1998 NISSAN PATROL wiring

BRAKE SYSTEM
SECTION
BR
CONTENTS
PRECAUTIONS AND PREPARATION ............................1
Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER''...............1
Precautions for Brake System .....................................1
Commercial Service Tools ...........................................1
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING .....................................................2
NVH Troubleshooting Chart.........................................2
CHECK AND ADJUSTMENT ..........................................3
Checking Brake Fluid Level.........................................3
Checking Brake Line ...................................................3
Changing Brake Fluid ..................................................3
Bleeding Brake System ...............................................4
BRAKE HYDRAULIC LINE/CONTROL VALVE ..............5
Brake Hydraulic Line ...................................................5
Load Sensing Valve .....................................................6
BRAKE PEDAL AND BRACKET ..................................10
Removal and Installation ...........................................10
Inspection...................................................................10
Adjustment .................................................................10
MASTER CYLINDER .....................................................12
Removal .....................................................................12
Disassembly...............................................................13
Inspection...................................................................13
Assembly ...................................................................13
Installation ..................................................................14
BRAKE BOOSTER ........................................................15
Brake Booster ............................................................15
VACUUM PIPING (LHD models) ..................................17
Vacuum Hose ............................................................17
VACUUM PIPING (RHD models) .................................18
Vacuum Hose ............................................................18
VACUUM PIPING ...........................................................19
VACUUM PUMP ............................................................20
Removal and Installation ...........................................20
FRONT DISC BRAKE ...................................................21
Pad Replacement ......................................................21
Removal .....................................................................23
Disassembly...............................................................23 Inspection Ð Caliper .................................................23
Inspection Ð Rotor ....................................................24
Assembly ...................................................................24
Installation ..................................................................24
REAR DISC BRAKE ......................................................25
Pad Replacement ......................................................25
Removal .....................................................................27
Disassembly...............................................................27
Inspection Ð Caliper .................................................27
Inspection Ð Rotor ....................................................28
Assembly ...................................................................28
Installation ..................................................................28
PARKING CENTER BRAKE CONTROL ......................29
Removal .....................................................................29
Inspection...................................................................29
Installation ..................................................................30
Adjustment .................................................................30
PARKING CENTER BRAKE .........................................31
Removal and Installation ...........................................31
Inspection Ð Drum ....................................................32
Inspection Ð Lining ...................................................32
ANTI-LOCK BRAKE SYSTEM ......................................33
Purpose......................................................................33
Operation ...................................................................33
ABS Hydraulic Circuit ................................................33
System Components .................................................34
System Description ....................................................34
Removal and Installation ...........................................36
TROUBLE DIAGNOSES ...............................................39
How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................39
Preliminary Check......................................................40
Component Parts and Harness Connector
Location .....................................................................41
Circuit Diagram for Quick Pinpoint Check.................42
Wiring Diagram Ð ABS Ð ........................................43
Self-diagnosis ............................................................47
CONSULT ..................................................................50
CONSULT Inspection Procedure...............................51
BR

Ground Circuit Check ................................................56
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC
ITEMS ........................................................................\
.....57
Diagnostic Procedure 1 (Wheel sensor or rotor) ......57
Diagnostic Procedure 2 (ABS actuator solenoid
valve and solenoid valve relay) .................................59
Diagnostic Procedure 3 (Motor relay or motor).........61
Diagnostic Procedure 4 (Low voltage) ......................63
Diagnostic Procedure 5 (G sensor) ...........................64
Diagnostic Procedure 6 (Control unit) .......................65
TROUBLE DIAGNOSES FOR SYMPTOMS .................66
Diagnostic Procedure 7 (ABS works frequently.) ......66
Diagnostic Procedure 8 (Unexpected pedal
action) ........................................................................\
67 Diagnostic Procedure 9 (Long stopping distance) ....67
Diagnostic Procedure 10 (ABS does not work.) .......68
Diagnostic Procedure 11 (Pedal vibration and
noise) ........................................................................\
.68
Diagnostic Procedure 12 (Warning lamp does
not come on when ignition switch is turned ON.) .....69
Diagnostic Procedure 13 (Warning lamp stays on
when ignition switch is turned ON.)...........................71
SERVICE DATA AND SPECIFICATIONS (SDS) ..........72
General Speci®cations ...............................................72
Inspection and Adjustment ........................................73
When you read wiring diagrams:
+ Read GI section, ``HOW TO READ WIRING DIAGRAMS''.
+ See EL section, ``POWER SUPPLY ROUTING'' for power distribution circuit.
When you perform trouble diagnoses, read GI section, ``HOW TO FOLLOW FLOW CHART
IN TROUBLE DIAGNOSES'' and ``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN
ELECTRICAL INCIDENT''.

Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER''
The Supplemental Restraint System such as ``AIR BAG'' and ``SEAT BELT PRE-TENSIONER'' used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger in a frontal collision.
The SRS system composition which is available to NISSAN MODEL Y61 is as follows (The composition var-
ies according to the destination.):
Driver air bag module (located in the center of the steering wheel), front passenger air bag module (located
on the instrument panel on passenger side), seat belt pre-tensioner, a diagnosis sensor unit, warning lamp,
wiring harness and spiral cable.
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
+ To 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 in¯ation, all maintenance must be performed
by an authorized NISSAN dealer.
+ Improper 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.
+ Do 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 either just before
the harness connectors or for the complete harness are related to the SRS.
Precautions for Brake System
+Use brake ¯uid ``DOT 3''.
+ Never reuse drained brake ¯uid.
+ Be careful not to splash brake ¯uid on painted areas; it
may cause paint damage. If brake ¯uid is splashed on
painted areas, wash it away with water immediately.
+ To clean master cylinder parts, disc brake caliper parts or
wheel cylinder parts, use clean brake ¯uid.
+ Never use mineral oils such as gasoline or kerosene. They
will ruin rubber parts of hydraulic system.
+ Use ¯are nut wrench when removing and installing brake
tubes.
+ Always torque brake lines when installing.
WARNING:
Clean brakes with a vacuum dust collector to minimize risk of
health hazard from powder caused by friction.
Commercial Service Tools
Tool name Description
j
1Flare nut crowfoot
j
2Torque wrench
NT360
Removing and installing each brake piping
a: 10 mm (0.39 in)
Brake ¯uid pressure gauge
NT151
Measuring brake ¯uid pressure
SBR686C
PRECAUTIONS AND PREPARATION
BR-1

How to Perform Trouble Diagnoses for Quick
and Accurate Repair
INTRODUCTION
The ABS system has an electronic control unit to control major
functions. The control unit accepts input signals from sensors and
instantly drives the actuators. It is essential that both kinds of sig-
nals are proper and stable. It is also important to check for conven-
tional problems: such as air leaks in booster lines, lack of brake
¯uid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or faulty wiring. In this case,
careful checking of suspicious circuits may help prevent the
replacement of good parts.
A visual check only may not ®nd the cause of the problems, so a
road test should be performed.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a ABS complaint. The customer
is a very good source of information on such problems; especially
intermittent ones. Through the talks with the customer, ®nd out what
symptoms are present and under what conditions they occur.
Start your diagnosis by looking for ``conventional'' problems ®rst.
This is one of the best ways to troubleshoot brake problems on an
ABS controlled vehicle.
SEF233G
SEF234G
TROUBLE DIAGNOSES
BR-39

Wiring Diagram Ð ABS Ð
TBR099
TROUBLE DIAGNOSES
BR-43

TBR100
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-44

TBR101
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-45

TBR102
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-46