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:

    P0043, P0044 HO2S3 heater
    Description SYSTEM DESCRIPTION The ECM performs ON/OFF control of the heated oxygen sensor 3 heater corresponding to the engine speed, amount of intake air and engine coolant temperature. OPERATION DTC Logic DTC DETECTION LOGIC DTC CONFIRMATION PROCEDURE 1.PRECONDITIONING If DTC C ...

    Oil pump fitting bolt
    Exploded View 1. Oil pump fitting bolt 2. O-ring 3. CVT assembly Removal and Installation Refer to the figure for removal and installation. CAUTION: • Do not reuse O-ring. • Apply CVT fluid to O-ring. • After installation is complete, check for CVT fluid leakage and CVT fluid ...

    Passenger side power window alone does not operate
    Diagnosis Procedure 1. CHECK POWER WINDOW AND DOOR LOCK/UNLOCK SWITCH RH Check power window and door lock/unlock switch RH. Refer to PWC-200, "PASSENGER SIDE : Component Function Check". Is the inspection result normal? YES >> GO TO 2 NO >> Repair or replace the malfu ...