brake INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSIS
BRC-33
< SERVICE INFORMATION >[VDC/TCS/ABS]
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P*: ON for 1 to 2 seconds after the touch, and then OFF
NOTE:
• If active test is performed with brake pedal depressed, pedal stroke may change. This is normal.
• “TEST IS STOPPED” is displayed approximately 10 seconds after operation starts.
• After “TEST IS STOPPED” is displayed, to perform test again, repeat Step 6.
ABS Motor
Touch “ON” and “OFF” on the screen. Check that ABS motor relay
operates as shown in table below.
NOTE:
• If active test is performed with brake pedal depressed, pedal
stroke may change. This is normal.
• “TEST IS STOPPED” is displayed approximately 10 seconds after
operation starts.
Booster Drive
CAUTION:
Perform active test subject to the conditions below.
• Do not operate brake pedal during active test.
• Make sure the engine revolution is over 500 rpm.
• Make sure the vehicle is not moving.
Touch "UP" and "DOWN" on the screen. Check that booster drive
operates as shown in table below.
NOTE:
"TEST IS STOPPED" is displayed approximately 10 seconds after operation starts.
FR LH SOL
FR LH ABS SOLE-
NOID (ACT)FR LH IN SOL OFF ON ON OFF OFF OFF
FR LH OUT SOL OFF OFF ON* OFF OFF OFF
RR RH SOL
RR RH ABS SOLE-
NOID (ACT)RR RH IN SOL OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH SOL
RR LH ABS SOLE-
NOID (ACT)RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
REAR SOLRR RH IN SOL OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF OperationABS solenoid valve ABS solenoid valve (ACT)
UP KEEP DOWN UPACTUA-
TOR UPACTUA-
TOR KEEP
Operation ON OFF
ABS actuator relay ON ON
ABS motor relay ON OFF
SFIA0593E
Operation UP DOWN
STOP LAMP SW ON OFF
BST OPER SIG ON OFF
PRESS SENSOR 50 ± 5 bar 0 bar
PRESS SEN 2 50 ± 5 bar 0 bar
STP OFF RLY OFF OFF
WFIA0350E

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-41
< SERVICE INFORMATION >[VDC/TCS/ABS]
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Check the voltage between the ABS actuator and electric unit (con-
trol unit) harness connector E125 terminal 41 and body ground.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-58, "
Removal and Installation".
NG >> GO TO 4.
4.STOP LAMP RELAY CIRCUIT INSPECTION
1. Disconnect the stop lamp relay harness connector E12.
2. Check the continuity between the ABS actuator and electric unit
(control unit) harness connector E125 (B) terminal 41 and stop
lamp relay harness connector E12 (A) terminal 4.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-58, "
Removal and Installation"BRC-
58, "Removal and Installation".
NG >> Refer to "Stop Lamp Switch System Inspection".
ABS/TCS/VDC Control Unit Power and Ground Systems InspectionINFOID:0000000003532792
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2.CONNECTOR INSPECTION
1. Disconnect the ABS actuator and electric unit (control unit) connector E125.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3.ABS/TCS/VDC CONTROL UNIT POWER AND GROUND CIRCUIT INSPECTION
Measure the voltage and continuity between the ABS actuator and electric unit (control unit) harness connec-
tor E125 and body ground.Brake pedal depressed : Battery voltage
(approx. 12V)
Brake pedal not depressed : Approx. 0V
WFIA0198E
Continuity should exist
WFIA0431E
Self-diagnosis results
BATTERY VOLTAGE
Signal nameABS actuator and electric unit
(control unit) connector E125Body
groundMeasured value
Power supply1
— Battery voltage (Approx. 12V)
32

BRC-42
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
OK or NG
OK >> Check the battery for loose terminals, low voltage, etc. Repair as necessary.
NG >> Repair the circuit.
Brake Fluid Level Switch System InspectionINFOID:0000000003532793
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
1. Check the brake reservoir tank fluid level. If the level is low, add brake fluid.
2. Erase the self-diagnosis results and check the self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2.CONNECTOR INSPECTION
1. Disconnect the ABS actuator and electric unit (control unit) connector E125 and brake fluid level switch
connector E21.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3.CHECK THE HARNESS BETWEEN THE BRAKE FLUID LEVEL SWITCH AND THE ABS ACTUATOR AND
ELECTRIC UNIT (CONTROL UNIT)
Check the continuity between the brake fluid level switch harness connector E21 and the ABS actuator and
electric unit (control unit) harness connector E125.
OK or NG
OK >> GO TO 4.
NG >> Repair the circuit.
4.CHECK BRAKE FLUID LEVEL SWITCH
Check continuity between brake fluid level switch terminals 1 and 2.
OK or NG
OK >> Perform self-diagnosis again. If the same results appear, replace ABS actuator and electric unit
(control unit). Refer to BRC-58, "
Removal and Installation".
NG >> Replace brake fluid level switch.Ground16
— Continuity should exist.
47
Self-diagnosis results
BR FLUID LEVEL LOW
ABS actuator and electric unit
(control unit) harness connector
E125Brake fluid level switch harness
connector E21Continuity
81Yes
8GroundNo
Ground 2 Yes
Continuity should not exist.

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-43
< SERVICE INFORMATION >[VDC/TCS/ABS]
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Active Booster System InspectionINFOID:0000000003532794
INSPECTION PROCEDURE
1.DISPLAY SELF DIAGNOSIS RESULTS
Check self-diagnosis results.
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 active booster connector E49 and ABS actuator and electric unit (control unit) connector
E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector.
3.ACTIVE BOOSTER CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and
active booster connector E49.
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.
Self-diagnosis results
ABS ACTIVE BOOSTER SV NG
ABS ACTIVE BOOSTER RESPONSE NG
ABS BRAKE RELEASE SW NG
ABS BRAKE BOOSTER DEFECT
ABS actuator and electric unit (con-
trol unit) connector E125Active booster connector
E49Continuity
17 3
Ye s 27 1
28 5
30 2
31 4
ABS actuator and electric unit (con-
trol unit) connector E125Body ground Continuity
17
—No 27
28
30
31

BRC-44
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
4.ACTIVE BOOSTER SENSOR INSPECTION
1. Reconnect the active booster and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "RELEASE SW NO" and "RELEASE SW NC" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace active booster.
Delta Stroke Sensor System InspectionINFOID:0000000003532795
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 delta stroke sensor connector E114 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.
3.DELTA STROKE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and delta
stroke sensor connector E114.
2. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and body
ground.ConditionData monitor display
RELEASE SW NO RELEASE SW NC
When brake pedal is depressed ON OFF
When brake pedal is released OFF ON
Self-diagnosis results
ABS DELTA S SEN NG
ABS actuator and electric unit
(control unit) connector E125Delta stroke sensor
connector E114Continuity
26 1
Ye s 39 3
40 5
ABS actuator and electric unit (con-
trol unit) connector E125Body ground Continuity
26
—No 39
40

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-45
< SERVICE INFORMATION >[VDC/TCS/ABS]
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OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
4.DELTA STROKE SENSOR INSPECTION
1. Reconnect the delta stroke sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "DELTA S SEN" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace delta stroke sensor.
Pressure Sensor System InspectionINFOID:0000000003532796
FRONT 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 front pressure sensor connector E31 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.
3.FRONT PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) harness connector E125
and front pressure sensor harness connector E31.
2. Measure the continuity between the ABS actuator and electric unit (control unit) harness connector E125
and body ground.ConditionData monitor display (Approx.)
DELTA S SEN
When brake pedal is released 0.00 mm (+0.6/-0.4)
When brake pedal is depressed 1.05–1.80 mm
Self-diagnosis results
PRESS SEN CIRCUIT
ABS actuator and electric unit
(control unit) harness connector
E125Front pressure sensor har-
ness connector E31Continuity
18 3
Ye s 19 1
20 2

BRC-46
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
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.
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.ABS actuator and electric unit
(control unit) harness connector
E125Body ground Continuity
18
—No 19
20
ConditionData 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
ABS actuator and electric unit (con-
trol unit) connector E125Rear pressure sensor con-
nector E32Continuity
21 1
Ye s 22 3
23 2

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-47
< SERVICE INFORMATION >[VDC/TCS/ABS]
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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 InspectionINFOID:0000000003532797
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-54, "
Adjustment of Steering Angle Sensor Neutral
Position".
OK or NG
OK >> GO TO 3.
NG >> Check steering angle sensor. Refer to BRC-36, "
Steering Angle Sensor System".
3.INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is off.
OK or NG
OK >> GO TO 4.
NG >> Perform basic inspection. Refer to BRC-22, "
Basic Inspection".
4.CHECK SELF-DIAGNOSTIC RESULTS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
NOTE:ABS actuator and electric unit (con-
trol unit) connector E125Body ground Continuity
21
—No 22
23
ConditionData monitor display (Approx.)
PRESS SEN 2
When brake pedal is depressed Positive value
When brake pedal is released 0 bar
Self-diagnosis results
ST ANGL SEN SAFE

BRC-50
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
TROUBLE DIAGNOSES FOR SYMPTOMS
ABS Works FrequentlyINFOID:0000000003532802
INSPECTION PROCEDURE
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-26, "
CONSULT-II Function (ABS)".
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 wheel bearing axial end play. Refer to FAX-5, "
On-Vehicle Inspection and Service" (front) or RAX-5,
"On-Vehicle Inspection and Service" (rear).
OK or NG
OK >> GO TO 4.
NG >> Repair as necessary.
4.CHECK BRAKE FLUID PRESSURE
Check brake fluid pressure distribution.
Refer to BRC-22, "
Basic Inspection".
Is brake fluid pressure distribution normal?
YES >> Inspection End.
NO >> Perform Basic Inspection. Refer to BRC-22, "
Basic Inspection".
Unexpected Pedal ActionINFOID:0000000003532803
INSPECTION PROCEDURE
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-26, "
CONSULT-II Function (ABS)".
2.CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
Is pedal stroke excessive?
YES >> Perform Basic Inspection. Refer to BRC-22, "Basic
Inspection".
NO >> GO TO 3.
SBR540A

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-51
< SERVICE INFORMATION >[VDC/TCS/ABS]
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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 LAN-
7.
OK or NG
OK >> GO TO 4.
NG >> Perform Basic Inspection. Refer to BRC-22, "
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.
Long Stopping DistanceINFOID:0000000003532804
INSPECTION PROCEDURE
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 LAN-
7.
OK or NG
OK >> Go to BRC-50, "ABS Works Frequently".
NG >> Perform Basic Inspection. Refer to BRC-22, "
Basic Inspection".
ABS Does Not WorkINFOID:0000000003532805
CAUTION:
The ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or less.
INSPECTION PROCEDURE
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-26, "CONSULT-II Function (ABS)".
NG >> Go to BRC-22, "
Basic Inspection".
Pedal Vibration or ABS Operation NoiseINFOID:0000000003532806
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.
INSPECTION PROCEDURE