Automatic Air Conditioner: Other Nissan Maxima A34

Precautions for 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 front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.

Information necessary to service the system safely is included in SUPPLEMENTAL RESTRAINT SYSTEM (SRS) and SEAT BELTS .

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

Contaminated Refrigerant

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

1. Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into the atmosphere.
2. Explain that recovery of the contaminated refrigerant could damage your service equipment and refrigerant supply.
3. Suggest the customer return the vehicle to the location of previous service where the contamination may have occurred.
4. 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
5. 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.
6. If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact NISSAN Customer Affairs for further assistance.

General Refrigerant Precautions

Precautions for Leak Detection Dye

1. 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.
2. Always wear fluorescence enhancing UV safety glasses to protect your eyes and enhance the visibility of the fluorescent dye.
3. The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluorescent dye leak detector should be used in conjunction with an electronic refrigerant leak detector (J-41995).
4. For your safety and the customer's satisfaction, read and follow all manufacturer's operating instructions and precautions prior to performing work.
5. 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).
6. Always remove any dye from the leak area after repairs are complete to avoid a misdiagnosis during a future service.
7. 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 .
8. Do not spray the fluorescent dye cleaning agent on hot surfaces (engine exhaust manifold, etc.).
9. Do not use more than one bottle of refrigerant dye, 40 m l (1/4 ounce), per A/C system.
10. Leak detection dyes for R-134a and R-12 A/C systems are different. Do not use R-134a leak detection dye in R-12 A/C systems or R-12 leak detection dye in R-134a A/C systems or A/C system damage may result.
11. The fluorescent properties of the dye will remain for over three (3) years unless a compressor failure occurs.

Precautions for Refrigerant Connection

A new type refrigerant connection has been introduced to all refrigerant lines except the following locations.

1. Expansion valve to cooling unit
2. Evaporator pipes to evaporator (inside cooling unit)
3. Refrigerant pressure sensor

Scheme 125

1. The O-ring has been relocated. It has also been provided with a groove for proper installation. This eliminates 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.
2. The reaction force of the O-ring will not occur in the direction that causes the joint to pull out, thereby facilitating piping connections.

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1. 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.
2. When connecting tubes, always use a torque wrench and a back-up wrench.
3. After disconnecting tubes, immediately plug all openings to prevent entry of dirt and moisture.
4. When installing an air conditioner in the vehicle, connect the pipes as the final stage of the operation. Do not remove the seal caps of pipes and other components until just before required for connection.
5. 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.
6. Thoroughly remove moisture from the refrigeration system before charging the refrigerant.
7. Always replace used O-rings.
8. 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 DH-PS Part number: KLH00-PAGS0
9. O-ring must be closely attached to dented portion of tube.
10. When replacing the O-ring, be careful not to damage O-ring and tube.
11. 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.
12. 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.

Precautions for Servicing Compressor

1. Plug all openings to prevent moisture and foreign matter from entering.
2. When the compressor is removed, store it in the same position as it is when mounted on the car.
3. When replacing or repairing compressor, follow "Maintenance of Lubricant Quantity in Compressor" exactly. Refer to «MAINTENANCE OF LUBRICANT QUANTITY IN COMPRESSOR»(ref-233653-S31574508422006052600000) .
4. 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.
5. After compressor service operation, turn the compressor shaft by hand more than 5 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 1 hour.
6. After replacing the compressor magnet clutch, apply voltage to the new one and check for normal operation. Refer to «MAGNET CLUTCH CIRCUIT»(ref-233653-S19758029252006052600000) .

RECOVERY/RECYCLING EQUIPMENT

Follow the manufacturer's instructions for machine operation and machine maintenance. Never introduce any refrigerant other than that specified into the machine.

ELECTRONIC LEAK DETECTOR

Follow the manufacturer's instructions for tester operation and tester maintenance.

VACUUM PUMP

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 situated near the hose-to-pump connection, as follows.

1. Usually vacuum pumps have a manual isolator valve as part of the pump. Close this valve to isolate the service hose from the pump.
2. 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.
3. 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.

Scheme 129

MANIFOLD GAUGE SET

Be certain that the gauge face indicates R-134a or 134a. Make sure the gauge set has 1/2"-16 ACME threaded connections for service hoses. Confirm the set has been used only with refrigerant HFC-134a (R-134a) along with specified lubricant.

Scheme 130

SERVICE HOSES

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.

Scheme 131

SERVICE COUPLERS

Never attempt to connect HFC-134a (R134-a) service couplers to a 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 CHART

Scheme 132

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.

Special Service Tools

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

Scheme 133

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.

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REFRIGERANT FLOW

The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with 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.

REFRIGERANT PRESSURE SENSOR

The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the condenser. If the system pressure rises above or falls below the specifications, the refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM. ECM makes the A/C relay go OFF and stops the compressor when pressure on the high pressure side detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm 2 , 398 psi), or below about 120 kPa (1.22 kg/cm 2 , 17.4 psi).

PRESSURE RELIEF VALVE

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 2 , 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere.

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LUBRICANT

LUBRICANT SPECIFICATION

CHECKING AND ADJUSTING

Adjust the lubricant quantity according to the test group shown below.

Scheme 140

1. LUBRICANT RETURN OPERATION Can lubricant return operation be performed? A/C system works properly. There is no evidence of a large amount of lubricant leakage. Yes or No Yes: GO TO 2 . No: GO TO 3 .
2. PERFORM LUBRICANT RETURN OPERATION, PROCEEDING AS FOLLOWS Start engine, and set the following conditions: Test conditions: Engine speed: Idling to 1,200 RPM A/C switch: ON Blower speed: Max. position Temp. control: Optional [Set so that intake air temperature is 25° to 30°C (77° to 86°F).] Intake position: Recirculation (REC) Perform lubricant return operation for about 10 minutes. Stop engine. CAUTION: If excessive lubricant leakage is noted, do not perform the lubricant return operation. : GO TO 3 .
3. CHECK COMPRESSOR Should the compressor be replaced? Yes or No Yes: GO TO «LUBRICANT ADJUSTMENT PROCEDURE FOR COMPRESSOR REPLACEMENT»(ref-233653-S41290754412006052600000) . No: GO TO 4 .
4. CHECK ANY PART Is there any part to be replaced? (Evaporator, condenser, liquid tank or in case there is evidence of a large amount of lubricant leakage.) Yes or No Yes: GO TO Lubricant Adjusting Procedure For Components Replacement Except Compressor. No: Carry out the A/C performance test. Lubricant Adjusting Procedure for Components Replacement Except Compressor After replacing any of the following major components, add the correct amount of lubricant to the system. Amount of Lubricant to be Added

Scheme 141

1. Before connecting the recovery/recycling equipment to vehicle, check the recovery/recycling equipment gauges. No refrigerant pressure should be displayed. If NG, recover refrigerant from equipment lines.
2. Connect the recovery/recycling equipment to vehicle. Confirm refrigerant purity in supply tank using the recovery/recycling equipment and refrigerant identifier. If NG, refer to «CONTAMINATED REFRIGERANT»(ref-233653-S28228768942006052600000) .
3. Confirm refrigerant purity in vehicle A/C system using the recovery/recycling equipment and refrigerant identifier. If NG, refer to «CONTAMINATED REFRIGERANT»(ref-233653-S28228768942006052600000) .
4. Discharge refrigerant into the refrigerant recovery/recycling equipment. Measure lubricant discharged into the recovery/recycling equipment.
5. Drain the lubricant from the "old" (removed) compressor into a graduated container and recover the amount of lubricant drained.
6. Drain the lubricant from the "new" compressor into a separate, clean container.
7. Measure an amount of new lubricant installed equal to amount drained from "old" compressor. Add this lubricant to "new" compressor through the suction port opening.
8. Measure an amount of new lubricant equal to the amount recovered during discharging. Add this lubricant to "new" compressor through the suction port opening.
9. If the liquid tank also needs to be replaced, add an additional 5 ml (0.2 US fl oz, 0.2 Imp fl oz) of lubricant at this time. CAUTION: Do not add this 5 ml (0.2 US fl oz, 0.2 Imp fl oz) of lubricant if only replacing the compressor.

System Construction

A small network is constructed between the unified meter and A/C amp., air mix door motor, mode door motor and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission lines and motor power supply lines. The LAN communication is achieved using the dedicated communication line and ground line between each door motor and the unified meter and A/C amp.

The unified meter and A/C amp. identifies each motor type by its unique Address. Serial communication includes positioning and error checking information.

The following functions are contained in LCU's built into the air mix motor, mode door motor, and intake door motor.

Scheme 142

1. Address
2. Motor opening angle signals
3. Data transmission
4. Motor stop and drive decision
5. Opening angle sensor [Position balanced resistor (PBR) function]
6. Comparison
7. Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)

TRANSMISSION DATA AND TRANSMISSION ORDER

Unified meter and A/C amp. 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 unified meter and A/C amp. is selected according to data-based decisions made by the air mix door motor, mode door motor and intake 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 usual, 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 air mix door motor, mode door motor and intake door motor.

Error data can be related to the following symptoms.

1. Unusual electrical frequency
2. Poor electrical connections
3. Signal leakage from transmission lines
4. Signal level fluctuation

Stop signal

At the end of each transmission, a stop operation, in-operation, or internal error message is delivered to the unified meter and A/C amp. This completes one data transmission and control cycle.

Scheme 143

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.

FAN SPEED CONTROL

Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle temperature, intake temperature, amount of sunload and air mix door position.

When pressing AUTO switch, 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

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

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

Scheme 144

When A/C switch or DEF switch is pressed, unified meter and A/C amp. inputs compressor ON signal to BCM.

BCM sends compressor ON signal to ECM, via CAN communication line.

ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant-pressure sensor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to IPDM E/R, via CAN communication line.

Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate compressor.

DISPLAY SCREEN

Displays the operational status of the system.

AUTO SWITCH

1. The compressor, intake doors, air mix doors, 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.
2. When pressing AUTO switch, air inlet, air outlet, fan speed, and discharge air temperature are automatically controlled.

TEMPERATURE SWITCH (TEMPERATURE CONTROL) (DRIVER SIDE)

Increases or decreases the set temperature.

TEMPERATURE SWITCH (TEMPERATURE CONTROL) (PASSENGER SIDE)

1. Increases or decreases the set temperature.
2. When the temperature switch is pressed, the dual switch indicator will automatically illuminate.

RECIRCULATION (REC) SWITCH

1. When REC switch is ON, REC switch indicator turns ON, and air inlet is set to REC.
2. When REC switch is ON and is pressed for approximately 1.5 seconds or longer, REC and FRE switch indicators blink twice. Then, automatic control mode is entered. Inlet status is displayed even when in automatic mode.
3. When FRE switch is turned ON, or when compressor is turned from ON to OFF, REC switch is automatically turned OFF (set to FRE mode). REC mode can be re-entered by pressing REC switch again.
4. REC switch is not operated when DEF switch is turned ON, or at the D/F position.

FRESH (FRE) SWITCH

1. When FRE switch is ON, FRE switch indicator turns ON, and air inlet is set to FRE.
2. When FRE switch is ON and is pressed for approximately 1.5 seconds or longer, REC and FRE switch indicators blink twice. Then, automatic control mode is entered. Inlet status is displayed even during automatically controlled.
3. When REC switch is turned ON, FRE switch is automatically turned OFF (set to REC mode). FRE mode can be re-entered by pressing FRE switch again.

DEFROSTER (DEF) SWITCH

Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position. The compressor remains ON until the ignition is turned OFF.

REAR WINDOW DEFOGGER SWITCH

When illumination is ON, rear window is defogged.

OFF SWITCH

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 (75% foot and 25% defrost) position.

A/C SWITCH

The compressor is ON or OFF. (Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)

MODE SWITCH

Controls the air discharge outlets.

FAN CONTROL SWITCH

Manually control the blower speed. Seven speeds are available for manual control (as shown on the display screen).

DUAL SWITCH (WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATE CONTROL SYSTEM)

1. When the DUAL switch indicator is not illuminated and the DUAL switch is pressed, the driver-side setting temperature and passenger-side setting temperature can each be set independently.
2. When DUAL switch indicator is illuminated and the DUAL switch is pressed, the driver-side setting temperature is applied to both sides.

Fail-safe Function

1. If a communication error exists between unified meter and A/C amp. for 30 seconds or longer, air conditioner is controlled under following conditions: Compressor: ON Air outlet: AUTO Air inlet: FRE (Fresh) Blower fan speed: AUTO Set temperature: Setting before communication error occurs.

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CONSULT-II Function (METER A/C AMP)

CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.

CONSULT-II FUNCTION CHART

Display Item List

DISPLAY ITEM LIST

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Unified Meter and A/C Amp. Terminals and Reference Value

Measure voltage between each terminal and ground by following TERMINALS AND REFERENCE VALUE FOR UNIFIED METER AND A/C AMP. .

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Scheme 156

AUXILIARY MECHANISM: TEMPERATURE SETTING TRIMMER

The trimmer compensates for differences in range of +/-3°C (+/-6°F) between temperature setting (displayed digitally) and temperature felt by driver.

Operating procedures for this trimmer are as follows

Scheme 157

1. Begin Self-diagnosis STEP 5 mode. Refer to «A/C SYSTEM SELF - DIAGNOSIS FUNCTION»(ref-233653-S28848502902006052600000) .
2. Press top of fan control switch to set system in auxiliary mode.
3. Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.
4. Press top of temperature switch (driver side) as desired. Temperature will change at a rate of 0.5°C (1.0°F) each time the switch is pressed.

When battery cable is disconnected, trimmer operation is canceled. Temperature set becomes that of initial condition, i.e. 0°C (0°F).

AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER

Air distribution ratio in FOOT mode can be set.

Operating procedures for this trimmer are as follows

Scheme 158

1. Begin Self-diagnosis STEP 5 mode. Refer to «A/C SYSTEM SELF-DIAGNOSIS FUNCTION»(ref-233653-S28848502902006052600000) .
2. Press top of fan control switch to set system in auxiliary mode.
3. Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.
4. Press the mode switch as desired.

AUXILIARY MECHANISM: INLET PORT MEMORY FUNCTION

When ignition key is turned from OFF to ON, inlet port can be set to AUTO or manual.

Operating procedures for this trimmer are as follows

Scheme 159

1. Begin Self-diagnosis STEP 5 mode. Refer to «A/C SYSTEM SELF-DIAGNOSIS FUNCTION»(ref-233653-S28848502902006052600000) .
2. Press top of fan control switch to set system in auxiliary mode.
3. Display shows 61 in auxiliary mechanism. It takes approximately 3 seconds.
4. Press the recirculation (REC) and fresh (FRE) switch as desired.

CHECKING MEMORY FUNCTION

1. Set the temperature to 90°F or 32°C.
2. Press OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press OFF switch.

If NG, go to trouble diagnosis procedure for MEMORY FUNCTION .

Scheme 160

If OK, continue with next check.

CHECKING BLOWER

1. Press top of fan control switch. Blower should operate on low speed. The fan symbol should have one blade lit.
2. Press top of fan control switch again, and continue checking blower speed and fan symbol until all speeds are checked.
3. Leave blower on MAX speed.

If NG, go to trouble diagnosis procedure for DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR

If OK, continue with next check.

Scheme 161

Scheme 162

1. Press MODE switch four times and DEF switch.
2. Each position indicator should change shape.
3. Confirm that discharge air comes out according to the air distribution table. Refer to «DISCHARGE AIR FLOW»(ref-233653-S11960973232006052600000) .

Mode door position is checked in the next step.

If NG, go to trouble diagnosis procedure for MODE DOOR MOTOR CIRCUIT .

If OK, continue with next check.

Note. Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at FRESH when the DEF or D/F is selected.

Scheme 163

CHECKING RECIRCULATION

1. Press recirculation (REC) switch one time. Recirculation indicator should illuminate.
2. Press fresh (FRE) switch one time. Fresh indicator should illuminate.
3. Listen for intake door position change (you should hear blower sound change slightly).

If NG, go to trouble diagnosis procedure for INTAKE DOOR MOTOR CIRCUIT .

If OK, continue with next check.

Scheme 164

Note. Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at FRESH when the DEF or D/F is selected.

CHECKING TEMPERATURE DECREASE

1. Press bottom of temperature switch (driver side) until 18°C (60°F) is displayed.
2. Check for cold air at discharge air outlets.

If NG, go to trouble diagnosis procedure for INSUFFICIENT COOLING .

If OK, continue with next check.

Scheme 165

CHECKING TEMPERATURE INCREASE

1. Press top of temperature switch (driver side) until 32°C (90°F) is displayed.
2. Check for hot air at discharge air outlets.

If NG, go to trouble diagnosis procedure for INSUFFICIENT HEATING .

If OK, continue with next check.

Scheme 166

CHECK A/C SWITCH

1. Press A/C switch when AUTO switch is ON.
2. A/C switch indicator will turn ON. Confirm that the compressor clutch engages (sound or visual inspection).

If NG, go to trouble diagnosis procedure for MAGNET CLUTCH CIRCUIT .

If OK, continue with next check.

Scheme 167

CHECKING AUTO MODE

1. Press AUTO switch.
2. Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection). (Discharge air and blower speed will depend on ambient, in-vehicle, and set temperatures.)

If NG, go to trouble diagnosis procedure for POWER SUPPLY AND GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP. , then if necessary, trouble diagnosis procedure for MAGNET CLUTCH CIRCUIT .

Scheme 168

If all operational checks are OK (symptom cannot be duplicated), go to malfunction Simulation Tests in HOW TO PERFORM TROUBLE DIAGNOSIS FOR QUICK AND ACCURATE REPAIR and perform tests as outlined to simulate driving conditions environment. If symptom appears, refer to HOW TO PERFORM TROUBLE DIAGNOSIS FOR QUICK AND ACCURATE REPAIR and SYMPTOM TABLE and perform applicable trouble diagnosis procedures.

Power Supply and Ground Circuit for Unified Meter and A/C Amp.

SYMPTOM: A/C system does not come on.

Scheme 169

Unified meter and A/C amp. (Automatic Amplifier)

The unified meter and A/C amp. has a built-in microcomputer which processes information sent from various sensors needed for air conditioner operation. The air mix door motors, mode door motor, intake door motor, blower motor and compressor are then controlled.

The unified meter and A/C amp. is unitized with control mechanisms. When the various switches and temperature dials are operated, data is input to the unified meter and A/C amp. from the BCM using CAN communication.

Self-diagnostic functions are also built into unified meter and A/C amp. to provide quick check of malfunctions in the auto air conditioner system.

Scheme 170

Potentio Temperature Control (PTC)

The PTC is built into the A/C switch. It can be set at an interval of 0.5°C (1.0°F) in the 18°C (60°F) to 32°C (90°F) temperature range by pressing the temperature switch. The set temperature is displayed.

Scheme 171

LAN System Circuit

SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.

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1. CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP. SIDE Turn ignition switch ON. Check voltage between unified meter and A/C amp. harness connector M89 terminal 54 (L/W) and ground. 54 - Ground: Battery voltage OK or NG OK: GO TO 2 . NG: Replace unified meter and A/C amp.
2. CHECK SIGNAL FOR UNIFIED METER AND A/C AMP. SIDE Confirm A/C LAN signal between unified meter and A/C amp. harness connector M89 terminal 43 (L/B) and ground using an oscilloscope. OK or NG OK: GO TO 3 . NG: Replace unified meter and A/C amp.
3. CHECK POWER SUPPLY FOR MOTOR SIDE Check voltage between mode door motor harness connector M40 terminal 1 (L/W), driver side air mix door motor harness connector M39 terminal 1 (L/W), passenger side air mix door motor harness connector M87 terminal 1 (L/W), intake door motor harness connector M58 terminal 1 (L/W) and ground. 1 - Ground: Battery voltage OK or NG OK: GO TO 4 . NG: Repair harness or connector.
4. CHECK SIGNAL FOR MOTOR SIDE Confirm A/C LAN signal between mode door motor harness connector M40 terminal 3 (L/B), driver side air mix door motor harness connector M39 terminal 3 (L/B), passenger side air mix door motor harness connector M87 terminal 3 (L/B), intake door motor harness connector M58 terminal 3 (L/B) and ground using an oscilloscope. OK or NG OK: GO TO 5 . NG: Repair harness or connector.
5. CHECK MOTOR GROUND CIRCUIT Turn ignition switch OFF. Disconnect door motor connector. Check continuity between mode door motor harness connector M40 terminal 2 (B), driver side air mix door motor harness connector M39 terminal 2 (B), passenger side air mix door motor harness connector M87 terminal 2 (B), intake door motor harness connector M58 terminal 2 (B) and ground. 2 - Ground: Continuity should exist. OK or NG OK: GO TO 6 . NG: Repair harness or connector.
6. CHECK MOTOR OPERATION Disconnect and reconnect the motor connector and confirm the motor operation. OK or NG OK: (Operates normally.) Poor contact in motor connector. NG: (Does not operate normally.) GO TO 7 .
7. CHECK MODE DOOR MOTOR OPERATION Disconnect mode door motor and air mix door motor (driver side, passenger side) connector. Reconnect mode door motor connector and confirm the mode door motor operation. OK or NG OK: (Mode door motor operates normally.) GO TO 8 . NG: (Mode door motor does not operate normally.) Replace mode door motor.
8. CHECK AIR MIX DOOR MOTOR OPERATION Disconnect mode door motor connector. Reconnect air mix door motor connector (driver side, passenger side) and confirm the air mix door motor operation. OK or NG OK: (Air mix door motor operates normally.) GO TO 9 . NG: (Air mix door motor does not operate normally.) GO TO 10 .
9. CHECK INTAKE DOOR MOTOR OPERATION Disconnect air mix door motor connector (driver side, passenger side). Reconnect intake door motor connector and confirm the intake door motor operation. OK or NG OK: (Intake door motor operates normally.) Repair unified meter and A/C amp. NG: (Intake door motor does not operate normally.) Repair intake door motor.
10. CHECK AIR MIX DOOR MOTOR OPERATION Disconnect air mix door motor (driver side) connector. Confirm the air mix door motor (passenger side) operation. OK or NG OK: (Air mix door motor operates normally.) Repair driver side air mix door motor. NG: (Air mix door motor does not operate normally.) Repair passenger side air mix door motor.

Mode Door Motor Circuit

SYMPTOM

1. Air outlet does not change.
2. Mode door motor does not operate normally.

Scheme 180

Component Parts

Mode door control system components are

1. Unified meter and A/C amp.
2. Mode door motor (LCU)
3. A/C LAN system (PBR built-into mode motor and air mix motor)
4. In-vehicle sensor
5. Ambient sensor
6. Sunload sensor
7. Intake sensor

Mode Door Motor

The mode door motor is attached to the heater and cooling unit assembly. It rotates so that air is discharged from the outlet set by the unified meter and A/C amp. Motor rotation is conveyed to a link which activates the mode door.

Scheme 181

Air Mix Door Motor Circuit

SYMPTOM

1. Discharge air temperature does not change.
2. Air mix door motor does not operate.

Scheme 182

Air mix door control system components are

1. Unified meter and A/C amp.
2. Air mix door motor (LCU)
3. A/C LAN system (PBR built-into mode motor and air mix motor)
4. In-vehicle sensor
5. Ambient sensor
6. Sunload sensor
7. Intake sensor

Air Mix Door Motor

The air mix door motor is attached to the heater and cooling unit assembly. It rotates so that the air mix door is opened or closed to a position set by the unified meter and A/C amp. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the unified meter and A/C amp. by PBR built-in air mix door motor.

Scheme 183

Scheme 184

Air Mix Door Motor PBR Circuit

SYMPTOM

1. Discharge air temperature does not change.
2. PBR circuit is open or shorted.

Intake Door Motor Circuit

SYMPTOM

1. Intake door does not change.
2. Intake door motor does not operate normally.

Scheme 185

Intake door control system components are

1. Unified meter and A/C amp.
2. Intake door motor
3. A/C LAN system (PBR built-in mode motor and air mix door motor)
4. In-vehicle sensor
5. Ambient sensor
6. Sunload sensor
7. Intake sensor

Intake Door Motor

The intake door motor is attached to the intake unit. It rotates so that air is drawn from inlets set by the unified meter and A/C amp. Motor rotation is conveyed to a lever which activates the intake door.

Scheme 186

Blower Motor Circuit

SYMPTOM

1. Blower motor operation is malfunctioning.

Scheme 187

Fan speed control system components are

1. Unified meter and A/C amp.
2. A/C LAN system (PBR built-in mode door motor and air mix door motor)
3. In-vehicle sensor
4. Ambient sensor
5. Sunload sensor
6. Intake sensor
7. Fan control amp

Scheme 188

Automatic Mode

In the automatic mode, the blower motor speed is calculated by the unified meter and A/C amp. based on input from the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.

When the air flow is increased, the duty ratio of the blower fan motor's drive signal is changed at 8%/sec. to prevent a sudden increase in air flow.

In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low water temperature starting control and high passenger compartment temperature starting control are available.

Starting Fan Speed Control

Start Up From COLD SOAK Condition (Automatic mode)

In a cold start up condition where the engine coolant temperature is below 56°C (133°F), the blower will not operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the ambient and engine coolant temperature.

In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above 56°C (133°F), at which time the blower speed will increase to the objective speed.

Start Up From Usual or HOT SOAK Condition (Automatic mode)

The blower will begin operation momentarily after the AUTO switch is pushed. The blower speed will gradually rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective blower speed).

Blower Speed Compensation

Sunload

When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low speed. The low speed will vary depending on the sunload. During conditions of low or no sunload, the blower low speed is usual low speed (duty ratio 25%). During high sunload conditions, the display and unified meter and A/C amp. causes the blower speed to increase (duty ratio 49%).

Scheme 189

Fan Control Amp

The fan control amplifier is located on the cooling unit. The fan control amp. receives a gate voltage from the unified meter and A/C amp. to steplessly maintain the blower fan motor voltage in the 5 to 12 volt range (approx.).

Scheme 190

Blower Motor

Confirm smooth rotation of the blower motor.

Scheme 191

1. Ensure that there are no foreign particles inside the blower unit.

Magnet Clutch Circuit

SYMPTOM: Magnet clutch does not engage.

Scheme 192

Low Temperature Protection Control

Unified meter and A/C amp. will turn the compressor ON or OFF as determined by a signal detected by intake sensor.

When intake air temperature is higher than 4°C (39°F), the compressor turns ON. The compressor turns OFF when intake air temperature is lower than 2.5°C (37°F).

Scheme 193

The refrigerant pressure sensor is attached to the condenser.

Scheme 194

Insufficient Cooling

SYMPTOM: Insufficient cooling

Scheme 195

Scheme 196

Scheme 197

Insufficient Heating

SYMPTOM: Insufficient heating

Scheme 198

Memory Function

SYMPTOM: Memory function does not operate.

Scheme 199

Ambient Sensor

The ambient sensor is attached on the radiator core support (left side). It detects ambient temperature and converts it into a resistance value which is then input into the unified meter and A/C amp.

Scheme 200

AMBIENT TEMPERATURE INPUT PROCESS

The unified meter and A/C amp. includes a processing circuit for the ambient sensor input. However, when the temperature detected by the ambient sensor increases quickly, the processing circuit retards the unified meter and A/C amp. function. It only allows the unified meter and A/C amp. to recognize an ambient temperature increase of 0.33°C (0.6°F) per 100 seconds.

As an example, consider stopping for a cup of coffee after high speed driving. Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor will increase. This is because the heat from the engine compartment can radiate to the front grille area, location of the ambient sensor.

After disconnecting ambient sensor connector, measure resistance between terminals 2 and 1 at sensor harness side, using the table below.

TEMPERATURE AND RESISTANCE CHART

If NG, replace ambient sensor.

Scheme 201

In-vehicle Sensor

The in-vehicle sensor is located on instrument lower driver panel. It converts variations in temperature of compartment air drawn from the aspirator into a resistance value. It is then input into the unified meter and A/C amp.

Scheme 202

Aspirator

The aspirator is located on driver's side of heater and cooling unit assembly. It produces vacuum pressure due to air discharged from the heater and cooling unit assembly, continuously taking compartment air in the aspirator.

Scheme 203

Scheme 204

After disconnecting in-vehicle sensor connector, measure resistance between terminals 1 and 2 at sensor harness side, using the table below.

TEMPERATURE AND RESISTANCE CHART

If NG, replace in-vehicle sensor.

Scheme 205

Sunload Sensor

The sunload sensor is located on the passenger side defroster grille. It detects sunload entering through windshield by means of a photo diode. The sensor converts the sunload into a current value which is then input into the unified meter and A/C amp.

Scheme 206

SUNLOAD INPUT PROCESS

The unified meter and A/C amp. also includes a processing circuit which averages the variations in detected sunload over a period of time. This prevents drastic swings in the ATC system operation due to small or quick variations in detected sunload.

For example, consider driving along a road bordered by an occasional group of large trees. The sunload detected by the sunload sensor will vary whenever the trees obstruct the sunlight. The processing circuit averages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily obstructing the sunlight does not cause any change in the ATC system operation. On the other hand, shortly after entering a long tunnel, the system will recognize the change in sunload, and the system will react accordingly.

Measure voltage between unified meter and A/C amp. harness connector M89 terminal 50 (O) and ground.

If NG, replace unified meter and A/C amp.

Scheme 207

Scheme 208

1. When checking sunload sensor, select a place where sun shines directly on it.

Intake Sensor

The intake sensor is located on the heater and cooling unit assembly. It converts temperature of air after it passes through the evaporator into a resistance value which is then input to the unified meter and A/C amp.

Scheme 209

After disconnecting intake sensor connector, measure resistance between terminals 1 and 2 at sensor harness side, using the table below.

TEMPERATURE AND RESISTANCE CHART

If NG, replace intake sensor.

Scheme 210

Scheme 211

1. Remove the shift knob.
2. Remove the shift bezel.
3. Remove cluster lid C. Refer to «CLUSTER LID C»(ref-233659-S22039194722006052600000) .
4. Remove cluster lid D. Refer to «CLUSTER LID D»(ref-233659-S16700258672006052600000) .
5. Remove the center stack.
6. Remove the bolts securing the rear of the unified meter and A/C auto amp.
7. Remove the bolts on either side of display screen.
8. Gently spread the top of the bracket and remove the unified meter and A/C auto amp.

FUNCTION

The air inside the passenger compartment is kept clean in either the recirculation or fresh mode by the in-cabin microfilter in the blower unit.

Scheme 212

Discharging Refrigerant

Scheme 213

Scheme 214

Scheme 215

Components

Refer to PRECAUTIONS FOR REFRIGERANT CONNECTION .

Scheme 216

Scheme 217

Clutch Disc

If the contact surface shows signs of damage due to excessive heat, replace clutch disc and pulley.

Pulley

Check the appearance of the pulley assembly. If the contact surface of the pulley shows signs of excessive grooving, replace the clutch disc and pulley. The contact surfaces of the pulley assembly should be cleaned with a suitable solvent before installation.

Coil

Check the magnet coil for a loose connection or cracked insulation.

Scheme 218

Scheme 219

Scheme 220

Scheme 221

1. Install the magnet coil. CAUTION: Be sure to align the magnet coil pin with the hole in the compressor front head.
2. Install the magnet coil harness clip using a screwdriver.
3. Install the pulley assembly using Tool and a wrench, and then install the snap ring using snap ring pliers. Tool number: - (J-38873-A)
4. Install the clutch disc on the drive shaft, together with the original shim(s). Press the clutch disc down using the drive plate installer.
5. Install the center bolt using Tool. Center bolt: 12 N.m (1.2 kg-m, 9 ft-lb). Tool number: (J-44614) After tightening the center bolt to specification, check that the pulley rotates smoothly.

Checking for Refrigerant Leaks

1. Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C lubricant leakage, damage and corrosion. A/C lubricant leakage may indicate an area of refrigerant leakage. Allow extra inspection time in these areas when using either an electronic refrigerant leak detector or fluorescent dye leak detector. If dye is observed, confirm the leak with an electronic refrigerant leak detector. It is possible a prior leak was repaired and not properly cleaned.
2. When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all system components and connections.
3. When searching for refrigerant leaks using an electronic leak detector, move the probe along the suspected leak area at 25 - 50 mm (1 - 2 in) per second and no further than 6 mm (1/4 in) from the component. CAUTION: Moving the electronic leak detector probe slower and closer to the suspected leak area will improve the chances of finding a leak.

Checking System for Leaks Using the Fluorescent Leak Detector

1. Check A/C system for leaks using the UV lamp and safety goggles (J-42220) in a low sunlight area (area without windows preferable). Illuminate all components, fittings and lines. The dye will appear as a bright green/yellow area at the point of leakage. Fluorescent dye observed at the evaporator drain opening indicates an evaporator core assembly (tubes, core or TXV) leak.
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or cloth, with the UV lamp for dye residue.
3. After the leak is repaired, remove any residual dye using dye cleaner (J-43872) to prevent future misdiagnosis.
4. Perform a system performance check and verify the leak repair with an approved electronic refrigerant leak detector. NOTE: Other gases in the work area or substances on the A/C components, for example, anti-freeze, windshield washer fluid, solvents and lubricants, may falsely trigger the leak detector. Make sure the surfaces to be checked are clean. Clean with a dry cloth or blow off with shop air. Do not allow the sensor tip of the detector to contact with any substance. This can also cause false readings and may damage the detector.

Dye Injection

Note. This procedure is only necessary when recharging the system or when the compressor has seized and was replaced.

1. Check A/C system static (at rest) pressure. Pressure must be at least 345 kPa (3.52 kg/cm 2 , 50 psi).
2. Pour one bottle (1/4 ounce / 7.4 cc) of the A/C refrigerant dye into the injector tool (J-41459).
3. Connect the injector tool to the A/C LOW PRESSURE side service fitting.
4. Start engine and switch A/C ON.
5. When the A/C operating (compressor running), inject one bottle (1/4 ounce / 7.4 cc) of fluorescent dye through the low-pressure service valve using dye injector tool J-41459 (refer to the manufacturer's operating instructions).
6. With the engine still running, disconnect the injector tool from the service fitting. CAUTION: If repairing the A/C system or replacing a component, pour the dye directly into the open system connection and proceed with the service procedures.
7. Operate the A/C system for a minimum of 20 minutes to mix the dye with the system oil. Depending on the leak size, operating conditions and location of the leak, it may take from minutes to days for the dye to penetrate a leak and become visible.

PRECAUTIONS FOR HANDLING LEAK DETECTOR

When performing a refrigerant leak check, use a J-41995 A/C leak detector or equivalent. Ensure that the instrument is calibrated and set properly per the operating instructions.

The leak detector is a delicate device. In order to use the leak detector properly, read the operating instructions and perform any specified maintenance.

Scheme 222

Scheme 223

Scheme 224

Scheme 225

1. Position probe approximately 5 mm (3/16 in) away from point to be checked.
2. When testing, circle each fitting completely with probe.
3. Move probe along component approximately 25 to 50 mm (1 to 2 in)/sec.

CHECKING PROCEDURE

To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette smoke in the vicinity of the vehicle. Perform the leak test in calm area (low air/wind movement) so that the leaking refrigerant is not dispersed.

Scheme 226

1. Turn engine OFF.
2. Connect a suitable A/C manifold gauge set to the A/C service ports.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm 2 , 50 psi) above 16°C (61°F). If less than specification, recover/evacuate and recharge the system with the specified amount of refrigerant. NOTE: At temperatures below 16°C (61°F), leaks may not be detected since the system may not reach 345 kPa (3.52 kg/cm 2 , 50 psi).
4. Conduct the leak test from the high side (compressor discharge a to evaporator inlet f) to the low side (evaporator drain hose g to shaft seal l). Refer to «COMPONENTS»(ref-233653-S09365557372006052600000) . Perform a leak check for the following areas carefully. Clean the component to be checked and move the leak detected probe completely around the connection/component. Compressor Check the fitting of high-and low-pressure hoses, relief valve and shaft seal. Liquid tank Check the refrigerant pressure sensor. Service valves Check all around the service valves. Make sure service valve caps are secured on the service valves (to prevent leaks). NOTE: After removing A/C manifold gauge set from service valves, wipe any residue from valves to prevent any false readings by leak detector. Cooling unit (Evaporator) With the engine OFF, turn the blower fan on High for at least 15 seconds to dissipate any refrigerant traces in the cooling unit. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer's recommended procedure for actual wait time) before inserting the leak detector probe into the drain hose. Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water or dirt that may be in the drain hose.
5. If a leak detector detects a leak, verify at least once by blowing compressed air into area of suspected leak, then repeat check as outlined above.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components. If no leaks are found, perform steps 7 - 10 .
7. Start engine.
8. Set the heater A/C control as follows; A/C switch is ON Face mode Intake position on Recirculation Max cold temperature Blower speed on High
9. Run the engine at 1,500 RPM for at least 2 minutes.
10. Turn the engine off and perform leak check again following steps 4 through 6 above. Refrigerant leaks should be checked immediately after stopping the engine. Begin with the leak detector at the compressor. The pressure on the high pressure side will gradually drop after refrigerant circulation stops and pressure on the low pressure side will gradually rise, as shown in the graph. Some leaks are more easily detected when the pressure is high.
11. Before connecting the recovery/recycling equipment to the vehicle, check the recovery/recycling equipment gauges. No refrigerant pressure should be displayed. If pressure is displayed, recover the refrigerant from the recovery/recycling equipment lines and then check the refrigerant purity.
12. Confirm the refrigerant purity in supply tank using the refrigerant identifier equipment.
13. Confirm the refrigerant purity in the A/C system using the refrigerant identifier equipment.
14. Discharge the A/C system using approved refrigerant recovery equipment. Repair the leaking fitting or component as necessary.
15. Evacuate and recharge the A/C system and perform the leak test to confirm that there are no refrigerant leaks.
16. Conduct the A/C performance test to ensure that the A/C system works properly.

COMPRESSOR

COMPRESSOR SERVICE DATA SPECIFICATIONS

Lubricant Service Data Specifications

REFRIGERANT

REFRIGERANT SERVICE DATA SPECIFICATIONS

ENGINE IDLING SPEED

Refer to IDLE SPEED AND IGNITION TIMING CHECK .

BELT TENSION

Refer to TENSION ADJUSTMENT .