Nissan Sentra manuals

Nissan Sentra Service Manual: System description

Refrigeration system

Component part location


  1. High-pressure service port
  2. High-pressure pipe
  3. Expansion valve
  4. Low-pressure service port
  5. Low-pressure flexible hose
  6. Compressor

  7. Refrigerant pressure sensor
  8. Condenser and liquid tank assembly
  9. High-pressure flexible hose

Refrigerant cycle

Refrigerant flow


  1. Electric compressor
  2. Pressure relief valve
  3. Liquid tank
  4. Refrigerant pressure sensor
  5. Condenser
  6. Expansion valve
  7. Evaporator
  8. Blower motor
  1. High-pressure gas
  2. High-pressure liquid
  3. Low-pressure liquid
  4. Low-pressure gas
  5. Suction port
  6. Discharge port
  7. Outside air

Refrigerant Flow

The refrigerant from the compressor flows through the condenser and liquid tank, the evaporator and returns to the compressor. The refrigerant evaporation in the evaporator is controlled by an expansion valve.

Freeze Protection

To prevent the evaporator from freezing up, the evaporator air temperature is monitored by the intake sensor and the voltage signal to the A/C auto amp. makes the A/C relay go OFF and stop the compressor

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 liquid tank. 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.

Preparation
Special service tool The actual shape of the tools may differ from those illustrated here. HFC-134a (r-134a) service tool and equipmen.T. Do not mix HFC-134a (R-134a) refrigerant and/or its s ...

Basic inspection
Diagnosis and repair workflow Workflow OVERALL SEQUENCE DETAILED FLOW 1.INTERVIEW CUSTOMER Interview the customer to obtain as much information as possible about the conditions and environm ...

Other materials:

Rear window defogger feedback signal
Description Turns the indicator lamp in the rear window defogger switch ON when operating the rear window defogger. Component function check 1.Check rear window defogger feedback signal Check that the indicator lamp of rear window defogger switch is illuminated when turning the rear window ...

Main line between ipdm-e and dlc circuit
Diagnosis procedure 1.Check connector Turn the ignition switch OFF. Disconnect the battery cable from the negative terminal. Check the following terminals and connectors for damage, bend and loose connection (connector side and harness side). Harness connector E4 Harness connec ...

Checking bulbs
With all doors closed, apply the parking brake and place the ignition switch in the ON position without starting the engine. The following lights will come on: If equipped, the following lights come on briefly and then go off: If any light fails to come on, it may indicate an open circuit ...

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