Air Conditioning: Overview Infiniti FX45 I

Description

1. One-touch joints are pipe joints which do not require tools during piping connection.
2. Unlike conventional connection methods using union nuts and flanges, controlling tightening torque at connection point is not necessary.
3. When removing a pipe joint, use a disconnector.

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Note. Garter spring cannot be removed from cage of male-side piping. Indicator ring remains near piping connection point, however, this is not a malfunction. (This is to check piping connection during factory assembly.)

Scheme 3

1. Clean piping connection point, and set a disconnector.
2. Slide disconnector in axial direction of piping, and stretch garter spring with tapered point of disconnector.
3. Slide disconnector farther so that inside diameter of garter spring becomes larger than outside diameter of female-side piping flare. Then male-side piping can be disconnected.

Scheme 4

1. Clean piping connection points, and insert male-side piping into female-side piping.
2. Push inserted male-side piping harder so that female-side piping flare stretches garter spring.
3. If inside diameter of garter spring becomes larger than outside diameter of female-side piping flare, garter spring seats on flare. Then, it fits in between male-side piping cage and female-side piping flare to anchor piping connection point.

Note. When garter spring seats on flare, and fits in between male-side piping cage and female-side piping flare, it clicks.

Note. One-touch joint connection is used in points below. Low-pressure pipe 1 to low-pressure pipe 2 (O-ring size: 16) High-pressure pipe 1 to high-pressure pipe 2 (O-ring size: 8) High-pressure pipe 2 to high-pressure pipe 3 (O-ring size: 8) Low-pressure flexible hose to low-pressure pipe 1 (O-ring size: 16) Condenser to high-pressure flexible hose (O-ring size: 12) Condenser to high-pressure pipe 1 (O-ring size: 8)

Identification

Note. Vehicles with factory installed fluorescent dye have a green label. Vehicles without factory installed fluorescent dye have a blue label.

Identification Label For Vehicle

Vehicles with factory installed fluorescent dye have this identification label on the front side of hood.

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General Information

1. The V-6 variable compressor differs from previous units. The vent temperatures of the V-6 variable compressor do not drop too far below 5°C (41°F) when: Evaporator intake air temperature is less than 20°C (68°F). 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 wobble (swash) plate has changed and is not a malfunction.
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.

Lubricant Return Operation

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

1. Check 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. CAUTION: If excessive lubricant leakage is noted, do not perform the lubricant return operation. 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 condition 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. GO TO 3 .
3. Check Replacement Part Should the compressor be replaced? YES: GO TO «LUBRICANT ADJUSTING PROCEDURE FOR COMPRESSOR REPLACEMENT»(ref-171325-S12454162892005020800000) . NO: GO TO «LUBRICANT ADJUSTING PROCEDURE FOR COMPONENTS REPLACEMENT EXCEPT COMPRESSOR»(ref-171325-S41754906142005020800000) .

DESCRIPTION OF AIR CONDITIONER LAN CONTROL SYSTEM

The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door motor and intake door motor.

A configuration of these components is shown in the diagram below.

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Operation

The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp. sends mode door, air mix door and intake door motor opening angle data to the mode door motor LCU, air mix door motor LCU and intake door motor LCU.

The mode door motor, air mix door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the unified meter and A/C amp. 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, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the unified meter and A/C amp.

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DESCRIPTION OF CONTROL SYSTEM

The control system consists of input sensors, switches, the unified meter and A/C amp. (microcomputer) and outputs.

The relationship of these components is shown in the figure below

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CAN COMMUNICATION SYSTEM DESCRIPTION

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only. For details, refer to CAN COMMUNICATION UNIT .

The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to applicable sections (items) for details. Shifting from usual control to the self-diagnostic system is accomplished by starting the engine (turning the ignition switch ON) and pressing "OFF" switch for at least 5 seconds. The "OFF" switch must be pressed within 10 seconds after starting the engine (ignition switch is turned ON). This system will be canceled by either pressing AUTO switch or turning the ignition switch OFF. Shifting from one step to another is accomplished by means of pressing temperature switch (driver side), as required.

Additionally shifting from STEP-5 (in (Scheme 10) ) to AUXILIARY MECHANISM is accomplished by means of pressing (fan) UP switch.

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1. Set In Self-Diagnostic Mode Turn ignition switch ON. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned ON.), press OFF switch for at least 5 seconds. CAUTION: If battery voltage drops below 12V during diagnosis STEP-3 (in (Scheme 10) ), actuator speed becomes slower and as a result, the system may generate an error even when operation is usual. To avoid this, start engine before performing this diagnosis. Former STEP-1 (in (Scheme 10) ) (LEDs and display screen are checked) does not exist in this self-diagnosis function. GO TO 2.
2. Step-2: Sensor Circuits Are Checked For Open Or Short Circuit NOTE: Perform self-diagnosis STEP- 2 under sunshine. Does code No. 20 appear on the display? YES: GO TO 3. NO: GO TO 13.
3. Check To Advance Self-Diagnosis Step-3 Press temperature (UP) switch (driver side). Advance to self-diagnosis STEP-3 (in (Scheme 10) )? YES: GO TO 4. NO: Malfunctioning temperature switch. Replace A/C and AV switch.
4. Check To Return Self-Diagnosis Step-2 Press temperature (DOWN) switch (driver side). Return to self-diagnosis STEP-2 (in (Scheme 10) )? YES: GO TO 5. NO: Malfunctioning temperature switch. Replace A/C and AV switch.
5. Step-3: Mode Door And Intake Door Positions Are Checked Press temperature (UP) switch (driver side). Does code No. 30 appear on the display? YES: GO TO 6. NO: GO TO 14.
6. Step-4: Operation Of Each Door Motor Is Checked Press temperature (UP) switch (driver side). Press (DEF) switch. Code No. of each door motor test is indicated on the display. GO TO 7.
7. Check Actuators Refer to the following chart and confirm discharge air flow, air temperature, blower motor voltage and compressor operation. Checks must be made visually, by listening to any noise, or by touching air outlets with your hand, etc. for improper operation. *01: FOOT position during automatic control. Refer to «AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER»(ref-171325-S02645216502005020800000). OK or NG OK: GO TO 8. NG: Air outlet does not change. Go to Mode Door Motor Circuit. Refer to «MODE DOOR MOTOR CIRCUIT»(ref-171325-S21842999852005020800000). Intake door does not change. Go to Intake Door Motor Circuit. Refer to «INTAKE DOOR MOTOR CIRCUIT»(ref-171325-S21914509082005020800000). Blower motor operation is malfunctioning. Go to Blower Motor Circuit. Refer to «BLOWER MOTOR CIRCUIT»(ref-171325-S22414248262005020800000). Magnet clutch does not engage. Go to Magnet Clutch Circuit. Refer to «MAGNET CLUTCH CIRCUIT»(ref-171325-S06144828832005020800000). Discharge air temperature does not change. Go to Air Mix Door Motor Circuit. Refer to «AIR MIX DOOR MOTOR CIRCUIT»(ref-171325-S22430978422005020800000).
8. Step-5: Temperature Of Each Sensor Is Checked Press temperature (UP) switch (driver side). Code No. 51 appears on the display. GO TO 9.
9. Check Ambient Sensor Press (DEF) switch one time. Temperature detected by ambient sensor is indicated on the display. NOTE: If temperature shown on display greatly differs from actual temperature, check sensor circuit first, then inspect sensor. OK or NG OK: GO TO 10. NG: Go to Ambient Sensor Circuit. Refer to «AMBIENT SENSOR CIRCUIT»(ref-171325-S07279756292005020800000).
10. Check In-Vehicle Sensor Press (DEF) switch a second time. Temperature detected by in vehicle sensor is indicated on the display. NOTE: If temperature shown on display greatly differs from actual temperature, check sensor circuit first, then inspect sensor. OK or NG OK: GO TO 11. NG: Go to In-vehicle Sensor Circuit. Refer to «IN-VEHICLE SENSOR CIRCUIT»(ref-171325-S25013891422005020800000).
11. Check Intake Sensor Press (DEF) switch a third time. Temperature detected by intake sensor is indicated on the display. NOTE: If temperature shown on display greatly differs from actual temperature, check sensor circuit first, then inspect sensor. OK or NG OK: GO TO 12. NG: Go to Intake Sensor Circuit. Refer to «INTAKE SENSOR CIRCUIT»(ref-171325-S04168671762005020800000).
12. Check Can Communication Error Press (REC) switch. CAN communication error between unified meter and A/C amp. and DISPLAY UNIT or DISPLAY CONTROL UNIT is detected. OK or NG OK: Turn ignition switch OFF or AUTO switch ON. INSPECTION END NG: Go to CAN communication. Refer to CAN COMMUNICATION INSPECTION USING CONSULT-II (SELF-DIAGNOSIS). Unified meter and A/C amp. - DISPLAY UNIT Unified meter and A/C amp. - DISPLAY CONTROL UNIT
13. Check Malfunctioning Sensor Refer to the following chart for malfunctioning code No. (If two or more sensors malfunction, corresponding code Nos. blink respectively twice.) NOTE: *1: Perform self-diagnosis STEP- 2 under sunshine. When performing indoors, aim a light (more than 60W) at sunload sensor, otherwise Code No. 25 will indicate despite that sunload sensor is functioning properly. INSPECTION END
14. Check Malfunctioning Door Motor Position Switch Mode or (and) intake door motor PBR (s) is (are) malfunctioning. (If two or more mode or intake doors are out of order, corresponding code numbers blink respectively twice.) INSPECTION END

OPERATIONAL CHECK

The purpose of the operational check is to confirm that the system operates properly.

1. Conditions : Engine running and at usual operating temperature.

System Operation

The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp. sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the unified meter and A/C amp. 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 or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the unified meter and A/C amp.

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The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp. sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the unified meter and A/C amp. 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 or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the unified meter and A/C amp.

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The intake door control determines intake door position based on the ambient temperature, the intake air temperature and the in-vehicle temperature. When the DEFROST, or OFF switches are pushed or A/C switch is OFF, the unified meter and A/C amp. sets the intake door at the FRESH position.

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System Description

Unified meter and A/C amp. controls compressor operation by ambient temperature and signal from ECM.

Break-in Operation

When replacing compressor clutch assembly, always carry out the break-in operation. This is done by engaging and disengaging the clutch about thirty times. Break-in operation raises the level of transmitted torque.

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1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove the air cleaner and air duct. Refer to «AIR CLEANER AND AIR DUCT»(ref-158850-S12244247462005020300000) (VQ35DE) or «AIR CLEANER AND AIR DUCT»(ref-158963-S32645370962005020300000) (VK45DE).
3. Remove mounting bolt for low-pressure flexible hose bracket.
4. Disconnect one-touch joint between low-pressure flexible hose and low-pressure pipe 1. Set a disconnector (92530-89916) on A/C piping. Slide a disconnector toward vehicle front until it clicks. Slide A/C piping toward vehicle front and disconnect it. CAUTION: Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air.
5. Remove mounting nut from low-pressure flexible hose.
6. Remove low-pressure flexible hose. CAUTION: Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air.
7. Remove low-pressure pipe (VK45DE).

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