PCM Scan Tool Data Definitions

The PCM Scan Tool Data Definitions contains a brief description of all HVAC related parameters available on the scan tool viewed through the Powertrain Control Module. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

A/C Relay Command: The scan tool displays On or Off. The A/C Clutch represents the PCM commanded state of the A/C clutch control relay. When the scan tool indicates ON, the A/C clutch should be engaged.

A/C High Side Pressure: The scan tool displays 103-3116 kPa/15-452 psi. This parameter represents the A/C refrigerant pressure sensor signal. The amount of pressure indicates the amount of load that the A/C compressor places on the engine. The PCM uses this information in order to adjust idle and in order to control the cooling fans.

A/C High Side Pressure: The scan tool displays 0-5 volts. This parameter represents the A/C refrigerant pressure sensor signal. The amount of pressure indicates the amount of load that the A/C compressor places on the engine. The PCM uses this information in order to adjust idle and in order to control the cooling fans.

A/C Request: The scan tool displays Yes or No. The A/C Request indicates the state of the A/C request input circuit from the HVAC controls (C60). Vehicles equipped with the CJ2 A/C system, uses the Class 2 serial data to inform the PCM that the A/C is requested. The PCM uses the A/C request signal in order to determine whether the A/C compressor operation is being requested.

A/C Status: The scan tool displays On or Off. The scan tool displays ON when the voltage is applied to the A/C compressor clutch.