Automatic Air Conditioner: Overview Nissan Murano Z50

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.

Scheme 1

Scheme 2

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. CAUTION: Female-side piping connection point is thin. So, when inserting male-side piping, take care not to deform female-side piping. Slowly insert it in axial direction. Insert piping securely until a click is heard. After piping connection is completed, pull male-side piping by hand to make sure connection does not come loose. 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)

Scheme 5

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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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.

Scheme 9

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. OK or NG OK: GO TO 2 . NG: 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-234022-S00986790942006052800000). NO: GO TO «LUBRICANT ADJUSTING PROCEDURE FOR COMPONENTS REPLACEMENT EXCEPT COMPRESSOR»(ref-234022-S05658043182006052800000).

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 (Scheme 10)

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 and intake door 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 is 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.

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 (Scheme 12)

Scheme 12

Scheme 13

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

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1. With the ignition switch OFF, connect CONSULT-II and "CONSULT-II CONVERTER" to the date link connector, and turn the ignition switch ON.
2. Touch "START (NISSAN BASED VHCL)".
3. Touch "BCM" on "SELECT SYSTEM" screen. If "BCM" is not indicated, go to «CONSULT-II DATE LINK CONNECTOR (DLC) CIRCUIT»(ref-233992-S34507144402006052800000).

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1. Touch "AIR CONDITIONER" on "SELECT TEST ITEM" screen.
2. Touch "DATA MONITOR" on "SELECT DIAG MODE" screen.
3. Touch either "ALL SIGNALS" or "SELECTION FROM MENU" on "DATA MONITOR" screen. DATA MONITOR All signals Monitors all the items. Selection from menu Selects and monitors the individual item selected.
4. When "SELECTION FROM MENU" is selected, touch items to be monitored. When "ALL SIGNALS" is selected, all the items will be monitored.
5. Touch "START".
6. Touch "RECORD" while monitoring, then the status of the monitored item can be recorded. To stop recording, touch "STOP". DISPLAY ITEM LIST - CONSULT-II Monitor item name "operation or unit" Contents IGN ON SW "ON/OFF" Displays "IGN Position (ON)/OFF, ACC Position (OFF)" status as judged from ignition switch signal. FAN ON SIG "ON/OFF" Displays "FAN (ON)/FAN (OFF)" status as judged from blower fan motor switch signal. AIR COND SW "ON/OFF" Displays "COMP (ON)/COMP (OFF)" status as judged from air conditioner switch signal.

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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 turning temperature control dial (driver side), as required.

Additionally shifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of turning $$ (fan) dial clockwise.

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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 12 V during diagnosis STEP-3, 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 (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 Does code No. 20 appear on the display? YES: GO TO 3. NO: GO TO 13.
3. CHECK TO ADVANCE SELF-DIAGNOSIS STEP-3 Turn temperature control dial (driver side) clockwise. Advance to self-diagnosis STEP-3? YES: GO TO 4. NO: Replace A/C and AV switch, (temperature control dial malfunctions.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2 Turn temperature control dial (driver side) counterclockwise. Return to self-diagnosis STEP-2? YES: GO TO 5. NO: Replace A/C and AV switch, (temperature control dial malfunctions.)
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED Turn temperature control dial (driver side) clockwise. Does code No. 30 appear on the display? YES: GO TO 6. NO: GO TO 14.
6. STEP-4: OPERATION OF EACH ACTUATOR IS CHECKED Turn temperature control dial (driver side) clockwise. Press $$ (DEF) switch. Code No. of each actuator test is indicated on the display. GO TO 7.
7. CHECK ACTUATORS (Scheme 29)and «DISCHARGE AIR FLOW»(ref-234022-S21991399432006052800000) table to confirm discharge air flow, air temperature, blower motor duty ratio and compressor operation. DISCHARGE AIR FLOW - 41 42 43 44 45 46 Mode door position VENT B/L1 B/L2 FOOT (1) D/F DEF Intake door position REC REC 20%FRE FRE FRE FRE Air mix door position FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT FULL HOT Blower motor duty ratio 37% 91% 65% 65% 65% 91% Compressor ON ON OFF OFF ON ON Checks must be made visually, by listening to any noise, or by touching air outlets with your hand, etc. for improper operation. - - - - - - (1) *1 FOOT position during automatic control. Refer to «AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER»(ref-234022-S02408335022006052800000). OK or NG OK: GO TO 8. NG: Air outlet does not change. Go to Mode Door Motor Circuit. Refer to «MODE DOOR MOTOR CIRCUIT»(ref-234022-S02168739032006052800000). Intake door does not change. Go to Intake Door Motor Circuit. Refer to «INTAKE DOOR MOTOR CIRCUIT»(ref-234022-S15307950082006052800000). Blower motor operation is malfunctioning. Go to Blower Motor Circuit. Refer to «BLOWER MOTOR CIRCUIT»(ref-234022-S09849620312006052800000). Magnet clutch does not engage. Go to Magnet Clutch Circuit. Refer to «MAGNET CLUTCH CIRCUIT»(ref-234022-S42230826832006052800000). Discharge air temperature does not change. Go to Air Mix Door Motor Circuit. Refer to «AIR MIX DOOR MOTOR CIRCUIT»(ref-234022-S04100457652006052800000).
8. STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED Turn temperature control dial (driver side) clockwise. Code No. 51 appears on the display. GO TO 9.
9. CHECK AMBIENT SENSOR Press $$ (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, and then inspect sensor. OK or NG OK: GO TO 10. NG: Go to Ambient Sensor Circuit. Refer to «AMBIENT SENSOR CIRCUIT»(ref-234022-S12162640452006052800000).
10. CHECK IN-VEHICLE SENSOR Press $$ (DEF) switch a second time. Temperature detected by in-vehicle sensor is indicated on the display. NOTE: If temperature shown on display greatly differs from actual temperature, check sensor circuit first, and then inspect sensor. OK or NG OK: GO TO 11. NG: Go to In-vehicle Sensor Circuit. Refer to «IN-VEHICLE SENSOR CIRCUIT»(ref-234022-S29017667052006052800000).
11. CHECK INTAKE SENSOR Press $$ (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, and then inspect sensor. OK or NG OK: GO TO 12. NG: Go to Intake Sensor Circuit. Refer to «INTAKE SENSOR CIRCUIT»(ref-234022-S30064435302006052800000).
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 SYSTEM DESCRIPTION»(ref-234025-S14518966772006052700000). Unified meter and A/C amp. - Display unit Unified meter and A/C amp. - Display control unit
13. CHECK MALFUNCTIONING SENSOR Refer to «MALFUNCTIONING SENSOR INSPECTION»(ref-234022-S13057973102006052800000) table for malfunctioning code No. If two or more sensors malfunction, corresponding code Nos. blink respectively twice. 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. MALFUNCTIONING SENSOR INSPECTION Code No. Malfunctioning sensor (Including circuits) Reference 21/-21 Ambient sensor «DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR»(ref-234022-S10258719282006052800000) 22/-22 In-vehicle sensor «DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR»(ref-234022-S25284024932006052800000) 24/-24 Intake sensor «DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR»(ref-234022-S30064435302006052800000) 25/-25 Sunload sensor (1) «DIAGNOSTIC PROCEDURE FOR SUNLOAD SENSOR»(ref-234022-S14316656412006052800000) 26/-26 Air mix door motor PBR (Driver side) «DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT»(ref-234022-S18986334022006052800000) 27/-27 Air mix door motor PBR (Passenger side) «DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT»(ref-234022-S18986334022006052800000) (1) Perform self-diagnosis STEP-2 under sunshine. INSPECTION END
14. CHECK MALFUNCTIONING DOOR MOTOR POSITION SWITCH Mode and/or 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. *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: FOOT position during automatic control. Refer to «AUXILIARY MECHANISM: FOOT POSITION SETTING TRIMMER»(ref-234022-S02408335022006052800000). *4: ATC-65, "Mode Door Motor Circuit". *5: ATC-71, "Intake Door Motor Circuit". INSPECTION END

Operational Check

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

1. Conditions: Engine running at usual operating temperature

Scheme 37

1. Set the temperature to 32°C (90°F).
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.

If OK, continue the check.

Scheme 38

1. Turn fan control dial clockwise. Blower should operate on low speed. The fan symbol should have one blade lit.
2. Turn fan control dial clockwise 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 the check.

Scheme 39

1. Press MODE switch 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-234022-S32584593712006052800000) and (Scheme 40).

Scheme 40

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

If OK, continue the 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.

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 door 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.

Scheme 41

Scheme 42

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 door 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.

Scheme 43

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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 cowl top cover. Refer to «COWL TOP»(ref-234018-S27219738992006052700000).
3. Remove air duct (inlet). Refer to «AIR CLEANER AND AIR DUCT»(ref-233993-S13601402462006052800000).
4. Remove mounting bolt from low-pressure flexible hose. (Compressor side)
5. Remove mounting bolt 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.

See also:
• CONSULT-II REFERENCE VALUE IN DATA MONITOR