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

Dimming Potentiometer

Data

Volts

Varies

Light Sensor

Data

Volts

1.75 Volts Maximum Light to 4.9 Volts Maximum Dark

Dimming Input

Data

Volts

Varies

Backlight Dimming

Data

Percent

Varies

Indicator Dimming

Data

Percent

Varies

Dimming Level

Data

Percent

0%

Key In Ignition

Inputs

Yes/No

Yes

Park Lamp Switch

Inputs

Active/Inactive

Inactive

Headlamp Switch

Inputs

Active/Inactive

Inactive

DRL Disable Switch

Inputs

Active/Inactive

Inactive

Flash to Pass Switch

Inputs

On/Off

Off

High Beam Switch

Inputs

On/Off

Off

Driver Door Ajar Sw.

Inputs

On/Off

Off

Park Brake Switch

Inputs

Set/Released

Released

Right Rear Door Ajar Sw

Inputs

On/Off

Off

Left Rear/Cargo Do

Inputs

On/Off

Off

Passenger Door Ajar Sw.

Inputs

On/Off

Off

Inadvertent Power Relay

Inputs

On/Off

Off

Courtesy Lamp Switch

Inputs

Active/Inactive

Inactive

Backup Light Request

Inputs

Active/Inactive

Inactive

Courtesy Lamp Relay

Inputs

On/Off

Off

Interior Lamp Defeat Switch

Inputs

On/Off

Off

Front Wiper Switch

Inputs

On/Off

Off

Ignition 1

Inputs

On/Off

On

Ignition 0

Inputs

On/Off

On

Ignition Accessory

Inputs

Active/Inactive

Active

Park Lamp Relay

Outputs

On/Off

Off

Daytime Running Lamps

Outputs

Active/Inactive

Active

High Beam Relay

Outputs

On/Off

Off

Headlamps On Indicator

Outputs

On/Off

Off

Backup Lamps

Outputs

On/Off

Off

Parking Lamp Relay

Output Control

On/Off

Off

Daytime Running Lamps

Output Control

Active/Inactive

Active

Backup Lamps

Output Control

On/Off

Off

Dimming

Output Control

Percent

Varies

Inadvertent Power

Output Control

On/Off

Off

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

Battery 1

Data

Volts

Varies

Battery 2

Data

Volts

Varies

Dimming Potentiometer

Data

Percent

Varies

Window Switch Backlight

Data

Percent

Varies

Memory Switch Backlight

Data

Percent

Varies

Mirror Switch Backlight

Data

Percent

Varies

Dimming Enable

Inputs

On/Off

On

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

Battery 1

Data

Volts

Varies

Battery 2

Data

Volts

Varies

Dimming Potentiometer

Data

Percent

Varies

Window Switch Backlight

Data

Percent

Varies

Memory Switch Backlight

Data

Percent

Varies

Door Ajar Switch

Inputs

On/Off

Off