A/C Pressure Sensor Volts Too High

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 above 4.9 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 open
- Sensor Internally Open
- PCM Failure
- Open Sensor Ground