2004 Volvo XC90 Base, FWDFACTORY OEM SERVICE PROCEDURE

Principle Sketch Of The Climate Control System

Fig 1: Identifying Principle Sketch Of Climate Control System
GLL145808Courtesy of VOLVO CARS CORPORATION

Included in the climate control system:

  1. Compressor
  2. Condenser
  3. Engine cooling fan (the same cooling fan used by the engine cooling system)
  4. Receiver drier
  5. Expansion valve
  6. Evaporator
  7. Blower fan.

Explanation:Β 

A - High pressure, warm fluid

B - Low pressure, cold fluid

C - Low pressure, cold gas

D - High pressure, warm gas

Dark arrow - Warm air

Light arrow - Cold air

The system is divided into:

  • a low pressure side (B, C)
  • a high pressure side (A, D).

The two sides are separated by the compressor (1) and the expansion valve (5). The evaporator (6) is located on the low pressure side and the condenser (2) is on the high pressure side.

The design of the climate control system in a vehicle is based on the laws of nature, which mean that liquids evaporate when they are subjected to a temperature increase or a reduction in pressure and that heat is absorbed during this process.

If the hot vapor is then cooled again, the heat that has been absorbed is released and the gas reverts to liquid form. This process is repeated as many times as necessary, so that "cooling is produced" continually. This is the same type of process as used in refrigerators, for example.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.