Ac system INFINITI QX4 2001 Factory Repair Manual

BRAKE SYSTEM
SECTION
BR
CONTENTS
PRECAUTIONS...............................................................3
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER²...............3
Precautions for Brake System .....................................3
Wiring Diagrams and Trouble Diagnoses....................4
PREPARATION...............................................................5
Special Service Tools ..................................................5
Commercial Service Tools ...........................................5
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING.....................................................6
NVH Troubleshooting Chart.........................................6
ON-VEHICLE SERVICE..................................................7
Checking Brake Fluid Level.........................................7
Checking Brake Line ...................................................7
Changing Brake Fluid ..................................................7
Bleeding Brake System ...............................................8
BRAKE HYDRAULIC LINE.............................................9
Hydraulic Circuit...........................................................9
Removal .....................................................................10
Inspection...................................................................10
Installation ..................................................................10
PROPORTIONING VALVE (2WD)................................ 11
Inspection................................................................... 11
Removal and Installation (Built-in type)..................... 11
LOAD SENSING VALVE (4WD)...................................12
Inspection...................................................................12
Removal and Installation ...........................................12
BRAKE PEDAL AND BRACKET..................................14
Removal and Installation ...........................................14
Inspection...................................................................14
Adjustment .................................................................14
MASTER CYLINDER.....................................................16
Removal .....................................................................16
Disassembly...............................................................16
Inspection...................................................................17
Assembly ...................................................................17
Installation ..................................................................18
BRAKE BOOSTER........................................................19
On-vehicle Service.....................................................19OPERATING CHECK...............................................19
AIRTIGHT CHECK...................................................19
Removal .....................................................................19
Inspection...................................................................19
OUTPUT ROD LENGTH CHECK..............................19
Installation ..................................................................20
VACUUM PIPING...........................................................21
Vacuum Hose ............................................................21
Removal and Installation ...........................................21
Inspection...................................................................21
HOSES AND CONNECTORS...................................21
CHECK VALVE........................................................21
FRONT DISC BRAKE...................................................22
Components...............................................................22
Pad Replacement ......................................................22
Removal .....................................................................23
Disassembly...............................................................24
Inspection...................................................................24
CALIPER.................................................................24
ROTOR...................................................................24
Assembly ...................................................................25
Installation ..................................................................25
Brake Burnishing Procedure......................................25
REAR DRUM BRAKE...................................................26
Components...............................................................26
Removal .....................................................................26
Inspection...................................................................27
WHEEL CYLINDER..................................................27
Wheel Cylinder Overhaul...........................................28
Inspection...................................................................28
DRUM.....................................................................28
LINING....................................................................28
Installation ..................................................................28
PARKING BRAKE CONTROL......................................30
Components...............................................................30
Removal and Installation ...........................................30
Inspection...................................................................30
Adjustment .................................................................31
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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

Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
NBBR0001The 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.
SBR686C
Precautions for Brake SystemNBBR0002IUse brake fluid ªDOT 3º.
INever reuse drained brake fluid.
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.
ITo clean master cylinder parts, disc brake caliper parts or
wheel cylinder parts, use clean brake fluid.
INever use mineral oils such as gasoline or kerosene. They
will ruin rubber parts of hydraulic system.
IUse flare nut wrench when removing and installing brake
tubes.
IAlways torque brake lines when installing.
WARNING:
IClean brakes with a vacuum dust collector to minimize
risk of health hazard from powder caused by friction.
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PRECAUTIONS
Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
BR-3

SBR451D
Checking Brake Fluid LevelNBBR0006ICheck fluid level in reservoir tank. It should be between Max
and Min lines on reservoir tank.
IIf fluid level is extremely low, check brake system.
IIf the brake warning lamp comes on, check brake fluid level
switch and parking brake switch.
SBR389C
Checking Brake LineNBBR0007CAUTION:
If leakage occurs around joints, retighten or, if necessary,
replace damaged parts.
1. Check brake lines (tubes and hoses) for cracks, deterioration
or other damage. Replace any damaged parts.
2. Check for oil leakage by fully depressing brake pedal while
engine is running.
SBR419C
Changing Brake FluidNBBR0008CAUTION:
IRefill with new brake fluid ªDOT 3º.
IAlways keep fluid level higher than minimum line on res-
ervoir tank.
INever reuse drained brake fluid.
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.
1. Clean inside of reservoir tank, and refill with new brake fluid.
2. Connect a vinyl tube to each air bleeder valve.
3. Drain brake fluid from each air bleeder valve by depressing
brake pedal.
4. Refill until brake fluid comes out of each air bleeder valve.
Use same procedure as in bleeding hydraulic system to refill
brake fluid.
Refer to ªBleeding Brake Systemº, BR-8.
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ON-VEHICLE SERVICE
Checking Brake Fluid Level
BR-7

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

SBR992
RemovalNBBR0011CAUTION:
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.
IAll hoses must be free from excessive bending, twisting
and pulling.
1. Connect vinyl tube to air bleeder valve.
2. Drain brake fluid from each air bleeder valve by depressing
brake pedal.
3. Remove flare nut connecting brake tube and hose, then with-
draw lock spring.
4. Cover openings to prevent entrance of dirt whenever discon-
necting brake line.
InspectionNBBR0012Check brake lines (tubes and hoses) for cracks, deterioration or
other damage. Replace any damaged parts.
SBR686C
InstallationNBBR0013CAUTION:
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
1. Tighten all flare nuts and connecting bolts.
Flare nut:
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
Connecting bolt:
: 17 - 19 N´m (1.7 - 2.0 kg-m, 12 - 14 ft-lb)
2. Refill until new brake fluid comes out of each air bleeder valve.
3. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
BRAKE HYDRAULIC LINE
Removal
BR-10

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

SBR379DC
1. Tighten all flare nuts and mounting bolts.
Flare nut:
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
2. Refill until new brake fluid comes out of each air bleeder valve.
3. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
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LOAD SENSING VALVE (4WD)
Removal and Installation (Cont'd)
BR-13

ABR190
InstallationNBBR0023CAUTION:
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
1. Place master cylinder onto brake booster and secure mount-
ing nuts lightly.
2. Torque mounting nuts.
: 12 - 15 N´m (1.2 - 1.5 kg-m,9-11ft-lb)
3. Fill up reservoir tank with new brake fluid.
4. Plug all ports on master cylinder with fingers to prevent air
suction while releasing brake pedal.
5. Have driver depress brake pedal slowly several times until no
air comes out of master cylinder.
6. Fit brake lines to master cylinder.
7. Tighten flare nuts.
: 15 - 17 N´m (1.5 - 1.8 kg-m, 11 - 13 ft-lb)
8. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
MASTER CYLINDER
Installation
BR-18

SBR116BG
Installation=NBBR0027CAUTION:
IBe careful not to deform or bend brake pipes during instal-
lation of booster.
IReplace clevis pin if damaged.
IRefill with new brake fluid ªDOT 3º.
INever reuse drained brake fluid.
ITake care not to damage brake booster mounting bolt
thread when installing. Due to the narrow angle of
installation, the threads can be damaged by the dash
panel.
1. Before fitting booster, temporarily adjust clevis to dimension
shown.
2. Fit booster, then secure mounting nuts (brake pedal bracket to
brake booster) lightly.
3. Connect brake pedal and booster input rod with clevis pin.
4. Secure mounting nuts.
Specification: 13 - 16 N´m (1.3 - 1.6 kg-m,9-12ft-lb)
5. Install master cylinder. Refer to ªInstallationº in ªMASTER
CYLINDERº, BR-18.
6. Adjust brake pedal height and free play. Refer to ªAdjustmentº
in ªBRAKE PEDAL AND BRACKETº, BR-14.
7. Secure lock nut for clevis.
: 16 - 22 N´m (1.6 - 2.2 kg-m, 12 - 16 ft-lb)
8. Bleed air. Refer to ªBleeding Brake Systemº, BR-8.
BRAKE BOOSTER
Installation
BR-20