GM Service Manual Online
For 1990-2009 cars only
Table 1: HVAC Control Module Scan Tool Data List
Table 2: Rear HVAC Control Module/RSA Scan Tool Data List
Table 3: Engine Control Module (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 LED

System Data

Off/On

Varies

A/C Head Pressure

A/C Permission Data

Normal/Out of Range

Normal

A/C Permission

A/C Permission Data

Withheld/Granted

Varies

A/C Request

A/C Permission Data

No/Yes

Varies

A/C Switch

Inputs Data

Inactive/Active

Varies

Ambient Air Temperature

A/C Permission Data

Normal/Out of Range

Normal

Air Inlet Door Actual

Door Positions

Counts

Varies

Air Inlet Door Commanded

Door Positions

0-255 Counts

Varies

Auxiliary Blower Motor PWM

System Data

%

Varies

Auxiliary LED

System Data

Off/On

Varies

Auxiliary Mode Door Commanded

Door Positions

0-255 Counts

Varies

Auxiliary Mode Switch Position

Inputs

Panel/Bilevel/Floor

Varies

Auxiliary Switch

Inputs

Inactive/Active

Varies

Auxiliary Temp Door Motor Command

Door Positions

0-255 Counts

Varies

Battery Voltage

A/C Permission

Normal/Out of Range

Normal

Blower Speed

A/C Permission

Normal/Off

Varies

Blower Motor Speed Command

System Data

%

Varies

Engine Coolant Temp

A/C Permission

Normal/Out of Range

Normal

Engine Running

A/C Permission

Yes/No

Varies

Temperature Door Motor Commanded

Door Positions

0-255 count

Varies

Temperature Door Position

Door Positions

0-255 count

Varies

Mode Switch Position

Inputs

Auto/Panel/Bi-Level/Floor/Defrost-Floor

Varies

Mode Door Actual

Door Positions

Counts

Varies

Mode Door Motor Commanded

Door Positions

0-255 Count

Varies

Outside Air Temp Filtered

Sensors

°C

Varies

Outside Air LED

System Data

Off/On

Varies

Outside Air Temp RAW

Sensors

°C

Varies

Outside Air Mode Switch

Inputs

Inactive/Active

Varies

Rear Defrost LED

System Data

Off/On

Off

Rear Defrost Switch

Inputs

Inactive/Active

Inactive

Rear Defrost State

System Data

Off/On

Off

Recirculation LED

System Data

Off/On

Varies

Recirculation Switch

Inputs

Inactive/Active

Inactive

Rear HVAC Control Module/RSA 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)

Battery Voltage Signal

Data Display

Volts

Varies

Display Dimming Signal

Data Display

Volts

Varies

Left Rear Heated Seat Switch

Data Display

Active

Varies

Rear HVAC Fan Down Switch

Data Display

Inactive/Active

Varies

Rear HVAC Fan Up Switch

Data Display

Inactive/Active

Varies

Rear HVAC Mode Switch

Data Display

Inactive/Active

Varies

Rear Temperature Down Switch

Data Display

Inactive/Active

Varies

Rear Temperature Up Switch

Data Display

Inactive/Active

Varies

Right Rear Heated Seat Switch

Data Display

Inactive/Active

Varies

Source Button

Data Display

Inactive/Active

Varies

Engine Control Module (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 Disengage 1 History

Data Display

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

None

A/C Disengage 2 History

Data Display

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

None

A/C Disengage 3 History

Data Display

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

None

A/C Disengage 4 History

Data Display

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

None

A/C Disengage 5 History

Data Display

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

None

A/C Disengage 6 History

Data Display

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

None

A/C Disengage 7 History

Data Display

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

None

A/C Disengage 8 History

Data Display

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

None

A/C High Side Pressure Sensor

Data Display

kPa

Varies

A/C High Side Pressure Sensor

Data Display

Volts

Varies

A/C off for WOT

Data Display

No/Yes

No

A/C Pressure Disable

Data Display

No/Yes

No

A/C Request Signal

Data Display

No/Yes

Varies

A/C Relay Command

Data Display

off/on

Varies

ECT Sensor

Data Display

°C/°F

°F

Engine Run Time

Data Display

seconds

Varies

Ignition 1 Signal

Data Display

Volts

Varies

Inside Air Temp

Data Display

°C/°F

°F