GM Service Manual Online
For 1990-2009 cars only
Table 1: HVAC Control Module Scan Tool Data List
Table 2: Aux. HVAC Control Module Scan Tool Data List
Table 3: ECM Scan Tool Data List

HVAC Control Module Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Engine idling, A/C ON, ambient air temperature between 22-27°C (70-80°F)

A/C Evap. Temperature Sensor

HVAC Sensors

°C/°F

Varies

A/C High Side Pressure Sensor

HVAC Sensors

kPa/psi

Varies

Ambient Air Temp. Sensor

HVAC Sensors, HVAC System Data, Open/Short Data

°C/°F

Varies

Aux. Mode Door Actual

HVAC Door Positions

Counts

Varies

Aux. Mode Door Command

HVAC Door Positions

Counts

Varies

Aux. Temp Dr. Position

HVAC Door Positions

Counts

Varies

Aux. Temp Dr. Motor Command

HVAC Door Positions

Counts

Varies

Blower Motor Relay Cmd.

HVAC System Data

On/Off

On

Blower Motor Speed command

HVAC System Data

%

Varies

Coolant Temperature

HVAC Sensors, HVAC System Data

°C/°F

Varies

Driver Temp. Dr. Motor Commanded

HVAC Door Positions

Counts

Varies

Driver Temp. Dr. Position

HVAC Door Positions

Counts

Varies

Inside Air Temp. Sensor

HVAC Sensors, HVAC System Data, Open/Short Data

°C/°F

Varies

Left Sunload Sensor

HVAC Sensors, Open/Short Data

Counts

Varies

Mode Dr. Motor Command

HVAC Door Positions

Counts

Varies

Mode Door Position

HVAC Door Positions

Counts

Varies

Psgr. Temp. Dr. Motor Command

HVAC Door Positions

Counts

Varies

Psgr. Temp. Dr. Position

HVAC Door Positions

Counts

Varies

Rear Defrost State

HVAC System Data

On/Off

Off

Recirculation Dr. Motor Command

HVAC Door Positions

Counts

Varies

Recirculation Dr. Position

HVAC Door Positions

Counts

Varies

Right Sunload Sensor

HVAC Sensors, Open/Short Data

Counts

Varies

Vehicle Speed

HVAC System Data

Km/h/mph

Varies

Water Pump Relay

HVAC System Data

On/Off

On

Aux. HVAC Control Module Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Engine idling, A/C ON, ambient air temperature between 22-27°C (70-80°F)

Aux. Blower Motor PWM

Data Display

%

Varies

ECM Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Engine idling, A/C ON, ambient air temperature between 22-27°C (70-80°F)

A/C Request Signal

Cooling/HVAC Data

Yes/No

Yes

A/C Relay Command

Cooling/HVAC Data

On/Off

On

A/C Relay Circuit Status

Cooling/HVAC Data

Incomplete, Short Gnd, Open Short to B+

Incomplete

A/C High Side Pressure Sensor

Cooling/HVAC Data

Volts

Varies

A/C High Side Pressure Sensor

Cooling/HVAC Data

kPa/Psi

629-845 kPa (85-120 psi)

A/C Off For WOT

Cooling/HVAC Data

Yes/No

No

A/C Pressure Disable

Cooling/HVAC Data

Yes/No

No

A/C Disengage 1 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 2 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 3 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 4 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 5 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 6 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 7 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

A/C Disengage 8 History

Cooling/HVAC Data

None, A/C Pressure, Engine Speed, Battery Voltage, Stall Prevention, RPM Unstable, WOT, Launch Performance, Coolant Hot

None

ECT Sensor

Cooling/HVAC Data

°C/°F

92°C (197°F)