2004 INFINITI QX56 air conditioning

2004
QUICK REFERENCE CHART: QX56

Disc Brake - Repair LimitsELS000ZU
Unit: mm (in)
Brake PedalELS000ZV
Unit: mm (in)
Refill CapacitiesELS000YO
Brake model CLZ31VC (Front) AD14VE (Rear)
Brake PadStandard thickness (new) 11.88 (0.468) 12.13 (0.478)
Repair limit thickness 1.0 (0.039) 1.0 (0.039)
Disc rotor Standard thickness (new) 26.0 (1.024) 14.0 (0.551)
Repair limit thickness 24.5 (0.965) 12.0 (0.472)
Maximum uneven wear (measured at 8 positions) 0.015 (0.0006) 0.015 (0.0006)
Runout limit (with it attached to the vehicle) 0.04 (0.0016) 0.05 (0.0020)
Brake pedal height (from dash lower panel top surface) 182.3
− 192.3 (7.18 − 7.57)
Depressed pedal height [under a force of 490 N (50 kg, 110 lb) with engine running] More than 90.3 (3.55)
Clearance between stopper rubber and the threaded end of stop lamp switch 0.74 − 1.96 (0.029 − 0.077)
Pedal play 3 − 11 (0.12 − 0.43)
Description Capacity (Approximate)
Metric US measure Imp measure
Fuel 105.8 28 gal 23 1/4 gal
Engine oil
Drain and refill With oil filter change
6.2 6 1/2 qt 5 1/2 qt
Without oil filter change 5.9 6 1/4 qt 5 1/4 qt
Dry engine (engine overhaul) 7.6 8 qt 6 3/4 qt
Cooling system With reservoir at MAX level 14.4 3 3/4 gal 3 1/8 gal
Automatic transmission fluid (ATF) 10.6 11 1/4 qt 9 3/8 qt
Rear final drive oil 1.75 3 3/4 pt 3 1/8 pt
Transfer fluid 3.0 3 1/8 qt 2 5/8 qt
Front final drive oil 1.6 3 3/8 pt 2 7/8 pt
Power steering fluid (PSF) 1.0 1 1/8 qt 7/8 qt
Windshield washer fluid 4.5 1 1/4 gal 1 gal
Air conditioning system refrigerant 1.08 ± 0.05 kg 2.38 ± 0.11 lb 2.38 ± 0.11 lb
Air conditioning system lubricants 290 m9.8 fl oz 10.2 fl oz

ATC-6
PRECAUTIONS
Revision: August 20072004 QX56

If you choose to perform the repair, recover the refrigerant using only dedicated equipment and contain-
ers. 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 avail-
able 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 NISSAN
Customer Affairs for further assistance.
General Refrigerant PrecautionsEJS002BI
WAR NIN G:

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 HFC-134a (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 refriger-
ant manufacturers.
Precautions for Leak Detection DyeEJS002BJ

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

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

The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluo-
rescent dye leak detector should be used in conjunction with an electronic refrigerant leak detector (J-
41995).

For your safety and the customer's satisfaction, read and follow all manufacturer's operating instructions
and precautions prior to performing work.

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 HFC-134a (R-134a) and CFC-12 (R-12) A/C systems are different. Do not use
HFC-134a (R-134a) leak detection dye in CFC-12 (R-12) A/C systems or CFC-12 (R-12) leak detection
dye in HFC-134a (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.

TROUBLE DIAGNOSIS
ATC-113
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AT C
Revision: August 20072004 QX56
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Te s t R e a d i n g
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
Vehicle location Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door window Open
Hood Open
TEMP. Max. COLD
Mode switch
(Ventilation) set
Recirculation (REC) switch
(Recirculation) set
Fan (blower) speedMax. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator
°C (°F) Relative humidity
%Air temperature
°C (°F)
50 - 6020 (68) 5.3 - 6.5 (42 - 44)
25 (77) 9.7 - 11.5 (49 - 53)
30 (86) 13.8 - 16.3 (57 - 61)
35 (95) 18.0 - 21.2 (64 - 70)
40 (104) 22.2 - 25.7 (72 - 78)
60 - 7020 (68) 6.5 - 7.7 (44 - 46)
25 (77) 11.5 - 13.3 (53 - 56)
30 (86) 16.3 - 18.8 (61 - 66)
35 (95) 21.2 - 24.0 (70 - 75)
40 (104) 25.7 - 29.2 (78 - 85)
Ambient air
High-pressure (Discharge side)
kPa (kg/cm
2 , psi)Low-pressure (Suction side)
kPa (kg/cm2 , psi) Relative humidity
%Air temperature
°C (°F)
50 - 7020 (68)680 - 840
(6.94 - 8.57, 98.6 - 121.8)160 - 198
(1.63 - 2.02, 23.2 - 28.7)
25 (77)800 - 985
(8.16 - 10.05, 116.0 - 142.8)198 - 245
(2.02 - 2.50, 28.7 - 35.5)
30 (86)940 - 1,150
(9.59 - 11.73, 136.3 - 166.8)225 - 278
(2.30 - 2.84, 32.6 - 40.3)
35 (95)1,160 - 1,410
(11.83 - 14.38, 168.2 - 204.5)273 - 335
(2.78 - 3.42, 39.6 - 48.6)
40 (104)1,325 - 1,620
(13.52 - 16.52, 192.1 - 234.9)325 - 398
(3.32 - 4.06, 47.1 - 57.7)

ATC-116
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.

Drain water from refrigerant
or replace refrigerant.

Replace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve′s pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.

If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).

If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.

Replace liquid tank.

Check lubricant for contami-
nation.
AC362A

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
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SECTION EC
A
EC
Revision: August 20072004 QX56 INDEX FOR DTC ........................................................ 8
Alphabetical Index .................................................... 8
DTC No. Index ....................................................... 12
PRECAUTIONS ........................................................ 16
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................ 16
On Board Diagnostic (OBD) System of Engine and
A/T .......................................................................... 16
Precaution .............................................................. 16
Wiring Diagrams and Trouble Diagnosis ................ 19
PREPARATION ......................................................... 20
Special Service Tools ............................................. 20
Commercial Service Tools ...................................... 22
ENGINE CONTROL SYSTEM .................................. 23
System Diagram ..................................................... 23
Vacuum Hose Drawing ........................................... 24
System Chart ......................................................... 25
Multiport Fuel Injection (MFI) System .................... 26
Electronic Ignition (EI) System ............................... 28
Nissan Torque Demand (NTD) Control System ..... 29
Air Conditioning Cut Control ................................... 30
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 30
CAN communication .............................................. 31
BASIC SERVICE PROCEDURE .............................. 32
Idle Speed and Ignition Timing Check .................... 32
Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment ............................................................. 33
Accelerator Pedal Released Position Learning ...... 44
Throttle Valve Closed Position Learning ................ 44
Idle Air Volume Learning ........................................ 44
Fuel Pressure Check .............................................. 46
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 49
Introduction ............................................................ 49
Two Trip Detection Logic ........................................ 49
Emission-related Diagnostic Information ................ 50
IVIS (Infiniti Vehicle Immobilizer System — NATS) ... 63
Malfunction Indicator Lamp (MIL) ........................... 63
OBD System Operation Chart ................................ 66TROUBLE DIAGNOSIS ............................................ 71
Trouble Diagnosis Introduction ............................... 71
DTC Inspection Priority Chart ................................. 76
Fail-safe Chart ........................................................ 77
Basic Inspection ..................................................... 79
Symptom Matrix Chart ............................................ 84
Engine Control Component Parts Location ............ 88
Circuit Diagram ....................................................... 94
ECM Harness Connector Terminal Layout ............. 96
ECM Terminals and Reference Value ..................... 96
CONSULT-II Function ...........................................103
Generic Scan Tool (GST) Function .......................116
CONSULT-II Reference Value in Data Monitor .....118
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................121
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .123
Description ............................................................123
Testing Condition ..................................................123
Inspection Procedure ............................................123
Diagnostic Procedure ...........................................124
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT .......................................................................127
Description ............................................................127
Diagnostic Procedure ...........................................127
POWER SUPPLY AND GROUND CIRCUIT ...........128
Wiring Diagram .....................................................128
Diagnostic Procedure ...........................................129
Ground Inspection ................................................133
DTC U1000, U1001 CAN COMMUNICATION LINE .135
Description ............................................................135
On Board Diagnosis Logic ....................................135
DTC Confirmation Procedure ...............................135
Wiring Diagram .....................................................136
Diagnostic Procedure ...........................................137
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .138
Description ............................................................138
CONSULT-II Reference Value in Data Monitor Mode
.138
On Board Diagnosis Logic ....................................138
DTC Confirmation Procedure ...............................139

ENGINE CONTROL SYSTEM
EC-25
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EC
Revision: August 20072004 QX56
System ChartUBS00GZD
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This input signal is sent to the ECM through CAN communication line.
*4: This output signal is sent from the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)

Camshaft position sensor (PHASE)

Crankshaft position sensor (POS)

Mass air flow sensor

Engine coolant temperature sensor

A/F sensor 1

Throttle position sensor

Accelerator pedal position sensor

Park/neutral position (PNP) switch

Intake air temperature sensor

Power steering pressure sensor

Ignition switch

Battery voltage

Knock sensor

Refrigerant pressure sensor

Stop lamp switch

ASCD steering switch

ASCD brake switch

Fuel level sensor*1 *3

EVAP control system pressure sensor

Fuel tank temperature sensor*1

Heated oxygen sensor 2*2

TCM (Transmission control module)*3

ABS actuator and electric unit (control unit)*3

Air conditioner switch*3

Wheel sensor*3

Electrical load signal*3
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Nissan torque demand control system

Electric throttle control actuator

Fuel injector
Fuel pump control Fuel pump relay
ASCD vehicle speed control Electric throttle control actuator
On board diagnostic system
MIL (On the instrument panel)*
4
A/F sensor 1 heater control A/F sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay*
4
Cooling fan control
Cooling fan relay*4
ON BOARD DIAGNOSIS for EVAP system EVAP canister vent control valve

EC-30Revision: August 2007
ENGINE CONTROL SYSTEM
2004 QX56
Air Conditioning Cut ControlUBS00GZH
INPUT/OUTPUT SIGNAL CHART
*1: Signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)UBS00GZI
INPUT/OUTPUT SIGNAL CHART
*1: Signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,400 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,400 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,000 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System, EC-26
.
Sensor Input signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed
Sensor Input signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut control Fuel injector Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Wheel sensor*
1Vehicle speed

GI-1
GENERAL INFORMATION
A GENERAL INFORMATION
CONTENTS
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SECTION GI
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 3
Description ............................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for NVIS/IVIS (NISSAN/INFINITI
VEHICLE IMMOBILIZER SYSTEM - NATS) (If
Equipped) ................................................................. 3
General Precautions ................................................ 4
Precautions for Three Way Catalyst ......................... 5
Precautions for Fuel (Unleaded Premium Gasoline
Required) ................................................................. 5
Precautions for Multiport Fuel Injection System or
Engine Control System ............................................ 6
Precautions for Hoses .............................................. 6
HOSE REMOVAL AND INSTALLATION ............... 6
HOSE CLAMPING ................................................ 6
Precautions for Engine Oils ...................................... 7
HEALTH PROTECTION PRECAUTIONS ............. 7
Precautions for Air Conditioning ............................... 7
HOW TO USE THIS MANUAL ................................... 8
Description ............................................................... 8
Terms ....................................................................... 8
Units ......................................................................... 8
Contents ................................................................... 8
Relation between Illustrations and Descriptions ...... 9
Components ........................................................... 10
SYMBOLS ........................................................... 10
How to Follow Trouble Diagnoses ...........................11
DESCRIPTION .....................................................11
HOW TO FOLLOW TEST GROUPS IN TROU-
BLE DIAGNOSES ................................................11
HARNESS WIRE COLOR AND CONNECTOR
NUMBER INDICATION ....................................... 12
KEY TO SYMBOLS SIGNIFYING MEASURE-
MENTS OR PROCEDURES ............................... 13
How to Read Wiring Diagrams ............................... 15
CONNECTOR SYMBOLS ................................... 15
SAMPLE/WIRING DIAGRAM - EXAMPL - ......... 16DESCRIPTION .................................................... 17
Abbreviations .......................................................... 22
SERVICE INFORMATION FOR ELECTRICAL INCI-
DENT ......................................................................... 24
How to Check Terminal ........................................... 24
CONNECTOR AND TERMINAL PIN KIT ............ 24
HOW TO PROBE CONNECTORS ...................... 24
How to Perform Efficient Diagnosis for an Electrical
Incident ................................................................... 27
WORK FLOW ...................................................... 27
INCIDENT SIMULATION TESTS ........................ 27
CIRCUIT INSPECTION ....................................... 30
Control Units and Electrical Parts ........................... 35
PRECAUTIONS .................................................. 35
SMJ INSTALLATION ........................................... 36
CONSULT-II CHECKING SYSTEM .......................... 37
Description .............................................................. 37
Function and System Application ........................... 37
Nickel Metal Hydride Battery Replacement ............ 38
Checking Equipment .............................................. 38
CONSULT-II Start Procedure .................................. 38
CONSULT-II Data Link Connector (DLC) Circuit .... 39
INSPECTION PROCEDURE .............................. 39
LIFTING POINT ......................................................... 40
Pantograph Jack ..................................................... 40
Garage Jack and Safety Stand ............................... 40
2-Pole Lift ............................................................... 41
TOW TRUCK TOWING ............................................. 42
Tow Truck Towing ................................................... 42
2WD MODELS .................................................... 42
4WD MODELS .................................................... 43
Vehicle Recovery (Freeing a stuck vehicle) ............ 43
TIGHTENING TORQUE OF STANDARD BOLTS .... 44
Tightening Torque Table ......................................... 44
RECOMMENDED CHEMICAL PRODUCTS AND
SEALANTS ............................................................... 45
Recommended Chemical Products and Sealants ... 45
IDENTIFICATION INFORMATION ............................ 46
Model Variation ....................................................... 46
Identification Number .............................................. 47