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.

A/C Evap. Temperature Sensor

--

Varies

This displays °F (°C). This is the current temperature of the evaporator temperature sensor.

A/C High Side Pressure Sensor

--

Varies

This displays kPa (psi). The voltage applied to the ECM input from the A/C refrigerant pressure sensor is converted to a pressure value.

Ambient Air Temp. Sensor

--

Varies

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

Coolant Temperature

--

Varies

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

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.

Left Sunload Sensor

--

Varies

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

Mode Door Position

--

Varies

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

Mode Dr. Motor Command

--

Varies

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

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 Dr. Motor Command

--

Varies

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

Recirculation 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.

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

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.

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.

Inside Air Temp. Sensor Fan

The scan tool displays Commanded State: On or Off. This function allows you to command the inside air temperature sensors fan On and Off.

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.

Rear Defog Request

The scan tool displays Commanded State: On or Off. This function allows you to command the rear defog On and Off.

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.

Segment Check

The scan tool displays Commanded State: On or Off. This function allows you to illuminate all segments on the HVAC control modules display.