A/C Pressure Sensor Volts Too Low

WHEN MONITORED
With the ignition on, the engine running, and the A/C relay energized.

SET CONDITION
The A/C pressure sensor signal at PCM cavity 48 goes below 0.5 volts or stays below 0.7 volts for 22 seconds when the A/C relay is energized.

THEORY OF OPERATION
The A/C pressure sensor informs the PCM if the A/C system pressure is too low or too high, allowing the PCM to determine whether it can engage the compressor clutch.

- If the A/C system pressure is too low, the PCM will not engage the compressor clutch.

- If the system pressure is too high, the PCM will disengage the compressor clutch and turn on the cooling fans to prevent the compressor head pressure from becoming too high.

SENSOR CONNECTIONS AT PCM
Sensor Signal - Provided to PCM (cavity 48).

Sensor 5-Volt Supply - Received from PCM (cavity 6).

Sensor Ground - Provided by PCM (cavity 4).

PROBABLE CAUSES
- Sensor signal shorted to ground
- Sensor Internally shorted
- PCM Failure