Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Scan Tool Data Definitions

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 - Engine Data 1 - A/C Compressor: The scan tool displays Engaged or Disengaged. Indicates whether or not the A/C compressor is engaged.

PCM - 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 - 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 - 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.