GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Vehicle in PARK/Park brake RELEASED/Headlamps in AUTO/All doors/tailgate closed

Battery Voltage

Data

Volts

Varies

Light Sensor

Data

Volts

1.75 Volts Maximum Light to 4.9 Volts Maximum Dark

Dimming Input

Data

Volts

Varies

Dimming Level

Data

Percent

0%

Backlight Dimming

Data

Percent

Varies

Indicator Dimming

Data

Percent

Varies

Ignition 0

Inputs

On/Off

On

Ignition 1

Inputs

On/Off

On

Ignition Accessory

Inputs

On/Off

On

Key In Ignition

Inputs

Yes/No

Yes

Front Fog Lamp Switch

Inputs

Active/Inactive

Inactive

Flash to Pass Switch

Inputs

On/Off

Off

Interior Lamp Defeat Sw

Inputs

On/Off

On/Off

Headlamp Switch

Inputs

Active/Inactive

Inactive

Parklamp Switch

Inputs

Active/Inactive

Inactive

High Beam Switch

Inputs

On/Off

Off

Courtesy Lamp Switch

Inputs

Active/Inactive

Inactive

Park Brake Switch

Inputs

Set/Released

Released

Inadvertent Power Relay

Inputs

On/Off

Off

High Beams

Output

On/Off

Off

Low Beams

Output

On/Off

Off

Park Lamp Relay

Output

On/Off

On/Off

Dimming Level

Output

Percent

Varies

Inadvertent Power Relay

Output

On/Off

On

Daytime Running Lamps

Output

Active/Inactive

Active

Driver Door Module (DDM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Vehicle in PARK/Park brake RELEASED/Headlamps in AUTO/All doors/tailgate closed

Door Ajar Switch

Inputs

On/Off

Off

Passenger Door Module (PDM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Vehicle in PARK/Park brake RELEASED/Headlamps in AUTO/All doors/tailgate closed

Door Ajar Switch

Inputs

On/Off

Off