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: Ignition ON, HVAC OFF

A/C Request

--

No

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

Ambient Air Temp. Sensor

--

Varies

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

Ambient Light Sensor

--

Varies

This displays Counts. This is the current ambient light measured in counts at the ambient light sensor.

Blower Motor Speed

--

0%

This displays %. This is the actual blower motor speed measured in percentage.

Blower Motor Speed Command

--

0%

This displays %. This is the commanded blower motor speed measured in percentage.

Compressor Clutch Status

--

Off

This displays Off or Auto. This is the status when the A/C is commanded Off or if the HVAC control module is automatically controlling the A/C compressor clutch.

Driver Program Number

--

Varies

This displays Counts. This is the driver program number measured in counts.

Driver Temp. Dr. Cal. Range

--

Varies

This displays Pulses. This is the driver temperature door calibration range measured in pulses.

Driver Temp. Dr. Motor Command

--

Varies

This displays Counts. This is the commanded driver temperature door motor request measured in counts.

Driver Temp. Dr. Position

--

Varies

This displays Counts or Pulses. This is the current driver temperature door position measured in either counts or pulses.

Inside Air Temp. Sensor

--

Varies

This displays °F (°C). This is the current temperature at the inside air temperature sensor.

LED Intensity

--

Varies

This displays Counts. This is the light emitting diode (LED) intensity measured in counts.

Left Sunload Sensor

--

Varies

This displays Counts. This is the current sunload measured in counts at the driver sunload sensor.

Load Management Status

--

Off

The scan tool displays On or Off. This is the status of the load management.

Lower Left Duct Temp. Sensor

--

Varies

This displays Counts. This is the current temperature at the driver lower duct temperature sensor measured in counts.

Lower Right Duct Temp. Sensor

--

Varies

This displays Counts. This is the current temperature at the passenger lower duct temperature sensor measured in counts.

Mode Door Position

--

Varies

This displays Counts or Pulses. This is the current mode door position measured in either counts or pulses.

Mode Dr. Cal. Range

--

Varies

This displays Pulses. This is the mode door calibration range measured in pulses.

Mode Dr. Motor Command

--

Varies

This displays Counts. This is the commanded mode door motor request measured in counts.

Mode Status

--

Off

The scan tool displays Off, Auto, Heater, Bi-Level, Defog, Defrost or Mid. This is the current mode of the HVAC system.

Psgr. Program Number

--

Varies

This displays Counts. This is the passenger program number measured in counts.

Psgr. Temp. Dr. Cal. Range

--

Varies

This displays Pulses. This is the passenger temperature door calibration range measured in pulses.

Psgr. Temp. Dr. Motor Command

--

Varies

This displays Counts. This is the commanded passenger temperature door motor request measured in counts.

Psgr. Temp. Dr. Position

--

Varies

This displays Counts or Pulses. This is the current passenger temperature door position measured in either counts or pulses.

Recirculation Temp. Dr. Cal. Range

--

Varies

This displays Pulses. This is the recirculation temperature door calibration range measured in pulses.

Recirculation Temp. Dr. Motor Command

--

Varies

This displays Counts. This is the commanded recirculation temperature door motor request measured in counts.

Recirculation Temp. Dr. Position

--

Varies

This displays Counts or Pulses. This is the current recirculation temperature door position measured in either counts or pulses.

Right Sunload Sensor

--

Varies

This displays Counts. This is the current sunload measured in counts at the passenger sunload sensor.

Upper Left Duct Temp. Sensor

--

Varies

This displays Counts. This is the current temperature at the driver upper duct temperature sensor measured in counts.

Upper Right Duct Temp. Sensor

--

Varies

This displays Counts. This is the current temperature at the passenger upper duct temperature sensor measured in counts.

Valet Switch

--

Inactive

The scan tool displays Active or Inactive. This is the state of the valet switch.

Vehicle Speed

--

0 km/h (0 mph)

This displays km/h (mph). This is the current vehicle speed.

HVAC Control Module Scan Tool Output Controls

Output Control

Description

Afterblow Option

When afterblow is activated the scan tool displays an *.

Blower Motor

The scan tool displays Off or On selections. This function allows you to command the blower motor to its maximum (100%) or minimum (0%) speeds for 5 seconds.

Compressor Clutch

The scan tool displays the A/C compressor clutch status: Engage or Disengage. This function allows you to command the A/C compressor clutch On and Off.

Driver Temp. Door

The scan tool displays On or Off selections. The selection drives the actuator to its minimum (cold) or maximum (hot) positions for 20 seconds.

Instant OAT Update

The scan tool displays Commanded State: On or Off. This function updates the HVAC control module ambient air temperature input to the current raw value.

Mode Door Position

The scan tool displays On or Off selections. This function drives the actuator to its minimum (defrost) or maximum (upper) positions for 20 seconds.

Passenger Temp. Door

The scan tool displays On or Off selections. The selection drives the actuator to its minimum (hot) or maximum (cold) positions for 20 seconds.

Recalibrate All Motors

When commanded the scan tool displays the actuators counts moving from hot to cold until the re-cal is complete.

Recirculation Door

The scan tool displays On or Off selections. This function drives the actuator to its minimum (outside air) or maximum (recirculate) stops for 20 seconds.