HVAC Scan Tool Data Definitions

The HVAC Scan Tool Data Definitions contains a brief description of all HVAC scan tool parameters.

ROM ID: The scan tool displays the ROM ID number for service identification.

Calibration ID: The scan tool displays the Calibration ID number for service identification.

ROM Part Number: The scan tool displays the ROM part number for service identification.

Rear Defog Output: The scan tool displays ON or OFF. When the commanded state of the rear defogger from the HVAC control assembly to the BCM is on the scan tool displays ON, when the commanded state is off the scan tool displays OFF.

Vacuum Solenoid 1: The scan tool displays ON or OFF. When the Vacuum Solenoid 1 (Defroster Solenoid) is energized the scan tool displays ON, and the Defroster Valve Vacuum Actuator opens the defroster outlets and closes the lower outlets. When the solenoid is de-energized the scan tool displays OFF.

Vacuum Solenoid 2: The scan tool displays ON or OFF. When the Vacuum Solenoid 2 (Heater Solenoid) is energized the scan tool displays ON, and the Defroster Valve Vacuum Actuator opens the lower outlets and closes the defroster outlets. When the solenoid is de-energized the scan tool displays OFF.

Vacuum Solenoid 3: The scan tool displays ON or OFF. When the Vacuum Solenoid 3 (Mode Closed Solenoid) is energized the scan tool displays ON, and the Mode Valve Vacuum Actuator opens the defroster and lower outlets and closes the upper outlets. When the solenoid is de-energized the scan tool displays OFF.

Vacuum Solenoid 4: The scan tool displays ON or OFF. When the Vacuum Solenoid 4 (Air Inlet Solenoid) is energized the scan tool displays ON, and the Air Inlet Valve Vacuum Actuator is in the recirculate position. When the solenoid is de-energized the scan tool displays OFF, and the Air Inlet Valve Vacuum Actuator is in the outside air position.

Vacuum Solenoid 5: The scan tool displays ON or OFF. When the Vacuum Solenoid 5 (Mode Open Solenoid) is energized the scan tool displays ON, and the Mode Valve Vacuum Actuator opens the upper outlets and closes the defroster and lower outlets. When the solenoid is de-energized the scan tool displays OFF.

Sunload Sensor: The scan tool displays 0-5 volts.The voltage displayed represents the Sunload sensor signal voltage input to the HVAC control assembly.

Outside Temp Sensor: The scan tool displays 0-5 volts.The voltage displayed represents the Ambient Outside Temperature sensor signal voltage input to the HVAC control assembly.

Inside Temp Sensor: The scan tool displays 0-5 volts.The voltage displayed represents the Inside Air Temperature sensor signal voltage input to the HVAC control assembly.

Desired Blower Motor Speed: The scan tool displays 0 or 15 to 111 counts. When the blower motor is commanded off the scan tool displays 0. The blower motor selected speed is displayed on the scan tool from 15 as the lowest speed setting to 111 the highest.

Driver Temp Dial: The scan tool displays 59°-89° Fahrenheit or 15°-32° Celsius. The temperature displayed represents the position of the DRIVER temperature dial.

Passenger Temp Dial: The scan tool displays 26-80 counts. The counts displayed represents the position of the PASSENGER temperature dial, 26 being the coolest setting and 80 the hottest.

LH Mix Motor Position Feedback: The scan tool displays 0-225 counts. The counts displayed reresents the LH Electric Actuator position sensor signal input to the HVAC control assembly.

RH Mix Motor Position Feedback: The scan tool displays 0-225 counts. The counts displayed reresents the RH Electric Actuator position sensor signal input to the HVAC control assembly.

LH Mix Motor Position Requested: The scan tool displays 0-225 counts. The counts displayed represents the commanded position of the LH Electric Actuator by the HVAC control assembly.

RH Mix Motor Position Requested: The scan tool displays 0-225 counts. The counts displayed represents the commanded position of the RH Electric Actuator by the HVAC control assembly.

Mix Motor State: When the LH and RH Electric Actuators are operating properly as seen by the HVAC control assembly the scan tool displays NORMAL.

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.

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.

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.

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.

Recirculate Button: The scan tool displays OFF or ON. When the Recirculate button is pressed the scan tool displays ON when released the scan tool displays OFF.

Fan Up Button: The scan tool displays OFF or ON. When the Blower Speed Control Up button is pressed the scan tool displays ON when released the scan tool displays OFF.

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.

A/C Button: The scan tool displays OFF or ON. When the A/C button is pressed the scan tool displays ON when released the scan tool displays OFF.

Outside Air Button: The scan tool displays OFF or ON. When the Outside Air button is pressed the scan tool displays ON when released the scan tool displays OFF.

Mode Button: The scan tool displays OFF or ON. When the MODE button is pressed the scan tool displays ON when released the scan tool displays OFF.

PCM Scan Tool Data Definitions

The PCM Scan Tool Data Definitions contains a brief description of 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.