ABS INFINITI QX4 2001 Factory Service Manual

Wheel Hub and Rotor Disc
COMPONENTSNBAX0007
SFA908B
SFA529A
REMOVALNBAX0008CAUTION:
Before removing the front axle assembly, disconnect the ABS
wheel sensor from the assembly. Then move it away from the
front axle assembly area. Failure to do so may result in dam-
age to the sensor wires and the sensor becoming inoperative.
1. Remove brake caliper assembly.
Brake hose need not be disconnected from brake caliper. In
this case, suspend caliper assembly with wire so as not to
stretch brake hose.
Be careful not to depress brake pedal, or piston will pop out.
Make sure brake hose is not twisted.
FRONT AXLE
Wheel Hub and Rotor Disc
AX-6

ComponentsNBAX0028
SRA756A
RemovalNBAX0029CAUTION:
IBefore removing the rear axle, disconnect the ABS wheel
sensor from the assembly. Then move it away from the
axle. Failure to do so may result in damage to the sensor
wires and the sensor becoming inoperative.
IWheel bearing does not require maintenance.
IIf growling noise is emitted from wheel bearing during
operation, replace wheel bearing assembly.
IIf the wheel bearing assembly is removed, it must be renewed.
The old assembly must not be re-used.
SAX002
1. Disconnect parking brake cable and brake tube.
2. Remove nuts securing wheel bearing cage with baffle plate.
SRA758A
3. Draw out axle shaft with Tool.
When drawing out axle shaft, be careful not to damage oil seal.
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REAR AXLE
Components
AX-19

SRA759A
4. Remove oil seal with a screwdriver.
Do not reuse oil seal once it is removed.
Always install new one.
5. Remove ABS sensor rotor.
SRA104
6. Unbend lock washer with a screwdriver.
Do not reuse lock washer once removed. Always install new
one.
SRA728
7. Remove bearing lock nut with Tool.
SRA729-B
8. Remove wheel bearing together with bearing cage and baffle
plate from axle shaft.
SRA106
9. Remove grease seal with a screwdriver.
10. Remove wheel bearing assembly with a brass drift.
REAR AXLE
Removal (Cont'd)
AX-20

SRA763A
6. Check wheel bearing preload.
a. Turn bearing cage (with respect to axle shaft) two or three
times. It must turn smoothly.
b. Attach spring gauge to bearing cage bolt (as shown at left) and
pull it at a speed of 10 rpm to measure preload.
Spring gauge indication:
6.9 - 48.1 N (0.7 - 4.9 kg, 1.5 - 10.8 lb)
SRA292A
7. Install new oil seal to rear axle housing using a suitable tool.
After installing new oil seal, coat sealing lip with multi-pur-
pose grease.
SRA012
8. Press ABS sensor rotor onto axle shaft until it contacts wheel
bearing lock nut.
9. Position axle shafts in rear axle housing with Tool as a guide.
Be careful not to damage oil seal.
SRA755A
10. Check axial end play.
a. Check that wheel bearings operate smoothly.
b. Check axial end play.
Axial end play:
0mm(0in)
Service Data and Specifications (SDS)
WHEEL BEARING (REAR)NBAX0032
Wheel bearing axial end play0mm(0in)
Wheel bearing lock nut tightening torque 245 - 314 N´m (25 - 32 kg-m, 181 - 231 ft-lb)
Wheel bearing preload measured at bearing cage bolt 6.9 - 48.1 N (0.7 - 4.9 kg, 1.5 - 10.8 lb)
REAR AXLE
Installation (Cont'd)
AX-22

ABS
DESCRIPTION...............................................................32
Purpose......................................................................32
Operation ...................................................................32
ABS Hydraulic Circuit ................................................32
System Components .................................................33
System Description ....................................................33
SENSOR.................................................................33
CONTROL UNIT (BUILT-IN ABS ACTUATOR AND
ELECTRIC UNIT)
.....................................................33
ABS ACTUATOR AND ELECTRIC UNIT....................33
G SENSOR (4WD MODELS ONLY)..........................34
Component Parts and Harness Connector
Location .....................................................................35
Schematic ..................................................................36
Wiring Diagram - ABS - .............................................37
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................41
Self-diagnosis ............................................................41
FUNCTION..............................................................41
SELF-DIAGNOSIS PROCEDURE..............................41
HOW TO READ SELF-DIAGNOSTIC RESULTS
(MALFUNCTION CODES)
........................................42
HOW TO ERASE SELF-DIAGNOSTIC RESULTS
(MALFUNCTION CODES)
........................................42
CONSULT-II ...............................................................43
CONSULT-II APPLICATION TO ABS..........................43
ECU (ABS CONTROL UNIT) PART NUMBER
MODE
.....................................................................43
CONSULT-II Inspection Procedure............................44
SELF-DIAGNOSIS PROCEDURE..............................44
SELF-DIAGNOSTIC RESULTS MODE.......................45
DATA MONITOR PROCEDURE................................46
ACTIVE TEST PROCEDURE....................................47
DATA MONITOR MODE...........................................48
ACTIVE TEST MODE...............................................48
TROUBLE DIAGNOSIS - INTRODUCTION..................49
How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................49
INTRODUCTION......................................................49
TROUBLE DIAGNOSIS - BASIC INSPECTION...........50
Preliminary Check......................................................50
Ground Circuit Check ................................................53
ABS ACTUATOR AND ELECTRIC UNIT GROUND.....53
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION...............................................................54
Malfunction Code/Symptom Chart.............................54
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC
ITEMS.............................................................................56Wheel Sensor or Rotor ..............................................56
DIAGNOSTIC PROCEDURE.....................................56
ABS Actuator Solenoid Valve or Solenoid Valve
Relay ..........................................................................59
DIAGNOSTIC PROCEDURE.....................................59
Motor Relay or Motor.................................................61
DIAGNOSTIC PROCEDURE.....................................61
Low Voltage ...............................................................63
DIAGNOSTIC PROCEDURE.....................................63
G Sensor and Circuit .................................................65
DIAGNOSTIC PROCEDURE.....................................65
ELECTRICAL COMPONENT INSPECTION................67
Control Unit ................................................................68
DIAGNOSTIC PROCEDURE.....................................68
TROUBLE DIAGNOSES FOR SYMPTOMS.................69
1. ABS Works Frequently ..........................................69
2. Unexpected Pedal Action ......................................69
3. Long Stopping Distance ........................................70
4. ABS Does Not Work ..............................................71
5. Pedal Vibration and Noise.....................................71
6. Warning Lamp Does Not Come On When
Ignition Switch Is Turned On .....................................72
7. Warning Lamp Stays On When Ignition Switch
Is Turned On ..............................................................74
8. Vehicle Vibrates Excessively When ABS Is
Operating ...................................................................77
REMOVAL AND INSTALLATION.................................80
Front Wheel Sensor...................................................80
Rear Wheel Sensor ...................................................80
Front Sensor Rotor ....................................................81
REMOVAL...............................................................81
INSTALLATION........................................................81
Rear Sensor Rotor.....................................................81
REMOVAL...............................................................81
INSTALLATION........................................................81
G Sensor....................................................................81
ABS Actuator and Electric Unit..................................82
REMOVAL...............................................................82
INSTALLATION........................................................82
SERVICE DATA AND SPECIFICATIONS (SDS).........83
General Specifications ...............................................83
Disc Brake .................................................................83
Drum Brake................................................................83
Brake Pedal ...............................................................83
Parking Brake Control ...............................................84
CONTENTS(Cont'd)
BR-2

SBR995
Bleeding Brake System=NBBR0009CAUTION:
ICarefully monitor brake fluid level at master cylinder dur-
ing bleeding operation.
IIf master cylinder is suspected to have air inside, bleed air
from master cylinder first. Refer to ªInstallationº, ªMAS-
TER CYLINDERº, BR-18.
IFill reservoir with new brake fluid ªDOT 3º. Make sure it is
full at all times while bleeding air out of system.
IPlace a container under master cylinder to avoid spillage
of brake fluid.
ITurn ignition switch OFF and disconnect ABS actuator
and electric unit connectors or battery ground cable.
IBleed air in the following order.
1. LSV air bleeder (4WD)
2. Left rear brake
3. Right rear brake
4. Left front brake
5. Right front brake
SBR419C
1. Connect a transparent vinyl tube to air bleeder valve.
2. Fully depress brake pedal several times.
3. With brake pedal depressed, open air bleeder valve to release
air.
4. Close air bleeder valve.
5. Release brake pedal slowly.
6. Repeat steps 2. through 5. until clear brake fluid comes out of
air bleeder valve.
7. Tighten air bleeder valve.
:7-9N´m(0.7 - 0.9 kg-m, 61 - 78 in-lb)
ON-VEHICLE SERVICE
Bleeding Brake System
BR-8

SBR822BA
InspectionNBBR0116
SBR823BA
SBR705AA
CAUTION:
ICarefully monitor brake fluid level at master cylinder.
IUse new brake fluid ªDOT 3º.
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
paint areas, wash it away with water immediately.
IDepress pedal slowly when raising front brake pressure.
ICheck rear brake pressure 2 seconds after front brake
pressure reaches specified value.
IDisconnect harness connectors from ABS actuator and
electric unit before checking.
1. Remove front LH tire.
2. Connect tool to air bleeders on front LH brake caliper and rear
LH or RH brake wheel cylinder.
3. Install front LH tire.
Before installing front LH tire, confirm the tool is not touching
the front LH wheel.
4. Bleed air from the tool.
5. Check fluid pressure by depressing brake pedal.
kPa (kg/cm2, psi)
Applied pressure (Front brake) D16,375 (65, 924)
Output pressure (Rear brake) D
23,432 - 3,825
(35 - 39, 498 - 555)
If output pressure is out of specifications, replace master cylinder
assembly (built-in type).
6. Bleed air after disconnecting the tool. Refer to ªBleeding Brake
Systemº, BR-8.
7. Install front LH tire.
Removal and Installation (Built-in type)NBBR0117Always replace together with master cylinder as an assembly.
IRefer to ªMASTER CYLINDERº, BR-16.
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PROPORTIONING VALVE (2WD)
Inspection
BR-11

InspectionNBBR0014CAUTION:
ICarefully monitor brake fluid level at master cylinder.
IUse new brake fluid ªDOT 3º.
IBe careful not to splash brake fluid on painted areas; it
may cause paint damage. If brake fluid is splashed on
paint areas, wash it away with water immediately.
IDepress pedal slowly when raising front brake pressure.
ICheck rear brake pressure 2 seconds after front brake
pressure reaches specified value.
IDisconnect harness connectors from ABS actuator and
electric unit before checking.
SBR212E
1. Park vehicle on a level surface with vehicle unloaded*.
* Fuel, radiator coolant and engine oil full. Spare tire, jack,
hand tools and mats in designated positions.
2. Press a lever to the stopper bolt, then check length ªBº as fol-
lows:
Length ªBº Reference (Length ªLº)
207.7 mm (8.18 in) 217.3 mm (8.56 in)
3. If length ªBº is not within specification, adjust sensor spring
length.
Removal and InstallationNBBR0015CAUTION:
IRefill with new brake fluid ªDOT 3º.
IBe 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.
IDo not reuse Load Sensing Valve once it is disassembled.
IReplace damaged Load Sensing Valve as an assembly.
IWhen disassembling, apply multi-purpose grease to all
rubbing areas.
LOAD SENSING VALVE (4WD)
Inspection
BR-12

PurposeNBBR0087The Anti-Lock Brake System (ABS) consists of electronic and hydraulic components. It allows for control of
braking force so locking of the wheels can be avoided.
1) Improves proper tracking performance through steering wheel operation.
2) Eases obstacle avoidance through steering wheel operation.
3) Improves vehicle stability.
OperationNBBR0088IWhen the vehicle speed is less than 10 km/h (6 MPH) this system does not work.
IThe Anti-Lock Brake System (ABS) has a self-test function. The system turns on the ABS warning lamp
for 1 second each time the ignition switch is turned ªONº. After the engine is started, the ABS warning lamp
turns off. The system performs a test the first time the vehicle reaches 6 km/h (4 MPH). A mechanical noise
may be heard as the ABS performs this self-test. This is a normal part of the self-test feature. If a mal-
function is found during this check, the ABS warning lamp will stay on.
IWhile driving, a mechanical noise may be heard during ABS operation. This is a normal condition.
ABS Hydraulic CircuitNBBR0089
SBR859D
1. Inlet solenoid valve
2. Outlet solenoid valve
3. Reservoir4. Pump
5. Motor
6. Inlet valve7. Outlet valve
8. Bypass check valve
9. Damper
DESCRIPTIONABS
Purpose
BR-32

System ComponentsNBBR0090
SBR447EB
SBR124B
System DescriptionNBBR0091SENSORNBBR0091S01The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The front sensors are installed on the front spindles
and the rear sensors are installed on the rear spindles. As the
wheel rotates, the sensor generates a sine-wave pattern. The fre-
quency and voltage increase(s) as the rotating speed increases.
SBR668E
CONTROL UNIT (BUILT-IN ABS ACTUATOR AND
ELECTRIC UNIT)
NBBR0091S02The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and motor relay. If any electrical malfunction should be
detected in the system, the control unit causes the warning lamp
to light up. In this condition, the ABS will be deactivated by the
control unit, and the vehicle's brake system reverts to normal
operation. (For control unit layout, refer to ABS ACTUATOR AND
ELECTRIC UNIT, BR-33.)
SBR482E
ABS ACTUATOR AND ELECTRIC UNITNBBR0091S03The ABS actuator and electric unit contains:
IAn electric motor and pump
ITwo relays
ISix solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
IABS control unit
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DESCRIPTIONABS
System Components
BR-33