GM Service Manual Online
For 1990-2009 cars only

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 and depends on the pressure inside the line. A higher pressure will result in a higher voltage out.

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 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 it fails. It is not repairable.