For 1990-2009 cars

### Compressor Control Relay

The compressor clutch coil is energized through the compressor control relay. This relay is activated by the PCM in A/C modes. The PCM provides cut-off of the relay under certain operating conditions such as wide open throttle.

### A/C Refrigerant Pressure Sensor

The electronic A/C refrigerant pressure sensor is mounted to the line between the condenser and the evaporator. The output to the PCM is variable. The output of the PCM depends on the pressure inside of the line. A higher pressure will result in a higher voltage output.

The PCM constantly monitors the A/C system pressure in order to achieve the following effects:

• | Disengage the A/C clutch if the pressure is above 2700 kPa (440 psi).

• | Disengage the A/C clutch if the pressure is below 285 kPa (38 psi).

• | Boost the idle air control in order to compensate for the A/C load at idle.

• | Control the cooling fan operation.

Replace the pressure sensor if the pressure sensor fails. The pressure sensor is not repairable. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement .