GM Service Manual Online
For 1990-2009 cars only
Table 1: BCM
Table 2: HVAC Control Module
Table 3: Rear HVAC/RSA (VIN 3)
Table 4: Rear HVAC/RSA (VIN 6)
Table 5: PCM

BCM

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)

Left Solar Sensor

Data

Counts

Varies

Right Solar Sensor

Data

Counts

Varies

SWC Switch Power

Outputs

On/Off

On

SWC Switch Voltage

Data

Volts

0.0 Volts

HVAC Control Module

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 Switch

Input/Output

On, Off

Off

AC Compressor Feedback

Input/Output

On, Off

Varies

AC Permission

Input/Output

Withheld, Granted

Varies

AC/Heater Door Actual

Door Positions

Counts

Varies

AC/Heater Door Commanded

Door Positions

Counts

Varies

AC/Heater Motor Drive

Door Positions

Stop, Increase, Decrease

Stop

Air Inlet Door Actual

Door Positions

Counts

Varies

Air Inlet Door Commanded

Door Positions

Counts

Varies

Air Inlet Motor Drive

Door Positions

Stop, Increase, Decrease

Stop

Air Mix Door Left Commanded

Door Positions

Counts

Varies

Air Mix Door Right Commanded

Door Positions

Counts

Varies

Auto Switch

Input/Output

On, Off

Off

Battery Voltage

Input/Output

Volts

13.5-14.5 V

Blower Motor PWM Speed

Door Positions

Percent

12-114%

Blower Speed

A/C Permission

Yes, No

No

Defrost Door Actual

Door Positions

Counts

Varies

Defrost Door Commanded

Door Positions

Counts

Varies

Defrost Motor Drive

Door Positions

Stop, Increase, Decrease

Stop

Engine Coolant Temp

A/C Permission

Yes, No

No

Engine Running

A/C Permission

Yes, No

No

Fan Down Button

Input/Output

On, Off

Off

Fan Up Button

Input/Output

On, Off

Off

Front Defrost Switch

Input/Output

On, Off

Off

Ign. Since Current DTC

Input/Output

Numeric

0

Inside Air Temp

Sensor Data

°C/°F

Varies

Inside Air Temp. Fan

Sensor Data

On, Off

On

Left Mix Door Actual

Door Positions

Counts

Varies

Left Mix Motor Drive

Door Positions

Stop, Increase, Decrease

Stop

Left Temp. Setting

Input/Output

°C/°F

Varies

LH AC Duct Actual

Sensor Data

Counts

Varies

LH AC Duct Desired

Sensor Data

Counts

Varies

LH Heater Duct Actual

Sensor Data

Counts

Varies

LH Heater Duct Desired

Sensor Data

Counts

Varies

Mode Select Position

Door Positions

Off, Auto, Defrost, Heater, Htr/Def, Bi-level, Panel

Varies

Mode Switch

Input/Output

On, Off

Off

Off Switch

Input/Output

On, Off

Off

Outside Air Temp

A/C Permission

Yes, No

No

Outside Air Temp. Filtered

Input/Output

°C/°F

22-27°C (70-80°F)

Outside Air Temp. Raw

Input/Output

°C/°F

Varies

Pressure Cycle Switch

A/C Permission

Yes, No

No

Pressure Cycle Switch

Input/Output

Low Pressure, Normal

Varies

Recirculate Switch

Input/Output

On, Off

Off

RH AC Duct Actual

Sensor Data

Counts

Varies

RH AC Duct Desired

Sensor Data

Counts

Varies

RH Heater Duct Actual

Sensor Data

Counts

Varies

RH Heater Duct Desired

Sensor Data

Counts

Varies

Right Mix Door Actual

Door Positions

Counts

Varies

Right Mix Motor Drive

Door Positions

Stop, Increase, Decrease

Stop

Right Temp. Setting

Input/Output

°C/°F

Varies

Rear HVAC/RSA (VIN 3)

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

Input/Output

Volts

13.5-14.5 V

Ign. Since Current DTC

Input/Output

Cycles

Varies

Rear HVAC Fan Down Sw.

Input/Output

Active, Inactive

Inactive

Rear HVAC Fan Speed

Input/Output

Off, Med, High

Varies

Rear HVAC Fan Up Switch

Input/Output

Active, Inactive

Inactive

Rear HVAC Mode Switch

Input/Output

Active, Inactive

Inactive

Rear HVAC Motor Pos.

Door Positions

Lower, Bi-level, Upper

Bi-level

Rear HVAC/RSA (VIN 6)

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)

Air Mix Door Actual

Door Positions

Counts

Varies

Air Mix Door Commanded

Door Positions

Counts

Varies

Battery Voltage

Input/Output

Volts

13.5-14.5 V

Console Mode Door Actual

Door Positions

Counts

0.0 Volts

Console Mode Door Commanded

Door Positions

Counts

Varies

Driver Override Switch

Input/Output

Rear, Off, Low, Med, High

Varies

Heater Water Valve

Input/Output

Open, Closed

Closed

Ign. Since Current DTC

Input/Output

Cycles

Varies

Mode Door Actual

Door Positions

Counts

Varies

Mode Door Commanded

Door Positions

Counts

Varies

Rear Blower Speed

Input/Output

%

Varies

Rear HVAC Fan Down Switch

Input/Output

Active, Inactive

Inactive

Rear HVAC Fan Speed

Input/Output

Off, Low, Med, High

Varies

Rear HVAC Fan Up Switch

Input/Output

Active, Inactive

Inactive

Rear HVAC Mode Switch

Input/Output

Active, Inactive

Inactive

Rear HVAC Motor Pos.

Door Positions

Lower, Bi-level, Upper

Bi-level

Rear Temp. Select Sw.

Input/Output

Up, Down, Inactive

Inactive

Rec. Mode from Front Control

Door Positions

Heater, Panel, Defrost, Bi-level, Htr./Def.

Varies

PCM

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 High Side Pressure Sensor

Engine Data 2

kPa, Psi

629-845 kPa (85-120 psi)

A/C High Side Pressure Sensor

Engine Data 2

Volts

Varies

A/C Relay Command

Engine Data 2

On, Off

Varies

A/C Request Signal

Engine Data 2

Yes, No

Varies

ECT Sensor

Engine Data 2

°C/°F

92°C (197°F)