2001 INFINITI QX4 wheel

3 CHECK WHEEL SENSOR ELECTRICAL
1. Disconnect ABS actuator and electric unit connector.
2. Check resistance between ABS actuator and electric unit connector E111 (body side) terminals.
Code No. 21 or 22 (Front RH wheel)
Terminals 4 and 5
Code No. 25 or 26 (Front LH wheel)
Terminals 6 and 7
Code No. 31 or 32 (Rear RH wheel)
Terminals 1 and 2
Code No. 35 or 36 (Rear LH wheel)
Terminals 8 and 9
SBR486E
Resistance:
Front 0.9 - 1.1 kW
Rear 1.44 - 1.76 kW
Is front resistance 0.9 - 1.1 kWand rear resistance 1.44 - 1.76 kW?
Ye s©GO TO 5.
No©GO TO 4.
4 CHECK WHEEL SENSOR
Check each sensor for resistance.
SBR487E
Resistance:
Front 0.9 - 1.1 kW
Rear 1.44 - 1.76 kW
Is front resistance 0.9 - 1.1 kWand rear resistance 1.44 - 1.76 kW?
Ye s©Check the following.
If NG, repair harness or connectors.
IHarness connectors E111, E14, E51, B8, B69
IHarness for open or short between wheel sensor connectors and ABS actuator and
electric unit
No©Replace wheel sensor.
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TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC ITEMSABS
Wheel Sensor or Rotor (Cont'd)
BR-57

5 CHECK TIRE
Check for inflation pressure, wear and size of each tire. (See NOTE)
Are tire pressure and size correct and is tire wear within specifications?
Ye s©GO TO 6.
No©Adjust tire pressure or replace tire(s). (See NOTE)
6 CHECK WHEEL BEARING
Check wheel bearing axial end play. (See NOTE)
Is wheel bearing axial end play within specifications? Refer to AX-4, ªFront Wheel Bearingº and AX-18, ªRear
Wheel Bearingº.
Ye s©GO TO 7.
No©Check wheel bearing. Refer to AX-4, ªFront Wheel Bearingº and AX-18, ªRear Wheel
Bearingº.
7 CHECK SENSOR ROTOR
Check sensor rotor for teeth damage. (See NOTE)
Is sensor rotor free from damage?
Ye s©Check ABS actuator and electric unit pin terminals for damage or the connection of ABS
actuator and electric unit harness connector. Reconnect ABS actuator and electric unit
harness connector. Then retest.
No©Replace sensor rotor. (See NOTE)
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC ITEMSABS
Wheel Sensor or Rotor (Cont'd)
BR-58

1. ABS Works FrequentlyNBBR0107
1 CHECK BRAKE FLUID PRESSURE
Check brake fluid pressure distribution.
Refer to ªInspectionº, ªLOAD SENSING VALVEº, BR-12.
Is brake fluid pressure distribution normal?
Ye s©GO TO 2.
No©Repair. Then perform Preliminary Check.
Refer to BR-50.
2 CHECK WHEEL SENSOR
1. Check wheel sensor connector for terminal damage or loose connections.
2. Perform wheel sensor mechanical check.
Refer to ª7. CHECK SENSOR ROTORº in ªDIAGNOSTIC PROCEDUREº, ªWheel Sensor or Rotorº, BR-56.
Is wheel sensor mechanism OK?
Ye s©GO TO 3.
No©Repair.
3 CHECK FRONT AXLE
Check front axles for excessive looseness. Refer to AX-4, ªFront Wheel Bearingº.
Is front axle installed properly?
Ye s©Go to ª3. CHECK WARNING LAMP INDICATIONº in ª2. Unexpected Pedal Actionº,
BR-70.
No©Repair.
2. Unexpected Pedal ActionNBBR0108
1 CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
SBR540A
Is brake pedal stroke excessively large?
Ye s©Perform Preliminary Check. Refer to BR-50.
No©GO TO 2.
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TROUBLE DIAGNOSES FOR SYMPTOMSABS
1. ABS Works Frequently
BR-69

2 CHECK MECHANICAL BRAKE SYSTEM PERFORMANCE
Disconnect ABS actuator and electric unit connector and check whether brake is effective.
Does brake system function properly when brake pedal is depressed?
Ye s©GO TO 3.
No©Perform Preliminary Check. Refer to BR-50.
3 CHECK WARNING LAMP INDICATION
Ensure warning lamp remains off while driving.
SBR672E
Is warning lamp turned off?
Ye s©GO TO 4.
No©Carry out self-diagnosis. Refer to BR-41, BR-44.
4 CHECK WHEEL SENSOR
1. Check wheel sensor connector for terminal damage or loose connection.
2. Perform wheel sensor mechanical check. Refer to ª7. CHECK SENSOR ROTORº in ªDIAGNOSTIC PROCEDUREº,
ªWheel Sensor or Rotorº, BR-56.
Is wheel sensor mechanism OK?
Ye s©Check ABS actuator and electric unit pin terminals for damage or the connection of ABS
actuator and electric unit harness connector.
Reconnect ABS actuator and electric unit harness connector.
Then retest.
No©Repair.
3. Long Stopping DistanceNBBR0109
1 CHECK MECHANICAL BRAKE SYSTEM PERFORMANCE
Disconnect ABS actuator and electric unit connector and check whether stopping distance is still long.
Does brake system function properly when brake pedal is depressed?
Ye s©Perform Preliminary Check and air bleeding (if necessary).
No©Go to ª3. CHECK WARNING LAMP INDICATIONº in ª2. Unexpected Pedal Actionº,
BR-70.
TROUBLE DIAGNOSES FOR SYMPTOMSABS
2. Unexpected Pedal Action (Cont'd)
BR-70

=NBBR0079
CAUTION:
Be careful not to damage sensor edge and sensor rotor teeth.
When removing the front or rear wheel hub assembly, discon-
nect the ABS wheel sensor from the assembly and move it
away.
Front Wheel SensorNBBR0079S01
SBR398D
Rear Wheel SensorNBBR0079S02
SBR399D
REMOVAL AND INSTALLATIONABS
BR-80

SBR873C
Front Sensor RotorNBBR0079S03REMOVALNBBR0079S03011. Remove the front wheel hub. Refer to AX-8, ªDisassemblyº.
2. Remove the sensor rotor using suitable puller, drift and bear-
ing replacer.
SBR400DA
INSTALLATIONNBBR0079S0302Install the sensor rotor using suitable drift and press.
IAlways replace sensor rotor with new one.
IPay attention to the direction of front sensor rotor as shown in
figure.
SRA800AA
Rear Sensor RotorNBBR0079S04REMOVALNBBR0079S0401IRemove the sensor rotor using Tool.
SBR402D
INSTALLATIONNBBR0079S0402Install the sensor rotor using suitable drift and press.
IAlways replace sensor rotor with new one.
IPay attention to the direction of front sensor rotor as shown in
figure.
SBR503E
G SensorNBBR0079S06Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn changes ABS control performance characteris-
tics.
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REMOVAL AND INSTALLATIONABS
Front Sensor Rotor
BR-81

Service NoticeNBBT0001IWhen removing or installing various parts, place a cloth or padding onto the vehicle body to prevent
scratches.
IHandle trim, molding, instruments, grille, etc. carefully during removing or installing. Be careful not to soil
or damage them.
IApply sealing compound where necessary when installing parts.
IWhen applying sealing compound, be careful that the sealing compound does not protrude from parts.
IWhen replacing any metal parts (for example body outer panel, members, etc.), be sure to take rust pre-
vention measures.
Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
NBBT0002The Supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of
collision. The SRS system composition which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag module (located in the center of the steer-
ing wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt
pre-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of side air bag module (located in the outer side of front seat),
satellite sensor, diagnosis sensor unit (one of components of air bags for a frontal collision), wiring harness,
warning lamp (one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
ITo avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized INFINITI dealer.
IImproper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation tape either just
before the harness connectors or for the complete harness are related to the SRS.
PRECAUTIONS
Service Notice
BT-2

Removal and InstallationNBBT0005IBumper fascia is made of plastic. Do not use excessive force and be sure to keep oil away from it.
IBack door lock system adjustment: Adjust lock & striker so that they are in the center.
After adjustment, check back door lock operation.
IBack door hatch lock system adjustment: Adjust lock & striker so that they are in the center.
After adjustment, check back door hatch lock operation.
WARNING:
IBe careful not to scratch back door stay and/or back door hatch stay when installing back door
and/or back door hatch. A scratched stay may cause gas leakage.
IThe contents of the back door stay and back door hatch stay are under pressure. Do not take apart,
puncture, apply heat or allow fire near them.
REAR BUMPER ASSEMBLYNBBT0005S011. Remove bolts and screws securing left and right mudguards and remove the mudguards.
2. Remove clips and screws securing left and right sides of wheel protector.
3. Remove clips and bolts securing left and right rear fenders to bumper fascia.
4. Remove bolts securing bumper reinforcement to bumper fascia.
5. Remove clips securing bumper fascia.
6. Extract bumper fascia assembly.
7. Remove bolts and nuts securing bumper reinforcement.
8. Extract bumper reinforcement.
SBT715
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BODY REAR END AND OPENER
Removal and Installation
BT-15