GM Service Manual Online
For 1990-2009 cars only
Table 1: Heating Ventilation and Air Conditioning Control Module Scan Tool Data Parameters
Table 2: Heating Ventilation and Air Conditioning Control Module Scan Tool Output Controls

Heating Ventilation and Air Conditioning Control Module Scan Tool Data Parameters

Parameter

System State

Expected Value

Description

Operating Conditions: Ignition ON

A/C Compressor Clutch Inhibit Reason

--

--

--

 

A/C Compressor Clutch Status

Engine running, A/C Off

Disengaged

The scan tool displays Engaged or Disengaged depending on the state of the A/C compressor.

Engine running, A/C On

Engaged

A/C Evaporator Temperature Sensor

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the A/C evaporator temperature sensor.

A/C High Side Pressure Sensor

--

--

--

A/C Indicator

A/C Off

Off

The scan tool displays On or Off depending on the state of the A/C mode.

A/C On

On

A/C Request Signal

A/C Off

Inactive

The scan tool displays Active or Inactive depending on the state of the A/C mode.

A/C On

Active

A/C Switch

A/C Switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the A/C switch.

A/C Switch pressed

Active

Air Recirculation Door Motor Command

--

--

--

Air Recirculation Door Position

--

--

--

Air Recirculation LED

Air recirculation mode is deactivated

Off

The scan tool displays On or Off depending on the state of the Recirculation mode.

Air recirculation mode is activated

On

Air Recirculation Mode Switch

Air recirculation switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the air recirculation mode switch.

Air recirculation switch pressed

Active

Ambient Air Temperature (Filtered)

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the ambient air temperature sensor.

Auto HVAC Button

Auto HVAC button released

Inactive

The scan tool displays On or Off depending on the state of the Auto HVAC button.

Auto HVAC button pressed

Active

Auto HVAC Indicator

Auto mode is deactivated

Off

The scan tool displays On or Off depending on the state of the Auto mode.

Auto mode is activated

On

Auxiliary Heater Output Status

--

OK

The scan tool displays OK or Malfunction. Malfunction is displayed if there is an auxiliary heater malfunction.

Battery Voltage

--

11-14 V

The scan tool displays V. This is the current battery voltage.

Bi-level Indicator

--

--

--

Blower Motor Speed

--

0-100%

The scan tool displays % depending on the state of the selected blower motor speed. The value increases stepwise from 0 to 100% depending the selected speed.

Blower Motor Speed Command

--

0-100%

The scan tool displays % depending on the state of the selected blower motor speed. The value increases stepwise from 0 to 100% depending the selected speed.

Blower Motor Switch

--

Varies

Only with C68

The scan tool displays OFF, 1 to 8 depending on the state of the selected blower motor speed.

Only with CJ2

The scan tool displays Up, Down or Inactive depending on the state of the blower motor switches.

Blower Speed Indicator

--

--

--

Desired Left Duct Temperature

--

--

--

Desired Left Temperature

--

--

The scan tool displays [ordm ]C ([ordm ]F) depending on the selected left temperature.

Desired Left Temperature Motor Door Position

--

--

--

Engine Coolant Temperature

--

-40 to +215°C (-40 to +419°F)

The scan tool displays [ordm ]C ([ordm ]F). This is the current engine coolant temperature.

Enhanced Defrost Indicator

Enhanced defrost mode is deactivated

Off

The scan tool displays On or Off depending on the state of the enhanced defrost mode.

Enhanced defrost mode is activated

On

Enhanced Defrost Switch

Enhanced defrost switch released

Off

The scan tool displays On or Off depending on the state of the enhanced defrost switch.

Enhanced defrost switch pressed

On

Floor Mode Indicator

Floor mode is deactivated

Off

The scan tool displays On or Off depending on the state of the floor mode.

Floor mode is activated

On

Floor Mode Switch

Floor mode switch released

Off

The scan tool displays On or Off depending on the state of the floor mode switch.

Floor mode switch pressed

On

Front Defrost Indicator

Front defrost mode is deactivated

Off

The scan tool displays On or Off depending on the state of the front defrost mode.

Front defrost mode is activated

On

Front Defrost Switch

Front defrost switch released

Off

The scan tool displays On or Off depending on the state of the front defrost switch.

Front defrost switch pressed

On

Front HVAC System Status

--

--

--

Heating Element 1 Duty Cycle Command

--

--

--

HVAC Actuators Supply Voltage

--

Active

The scan tool displays Active or Inactive. Inactive is displayed if there is a malfunction at the actuators supply voltage circuit.

Instrument Panel Vents Indicator

Instrument panel vents mode is deactivated

Off

The scan tool displays On or Off depending on the state of the instrument panel vents mode.

Instrument panel vents mode is activated

On

Instrument Panel Vents switch

Instrument panel vents switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the instrument panel vents switch.

Instrument panel vents switch pressed

Active

Left Front Seat Heating Switch

Left front seat heating switch released

Off

The scan tool displays On or Off depending on the state of the left front seat heating switch.

Left front seat heating switch pressed

On

Left Front Seat Ventilation Switch

Left front seat ventilation switch released

Off

The scan tool displays On or Off depending on the state of the left front seat ventilation switch.

Left front seat ventilation switch pressed

On

Left Mode Door Motor Direction

--

--

--

Left Temperature Door Motor Calibration Status

--

--

--

Left Temperature Door Motor Direction

--

--

The scan tool displays Stop, Increase or Decrease. During the movement of the left temperature door, the scan tool shows Increase or Decrease depending the movement direction. When the selected position of the door is reached, the scan tool displays Stop.

Left Temperature Door Position

--

--

--

Left Temperature Knob Position

--

Varies

The scan tool displays Counts. The value varies between -6 to +6 depending the selected temperature knob position. At the left end position is the value 18 and at the right end position -18.

Left Temperature Switch

--

--

--

Lower Left Duct Temperature Sensor

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the lower left duct temperature sensor.

Lower Right Duct Temperature Sensor

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the lower right duct temperature sensor.

Mode Door 1 Motor Command

--

--

--

Mode Door Motor Calibration Status

--

--

--

Mode Door Position

--

--

--

Odor Sensor

--

--

Counts

??? Sensor-CTS 5-95%

Passenger Compartment Air Temperature (Filtered Data)

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the passenger compartment air temperature sensor.

Passenger Compartment Air Temperature (Unfiltered Data)

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the passenger compartment air temperature sensor.

Passenger Compartment Humidity

--

3-100%

The scan tool displays %. This is the current relative humidity level at the windshield temperature and inside moisture sensor.

Passenger Compartment Humidity Sensor Temperature

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the humidity sensing element temperature sensor.

Rear Defogger LED Command

Rear defogger is deactivated

Off

The scan tool displays On or Off depending on the state of the rear defogger.

Rear defogger is activated

On

Rear Defogger Status

Rear defogger is deactivated

Off

The scan tool displays On or Off depending on the state of the rear defogger.

Engine running /Rear defogger is activated

On

Rear Defogger Switch

Rear defogger switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the rear defogger switch.

Rear defogger switch pressed

Active

Recirculation Door Motor Direction

--

--

--

Recirculation Door Motor Direction

Air recirculation mode is deactivated

Outside Air

The scan toll displays Stop, Outside Air, Increase, Recirculation, Decrease or Not Used depending on the state of the recirculation door. During the movement of the door, the scan tool shows Increase or Decrease depending the movement direction.

Air recirculation mode is activated

Recirculation

Remote Vehicle Start Status

--

--

--

Requested Idle Boost Level

--

--

--

Right Front Seat Heating Switch

Right front seat heating switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the right front seat heating switch.

Right front seat heating switch pressed

Active

Right Front Seat Ventilation Switch

Right front seat ventilation switch released

Inactive

The scan tool displays Active or Inactive depending on the state of the right front seat ventilation switch.

Right front seat ventilation switch pressed

Active

Right Mode Door Motor Direction

--

--

The scan tool displays Stop, Increase or Decrease. During the movement of the door, the scan tool shows Increase or Decrease depending the movement direction. When the selected position of the door is reached, the scan tool displays Stop.

Sun Azimuth

--

0-90°

The scan tool displays °. This is the current angle in the horisontal plane between the sun and the vehicle driving direction.

Sun Elevation

--

0-360°

The scan tool displays °. This is the current angle in the vertical sun height.

Sunload

--

0-1200 W/m²

The scan tool displays W/m². This is the current sun heat intensity.

Upper Left Duct Temperature Sensor

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the upper left duct temperature sensor.

Windshield Temperature

--

-40 to +80°C (-40 to + 176°F)

The scan tool displays °C (°F). This is the current temperature at the windshield temperature sensor.

Heating Ventilation and Air Conditioning Control Module Scan Tool Output Controls

Output Control

Description

A/C Evaporator Temperature

--

A/C Indicator

The HVAC control module illuminates the A/C indicator when commanded from the scan tool.

A/C Switch

--

Air Recirculation LED

The HVAC control module illuminates the Air Recirculation indicator when commanded from the scan tool.

Air Recirculation Mode Switch

When On is selected, the HVAC control module commands the air recirculation door from outside air to recirculation. When Off is selected, the HVAC control module commands the air recirculation door from recirculation to outside air.

Ambient Air Temperature

--

Auto HVAC Indicator

The HVAC control module illuminates the Auto indicator when commanded from the scan tool.

Auxiliary Heater Request

When On is selected, the HVAC control module sends a request signal to the auxiliary heater.

Auxiliary Mode Door Position

--

Auxiliary Mode Switch Position

--

Bi-level Indicator

--

Blower Motor Switch

--

Blower Speed Indicator

--

Enhanced Defrost Indicator

The HVAC control module illuminates the enhanced defrost indicator when commanded from the scan tool.

Floor Mode Indicator

The HVAC control module illuminates the floor mode indicator when commanded from the scan tool.

Fresh Air Indicator

--

Front Defrost Indicator

The HVAC control module illuminates the front defrost indicator when commanded from the scan tool.

HVAC Actuators

Learned/Not Learned

Motor Learn Routine Enable; Motor Learn Routine Control

HVAC Afterblow Configuration

Disable/Enable Setup

Instrument Panel Vents Indicator

The HVAC control module illuminates the instrument panel vents indicator when commanded from the scan tool.

Left Temperature Door Motor Direction

When Increase is selected, the left temperature door position increases stepwise. When Decrease is selected, the left temperature door position decreases stepwise.

Left Temperature Door Position

This commands the left temperature door position from Cold to Hot.

Left Temperature Knob Position

When Increase is selected, the left temperature increases stepwise. When Decrease is selected, the left temperature decreases stepwise.

Left Temperature Switch

--

Lower Right Duct Temperature Sensor

--

Mode Door Motor Command

The HVAC control module commands the mode actuator stepwise from defrost to floor and back again.

Mode Door Position

When Floor is selected, the HVAC control module commands the mode actuator to the floor position. When Defrost is selected, the HVAC control module commands the actuator to the defrost position.

Mode Switch

--

MULTI-ZONE Switch

--

Rear Defog

The HVAC control module commands the rear defogger On and Off.

Rear Defogger Status

The HVAC control module commands the rear defogger On and Off.

Recirculation Door

The HVAC control module commands the recirculation actuator stepwise from outside air to recirculation and back again.

Recirculation Door Motor Direction

--

Right Temperature Door Position

When Increase is selected, the right temperature door position increases stepwise. When Decrease is selected, the right temperature door position decreases stepwise.

Right Temperature Door Position

This commands the right temperature door position from Cold to Hot.

Right Temperature Knob Position

When Increase is selected, the right temperature increases stepwise. When Decrease is selected, the right temperature decreases stepwise.

Right Temperature Switch

--

Temp. Door Position

--

Upper Right Duct Temperature Sensor

--

Windshield Temperature

--