How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................29
Operational Check .....................................................30
Symptom Chart..........................................................36
Self-diagnosis ............................................................37
Preliminary Check......................................................55
Performance Test Diagnoses ....................................63
Performance Chart ....................................................65
Trouble Diagnoses for Abnormal Pressure ...............66
Component Location..................................................69
Circuit Diagram/Without Navigation System .............71
Wiring Diagram - A/C -/Without Navigation
System .......................................................................72
Circuit Diagram/With Navigation System ..................77

Wiring Diagram - A/C, A -/With Navigation
System .......................................................................78
Auto Amp. Terminals and Reference Value...............83
Main Power Supply and Ground Circuit Check ........86
Self-diagnosis Circuit .................................................88
Multiplex Communication Circuit ...............................89
Ambient Sensor Circuit..............................................90
In-vehicle Sensor Circuit............................................93
Intake Sensor Circuit .................................................96
Sunload Sensor Circuit..............................................97
Mode Door Motor Circuit (LAN)...............................100
Air Mix Door Motor Circuit (LAN) ............................102
Bi-level Door Motor Circuit (LAN)............................104
LAN System Circuit .................................................106
Intake Door Motor Circuit ........................................109
Blower Motor Circuit ................................................ 113
Magnet Clutch Circuit .............................................. 118
Rear Vent Door Motor Circuit ..................................122
Control Linkage Adjustment.....................................123

SERVICE PROCEDURES ...........................................125

HFC-134a (R-134a) Service Procedure ..................125
Maintenance of Lubricant Quantity in
Compressor .............................................................128
Refrigerant Lines .....................................................130
Checking Refrigerant Leaks ....................................131
Electronic Refrigerant Leak Detector ......................131
Fluorescent Dye Leak Detector...............................134
Compressor Mounting .............................................135
Belt Tension .............................................................135
Fast Idle Control Device (FICD) ..............................135
Compressor .............................................................136
Compressor Clutch ..................................................136
Ventilation Air Filter..................................................139

SERVICE DATA AND SPECIFICATIONS (SDS) ........140

General Specifications.............................................140
Inspection and Adjustment ......................................140

IDX

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”.

CONTENTS

(Cont’d)

HA-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 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 (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.

Precautions for Working with HFC-134a
(R-134a)

WARNING:

CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refrigerant are not compatible. If the refriger-
ants are mixed, compressor malfunction is likely to occur, refer to “Contaminated refrigerant”
below. To determine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use
Refrigerant Recovery/Recycling Recharging equipment (ACR4) (J-39500-INF) and Refrigerant
Identifier.

Use only specified lubricant for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) com-
ponents. If lubricant other than that specified is used, compressor failure is likely to occur.

The specified HFC-134a (R-134a) lubricant rapidly absorbs moisture from the atmosphere.
The following handling precautions must be observed:
a: When removing refrigerant components from a vehicle, immediately cap (seal) the component

to minimize the entry of moisture from the atmosphere.

b: When installing refrigerant components to a vehicle, do not remove the caps (unseal) until

just before connecting the components. Connect all refrigerant loop components as quickly
as possible to minimize the entry of moisture into system.

c: Only use the specified lubricant from a sealed container. Immediately reseal containers of

lubricant. Without proper sealing, lubricant will become moisture saturated and should not
be used.

d: Avoid breathing A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose

and throat. Remove R-134a from the A/C system, using certified service equipment meeting
requirements of SAE J2210 (R-134a recycling equipment), or J2209 (R-134a recovery equip-
ment). If accidental system discharge occurs, ventilate work area before resuming service.
Additional health and safety information may be obtained from refrigerant and lubricant
manufacturers.

e: Do not allow lubricant (Nissan A/C System Oil Type S) to come in contact with styrofoam

parts. Damage may result.

IDX

PRECAUTIONS AND PREPARATION

HA-3

Contaminated refrigerant

If a refrigerant other than pure R-134a is identified in a vehicle, your options are:

Explain to the customer that environmental regulations prohibit the release of contaminated

refrigerant into the atmosphere.

Explain that recovery of the contaminated refrigerant could damage your service equipment and
refrigerant supply.

Suggest the customer return the vehicle to the location of previous service where the contamina-

tion may have occurred.

If you choose to perform the repair, recover the refrigerant using only dedicated equipment and
containers. Do not recover contaminated refrigerant into your existing service equipment. If your
facility does not have dedicated recovery equipment, you may contact a local refrigerant product
retailer for available service. This refrigerant must be disposed of in accordance with all federal
and local regulations. In addition, replacement of all refrigerant system components on the vehicle
is recommended.

If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact

INFINITI Customer Affairs for further assistance.

General Refrigerant Precautions

WARNING:

Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the
refrigerant every time an air conditioning system is discharged.

Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or
air conditioning system.

Do not store or heat refrigerant containers above 52°C (125°F).

Do not heat a refrigerant container with an open flame; if container warming is required, place the
bottom of the container in a warm pail of water.

Do not intentionally drop, puncture, or incinerate refrigerant containers.

Keep refrigerant away from open flames: poisonous gas will be produced if refrigerant burns.

Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent
suffocation.

Do not pressure test or leak test HFC-134a (R-134a) service equipment and/or vehicle air condi-
tioning systems with compressed air during repair. Some mixtures of air and R-134a have been
shown to be combustible at elevated pressures. These mixtures, if ignited, may cause injury or
property damage. Additional health and safety information may be obtained from refrigerant manu-
facturers.

Precautions for Leak Detection Dye

The A/C system contains a fluorescent leak detection dye used for locating refrigerant leaks. An ultravio-
let (UV) lamp is required to illuminate the dye when inspecting for leaks.

Always wear fluorescence enhancing UV safety glasses to protect your eyes and enhance the visibility of
the fluorescent dye.

A compressor shaft seal should not be repaired because of dye seepage. The compressor shaft seal
should only be repaired after confirming the leak with an electronic refrigerant leak detector (J-41995).

Always remove any dye from the leak area after repairs are complete to avoid a misdiagnosis during a
future service.

Do not allow dye to come into contact with painted body panels or interior components. If dye is spilled,
clean immediately with the approved dye cleaner. Fluorescent dye left on a surface for an extended period
of time cannot be removed.

Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).

Do not use more than one refrigerant dye bottle (1/4 ounce / 7.4 cc) per A/C system.

Leak detection dyes for R-134a and R12 A/C systems are different. Do not use R-134a leak detection dye
in R-12 A/C system or R-12 leak detection dye in R-134a A/C systems or A/C system damage may result.

The fluorescent properties of the dye will remain for over three (3) years unless a compressor failure
occurs.

PRECAUTIONS AND PREPARATION

Precautions for Working with HFC-134a
(R-134a) (Cont’d)

HA-4

Content .. 457 458 459 460 ..