2001 INFINITI QX4 Ac system

Diagnostic ProcedureNBAT0095SYMPTOM 1:
ISelector lever cannot be moved from ªPº position with key
in ªONº position and brake pedal applied.
ISelector lever can be moved from ªPº position with key in
ªONº position and brake pedal released.
ISelector lever can be moved from ªPº position when key
is removed from key cylinder.
SYMPTOM 2:
Ignition key cannot be removed when selector lever is set to
ªPº position. It can be removed when selector lever is set to
any position except ªPº.
1 CHECK KEY INTERLOCK CABLE
Check key interlock cable for damage.
OK or NG
OK©GO TO 2.
NG©Repair key interlock cable. Refer to ªKey Interlock Cableº, AT-271.
2 CHECK SELECTOR LEVER POSITION
Check selector lever position for damage.
OK or NG
OK©GO TO 3.
NG©Check selector lever. Refer to ªON-VEHICLE SERVICE Ð PNP Switch and Manual Con-
trol Linkage Adjustmentº, AT-276 and AT-276.
3 CHECK POWER SOURCE
1. Turn ignition switch to ON position. (Do not start engine.)
2. Check voltage between A/T device harness terminal 5 and ground.
SAT758JA
OK or NG
OK©GO TO 5.
NG©GO TO 4.
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A/T SHIFT LOCK SYSTEM
Diagnostic Procedure
AT-267

4 DETECT MALFUNCTIONING ITEM
Check the following items:
1. Harness for short or open between ignition switch and A/T device harness terminal 5
2. 7.5A fuse [No. 11, located in the fuse block (J/B)]
3. Ignition switch (Refer to EL-9, ªSchematicº.)
OK or NG
OK©GO TO 5.
NG©Repair or replace damaged parts.
5 CHECK INPUT SIGNAL A/T DEVICE
Turn ignition switch to OFF position.
ICheck voltage between A/T device harness terminal 7 and ground.
SAT179K
OK or NG
OK©GO TO 7.
NG©GO TO 6.
6 DETECT MALFUNCTIONING ITEM
Check the following items:
1. Harness for short or open between battery and stop lamp switch harness connector 1
2. Harness for short or open between stop lamp switch harness connector 2 and A/T device harness connector 7
3. Diode
4. 10A fuse [No. 14, located in the fuse block (J/B)]
5. Stop lamp switch
a. Check continuity between terminals 1 and 2.
SAT146K
Check stop lamp switch after adjusting brake pedal Ð refer to BR-14, ªAdjustmentº.
OK or NG
OK©GO TO 7.
NG©Repair or replace damaged parts.
A/T SHIFT LOCK SYSTEM
Diagnostic Procedure (Cont'd)
AT-268

7 CHECK GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect A/T device harness connector.
3. Check continuity between A/T device harness terminal 6 and ground. Refer to wiring diagram Ð SHIFT Ð.
Continuity should exist.
If OK, check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK RELAY CIRCUIT
1. Turn ignition switch to ON and OFF position.
ICheck continuity between terminals 1, 2, 3 and 5.
SAT775J
YesorNo
Ye s©GO TO 9.
No©Replace relay.
9 CHECK PARK POSITION SWITCH
ICheck continuity between A/T device harness terminal 6 and relay (park position switch) harness terminal 1.
SAT180K
OK or NG
OK©GO TO 10.
NG©Replace park position switch.
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A/T SHIFT LOCK SYSTEM
Diagnostic Procedure (Cont'd)
AT-269

10 CHECK SHIFT LOCK SOLENOID
ICheck operation by applying battery voltage shift lock solenoid harness terminals 1 and 3.
SAT762J
OK or NG
OK©GO TO 11.
NG©Replace shift lock solenoid.
11 CHECK SHIFT LOCK OPERATION
1. Reconnect shift lock harness connector.
2. Turn ignition switch from OFF to ON position. (Do not start engine.)
3. Recheck shift lock operation.
OK or NG
OK©INSPECTION END
NG©GO TO 12.
12 CHECK A/T DEVICE INSPECTION
1. Perform A/T device input/output signal inspection test.
2. If NG, recheck harness connector connection.
OK or NG
OK©INSPECTION END
NG©Repair or replace damaged parts.
A/T SHIFT LOCK SYSTEM
Diagnostic Procedure (Cont'd)
AT-270

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