Scan Tool Data Definitions

Use the Scan Tool Data Display Values and Definitions Information in order to assist in diagnosing the HVAC Control Module 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 ignition switch is in the ON position.
- The engine is running at idle.
- The vehicle is in PARK.
- The doors are closed.
- The windows are closed.
- The A/C is ON, in UPPER mode.
- The ambient air temperatures are at 22-27°C (70-80°F).

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.

Heating and Air Conditioning - Data - Desired Blower Mtr Speed: The scan tool displays 0-111 Counts. When the blower motor is OFF, the scan tool displays 0 Counts. When the blower motor controls are placed in the maximum speed setting, the scan tool displays 111 Counts.

Heating and Air Conditioning - Data - Driver Temp Dial: The scan tool displays 15-32°C (59-89°F). The temperature displayed represents the desired system discharge temperature selected by the driver.

Heating and Air Conditioning - Data - Inside Temp Sensor: The scan tool displays 0-5.0 Volts. The voltage displayed represents the inside air temperature sensor signal to the HVAC control module.

Heating and Air Conditioning - Data - LH Mix Mtr Position Feedback: The scan tool displays 0-255 Counts. The counts displayed represent the position of the left air temperature actuator.

Heating and Air Conditioning - Data - LH Mix Mtr Position Requested: The scan tool displays 0-255 Counts. The counts displayed represent the commanded position of the left air temperature actuator.

Heating and Air Conditioning - Data - Mix Motor State: When the left and right air temperature actuators are operating properly, the scan tool displays Normal.

Heating and Air Conditioning - Data - Outside Temp Sensor The scan tool displays 0-5.0 Volts. The voltage displayed represents the value of the outside air temperature sensor signal.

Heating and Air Conditioning - Data - Passenger Temp Dial: The scan tool displays 80-176 Counts. The counts displayed represent the position of the PASSENGER temperature dial, 80 being the coolest setting and 176 being the warmest.

Heating and Air Conditioning - Data - Rear Defog Output: The scan tool displays On or Off. When the rear defog button is pressed the scan tool displays On. When the rear defog button is pressed again, the scan tool displays Off.

Heating and Air Conditioning - Data - RH Mix Mtr Position Feedback: The scan tool displays 0-255 Counts. The counts displayed represent the position of the right air temperature actuator.

Heating and Air Conditioning - Data - RH Mix Mtr Position Requested: The scan tool displays 0-226 Counts. The counts displayed represent the commanded position of the right air temperature actuator.

Heating and Air Conditioning - Data - Sun Load Sensor: The scan tool displays 0-5.0 Volts. The voltage displayed represents the value of the sunload sensor signal.

Heating and Air Conditioning - Data - Vacuum Solenoid 1: The scan tool displays On or Off. When Vacuum Solenoid 1 is energized the scan tool displays On. When the solenoid is de-energized the scan tool displays Off.

Heating and Air Conditioning - Data - Vacuum Solenoid 2: The scan tool displays On or Off. When Vacuum Solenoid 2 is energized the scan tool displays On. When the solenoid is de-energized the scan tool displays Off.

Heating and Air Conditioning - Data - Vacuum Solenoid 3: The scan tool displays On or Off. When Vacuum Solenoid 3 is energized the scan tool displays On. When the solenoid is de-energized the scan tool displays Off.

Heating and Air Conditioning - Data - Vacuum Solenoid 4: The scan tool displays On or Off. When Vacuum Solenoid 4 is energized the scan tool displays On. When the solenoid is de-energized the scan tool displays Off, and the Air Inlet Valve Vacuum Actuator is in the outside air position.

Heating and Air Conditioning - Data - Vacuum Solenoid 5: The scan tool displays On or Off. When Vacuum Solenoid 5 is energized the scan tool displays On. When the solenoid is de-energized the scan tool displays Off.

Heating and Air Conditioning - Inputs - Auto Button: The scan tool displays Off or On. When the AUTO button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Driver Temp Down Button: The scan tool displays Off or On. When the DRIVER TEMP DOWN button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Driver Temp Up Button: The scan tool displays Off or On. When the DRIVER TEMP UP button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Dual Button: The scan tool displays Off or On. When the DUAL button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Fan Down Button: The scan tool displays Off or On. When the BLOWER SPEED CONTROL DOWN button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Fan Up Button: The scan tool displays Off or On. When the BLOWER SPEED CONTROL DOWN button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Front Defrost Button: The scan tool displays Off or On. When the FRONT DEFROST button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Mode Down Button: The scan tool displays Off or On. When the MODE DOWN button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Mode Up Button: The scan tool displays Off or On. When the MODE UP button is pressed the scan tool displays On.When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Off Button: The scan tool displays Off or On. When the OFF button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Passenger Temp Down Button: The scan tool displays Off or On. When the PASSENGER TEMP DOWN button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Passenger Temp Down Button: The scan tool displays Off or On. When the PASSENGER TEMP UP button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Rear Defrost Button: The scan tool displays Off or On. When the REAR DEFROST button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Recirculate Button: The scan tool displays Off or On. When the RECIRCULATION button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Inputs - Vent Button: The scan tool displays Off or On. When the VENT button is pressed the scan tool displays On. When released, the scan tool displays Off.

Heating and Air Conditioning - Module Information - Calibration ID: The scan tool displays the Calibration ID number for service identification.

Heating and Air Conditioning - Module Information - ROM ID: The scan tool displays the ROM ID number for service identification.

Heating and Air Conditioning - Module Information - ROM Part Number: The scan tool displays the ROM part number for service identification.

PCM - A/C High Side Pressure: The scan tool displays -103 to +3119 kPa (-14 to +452 psi). This parameter represents the A/C refrigerant pressure sensor voltage signal converted to pressure.

PCM - A/C High Side Pressure: The scan tool displays 0.00-5.00 Volts. This parameter represents the A/C refrigerant pressure sensor signal.

PCM - A/C Off for WOT: The scan tool displays Yes or No. Yes is displayed when the PCM de-energizes the A/C compressor clutch relay to reduce engine load during wide open throttle.

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

PCM - 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.

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 - A/C Request Signal: The scan tool displays Yes or No. Yes is displayed when the HVAC Control Module is requesting A/C system operation.

PCM - ECT Sensor: The scan tool displays degrees. Scan tool shows the temperature of the ECT Sensor.