Nissan Altima 2007-2012 Service Manual: Refrigeration system

Refrigerant Cycle

Refrigerant flow

The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank, through the evaporator, and back to the compressor. The refrigerant evaporation through the evaporator coil is controlled by an externally equalized expansion valve, located inside the evaporator case.

Refrigerant System Protection

Refrigerant pressure sensor

The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the condenser. If the system pressure rises above or falls below the specifications, the refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM.

The ECM then ceases to supply power to the A/C relay which disengages and stops the compressor when pressure on the high pressure side (as detected by refrigerant pressure sensor) is over approximately 2,746 kPa (28 kg/cm2, 398 psi), or below approximately 120 kPa (1.22 kg/cm2, 17.4 psi).

Pressure Relief Valve

The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.

When the pressure of refrigerant in the system increases to an abnormal level [more than 3,727 kPa (38 kg/ cm2, 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere.

    Function information
    Component Part Location ENGINE COMPARTMENT 1. A/C compressor F3 2. Ambient sensor E211 3. Refrigerant pressure sensor E219 4. A/C relay (internal to IPDM E/R) 1. A/C compressor F3 2. Ambie ...

    Automatic air conditioner system
    System Diagram CONTROL SYSTEM The control system consists of input sensors, switches, front air control and outputs. The relationship of these components is shown in the figure below: System ...

    Other materials:

    M&A branch line circuit
    Diagnosis Procedure INSPECTION PROCEDURE 1.CHECK CONNECTOR 1. Turn the ignition switch OFF. 2. Disconnect the battery cable from the negative terminal. 3. Check the terminals and connectors of the combination meter for damage, bend and loose connection (unit side and connector side). ...

    P2118 throttle control motor
    Description The throttle control motor is operated by the ECM and it opens and closes the throttle valve. The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feedback to the ECM to control the throttle control motor to make the thrott ...

    Hazard warning flasher switch
    Push the switch on to warn other drivers when you must stop or park under emergency conditions. All turn signal lights flash. WARNING ● If stopping for an emergency, be sure to move the vehicle well off the road. ● Do not use the hazard warning flashers while moving on the hig ...