Automatic Air Conditioner: Overview — Infiniti M45 III (2005-2008)

OPERATION PROCEDURE

Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
Use the Intelligent Key or mechanical key to turn the ignition switch to the "ACC" position. At this time, the steering lock will be released.
Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
Perform the necessary repair operation.
When the repair work is completed, return the ignition switch to the "LOCK" position before connecting the battery cables. (At this time, the steering lock mechanism will engage.)
Perform a self-diagnosis check of all control units using CONSULT-II.

Description

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

Scheme 2

Scheme 2: COMPONENT PARTS

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

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.
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.

LUBRICANT RETURN OPERATION

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

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, never perform the lubricant return operation. OK or NG OK: GO TO 2. NG: GO TO 3 .
PERFORM LUBRICANT RETURN OPERATION, PROCEEDING AS FOLLOWS Start the engine, and set to the following conditions: Engine speed: Idling to 1,200 rpm A/C switch: ON Blower speed: Max. position 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 the engine. : GO TO 3.
CHECK REPLACEMENT PART Should the compressor be replaced? YES: GO TO " «LUBRICANT ADJUSTING PROCEDURE FOR COMPRESSOR REPLACEMENT»(ref-239111-S39764951212006072700000) ". NO: GO TO " «LUBRICANT ADJUSTING PROCEDURE FOR COMPONENTS REPLACEMENT EXCEPT COMPRESSOR»(ref-239111-S31146989892006072700000) ".

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 3

Scheme 3: Description of Air Conditioner LAN Control System

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 LCU, air mix door motor LCU, upper ventilator door motor LCU and intake door motor LCU.

The mode door motor, 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 4

Scheme 4: OPERATION

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 5

Scheme 5: Description of Control System

Scheme 6

Scheme 6: DISPLAY SCREEN

Scheme 7

Scheme 7: MULTIFUNCTION SWITCH

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 ".

CONSULT-II BASIC OPERATION

Refer to " CONSULT-II START PROCEDURE ".

Touch "ENGINE" on "SELECT SYSTEM" screen.
Touch "DATA MONITOR" on "SELECT DIAG MODE" screen.
Touch either "ALL SIGNALS" or "SELECTION FROM MENU" on "DATA MONITOR" screen. SIGNALS REFERENCE All signals Monitors all the items. Selection from menu Selects and monitors the individual item selected.
When "SELECTION FROM MENU" is selected, touch items to be monitored. When "ALL SIGNALS" is selected, all the items will be monitored.
Touch "START".
Touch "RECORD" while monitoring, then the status of the monitored item can be recorded. To stop recording, touch "STOP".

The self-diagnosis system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to applicable articles (items) for details. Shifting from usual 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 to another 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 8

Scheme 8: DESCRIPTION

Scheme 9

Scheme 9: FUNCTION CONFIRMATION PROCEDURE

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Scheme 18

SET IN SELF-DIAGNOSIS MODE Turn ignition switch ON. Set in self-diagnosis 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 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.
STEP-2: SENSOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT Does code No. 20 appear on the display? YES: GO TO 3. NO: GO TO 13 .
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.)
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-239111-S40538729582006072700000) ".
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 .
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.
CHECK ACTUATORS Refer to the following chart and check discharge air flow, air temperature, blower motor duty ratio and compressor operation. CODE DESCRIPTION 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) FOOT position during automatic control. Refer to " «AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER»(ref-239111-S32189820242006072700000) ". Checks must be made visually, by listening the sound, or by touching air outlets with hand, etc. for improper operation. 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-239111-S35154992962006072700000) ". Upper ventilator outlet does not change. Go to Upper Ventilator Door Motor Circuit. Refer to " «UPPER VENTILATOR DOOR MOTOR CIRCUIT»(ref-239111-S28396691422006072700000) ". Intake door does not change. Go to Intake Door Motor Circuit. Refer to " «INTAKE DOOR MOTOR CIRCUIT»(ref-239111-S15909834712006072700000) ". Blower motor operation is malfunctioning. Go to Blower Motor Circuit. Refer to " «BLOWER MOTOR CIRCUIT»(ref-239111-S24101361072006072700000) ". Magnet clutch does not engage. Go to Magnet Clutch Circuit. Refer to " «MAGNET CLUTCH CIRCUIT»(ref-239111-S40047887852006072700000) ". Discharge air temperature does not change. Go to Air Mix Door Motor Circuit. Refer to " «AIR MIX DOOR MOTOR CIRCUIT»(ref-239111-S17612434502006072700000) ".
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.
CHECK AMBIENT SENSOR Press (DEF) switch one time. Temperature detected by ambient sensor is indicated on the display. NOTE: If the temperature indicated on the display greatly differs from the actual temperature, check sensor circuit first, and then check sensor. OK or NG OK: GO TO 10. NG: Go to Ambient Sensor Circuit. Refer to " «AMBIENT SENSOR CIRCUIT»(ref-239111-S32249452582006072700000) ".
CHECK IN-VEHICLE SENSOR Press (DEF) switch for the second time. Temperature detected by in-vehicle sensor is indicated on the display. NOTE: If the temperature indicated on the display greatly differs from the actual temperature, check sensor circuit first, and then check sensor. OK or NG OK: GO TO 11. NG: Go to In-vehicle Sensor Circuit. Refer to " «IN-VEHICLE SENSOR CIRCUIT»(ref-239111-S25529960772006072700000) ".
CHECK INTAKE SENSOR Press (DEF) switch for the third time. Temperature detected by intake sensor is indicated on the display. NOTE: If the temperature indicated on the display greatly differs from the actual temperature, check sensor circuit first, and then check sensor. OK or NG OK: GO TO 12. NG: Go to Intake Sensor Circuit. Refer to " «INTAKE SENSOR CIRCUIT»(ref-239111-S33653416682006072700000) ".
CHECK CAN COMMUNICATION ERROR Press intake switch. CAN communication error between the unified meter and A/C amp. and the AV control unit or NAVI control unit can be detected as self-diagnosis results. (If plural errors occur, the display of each error will blink twice for 0-5 second intervals.) OK or NG OK: Turn ignition switch OFF or AUTO switch ON. INSPECTION END NG: Go to CAN communication. Refer to " «DTC [U1000] CAN COMMUNICATION CIRCUIT»(ref-239120-S27014540752006072600000) ". Unified meter and A/C amp. - AV control unit or NAVI control unit
CHECK MALFUNCTIONING SENSOR Refer to the following chart for malfunctioning code No. (If two or more sensors malfunction, corresponding code Nos. blink respectively twice.) *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. CODE NO AND REFERENCE Code No. Malfunctioning sensor (Including circuits) Reference 21 / -21 Ambient sensor (1) 22 / -22 In-vehicle sensor (2) 24 / -24 Intake sensor (3) 25 / -25 Sunload sensor (4) 26 / -26 Air mix door motor PBR (Driver side) (5) 27 / -27 Air mix door motor PBR (Passenger side) (1) " «DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR»(ref-239111-S16242684372006072700000) ". (2) " «DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR»(ref-239111-S03476506172006072700000) ". (3) " «DIAGNOSIS PROCEDURE FOR INTAKE SENSOR»(ref-239111-S22938685862006072700000) ". (4) " «DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR»(ref-239111-S02900742072006072700000) ". (5) " «DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR»(ref-239111-S22143181562006072700000) ". : INSPECTION END
CHECK MALFUNCTIONING DOOR MOTOR POSITION SWITCH Mode and/or intake door motor PBR(s) is/are malfunctioning. CODE NO AND INTAKE DOOR MOTOR POSITION REFERENCE Code No. (1) (2) Mode or intake door position Reference 31 VENT (Driver side) Mode door motor (3) 32 DEF (Driver side) 33 VENT (Passenger side) 34 DEF (Passenger side) 35 UPPER VENT (Open) Upper ventilator door motor (4) 36 UPPER VENT (Shut) 37 FRE Intake door motor (5) 38 20% FRE 39 REC (If two or more mode or intake doors are out of order, corresponding code numbers blink respectively twice.) (1) If mode door motor harness connector is disconnected, the following display pattern will appear. 31-->32-->33-->34-->35-->36-->Return to 31 (2) If intake door motor harness connector is disconnected, the following display pattern will appear. 37-->38-->39-->Return to 37 (3) " «DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR»(ref-239111-S36005762162006072700000) ". (4) " «DIAGNOSIS PROCEDURE FOR UPPER VENTILATOR DOOR MOTOR»(ref-239111-S23135117842006072700000) ". (5) " «DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR»(ref-239111-S09480987692006072700000) ". : 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

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

The air mix door motor, mode door motor, 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. 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 19

Scheme 19: System Operation

Scheme 20

Scheme 20: Mode Door Control Specification

Scheme 21

Scheme 21: System Operation

Scheme 22

Scheme 22: Upper Ventilator Door Control Specification

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.

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. 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 23

Scheme 23: System Operation

Scheme 24

Scheme 24: Air Mix Door Control Specification

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 FRESH position.

Scheme 25

Scheme 25: System Operation

Scheme 26

Scheme 26: Intake Door Control Specification

SYSTEM DESCRIPTION

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

Automatic Air Conditioner: Overview Infiniti M45 III