The HVAC Scan Tool Data Definitions contains a brief description of all HVAC related parameters available on the scan tool. The list is in alphabetical order. 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.

PCM w/6.5L (L65) -- Engine Data 1 -- A/C Compressor: The scan tool displays Engaged or Disengaged. Indicates whether or not the A/C compressor is engaged.

PCM w/6.5L (L65) -- Engine Data 1 -- A/C Relay: The scan tool displays Enabled or Disabled. Represents the commanded state of the A/C compressor clutch relay control circuit.

PCM w/6.5L (L65) -- Engine Data 1 -- A/C Request: The scan tool displays On or Off. Represents the state of the A/C request input circuit from the control head.

PCM w/6.5L (L65) -- Engine Data 1 -- Calc. A/C Load: The scan tool displays 0-255 Counts. Represents the amount of load the A/C compressor is putting on the engine.

PCM (except 6.5L) -- A/C Relay Command: The scan tool displays On or Off. This parameter displays the PCM commanded state of the A/C compressor clutch relay. When the scan tool displays ON, the A/C compressor clutch should be engaged.

PCM (except 6.5L) -- Engine Data 2 -- A/C Compressor Cycling Switch: The scan tool displays Open or Closed. This parameter displays the state of the A/C compressor cycling switch. The A/C compressor cycling switch is a normally closed switch.

PCM (except 6.5L) -- Engine Data 2 -- A/C Sec. High Press. Switch: The scan tool displays Open or Closed. This parameter displays the state of the A/C secondary high pressure switch. The A/C secondary high pressure switch is normally open.

PCM (except 6.5L) -- Engine Data 2 -- A/C Request: The scan tool displays Yes or No. The A/C Request displays the state of the A/C request input circuit from the heating, ventilation, and air conditioning (HVAC) controls. The powertrain control module (PCM) uses the A/C request signal in order to determine whether the A/C compressor operation is being requested.