Checking Brake Fluid Level.........................................6
Checking Brake Line ...................................................6
Changing Brake Fluid ..................................................6
Brake Burnishing Procedure........................................6
Bleeding Brake System ...............................................7

BRAKE HYDRAULIC LINE .............................................8

Removal.......................................................................8

Inspection.....................................................................8

Installation....................................................................8

CONTROL VALVE ...........................................................9

Proportioning Valve......................................................9

BRAKE PEDAL AND BRACKET..................................10

Removal and Installation ...........................................10
Inspection...................................................................10
Adjustment .................................................................10

MASTER CYLINDER.....................................................12

Removal.....................................................................12
Disassembly...............................................................12
Inspection...................................................................13
Assembly ...................................................................13
Installation..................................................................14

BRAKE BOOSTER........................................................15

On-vehicle Service.....................................................15
Removal.....................................................................15
Inspection...................................................................15
Installation..................................................................15

VACUUM HOSE.............................................................17

Removal and Installation ...........................................17
Inspection...................................................................17

FRONT DISC BRAKE ...................................................18

Pad Replacement ......................................................18
Components...............................................................19
Removal.....................................................................19

Disassembly...............................................................20
Inspection - Caliper....................................................20
Inspection - Rotor ......................................................20
Assembly ...................................................................21
Installation..................................................................21

REAR DISC BRAKE......................................................22

Pad Replacement ......................................................22
Components...............................................................23
Removal.....................................................................23
Disassembly...............................................................24
Inspection - Caliper....................................................24
Inspection - Rotor ......................................................24
Assembly ...................................................................25
Installation..................................................................25

REAR DISC BRAKE - Parking Drum Brake ...............26

Removal.....................................................................26
Inspection - Drum ......................................................27
Inspection - Lining .....................................................28
Installation..................................................................28
Shoe Clearance Adjustment ......................................29
Breaking in Drum and Lining.....................................29

PARKING BRAKE CONTROL ......................................30

Removal and Installation ...........................................30
Inspection...................................................................31
Adjustment .................................................................31

TRACTION CONTROL SYSTEM - TCS -.....................32

Purpose......................................................................32
System Components .................................................33
ABS (Anti-lock brake system) Operation...................34
ABS Hydraulic Circuit ................................................34
TCS (Traction Control System) Operation ................35
Throttle Control + Engine Control TCS System
Configuration (Tandem Throttle System)...................35
Secondary Throttle Fully-closed Position Self-
learning Control .........................................................36
Removal and Installation ...........................................37

TROUBLE DIAGNOSES ...............................................41

How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................41
Symptom Chart..........................................................45
Preliminary Check (Check brake fluid level in
reservoir tank and brake line for leakage.) ...............48

IDX

Component Parts and Harness Connector
Location .....................................................................49
Schematic ..................................................................50
Wiring Diagram - TCS -.............................................51
Self-diagnosis for ABS/TCS Control Unit ..................59
CONSULT-II for ABS/TCS Control Unit.....................62
CONSULT-II Inspection Procedure for ABS/TCS
Control Unit................................................................63
Self-diagnosis for TAC Module ..................................70
CONSULT-II for TAC Module.....................................72
CONSULT-II Inspection Procedure for TAC
Module .......................................................................73
Ground Circuit Check ................................................79

TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC
ITEMS.............................................................................80

TROUBLE DIAGNOSES FOR SYMPTOMS............... 112

TROUBLE DIAGNOSES FOR TCS ............................125

Electrical Component Inspection .............................125

SERVICE DATA AND SPECIFICATIONS (SDS) ........128

General Specifications.............................................128
Inspection and Adjustment ......................................128

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”.

CONTENTS

(Cont’d)

BR-2

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 for certain types of
collision. The SRS system composition which is available to INFINITI Q45 is as follows:

For 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.

For 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 the RS section of 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 inflation, all maintenance should be per-
formed by an authorized INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by intentional 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 (except satellite sensor and side air bag mod-
ule) covered with yellow insulation tape either just before the harness connectors or for the com-
plete harness are related to the SRS.

SBR686C

Precautions for Brake System

Use brake fluid “DOT 3”.

Never reuse drained brake fluid.

Be 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.

To clean master cylinder parts, disc brake caliper parts or
wheel cylinder parts, use clean brake fluid.

Never use mineral oils such as gasoline or kerosene. They
will ruin rubber parts of hydraulic system.

Use flare nut wrench when removing and installing brake
tubes.

Always torque brake lines when installing.

Burnish the brake contact surfaces after refinishing or
replacing drums or rotors, after replacing pads or linings,
or if a soft pedal occurs at very low mileage. Refer to
“Brake Burnishing Procedure”, “ON-VEHICLE SERVICE”,
BR-6.

WARNING:

Clean brakes with a vacuum dust collector to minimize
risk of health hazard from powder caused by friction.

IDX

PRECAUTIONS AND PREPARATION

BR-3

Commercial Service Tools

Tool name

Description

Flare nut crowfoot

Torque wrench

NT360

Removing and installing each brake piping

a: 10 mm (0.39 in)

Brake fluid pressure gauge

NT151

Measuring brake fluid pressure

PRECAUTIONS AND PREPARATION

BR-4

Content .. 69 70 71 72 ..