Automatic Air Conditioner: Overview Infiniti M45 III рестайлинг

OPERATION PROCEDURE

1. Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock will remain released with both battery cables disconnected and the steering wheel can be turned.
4. Perform the necessary repair operation.
5. When the repair work is completed, re-connect both battery cables. With the brake pedal released, turn the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering wheel will lock when the push-button ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.

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 the identification label on the front side of hood.

GENERAL INFORMATION

1. The 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.
2. For air conditioning systems with the 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.

DESCRIPTION

General

The variable compressor is 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 continuously change from approx. 0 to 171 cm 3 (0 to 10.4 cu in).

Scheme 6

Operation

Scheme 7

Scheme 8

1. Control Valve By changing high-pressure valve lift amount, built-in electronic control valve executes the following: Controls high-pressure valve discharge amount. Changes crankcase pressure in compressor. Changes angle of swash plate. Amount of high-pressure valve lift is determined by factors below. Low-pressure applied to diaphragm Spring load of set spring Balance of magnetic force generated in magnet coil Electronic control valve (ECV) magnet coil receives electric signal (duty control) from unified meter and A/C amp. Then, magnetic force generated by electric current is changed to control high-pressure valve lift amount.
2. Maximum Cooling High-pressure valve is closed by magnetic force generated by electric signal sent from unified meter and A/C amp. At this time, cylinder moves full stroke due to pressure balance between inside crankcase (Pc) and suction line (Ps). Under this condition, the swash plate is set to the maximum stroke position.
3. Capacity Control When no electric signal is sent from unified meter and A/C amp. (current: OFF), high-pressure valve is opened by spring force. 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. The force acts around the link near the swash plate, and is generated by the pressure difference before and behind the piston. The thrust flange and link are located where the piston generates the highest pressure. Piston pressure is between suction pressure PS and discharge pressure PD, which is close to suction pressure PS. If crankcase pressure PC rises due to capacity control, the force around the link 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.

Scheme 9

Description of Air Conditioner LAN Control System

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

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

Scheme 10

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, upper ventilator door and intake door opening angle data to the mode door motor LCUs, air mix door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.

The mode door motors, air mix door motors, upper ventilator 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 is compared by the LCUs in each door motor with the existing decision and opening angles. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/REC operation is selected. The new selection data is returned to the unified meter and A/C amp.

Scheme 11

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

Scheme 12

Scheme 13

Scheme 14

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 SYSTEM SPECIFICATION CHART ".

The self-diagnosis system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to applicable items for details. Shifting from normal control to the self-diagnosis 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 is accomplished by means of pressing temperature control switch (driver side), as required.

Shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing fan (UP: +) switch.

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

1. SET IN SELF-DIAGNOSIS MODE Turn ignition switch ON. Set in self-diagnosis mode as per the following. Press OFF switch for at least 5 seconds Within 10 seconds after starting engine (ignition switch is turned ON). NOTE: If battery voltage drops below 12 V during diagnosis STEP-3, door motor speed becomes slower and as a result, the system may generate an error even when operation is normal. To avoid this, start engine before performing this diagnosis. Former STEP-1 (LEDs and display screen are checked) does not exist in this self-diagnosis function. GO TO 2.
2. STEP-2: SENSOR AND DOOR MOTOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT 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 control (UP) switch (driver side). Advance to self-diagnosis STEP-3? YES: GO TO 4. NO: Replace Multifunction switch. (Temperature control switch is malfunctioning.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2 Press temperature control (DOWN) switch (driver side). Return to self-diagnosis STEP-2? YES: GO TO 5. NO: Malfunctioning multifunction switch or unified meter and A/C amp. Refer to " «SELF-DIAGNOSIS»(ref-356249-S02872234142010021300000) ".
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED Press temperature control (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 control (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 «MODE DOOR POSITION CHART»(ref-356249-S13220437982010021300000) and check discharge air flow, air temperature, blower motor duty ratio and compressor operation. MODE DOOR POSITION CHART Code No. 41 42 43 44 45 46 Mode door position VENT B/L 1 B/L 2 FOOT (1) D/F DEF Upper ventilator door position OPEN SHUT SHUT SHUT SHUT SHUT Intake door position REC REC 20% FRE FRE FRE FRE Air mix door position FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT FULL HOT Blower motor duty ratio 37% 91% 65% 65% 65% 91% Compressor ON ON OFF OFF ON ON Electronic control valve (ECV) duty ratio 100% 100% 0% 0% 50% 100% (1) Mode door position is in a condition of FOOT position setting trimmer (automatic control). Refer to " «FOOT POSITION SETTING TRIMMER»(ref-356249-S41443882352010021300000) ". Checks must be made visually, by listening the sound, or by touching air outlets with hand, etc. for improper operation. Is this inspection result normal? YES: GO TO 8. NO-1: Air outlet does not change. Refer to " «MODE DOOR MOTOR CIRCUIT»(ref-356249-S00205665342010021300000) ". NO-2: Upper ventilator outlet does not change. Refer to " «UPPER VENTILATOR DOOR MOTOR CIRCUIT»(ref-356249-S23114453252010021300000) ". NO-3: Intake door does not change. Refer to " «INTAKE DOOR MOTOR CIRCUIT»(ref-356249-S37498890682010021300000) ". NO-4: Discharge air temperature does not change. Refer to " «AIR MIX DOOR MOTOR CIRCUIT»(ref-356249-S02835576952010021300000) ". NO-5: Blower motor operation is malfunctioning. Refer to " «BLOWER MOTOR CIRCUIT»(ref-356249-S22388012282010021300000) ". NO-6: Magnet clutch does not engage. Refer to " «MAGNET CLUTCH CIRCUIT»(ref-356249-S33695836202010021300000) ".
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED Press temperature control (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: Check sensor circuit first if the temperature indicated on the display greatly differs from the actual temperature, and then check sensor. Is this inspection result normal? YES: GO TO 10. NO: Go to Ambient Sensor Circuit. Refer to " «AMBIENT SENSOR CIRCUIT»(ref-356249-S18248452392010021300000) ".
10. CHECK IN-VEHICLE SENSOR Press DEF switch for the second time. Temperature detected by in-vehicle sensor is indicated on the display. NOTE: Check sensor circuit first if the temperature indicated on the display greatly differs from the actual temperature, and then check sensor. Is this inspection result normal? YES: GO TO 11. NO: Go to In-vehicle Sensor Circuit. Refer to " «IN-VEHICLE SENSOR CIRCUIT»(ref-356249-S42308621932010021300000) ".
11. CHECK INTAKE SENSOR Press DEF switch for the third time. Temperature detected by intake sensor is indicated on the display. NOTE: Check sensor circuit first if the temperature indicated on the display greatly differs from the actual temperature, and then check sensor. Is this inspection result normal? YES: GO TO 12. NO: Go to Intake Sensor Circuit. Refer to " «INTAKE SENSOR CIRCUIT»(ref-356249-S31489164352010021300000) ".
12. CHECK CAN COMMUNICATION ERROR Press intake switch. CAN communication error between each unit that uses the unified meter and A/C amp. can be detected as self-diagnosis results. (If plural errors occur, the display of each error will blink twice for 0 - 5 second intervals.) Is this inspection result normal? YES: INSPECTION END NO: Go to CAN communication (Unified meter and A/C amp. - AV control unit). Refer to " «DTC [U1000] CAN COMMUNICATION CIRCUIT»(ref-356277-S14951125992010021300000) ".
13. CHECK MALFUNCTIONING SENSOR AND DOOR MOTOR Refer to «AMBIENT SENSOR REFERENCE»(ref-356249-S14947955522010021300000) for malfunctioning code No . (Corresponding code Nos. indicates 1 second each if two or more sensors and door motors malfunction.) (Corresponding code Nos. indicates 0.5 second each if two door motors malfunction.) AMBIENT SENSOR REFERENCE Code No. Malfunctioning sensor and door motor (Including circuits) Reference 21/-21 Ambient sensor " «AMBIENT SENSOR CIRCUIT»(ref-356249-S18248452392010021300000) ". 22/-22 In-vehicle sensor " «IN-VEHICLE SENSOR CIRCUIT»(ref-356249-S42308621932010021300000) ". 24/-24 Intake sensor " «INTAKE SENSOR CIRCUIT»(ref-356249-S31489164352010021300000) ". 25/-25 Sunload sensor (1) " «SUNLOAD SENSOR CIRCUIT»(ref-356249-S26292109592010021300000) ". 26/-26 Air mix door motor PBR (Driver side) " «AIR MIX DOOR MOTOR PBR CIRCUIT»(ref-356249-S18424216432010021300000) ". 27/-27 Air mix door motor PBR (Passenger side) (1) Perform self-diagnosis STEP-2 under sunshine. When performing indoors, aim a light (more than 60 W) 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 Door motor PBR is malfunctioning. DOOR POSITION REFERENCE Code No. (1) (2) (3) Door position Reference 31 VENT (Driver side) Mode door motor " «MODE DOOR MOTOR CIRCUIT»(ref-356249-S00205665342010021300000) ". 32 DEF (Driver side) 33 VENT (Passenger side) 34 DEF (Passenger side) 35 UPPER VENT (Open) Upper ventilator door motor " «UPPER VENTILATOR DOOR MOTOR CIRCUIT»(ref-356249-S23114453252010021300000) ". 36 UPPER VENT (Shut) 37 FRE Intake door motor " «INTAKE DOOR MOTOR CIRCUIT»(ref-356249-S37498890682010021300000) ". 38 20% FRE 39 REC (If two or more door motors malfunction, corresponding code Nos. indicates 1 second each.) (1) If mode door motor (driver and passenger side) harness connector is disconnected, the following display pattern will appear .31-->32-->33-->34-->Return to 31 (2) If upper ventilator door motor harness connector is disconnected, the following display pattern will appear .35-->36-->Return to 35 (3) If intake door motor harness connector is disconnected, the following display pattern will appear. 37-->38-->39-->Return to 37 INSPECTION END

Operational Check

The purpose of the operational check is to check if the individual system operates properly.

Conditions : Engine running at normal operating temperature

COMPONENT DESCRIPTION

Unified Meter and A/C Amp. (Automatic Amplifier)

1. 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 motor, mode door motor, upper ventilator door motor, intake door motor, blower motor and compressor are then controlled.
2. When the various switches and temperature control switch are operated, data is input to the unified meter and A/C amp. from the AV control unit using CAN communication.
3. Self-diagnosis functions are also built into unified meter and A/C amp. to provide quick check of malfunctions in the auto air conditioner system.

Potentio Temperature Control (PTC)

The PTC is built into the multifunction 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 temperature control switch. The set temperature is displayed.

Scheme 26

System Operation

1. 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, upper ventilator door and intake door opening angle data to the air mix door motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
2. The air mix door motors, mode door motors, upper ventilator 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 door motor with the existing decision and opening angles.
3. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/REC operation is selected. The new selection data are returned to the unified meter and A/C amp.

Scheme 27

1. 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, upper ventilator door and intake door opening angle data to the air mix door motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
2. The air mix door motors, mode door motors, upper ventilator 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 door motor with the existing decision and opening angles.
3. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/REC operation is selected. The new selection data are returned to the unified meter and A/C amp.

Scheme 28

Upper Ventilator Door Control Specification

Scheme 29

Upper Ventilator Door Motor

The upper ventilator door motor is attached to the heater & 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 rod which activates the upper ventilator door.

Scheme 30

1. 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, upper ventilator door and intake door opening angle data to the air mix door motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
2. The air mix door motors, mode door motors, upper ventilator 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 door motor with the existing decision and opening angles.
3. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/REC operation is selected. The new selection data are returned to the unified meter and A/C amp.

Scheme 31

The intake door control determines intake door position based on the ambient temperature, the intake air temperature and the in-vehicle temperature. When shifting mode position D/F, when the DEF or OFF switches are pressed, or when A/C switch is OFF, the unified meter and A/C amp. sets the intake door at the FRE position.

Scheme 32

SYSTEM DESCRIPTION

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

Low Temperature Protection Control

Scheme 33

1. Unified meter and A/C amp. will turn compressor ON or OFF as determined by a signal detected by ambient sensor and intake sensor.
2. When ambient temperature is higher than -2°C (28°F), the compressor turns ON. The compressor turns OFF when ambient temperature is lower than -5°C (23°F).
3. When intake air temperature is higher than 1°C (34°F), the compressor turns ON. The compressor turns OFF when intake air temperature is lower than -5°C (23°F).

Scheme 34

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 35

Ambient Sensor Circuit

Scheme 36

Sunload Sensor

The sunload sensor is located on the driver's side front 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 37

Sunload Sensor Circuit

Scheme 38

Intake Sensor

The intake sensor is located on the evaporator 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 39

Scheme 40