wheel INFINITI QX4 2001 Factory Workshop Manual

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

Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
NBEC0002The 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 front 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 for On Board Diagnostic (OBD)
System of Engine and A/T
NBEC0003The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
IBe sure to turn the ignition switch OFF and disconnect the negative battery terminal before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc.
will cause the MIL to light up.
IBe sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
ICertain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to EL-6, ªHARNESS
CONNECTOR (SLIDE-LOCKING TYPE)º.
IBe sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to light up due to the short circuit.
IBe sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the fuel injection system, etc.
IBe sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PRECAUTIONS
Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
EC-14

IAir intake system
(Oil filler cap, oil level gauge, etc.)
IFuel pressure
IEngine compression
IThrottle valve
IEvaporative emission system
2) On air conditioner equipped models, checks should be carried out while the air conditioner is ªOFFº.
3) On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in ªNº position.
4) When measuring ªCOº percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5) Turn off headlamps, heater blower, rear defogger.
6) Keep front wheels pointed straight ahead.
7) Make the check after the cooling fan has stopped.
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-44

SEF452Y
Idle Air Volume LearningNBEC0642
SEF454Y
SEF455Y
DESCRIPTIONNBEC0642S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
IEach time IACV-AAC valve, throttle body or ECM is replaced.
IIdle speed or ignition timing is out of specification.
PRE-CONDITIONINGNBEC0642S02Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
IBattery voltage: More than 12.9V (At idle)
IEngine coolant temperature: 70 - 99ÉC (158 - 210ÉF)
IPNP switch: ON
IElectric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime running light systems, if
the parking brake is applied before the engine is started the
headlamp will not illuminate.
ICooling fan motor: Not operating
ISteering wheel: Neutral (Straight-ahead position)
IVehicle speed: Stopped
ITransmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
For A/T models without CONSULT-II, drive vehicle for 10 min-
utes.
OPERATION PROCEDURENBEC0642S03With CONSULT-IINBEC0642S03011. Turn ignition switch ªONº and wait at least 1 second.
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
8. Touch ªSTARTº and wait 20 seconds.
9. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed 750±50 rpm (in ªPº or ªNº position)
Ignition timing 15ɱ5É BTDC (in ªPº or ªNº position)
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BASIC SERVICE PROCEDURE
Idle Air Volume Learning
EC-57

DATA MONITOR MODE=NBEC0034S06
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]qqIIndicates the engine speed computed
from the REF signal (120É signal) of the
crankshaft position sensor (REF).
CKPS´RPM (POS)
[rpm]qIIndicates the engine speed computed
from the POS signal (1É signal) of the
crankshaft position sensor (POS).IAccuracy becomes poor if engine
speed drops below the idle rpm.
IIf the signal is interrupted while the
engine is running, an abnormal value
may be indicated.
POS COUNTqIIndicates the number of signal plate
(Flywheel/Drive Plate) cogs (tooth) dur-
ing one revolution of the engine.
MAS A/F SE-B1 [V]qqIThe signal voltage of the mass air flow
sensor is displayed.IWhen the engine is stopped, a certain
value is indicated.
COOLAN TEMP/S
[ÉC] or [ÉF]qqIThe engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.IWhen the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the
ECM is displayed.
HO2S1 (B1) [V]qq
IThe signal voltage of the front heated
oxygen sensor is displayed.
HO2S1 (B2) [V]qq
HO2S2 (B1) [V]qq
IThe signal voltage of the rear heated
oxygen sensor is displayed.
HO2S2 (B2) [V]qq
HO2S1 MNTR (B1)
[RICH/LEAN]qIDisplay of front heated oxygen sensor
signal during air-fuel ratio feedback
control:
RICH ... means the mixture became
ªrichº, and control is being affected
toward a leaner mixture.
LEAN ... means the mixture became
ªleanº, and control is being affected
toward a rich mixture.IAfter turning ON the ignition switch,
ªRICHº is displayed until air-fuel mixture
ratio feedback control begins.
IWhen the air-fuel ratio feedback is
clamped, the value just before the
clamping is displayed continuously. HO2S1 MNTR (B2)
[RICH/LEAN]q
HO2S2 MNTR (B1)
[RICH/LEAN]qIDisplay of rear heated oxygen sensor
signal:
RICH ... means the amount of oxygen
after three way catalyst is relatively
small.
LEAN ... means the amount of oxygen
after three way catalyst is relatively
large.IWhen the engine is stopped, a certain
value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]q
VHCL SPEED SE
[km/h] or [mph]qqIThe vehicle speed computed from the
vehicle speed sensor signal is dis-
played.
BATTERY VOLT [V]qqIThe power supply voltage of ECM is
displayed.
THRTL POS SEN [V]qqIThe throttle position sensor signal volt-
age is displayed.
FUEL T/TMP SE
[ÉC] or [ÉF]IThe fuel temperature judged from the
tank fuel temperature sensor signal
voltage is displayed.GI
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-87