Nissan Murano: Heater & Air Conditioning Control System :: System Description / Component Parts. Automatic Air Conditioning System

Component Parts Location

• Intake sensor is located on the evaporator.

• Intake sensor measures temperature of evaporator fin temperature. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

• Air mix door motor LH is installed on the A/C unit assembly.

• Air mix door motor LH consists of motor that drives door, PBR (Potentio Balance Register) that detects door position and LCU (Local Control Unit) that perform multiplex communication control (LIN) with A/C auto amp. Refer to Door Control.

• Rotation of motor is transmitted to air mix door LH by link and lever. Air flow temperature is switched.

• Air mix door motor RH is installed on the A/C unit assembly.

• Air mix door motor RH consists of motor that drives door, PBR (Potentio Balance Register) that detects door position and LCU (Local Control Unit) that perform multiplex communication control (LIN) with A/C auto amp. Refer to Door Control.

• Rotation of motor is transmitted to air mix door RH by link and lever. Air flow temperature is switched.

• Mode door motor is installed on the A/C unit assembly.

• Mode door motor consists of motor that drives door, PBR (Potentio Balance Register) that detects door position and LCU (Local Control Unit) that perform multiplex communication control (LIN) with A/C auto amp. Refer to Door Control.

• Rotation of motor is transmitted to mode door (ventilator door, foot door, and defroster door) by link and lever. Air outlet is switched.

• Intake door motor is installed on the blower assembly.

• Intake door motor consists of motor that drives door, PBR (Potentio Balance Register) that detects door position and LCU (Local Control Unit) that perform multiplex communication control (LIN) with A/C auto amp. Refer to Door Control.

• Rotation of motor is transmitted to intake door by lever. Air inlet is switched.

• Front blower motor is installed on the blower assembly.

• The blower motor utilizes a brush-less motor with a rotating magnet.

  

• Quietness is improved over previous motors where the brush was the point of contact and the coil rotated.

  

• A/C compressor is installed on RH side of the engine.

• Vaporized refrigerant is drawn into the A/C compressor from the evaporator, where it is compressed to a high pressure, high temperature vapor. The hot compressed vapor is then discharged to the condenser.

  

MAGNET CLUTCH

Description

A/C compressor is driven by the magnet clutch which is magnetized by electric power supply.

Structure and Operation

• Magnet clutch consists of pulley, clutch disc, and field coil.

  

  • Pulley is connected with crankshaft pulley of engine via drive belt and is always rotated while engine is running.

  • Clutch disc is connected with drive shaft of A/C compressor.

  • Field coil, which becomes a strong electric magnet when electricity is supplied, strongly pulls clutch disc and presses it to pulley.

• When A/C relay integrated in IPDM E/R turns ON, electricity is supplied to field coil, clutch disc is presses to pulley, and engine rotational movement is transmitted from crankshaft pulley ⇒ drive belt ⇒ pulley ⇒ clutch disc ⇒ drive shaft. A/C compressor is operated. When A/C relay turns OFF, electricity is not supplied to field coil, and clutch disc is released from pulley. A/C compressor is not operated.

ECV (ELECTRICAL CONTROL VALVE)

ECV (electrical control valve) is installed on the A/C compressor and controls emitting the appropriate amount of refrigerant when necessary.

• A/C auto amp. is installed behind center of the instrument panel.

• A/C auto amp. controls automatic air conditioning system by inputting and calculating signals from each sensor and each switch. A/C auto amp. has self-diagnosis function. Diagnosis of automatic air conditioning system can be performed quickly.

  

• Ambient sensor is installed behind LH side of the front bumper.

• Ambient sensor measures ambient air temperature. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

• In-vehicle sensor is installed on the instrument lower panel.

• In-vehicle sensor measures temperature of intake air that flows through aspirator to passenger room. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

• Sunload sensor is installed on center of the instrument panel.

• Sunload sensor measures sunload amount. This sensor converts sunload amount to voltage signal by photodiode and transmits to A/C auto amp.

DESCRIPTION

• Refrigerant pressure sensor is installed on the high pressure pipe.

• The refrigerant pressure sensor converts high-pressure side refrigerant pressure into voltage and outputs it to ECM.

• ECM operates cooling system protection and idle speed control according to voltage value that is input.

  

STRUCTURE AND OPERATION

• The refrigerant pressure sensor is a capacitance type sensor. It consists of a pressure detection area and a signal processing area.

• The pressure detection area, which is a variable capacity condenser, changes internal static capacitance according to pressure force.

• The signal processing area detects the static capacitance of the pressure detection area, converts the static capacitance into a voltage value, and transmits the voltage value to ECM.