Use the Scan Tool Data Display Values and Definitions Information in order to assist in diagnosing the Body Control Module (BCM) problems. Compare the vehicles actual scan tool data with the typical data display value table information. Use the data information in order to aid in understanding the nature of the problem when the vehicle does not match with the typical data display values.

The scan tool data values were taken from a known good vehicle under the following conditions:

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.

BCM -- BCM Data -- A/C Clutch Mode: The scan tool displays Engaged or Disengaged. Represents the state of the A/C compressor clutch relay control circuit.

BCM -- BCM Data -- A/C Request: The scan tool displays Yes or No. The PCM uses the A/C request signal in order to determine if A/C compressor operation is being requested by the BCM.

PCM -- A/C Relay Command: The scan tool displays On or Off. On is displayed when the PCM has energized the A/C compressor clutch relay.

PCM -- Engine Data 2 -- A/C High Side Pressure: The scan tool displays 0 to 4000 kPa (0 to 580 psi). This parameter represents the A/C refrigerant pressure sensor voltage signal converted to pressure.

PCM -- Engine Data 2 -- A/C High Side Pressure: The scan tool displays 0 to 5.00 volts. The output of the A/C refrigerant pressure sensor.

PCM -- Engine Data 2 -- A/C Pressure Disable: The scan tool displays Yes or No. Yes is displayed when the system pressure exceeds 2968 kPa (430 psi).

PCM -- Output Driver Data -- A/C Relay Circuit Status: The scan tool displays OK or Fault. Fault is displayed when an open or short is detected in the A/C compressor clutch relay ground circuit.