAGNOSIS RESULTS
Check self-diagnosis result display item.
Is the above displayed in the self-diagnosis display items?
YES or NO
YES >> GO TO 2.
NO >> Inspection End.
2. CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the rear pressure sensor connector E32 and ABS actuator and electric unit (control unit) con- nector E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector. Condition
Data monitor display (Approx.)
PRESS SENSOR
When brake pedal is depressed Positive value
When brake pedal is released 0 bar
Self-diagnosis results
PRESS SEN CIRCUIT

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSBRC-53
[VDC/TCS/ABS]
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Revision: November 2009 2006 QX56
3. REAR PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and rear pressure sensor connector E32.
2. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and body ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
4. REAR PRESSURE SENSOR INSPECTION
1. Reconnect the rear pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "PRESS SEN 2" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace rear pressure sensor.
Steering Angle Sensor Safe Mode InspectionEFS0068B
INSPECTION PROCEDURE
1. INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is on.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Adjust steering angle sensor neutral position. Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral
Position" .
OK or NG
OK >> GO TO 3.
NG >> Check steering angle sensor. Refer to BRC-40, "
Steering Angle Sensor System" .
ABS actuator and electric unit
(control unit) connector E125 Rear pressure sensor con-
nector E32 Continuity
21 1
Yes
22 3
23 2
ABS actuator and electric unit (control unit) connector E125 Body ground
Continuity
21 —No
22
23
Condition Data monitor display (Approx.)
PRESS SEN 2
When brake pedal is depressed Positive value
When brake pedal is released 0 bar

TROUBLE DIAGNOSES FOR SYMPTOMSBRC-57
[VDC/TCS/ABS]
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Revision: November 2009 2006 QX56
TROUBLE DIAGNOSES FOR SYMPTOMSPFP:99999
ABS Works FrequentlyEFS004Y9
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
2. CHECK WHEEL SENSORS
Check the following.

Wheel sensor mounting for looseness

Wheel sensors for physical damage

Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3. CHECK FRONT AND REAR AXLES
Check front and rear axles for excessive looseness. Refer to FAX-5, "
WHEEL BEARING INSPECTION" or
RAX-5, "
WHEEL BEARING INSPECTION" .
OK or NG
OK >> GO TO 4.
NG >> Repair as necessary.
4. CHECK BRAKE FLUID PRESSURE
Check brake fluid pressure distribution.
Refer to BRC-23, "
Basic Inspection" .
Is brake fluid pressure distribution normal?
YES >> Inspection End.
NO >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .

BRC-58
[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: November 20092006 QX56
Unexpected Pedal ActionEFS004YA
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
2. CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
Is pedal stroke excessive?
YES >> Perform Basic Inspection. Refer to BRC-23, "Basic
Inspection" .
NO >> GO TO 3.
3. CHECK CONNECTOR AND BRAKING PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation. NOTE:

Stopping distance may be longer than vehicles without ABS when road condition is slippery.

Driving the vehicle with the ABS actuator and electric unit (control unit) disconnected may induce DTCs
in electrical control units using CAN communication. After the inspection, clear all DTCs. Refer to BRC-
10, "CAN COMMUNICATION" .
OK or NG
OK >> GO TO 4.
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
4. CHECK WHEEL SENSORS
Check the following.

Wheel sensor mounting for looseness

Wheel sensors for physical damage

Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> Check ABS actuator and electric unit (control unit) connector terminals for deformation, discon- nection, looseness or damage. Reconnect ABS actuator and electric unit (control unit) harness
connector. Then retest.
NG >> Repair or replace as necessary.
SBR540A

TROUBLE DIAGNOSES FOR SYMPTOMSBRC-59
[VDC/TCS/ABS]
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Revision: November 2009 2006 QX56
Long Stopping DistanceEFS004YB
1. CHECK BASE BRAKING SYSTEM PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation. NOTE:

Stopping distance may be longer than vehicles without ABS when road condition is slippery.

Driving the vehicle with the ABS actuator and electric unit (control unit) disconnected may induce DTCs
in electrical control units using CAN communication. After the inspection, clear all DTCs. Refer to BRC-
10, "CAN COMMUNICATION" .
OK or NG
OK >> Go to BRC-57, "ABS Works Frequently" .
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
ABS Does Not WorkEFS004YC
CAUTION:
The ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or less.
1. CHECK WARNING LAMP ACTIVATION
Turn ignition switch ON and check for warning lamp activation.

Warning lamp should activate for approximately 2 seconds after turning the ignition switch ON.
OK or NG
OK >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NG >> Go to BRC-60, "
ABS Warning Lamp Does Not Come On When Ignition Switch Is Turned On" .
Pedal Vibration or ABS Operation NoiseEFS004YD
NOTE:
During ABS activation, pedal vibration may be felt and a noise may be heard. This is normal and does not indi-
cate a malfunction.
1. CHECK SYMPTOM
1. Apply brake.
2. Start engine.
Does the symptom occur only when engine is started?
YES >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NO >> GO TO 2.
2. RECHECK SYMPTOM
Does the symptom occur only when electrical equipment switches (such as headlamps) are turned on?
YES >> Check for radio, antenna or related wiring that is routed too close to the ABS actuator and electric unit (control unit) and reroute as necessary.
NO >> Go to BRC-57, "
ABS Works Frequently" .

BRC-64
[VDC/TCS/ABS]
WHEEL SENSORS
Revision: November 20092006 QX56
WHEEL SENSORSPFP:47910
Removal and InstallationEFS0068D
REMOVAL
1. Remove wheel sensor bolt.

When removing the front wheel sensor, first remove the disc rotor to gain access to the front wheel sen-
sor bolt. Refer to BR-22, "
Removal and Installation of Brake Caliper and Disc Rotor" .

When removing the rear wheel sensor, first remove the rear hub and bearing assembly to gain access
to the rear wheel sensor bolt. Refer to RAX-5, "
Removal and Installation" .
2. Pull out the sensor, being careful to turn it as little as possible. CAUTION:

Do not pull on the sensor harness.
3. Disconnect wheel sensor harness electrical connector, then remove harness from attaching points.
INSTALLATION
Installation is in the reverse order of removal. Tighten wheel sensor bolt to specification.
CAUTION:
Installation should be performed while paying attention to the following.

Inspect wheel sensor O-ring, replace sensor assembly if damaged.

Before installing wheel sensor, make sure no foreign materials (such as iron fragments) are
adhered to the pick-up part of the sensor, to the inside of the sensor hole or on the rotor mating
surface.

Apply a coat of suitable grease to the wheel sensor O-ring and hole. Refer to MA-11, "RECOM-
MENDED FLUIDS AND LUBRICANTS" .
WFIA0376E

BRC-66
[VDC/TCS/ABS]
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
Revision: November 20092006 QX56
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)PFP:47660
Removal and InstallationEFS0068F
REMOVAL
1. Disconnect the negative battery terminal.
2. Remove the cowl top extension. Refer to EI-18, "
Removal and Installation" .
3. Drain the brake fluid. Refer to BR-10, "
Drain and Refill" .
4. Disconnect the actuator harness from the ABS actuator and electric unit (control unit). CAUTION:

To remove the brake tubes, use a flare nut wrench to prevent the flare nuts and brake tubes from
being damaged.

Be careful not to splash brake fluid on painted areas; it may cause paint damage. If brake fluid is
splashed on painted areas, wash it away with water immediately.
5. Disconnect the brake tubes.
6. Remove the three bolts and remove the ABS actuator and electric unit (control unit).
1. To left front 2. To rear right 3. To rear left
4. To front right 5. From the master cylinder secondary
side 6. From the master cylinder primary
side
7. ABS actuator and electric unit (con- trol unit) 8. Harness connector
WFIA0375E

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)BRC-67
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Revision: November 2009 2006 QX56
INSTALLATION
Installation is in the reverse order of removal.
NOTE:
To install, use a flare nut wrench (commercial service tool). Tighten brake tubes to specification when install-
ing. Refer to BR-12, "
Hydraulic Circuit" .

After installation of the ABS actuator and electric unit (control unit), refill the brake system with new brake
fluid. Refer to MA-11, "
RECOMMENDED FLUIDS AND LUBRICANTS" . Then bleed the air from the sys-
tem. Refer to BR-11, "
Bleeding Brake System" .
CAUTION:

Never reuse drained brake fluid.

Adjust the steering angle sensor. Refer to BRC-62, "Adjustment of Steering Angle Sensor Neu-
tral Position" .

Calibrate the yaw rate/side/decel G sensor. Refer to BRC-62, "Calibration of Decel G Sensor" .

OVERHEATING CAUSE ANALYSISCO-7
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Revision: November 2009 2006 QX56
Except cool-
ing system
parts mal-
function—
Overload on engine Abusive driving
High engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system mal-
function
—
Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flow Blocked bumper
—
—
Blocked radiator grille
Installed car brassiere
Mud contamination or
paper clogging
Blocked radiator —
Blocked condenser Blocked air flow
Installed large fog lamp
Symptom
Check items

DI-66
REAR SONAR SYSTEM
Revision: November 20092006 QX56
Pre-diagnosis InspectionEKS00BD7
SENSOR STATUS CHECK

Check that the rear sonar sensor is properly aligned (bumper is not misaligned, no deformation in sensor
mounting area.

Check that snow, mud, or other foreign objects are not adhering to the rear sonar sensor.

Check that there is no deformation, scratches, or other damage to the rear sonar sensor.

Check that water has not accumulated in the rear sonar sensor.
CAUTION:
Use water, cotton swab, or other soft material for cleaning the sensor.
1. Check that there are no obstacles within each rear sonar sensor's detection range.
2. Check that there are no nearby ultrasound sources (such as the sounds of vehicle horns, motorcycle engines, or truck air brakes).
3. Check that the vehicle is on a level surface.
Self-diagnosis FunctionEKS00BD8
There are four modes of self-diagnosis; entering diagnostics, requesting number of fault codes, requesting
fault codes, and idling or clearing fault codes. These steps must be followed in order. Self-diagnosis can be
manually exited by turning the ignition switch OFF, or selecting reverse gear. Self-diagnosis will exit unless a
fault code request occurs before a message is repeated five times without acknowledgement.
ENTERING DIAGNOSTICS MODE
1. Turn ignition switch ON. Rear sonar system OFF switch indica- tor lamp illuminates for three seconds and then turns off.
2. Immediately push rear sonar system OFF switch ten times within five seconds.
3. The sonar buzzer will sound once and the rear sonar system OFF indicator will flash once.
REQUESTING NUMBER OF FAULT CODES MODE
1. While in diagnostic mode, push rear sonar system OFF switch
once.
2. The sonar buzzer will sound once.
3. Rear sonar system OFF indicator will flash once and sonar buzzer will sound once for each fault code detected.
4. There will be a four second pause.
5. The number of fault codes will repeat five times then pause. NOTE:
Self-diagnosis will exit unless requesting fault codes occurs
before five repeats ends.
Detection range
Rear sonar sensors Approx. 1.8 m (5.9 ft.) maximum
LKIA0389E
LKIA0388E