Nissan Pathfinder Heater Air Condition HA 2000 Owner's Manual

EXIT

CONTENTS

AUTO

PRECAUTIONS ...............................................................3

Supplemental Restraint System (SRS) ″AIR

BAG″ and ″SEAT BELT PRE-TENSIONER″...............3

Precautions for Working with HFC-134a (R-134a) .....3

General Refrigerant Precautions.................................4

Precautions for Refrigerant Connection......................4

Precautions for Servicing Compressor........................7

Precautions for Service Equipment.............................7

Wiring Diagrams and Trouble Diagnoses....................9

PREPARATION .............................................................10

Special Service Tools ................................................10

HFC-134a (R-134a) Service Tools and

Equipment..................................................................11

DESCRIPTION...............................................................14

Refrigeration System.................................................14

V-6 Variable Displacement Compressor....................15

Component Layout ....................................................21

Introduction................................................................22

Features.....................................................................22

Overview of Control System......................................25

Control Operation ......................................................25

Discharge Air Flow.....................................................27

System Description....................................................28

TROUBLE DIAGNOSES................................................29

Component Location..................................................29

Circuit Diagram..........................................................31

Wiring Diagram - A/C, A -..........................................32

Auto Amp. Terminals and Reference Value...............36

Self-diagnosis ............................................................38

How to Perform Trouble Diagnoses for Quick

and Accurate Repair..................................................48

Operational Check.....................................................49

A/C System................................................................52

Mode Door Motor.......................................................54

Air Mix Door Motor ....................................................60

Intake Door Motor......................................................64

Blower Motor..............................................................71

HEATER &

AIR CONDITIONER

SECTION

Magnet Clutch............................................................79

Insufficient Cooling ....................................................85

Insufficient Heating....................................................93

Noise..........................................................................94

Self-diagnosis ............................................................95

Memory Function.......................................................96

ECON (ECONOMY) Mode........................................97

Ambient Sensor Circuit..............................................97

In-vehicle Sensor Circuit..........................................101

Sunload Sensor Circuit............................................104

Intake Sensor Circuit...............................................108

Air Mix Door Motor PBR Circuit ..............................110

SERVICE PROCEDURE..............................................111

HFC-134a (R-134a) Service Procedure..................111

Maintenance of Lubricant Quantity in

Compressor .............................................................113

Compressor .............................................................116

Compressor Clutch..................................................116

Refrigerant Lines .....................................................120

Belt...........................................................................124

Fast Idle Control Device (FICD)..............................124

SERVICE DATA AND SPECIFICATIONS (SDS).......125

Auto..........................................................................125

PRECAUTIONS ...........................................................126

Supplemental Restraint System (SRS) ″AIR

BAG″ and ″SEAT BELT PRE-TENSIONER″...........126

Precautions for Working with HFC-134a (R-134a) .126

General Refrigerant Precautions.............................127

Precautions for Refrigerant Connection..................127

Precautions for Servicing Compressor....................130

Precautions for Service Equipment.........................130

Wiring Diagrams and Trouble Diagnoses................132

PREPARATION ...........................................................133

Special Service Tools ..............................................133

HFC-134a (R-134a) Service Tools and

Equipment................................................................134

MANUAL

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CONTENTS (Cont’d)

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DESCRIPTION.............................................................137

Refrigeration System...............................................137

V-6 Variable Displacement Compressor..................138

Component Layout ..................................................144

Control Operation ....................................................145

Discharge Air Flow...................................................146

System Description..................................................147

TROUBLE DIAGNOSES..............................................148

Component Location................................................148

Wiring Diagram - HEATER -....................................150

Circuit Diagram - Air Conditioner.............................151

Wiring Diagram - A/C, M -.......................................152

How to Perform Trouble Diagnoses for Quick

and Accurate Repair................................................155

Operational Check...................................................156

Intake Door..............................................................158

Blower Motor............................................................165

Insufficient Cooling ..................................................172

Insufficient Heating..................................................180

Air Outlet..................................................................182

Magnet Clutch..........................................................184

Noise........................................................................191

SERVICE PROCEDURE..............................................192

HFC-134a (R-134a) Service Procedure..................192

Maintenance of Lubricant Quantity in

Compressor .............................................................194

Compressor .............................................................197

Compressor Clutch..................................................197

Refrigerant Lines .....................................................201

Belt...........................................................................205

Fast Idle Control Device (FICD)..............................205

SERVICE DATA AND SPECIFICATIONS (SDS).......206

Manual.....................................................................206

HA-2

PRECAUTIONS

Supplemental Restraint System (SRS) “AIR BAG” and “SEAT BELT PRE-TENSIONER”

AUTO

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Supplemental Restraint System (SRS) “AIR BAG” and “SEAT BELT PRE-TENSIONER”

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELTPRE-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 NISSAN MODEL R50 is as follows:

I For a frontal collision

The Supplemental Restraint System consists of 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-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.

I For 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 ofcomponents 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:

I 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 must be performed by an authorized NISSAN dealer.

I 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.

I 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 tape either just before the harness connectors or for the complete harness are related to the SRS.

NAHA0153

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

WARNING:

I CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refrigerant are not compatible. If the refrigerants

are mixed and compressor failure 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-NI) and Refrigerant Identifier.

I Use only specified lubricant for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) compo-

nents. If lubricant other than that specified is used, compressor failure is likely to occur.

I The specified HFC-134a (R-134a) lubricant rapidly absorbs moisture from the atmosphere. The fol-

lowing 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 lubri-

cant. 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 equipment). 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.

CONTAMINATED REFRIGERANT

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

I Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into

the atmosphere.

I Explain that recovery of the contaminated refrigerant could damage your service equipment and refriger-

ant supply.

NAHA0154

NAHA0154S01

IDX

HA-3

PRECAUTIONS

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

AUTO

I Suggest the customer return the vehicle to the location of previous service where the contamination may

have occurred.

I If you choose to perform the repair, recover the refrigerant using only dedicated equipment and con-

tainers. Do not recover contaminated refrigerant into your existing service equipment. If your facil-

ity 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.

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

Customer Affairs for further assistance.

EXIT

General Refrigerant Precautions

NAHA0155

WARNING:

I Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the

refrigerant every time an air conditioning system is discharged.

I Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or

air conditioning system.

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

I Do not intentionally drop, puncture, or incinerate refrigerant containers. I Keep refrigerant away from open flames: poisonous gas will be produced if refrigerant burns. I Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent

suffocation.

I 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 manufacturers.

Precautions for Refrigerant Connection

NAHA0156

A new type refrigerant connection has been introduced to all refrigerant lines except the following location. I Expansion valve to cooling unit

FEATURES OF NEW TYPE REFRIGERANT CONNECTION

NAHA0156S01

I The O-ring has been relocated. It has also been provided with a groove for proper installation. This elimi-

nates the chance of the O-ring being caught in, or damaged by, the mating part. The sealing direction of the O-ring is now set vertically in relation to the contacting surface of the mating part to improve sealing characteristics.

I The reaction force of the O-ring will not occur in the direction that causes the joint to pull out, thereby

facilitating piping connections.

HA-4

PRECAUTIONS

O-RING AND REFRIGERANT CONNECTION

AUTO

Precautions for Refrigerant Connection (Cont’d)

SHA815E

NAHA0156S02

EXIT

SHA280FB

CAUTION:

The new and former refrigerant connections use different O-ring configurations. Do not confuse O-rings since they are not interchangeable. If a wrong O-ring is installed, refrigerant will leak at, or around, the connection.

HA-5

IDX

Precautions for Refrigerant Connection (Cont’d)

PRECAUTIONS

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EXIT

O-Ring Part Numbers and Specifications

Connection type

New

Former 92470 N8200 6.07 (0.2390) 1.78 (0.0701)

New

Former 92475 71L00 11.0 (0.433) 2.4 (0.094)

New

Former 92475 72L00 14.3 (0.563) 2.3 (0.0906)

SHA814E

New

Former 92477 N8200 17.12 (0.6740) 1.78 (0.0701)

O-ring

size

Part number D mm (in) W mm (in)

92471 N8210 6.8 (0.268) 1.85 (0.0728)

92472 N8210 10.9 (0.429) 2.43 (0.0957)

92473 N8210 13.6 (0.535) 2.43 (0.0957)

92474 N8210 16.5 (0.650) 2.43 (0.0957)

NAHA0156S0201

WARNING:

Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is less than atmospheric pressure. Then gradually loosen the discharge side hose fitting and remove it.

CAUTION:

When replacing or cleaning refrigerant cycle components, observe the following. I When the compressor is removed, store it in the same position as it is when mounted on the car.

Failure to do so will cause lubricant to enter the low pressure chamber.

I When connecting tubes, always use a torque wrench and a back-up wrench. I After disconnecting tubes, immediately plug all openings to prevent entry of dirt and moisture. I When installing an air conditioner in the vehicle, connect the pipes as the final stage of the opera-

tion. Do not remove the seal caps of pipes and other components until just before required for connection.

I Allow components stored in cool areas to warm to working area temperature before removing seal

caps. This prevents condensation from forming inside A/C components.

I Thoroughly remove moisture from the refrigeration system before charging the refrigerant. I Always replace used O-rings. I When connecting tube, apply lubricant to circle of the O-rings shown in illustration. Be careful not

to apply lubricant to threaded portion. Lubricant name: Nissan A/C System Oil Type S Part number: KLH00-PAGS0

I O-ring must be closely attached to dented portion of tube. I When replacing the O-ring, be careful not to damage O-ring and tube. I Connect tube until you hear it click, then tighten the nut or bolt by hand until snug. Make sure that

the O-ring is installed to tube correctly.

I After connecting line, conduct leak test and make sure that there is no leakage from connections.

When the gas leaking point is found, disconnect that line and replace the O-ring. Then tighten connections of seal seat to the specified torque.

HA-6

PRECAUTIONS

Precautions for Refrigerant Connection (Cont’d)

Precautions for Servicing Compressor

I Plug all openings to prevent moisture and foreign matter from entering. I When the compressor is removed, store it in the same position as it is when mounted on the car. I When replacing or repairing compressor, follow “Maintenance of Lubricant Quantity in Compres-

sor” exactly. Refer to HA-113.

I Keep friction surfaces between clutch and pulley clean. If the surface is contaminated, with

lubricant, wipe it off by using a clean waste cloth moistened with thinner.

I After compressor service operation, turn the compressor shaft by hand more than five turns in

both directions. This will equally distribute lubricant inside the compressor. After the compressor is installed, let the engine idle and operate the compressor for one hour.

I After replacing the compressor magnet clutch, apply voltage to the new one and check for normal

operation.

AUTO

RHA861F

NAHA0157

EXIT

Precautions for Service Equipment

RECOVERY/RECYCLING EQUIPMENT

Be certain to follow the manufacturers instructions for machine operation and machine maintenance. Never introduce any refrigerant other than that specified into the machine.

ELECTRONIC LEAK DETECTOR

Be certain to follow themanufacturer’s instructionsfor tester operation and tester maintenance.

NAHA0158

NAHA0158S01

NAHA0158S02

IDX

HA-7

Precautions for Service Equipment (Cont’d)

PRECAUTIONS

AUTO

EXIT

RHA270DA

VACUUM PUMP

NAHA0158S03

The lubricant contained inside the vacuum pump is not compatible with the specified lubricant for HFC-134a (R-134a) A/C systems. The vent side of the vacuum pump is exposed to atmospheric pressure. So the vacuum pump lubricant may migrate out of the pump into the service hose. This is possible when the pump is switched off after evacuation (vacuuming) and hose is connected to it. To prevent this migration, use a manual valve placed near the hose-to-pump connection, as follows.

I Usually vacuum pumps have a manual isolator valve as part

of the pump. Close this valve to isolate the service hose from the pump.

I For pumps without an isolator, use a hose equipped with a

manual shut-off valve near the pump end. Close the valve to isolate the hose from the pump.

I If the hose has an automatic shut off valve, disconnect the

hose from the pump. As long as the hose is connected, the valve is open and lubricating oil may migrate.

Some one-way valves open when vacuum is applied and close under a no vacuum condition. Such valves may restrict the pump’s ability to pull a deep vacuum and are not recommended.

MANIFOLD GAUGE SET

NAHA0158S04

Be certain that the gauge face indicates R-134a or 134a. Be sure the gauge set has 1/2″-16 ACME threaded connections for service hoses. Confirm the set has been used only with refrigerant HFC134a (R-134a) and specified lubricants.

SHA533D

RHA272D

RHA273D

SERVICE HOSES

NAHA0158S05

Be certain that the service hoses display the markings described (colored hose with black stripe). All hoses must include positive shut off devices (either manual or automatic) near the end of the hoses opposite the manifold gauge.

SERVICE COUPLERS

NAHA0158S06

Never attempt to connect HFC-134a (R-134a) service couplers to an CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will not properly connect to the CFC-12 (R-12) system. However, if an improper connection is attempted, discharging and contamination may occur.

Shut-off valve rotation A/C service valve Clockwise Open Counterclockwise Close

HA-8

PRECAUTIONS

AUTO

Precautions for Service Equipment (Cont’d)

EXIT

RHA274D

REFRIGERANT WEIGHT SCALE

Verify that no refrigerant other than HFC-134a (R-134a) and specified lubricants have been used with the scale. If the scale controls refrigerant flow electronically, the hose fitting must be 1/2″-16 ACME.

CALIBRATING ACR4 WEIGHT SCALE

Calibrate the scale every three months. To calibrate the weight scale on the ACR4 (J-39500-NI):

1. Press Shift/Reset and Enter at the same time.

2. Press 8787.“A1” will be displayed.

3. Remove all weight from the scale.

4. Press 0, then press Enter.“0.00” will be displayed and change to “A2”.

5. Place a known weight (dumbbell or similar weight), between

4.5 and 8.6 kg (10 and 19 lb) on the center of the weight scale.

6. Enter the known weight using four digits. (Example 10 lb =

10.00, 10.5 lb = 10.50)

7. Press Enter — the display returns to the vacuum mode.

8. Press Shift/Reset and Enter at the same time.

9. Press 6 — the known weight on the scale is displayed.

10. Remove the known weight from the scale. “0.00” will be displayed.

11. Press Shift/Reset to return the ACR4 to the program mode.

NAHA0158S07

NAHA0158S08

CHARGING CYLINDER

Using a charging cylinder is not recommended. Refrigerant may be vented into air from cylinder’s top valve when filling the cylinder with refrigerant. Also, the accuracy of the cylinder is generally less than that of an electronic scale or of quality recycle/recharge equipment.

Wiring Diagrams and Trouble Diagnoses

When you read wiring diagrams, refer to the following:

I GI-11, “HOW TO READ WIRING DIAGRAMS” I EL-10, “Wiring Diagram — POWER —”.

When you perform trouble diagnoses, refer to the following:

I GI-33, “HOW TO FOLLOW TROUBLE DIAGNOSES” I GI-23,“HOWTOPERFORMEFFICIENTDIAGNOSISFORAN

ELECTRICAL INCIDENT”

NAHA0158S09

NAHA0159

IDX

HA-9

Special Service Tools

PREPARATION

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EXIT

Special Service Tools

The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.

Tool number (Kent-Moore No.) Tool name

KV99106100 (J-41260) Clutch disc wrench

Description

Removing center bolt

NT232

NAHA0160

KV99232340 (J-38874) or KV992T0001 (—) Clutch disc puller

KV99106200 (J-41261) Pulley installer

NT378

Removing clutch disc

NT376

Installing pulley

NT235

HA-10

PREPARATION

AUTO

HFC-134a (R-134a) Service Tools and Equipment

EXIT

HFC-134a (R-134a) Service Tools and Equipment

Never mix HFC-134a refrigerant and/or its specified lubricant with CFC-12 (R-12) refrigerant and/or its lubricant. Separate and non-interchangeable service equipment must be used for handling each type of refrigerant/ lubricant. Refrigerant container fittings, service hose fittings and service equipment fittings (equipment which handles refrigerant and/or lubricant) are different between CFC-12 (R-12) and HFC-134a (R-134a). This is to avoid mixed use of the refrigerants/lubricant. Adapters that convert one size fitting to another must never be used: refrigerant/lubricant contamination will occur and compressor failure will result.

Tool number (Kent-Moore No.) Tool name

HFC-134a (R-134a) refrigerant

KLH00-PAGS0 (—) Nissan A/C System Oil Type S

(J-39500-NI) Recovery/Recycling Recharging equipment (ACR4)

Description

Container color: Light blue Container marking: HFC-134a (R-134a) Fitting size: Thread size I Large container 1/2″-16 ACME

NT196

Type: Poly alkylene glycol oil (PAG), type S Application: HFC-134a (R-134a) swash plate (piston) compressors (Nissan only) Lubricity: 40 m (1.4 US fl oz, 1.4 Imp fl oz)

NT197

Function: Refrigerant Recovery and Recycling and Recharging

=NAHA0161

(J-41995) Electrical leak detector

NT195

AHA281A

Power supply: I DC 12V (Cigarette lighter)

IDX

HA-11

PREPARATION

HFC-134a (R-134a) Service Tools and Equipment (Cont’d)

Tool number (Kent-Moore No.) Tool name

Description

AUTO

EXIT

(J-39183) Manifold gauge set (with hoses and couplers)

Service hoses I High side hose

(J-39501-72)

I Low side hose

(J-39502-72)

I Utility hose

(J-39476-72)

Service couplers I High side coupler

(J-39500-20)

I Low side coupler

(J-39500-24)

(J-39650) Refrigerant weight scale

Identification: I The gauge face indicates R-134a. Fitting size: Thread size I 1/2″-16 ACME

NT199

Hose color:

I Low hose: Blue with black stripe I High hose: Red with black stripe I Utility hose: Yellow with black stripe or green

with black stripe Hose fitting to gauge: I 1/2″-16 ACME

NT201

Hose fitting to service hose: I M14 x 1.5 fitting is optional or permanently

attached.

NT202

For measuring of refrigerant Fitting size: Thread size I 1/2″-16 ACME

(J-39649) Vacuum pump (Including the isolator valve)

NT200

Capacity:

I Air displacement: 4 CFM I Micron rating: 20 microns I Oil capacity: 482 g (17 oz)

Fitting size: Thread size I 1/2″-16 ACME

NT203

HA-12

PREPARATION

HFC-134a (R-134a) Service Tools and Equipment (Cont’d)

AUTO

EXIT

COMMERCIAL SERVICE TOOL

Tool name Description Refrigerant identifier

equipment

NT765

NAHA0161S01

For checking refrigerant purity and for system contamination

HA-13

IDX

DESCRIPTION

Refrigeration System

AUTO

Refrigeration System

REFRIGERATION CYCLE Refrigerant Flow

The refrigerant flows in the standard pattern, that is, through the compressor, the condenser, the liquid tank, through the evaporator, and back to the compressor. The refrigerant evaporation through the evaporator coil is controlled by an externally equalized expansion valve, located inside the evaporator case.

NAHA0162

NAHA0162S01

EXIT

Freeze Protection

NAHA0162S02

Under normal operating conditions, when the A/C is switched ON, the compressor runs continuously, and the evaporator pressure, and therefore temperature, is controlled by the V-6 variable displacement compressor to prevent freeze up.

Refrigerant System Protection

Dual-pressure Switch

NAHA0162S03

NAHA0162S0301

The refrigerant system is protected against excessively high or low pressures by the dual-pressure switch, located on the liquid tank. If the system pressure rises above, or falls below the specifications, the dual-pressure switch opens to interrupt the compressor operation.

Pressure Relief Valve

NAHA0162S0302

The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor. When the pressure of refrigerant in the system increases to an abnormal level [more than 3,727 kPa (38

kg/cm

, 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant

into the atmosphere.

HA-14

RHA896FA

DESCRIPTION

AUTO

V-6 Variable Displacement Compressor

EXIT

V-6 Variable Displacement Compressor

GENERAL INFORMATION

1. The V-6 variable compressor differs from previous units. The vent temperatures of the V-6 variable compress do not drop too far below 5°C (41°F) when:

I evaporator intake air temperature is less than 20°C (68°F) I engine is running at speeds less than 1,500 rpm.

This is because the V-6 compressor provides a means of “capacity” control.

2. The V-6 variable compressor provides refrigerant control under varying conditions. During cold winters, it may not produce high refrigerant pressure discharge (compared to previous units) when used with air conditioning systems.

3. A “clanking” sound may occasionally be heard during refrigerant charge. The sound indicates that the tilt angle of the swash plate has changed and is not a problem.

4. For air conditioning systems with the V-6 compressor, the clutch remains engaged unless: the system main switch, fan switch or ignition switch is turned OFF. When ambient (outside) temperatures are low or when the amount of refrigerant is insufficient, the clutch is disengaged to protect the compressor.

5. A constant range of suction pressure is maintained when engine speed is greater than a certain value. It normally ranges from 147 to 177 kPa (1.5 to 1.8 kg/cm In previous compressors, however, suction pressure was reduced with increases in engine speed.

, 21 to 26 psi) under varying conditions.

=NAHA0163

HA-15

IDX

V-6 Variable Displacement Compressor (Cont’d)

DESCRIPTION

AUTO

EXIT

DESCRIPTION General

=NAHA0164

NAHA0164S01

The variable compressor is basically a swash plate type that changes piston stroke in response to the required cooling capacity. The tilt of the swash plate allows the piston’s stroke to change so that refrigerant discharge can be continuously changed from 14.5 to 184 cm

(0.885 to 11.228 cu in).

HA-16

RHA037DD

DESCRIPTION

AUTO

V-6 Variable Displacement Compressor (Cont’d)

EXIT

Operation

1. Operation Control Valve

Operation control valve is located in the suction port (low-pressure) side, and opens or closes in response to changes in refrigerant suction pressure. Operation of the valve controls the internal pressure of the crankcase. The angle of the swash plate is controlled between the crankcase’s internal pressure and the piston cylinder pressure.

2. Maximum Cooling

Refrigerant pressure on the low-pressure side increases with an increase in heat loads. When this occurs, the control valve’s bellows compress to open the low-pressure side valve and close the high-pressure side valve. This causes the following pressure changes:

I the crankcase’s internal pressure to equal the pressure on the low-pressure side; I the cylinder’s internal pressure to be greater than the crankcase’s internal pressure.

Under this condition, the swash plate is set to the maximum stroke position.

=NAHA0164S02

NAHA0164S0201

NAHA0164S0202

RHA473C

HA-17

IDX

V-6 Variable Displacement Compressor (Cont’d)

DESCRIPTION

AUTO

EXIT

3. Capacity Control

=NAHA0164S0203

I Refrigerant pressure on suction side is low during high speed driving or when ambient or interior tempera-

ture is low.

I The bellows expands when refrigerant pressure on the suction pressure side drops below approximately

177 kPa (1.8 kg/cm

, 26 psi). Since suction pressure is low, it makes the suction port close and the discharge port open. Thus, crankcase pressure becomes high as high pressure enters the crankcase.

I The force acts around the journal pin near the swash plate, and is generated by the pressure difference

before and behind the piston. The drive lug and journal pin are located where the piston generates the highest pressure. Piston pressure is between suction pressure Ps and discharge pressure Pd, which is near suction pressure Ps. If crankcase pressure Pc rises due to capacity control, the force around the journal pin makes the swash plate angle decrease and also the piston stroke decrease. In other words, crankcase pressure increase triggers pressure difference between the piston and the crankcase. The pressure difference changes the angle of the swash plate.

RHA474C

HA-18

DESCRIPTION

AUTO

V-6 Variable Displacement Compressor (Cont’d)

EXIT

FICD CONTROL SYSTEM General

With the variable displacement compressor, the compressor power requirements differ from when the ambient temperature is high and maximum cooling effect is required (i.e., when refrigerating load is large and the tilt angle of the compressor swash plate is large) to when the ambient temperature is low and less cooling effect is required (i.e., when refrigerating load is small and the tilt angle of the swash plate is small). To correspond correctly to this change in compressor power requirements, it is also necessary to control the operation of the IACV-FICD according to the refrigerating load. Thus, an ambient air temperature switch is provided on the front face of the condenser so that the IACV-FICD can be controlled depending on the ambient temperature.

=NAHA0165

NAHA0165S01

RHA872CB

HA-19

IDX

V-6 Variable Displacement Compressor (Cont’d)

DESCRIPTION

AUTO

EXIT

Operation

=NAHA0165S02

When the air conditioner is OFF, the ECM detects the load applied to the engine, and controls the IACV-AAC valve to adjust the engine idling speed to the appropriate rpm by supplying additional air from the IACV-AAC valve. When the air conditioner is ON (A/C relay is ON), and when the ambient air temperature switch is ON [this switch turns ON automatically when the ambient temperature rises to approx. 25.0°C (77°F) or higher], the IACV-FICD solenoid valve is energized and additional air is supplied to the engine. If the appropriate engine speed is not reached, the IACV-AAC valve supplies the additional air required to increase the engine rpm. If the ambient air temperature switch is OFF [this switch turns OFF when the ambient temperature is below

19.0°C (66°F)] even when the air conditioner is ON (A/C relay is ON), the IACV-FICD solenoid valve is deenergized, and the idling speed is controlled so that the appropriate rpm can be achieved by operation of the IACV-AAC valve only.

RHA045G

RHA873CC

HA-20

DESCRIPTION

AUTO

Component Layout

EXIT

Component Layout

NAHA0166

HA-21

RHA451G

IDX

Introduction

DESCRIPTION

AUTO

EXIT

Introduction

AIR CONDITIONER LAN SYSTEM OVERVIEW CONTROL SYSTEM

NAHA0167

NAHA0167S01

The LAN system consists of auto amp., mode door motor and air mix door motor. A configuration of these components is shown in the diagram below.

RHA439G

Features

SYSTEM CONSTRUCTION (LAN)

NAHA0168

NAHA0168S01

A small network is constructed between the auto amplifier, mode door motor and air mix door motor. The auto amplifier and motors are connected by data transmission lines and motor power supply lines. The LAN network is built through the ground circuits of the two motors. Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted through the data transmission lines connecting the auto amplifier and two motors. The following functions are contained in LCUs built into the mode door motor and the air mix door motor.

I Address I Motor opening angle signals I Data transmission I Motor stop and drive decision I Opening angle sensor (PBR function) I Comparison I Decision (Auto amplifier indicated value and motor opening angle comparison)

RHA440GA

Operation

NAHA0168S0101

The auto amplifier receives data from each of the sensors. The amplifier sends mode door and air mix door opening angle data to the mode door motor LCU and air mix door motor LCU. The mode door motor and air mix door motor read their respective signals according to the address signal. Opening angle indication signals received from the auto amplifier and each of the motor position sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/ COLD or DEFROST/VENT operation is selected. The new selection data is returned to the auto amplifier.

HA-22

DESCRIPTION

AUTO

Features (Cont’d)

RHA441GA

EXIT

Transmission Data and Transmission Order

Amplifier data is transmitted consecutively to each of the door motors following the form shown in figure below. Start: Initial compulsory signal sent to each of the door motors. Address: Data sent from the auto amplifier is selected according to data-based decisions made by the mode door motor and air mix door motor. If the addresses are identical, the opening angle data and error check signals are received by the door motor LCUs. The LCUs then make the appropriate error decision. If the opening angle data is normal, door control begins. If an error exists, the received data is rejected and corrected data received. Finally, door control is based upon the corrected opening angle data. Opening angle: Data that shows the indicated door opening angle of each door motor. Error check: Procedure by which sent and received data is checked for errors. Error data is then compiled. The error check prevents corrupted data from being used by the mode door motor and air mix door motor. Error data can be related to the following problems.

I Abnormal electrical frequency I Poor electrical connections I Signal leakage from transmission lines I Signal level fluctuation

Stop signal: At the end of each transmission, a stop operation, in-operation, or internal problem message is delivered to the auto amplifier. This completes one data transmission and control cycle.

NAHA0168S0102

RHA442G

Air Mix Door Control (Automatic Temperature Control)

The air mix door is automatically controlled so that in-vehicle temperature is maintained at a predetermined value by: The temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.

NAHA0168S0103

HA-23

IDX

Features (Cont’d)

DESCRIPTION

AUTO

EXIT

Fan Speed Control

NAHA0168S0104

Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle temperature, intake temperature, amount of sunload and air mix door position. With FAN switch set to “AUTO”, the blower motor starts to gradually increase air flow volume. When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flowing.

Intake Door Control

NAHA0168S0105

The intake doors are automatically controlled by: The temperature setting, ambient temperature, in-vehicle temperature, intake temperature, amount of sunload and ON-OFF operation of the compressor.

Outlet Door Control

NAHA0168S0106

The outlet door is automatically controlled by: The temperature setting, ambient temperature, in-vehicle temperature, intake temperature and amount of sunload.

Magnet Clutch Control

NAHA0168S0107

The ECM controls compressor operation using input signals from the throttle position sensor and auto amplifier.

Self-diagnostic System

NAHA0168S0108

The self-diagnostic system is built into the auto amplifier (LCU) to quickly locate the cause of problems.

HA-24

DESCRIPTION

AUTO

Overview of Control System

EXIT

Overview of Control System

The control system consists of input sensors, switches, the automatic amplifier (microcomputer) and outputs. The relationship of these components is shown in the diagram below:

=NAHA0169

Control Operation

SHA435F

NAHA0170

HA-25

RHA452G

IDX

Control Operation (Cont’d)

DESCRIPTION

AUTO

EXIT

DISPLAY SCREEN

NAHA0170S01

Displays the operational status of the system.

AUTO SWITCH

NAHA0170S02

The compressor, intake doors, air mix door, outlet doors, and blower speed are automatically controlled so that the in-vehicle temperature will reach, and be maintained at the set temperature selected by the operator.

ECON SWITCH

NAHA0170S03

By pressing the ECON switch, the display should indicate ECON and the compressor always turns OFF. With the compressor OFF, the system will not remove heat (cool) or de-humidify. The system will maintain the invehicle temperature at the set temperature when the set temperature is above the ambient (outside) temperature. The system will set the intake doors to the outside air position.

TEMPERATURE SWITCH (POTENTIO TEMPERATURE CONTROL)

NAHA0170S04

Increases or decreases the set temperature.

OFF SWITCH

NAHA0170S05

The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet doors are set to the foot (80% foot and 20% defrost) position.

FAN SWITCH

NAHA0170S06

Manual control of the blower speed. Four speeds are available for manual control (as shown on the display screen): low

RECIRCULATION (REC) SWITCH

, medium low , medium high , high

NAHA0170S07

OFF position: Outside air is drawn into the passenger compartment. ON position: Interior air is recirculated inside the vehicle.

DEFROSTER (DEF) SWITCH

NAHA0170S08

Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position.

MODE SWITCH

NAHA0170S09

Controls the air discharge outlets.

HA-26

DESCRIPTION

AUTO

Discharge Air Flow

EXIT

Discharge Air Flow

NAHA0171

HA-27

RHA043G

IDX

System Description

DESCRIPTION

AUTO

EXIT

System Description

SWITCHES AND THEIR CONTROL FUNCTIONS

Position or switch

VENT B/L FOOT D/F ON OFF ON OFF

MODE SW DEF SW

AUTOSWECON

NAHA0246

NAHA0246S01

RHA044GA

REC SW Temperature SW

Door 18.0°C

(65°F)

Ventilator door

Foot door

Defroster door

Air mix door

Intake door

*1: Automatically controlled when REC switch is OFF.

ABCCC

ABCCA — —

AABCC — —

— — — A AUTO B

— C A AUTO*1 —

— AUTO AUTO

——

—

32.0°C (85°F)

HA-28

TROUBLE DIAGNOSES

AUTO

Component Location

EXIT

Component Location

ENGINE COMPARTMENT

NAHA0172

NAHA0172S01

HA-29

SHA282F

IDX

Component Location (Cont’d)

TROUBLE DIAGNOSES

AUTO

EXIT

PASSENGER COMPARTMENT

NAHA0172S02

HA-30

RHA498GB

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