GM Service Manual Online
For 1990-2009 cars only
Table 1: HVAC Control Module Scan Tool Data Parameters
Table 2: HVAC Control Module Scan Tool Output Controls

HVAC Control Module Scan Tool Data Parameters

Parameter

System State

Expected Value

Description

Operating Conditions: Engine ON

A/C Requested

--

No

The scan tool displays Yes or No. Yes is displayed if the air conditioning is requested.

Air Inlet Dr Actual

--

Varies

This displays Volts. This is the current numeric value of the air inlet door as monitored by the HVAC module.

Air Inlet Dr Actual Commanded

--

Varies

This displays Volts. This is the current numeric value of the air inlet door as commanded by the HVAC module.

Commanded Blower

--

Varies

This displays percent. This is the percentage of power supplied to the blower motor.

Coolant Temperature

--

Varies

This displays °C (°F). This is the current temperature of the engine coolant.

Driver Heated Seat

--

Off

The scan tool displays On or Off. This is the current state of the driver heated seat.

Driver Program Number

--

Varies

This displays Counts.

Inside Air Temp.

--

Varies

This displays °C (°F). This is the current temperature of the vehicle interior.

Left AC Duct Temp.

--

Varies

This displays Counts. This is the numeric value of the left A/C duct temperature as commanded by the HVAC module.

Left Duct Temp. Desired

--

Varies

This displays Counts. This is the numeric value of the left duct temperature as commanded by the HVAC module.

Left Htr. Duct Temp.

--

Varies

This displays Counts. This is the numeric value of the left duct temperature door as reported to the HVAC module.

Left Solar

--

Varies

This displays Counts. This is an approximate value at the left sunload sensor.

Left Temp Dr Actual

--

Varies

This displays Volts. This is the current voltage of the driver temperature door as monitored by the HVAC module.

Left Temp. Dr. Commanded

--

Varies

This displays Volts. This is the voltage of the driver temperature door commanded by the HVAC module.

Mode Dr. Motor Command

--

Varies

This displays Volts. This is the voltage of the mode door commanded by the HVAC module.

Mode Door Position

--

Varies

This displays Counts or Volts. This is the actual voltage of the mode door reported the HVAC module.

Outside Air Temp.

--

Varies

This displays °C (°F). This is the raw value of the outside air temperature.

Passenger Heated Seat

--

Off

The scan tool displays On or Off. This is the current state of the passenger heated seat.

Psgr. Program Number

--

Varies

This displays Counts.

Remote Start Request

--

Disabled

The scan tool displays Enabled or Disabled.

Right AC Duct Temp.

--

Varies

This displays Counts. This is the numeric value of the right A/C duct temperature as commanded by the HVAC module.

Right Duct Temp. Desired

--

Varies

This displays Counts. This is the numeric value of the right duct temperature as commanded by the HVAC module.

Right Htr. Duct Temp.

--

Varies

This displays Counts. This is the numeric value of the right duct temperature door as reported to the HVAC module.

Right Solar

--

Varies

This displays Counts. This is an approximate value at the right sunload sensor.

Right Temp Dr Actual

--

Varies

This displays Volts. This is the current voltage of the passenger temperature door as monitored by the HVAC module.

Right Temp. Dr. Commanded

--

Varies

This displays Volts. This is the voltage of the passenger temperature door commanded by the HVAC module.

Selected Air Mode

--

Varies

The scan tool displays Auto; Upper; Bi-Level; Heat/Defrost; Defrost; Off or N/A. This displays the current air delivery mode commanded by the HVAC control module.

System Program Number

--

Varies

This displays Counts.

Vehicle Speed Signal

--

0 mph

This displays the current vehicle speed in MPH.

HVAC Control Module Scan Tool Output Controls

Output Control

Description

A/C Request

This command allows you to turn the A/C Relay On and Off. When the A/C Relay is commanded On, the A/C compressor clutch should be engaged.

Air Inlet Door

The scan tool displays On or Off selections. The selection drives the actuator to its minimum or maximum positions.

All Status LEDs

All HVAC status LEDs illuminate when ON is selected and turn off when OFF is selected.

Blower Motor

The scan tool displays Off or On selections. This function allows you to command the blower motor to its maximum or minimum speeds.

Left Temp. Door Position

The scan tool displays On or Off selections. The selection drives the actuator to its minimum or maximum positions.

Mode Door Position

The scan tool displays On or Off selections. The selection drives the actuator to its minimum or maximum positions.

Recalibrate All Motors

When ON is selected, all air temp and mode actuators have the capability to perform a recalibration.

Right Temp. Door Position

The scan tool displays On or Off selections. The selection drives the actuator to its minimum or maximum positions.

Segment Check

The scan tool displays On or Off selections. Selecting ON activates all display segments and lamps in the HVAC control.

Temp. Door Position

The scan tool displays On or Off selections. The selection drives the actuator to its minimum or maximum positions.