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/System Data

Withheld/Granted

Varies

A/C Request

A/C Permission Data / System Data

No/Yes

Varies

A/C Switch

Inputs

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

Air Inlet Motor Drive

Door Positions

Ambient Air/Increase/Recirculate/Decrease/Stop

Varies

Auto Switch

Inputs

Inactive/Active

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 Signal

A/C Permission

Normal/Out of Range

Normal

Battery Voltage Signal

System Data

Volts

Varies

Blower Speed

A/C Permission

Normal/Off

Varies

Blower Motor Speed Command

System Data

%

Varies

Coolant Temperature

System Data

°C/°F

°F

Driver Heated Seat LED

System Data

Off/On

Off

Driver Heated Seat Status

System Data

Off/Low/High

Off

Driver Heated Seat Switch

Inputs

Inactive/Active

Inactive

Engine Coolant Temp

A/C Permission

Normal/Out of Range

Normal

Engine Running

A/C Permission

Yes/No

Varies

Fan Down Button

Inputs

Inactive/Active

Varies

Fan Up Button

Inputs

Inactive/Active

Varies

Front Defrost LED

Data Display

Off/On

Off

Front Defrost Switch

Inputs

Inactive/Active

Inactive

Inside Air Temp Sensor

Sensors

°C/°F

Varies

Left Hand A/C Duct Actual Temp

Sensors

°C/°F

°F

Left Hand A/C Duct Desired Temp

Sensors

°C/°F

°F

Left Hand Heater Duct Actual Temp

Sensors

°C/°F

°F

Left Hand Heater Duct Desired Temp

Sensors

°C/°F

°F

Left Temp Setting

Inputs

°C/°F

°F

Left Temp Door Commanded

Door Positions

0-255 count

Varies

Left Sunload Sensor

Sensors

Counts

Varies

Low Pressure Switch

Data Display

Open/Close

Close

Low Coolant Switch

System Data

Open/Close

Close

Mode Down Switch

Inputs

Inactive/Active

Varies

Mode Switch Position

Inputs

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

Varies

Mode Up Switch

Inputs

Inactive/Active

Varies

Mode Door Actual

Door Positions

Counts

Varies

Mode Door Motor Command

Door Positions

0-255 Count

Varies

Mode Select Position

Door Positions

Bi-Level/Panel/Off/Auto/Defrost/Heater/Htr. Defrost

Varies

On/Off Switch

Inputs

Inactive/Active

Varies

Outside Air Temp Filtered

Sensors

°C/°F

°F

Outside Air LED

System Data

Off/On

Varies

Outside Air Temp RAW

Sensors

°C/°F

°F

Outside Air Mode Switch

Inputs

Inactive/Active

Varies

Passenger Heated Seat Status

System Data

Off/Low/High

Off

Passenger Heated Seat Switch

Inputs

Inactive/Active

Inactive

Passenger Heated Seat LED

System Data

Off/On

Off

Rear Defrost LED

System Data

Off/On

Off

Rear Defrost Switch

Inputs

Inactive/Active

Inactive

Rear Defrost State

System Data

Off/On

Off

Recirculation Switch

Inputs

Inactive/Active

Inactive

Right Hand A/C Duct Actual

Sensors

°C/°F

°F

Right Hand A/C Duct Desired

Sensors

°C/°F

°F

Right Hand Heater Duct Actual

Sensors

°C/°F

°F

Right Hand Heater Duct Desired

Sensors

°C/°F

°F

Right Sunload Sensor

Sensors

Counts

Varies

Right Temp Door Commanded

Door Positions

Counts

Varies

Right Temp Door Actual

Door Positions

Counts

Varies

Right Temp Setting

Inputs

°C/°F

°F

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

Inactive/Active

Varies

Power Button

Data Display

Inactive/Active

Active

Program Switch

Data Display

Inactive/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