GM Service Manual Online
For 1990-2009 cars only
Table 1: Body Control Module (BCM)
Table 2: Driver Door Switch
Table 3: Export Body Control Module (XBCM)
Table 4: Passenger Door Switch

Body Control Module (BCM)

Scan Tool Parameter

Data Display

Units Displayed

Typical Data Value

Operating Conditions: Ignition in the ON position, bright light applied to the ambient light sensor, park brake not set, headlamp switch in the OFF position, dome lamp switch in the OFF position, fog lamp switch in the OFF position, and all doors closed.

Ambient Light Sensor

Exterior Lighting

Volts

Approximately 0.67 Volts

Ambient Light Status

Exterior Lighting

Night/ Day/ Unknown/ Invalid

Day

Auto Hdlp. Disable Sw.

Exterior Lighting

Inactive/Active

Inactive

Backup Lamps

Exterior Lighting

Off/On

Off

Courtesy Lamp PWM Cmd.

Interior Lighting

Percent

0%

Cruise Ctrl. LED Dimming Cmd.

Interior Lighting

Percent

2%

Ctsy. Lamp Actv. Reason

Interior Lighting

Off/Panic/Manual/Air Bag/Door Open/RFA/RFA Theft/Door Closed/Exit/Manual Defeat

Off

Dimming Control Reference

Interior Lighting

Volts

Approximately 3.0 Volts

Dimming Control Signal

Interior Lighting

Percent

Varies 9% - 100%

Dimming Control Signal

Interior Lighting

Volts

Varies 0.23 - 3.0 Volts

DRL Relay Command

Exterior Lighting

Off/On

Off

Flash to Pass Switch

Exterior Lighting

Inactive/Active

Inactive

Front Fog Lamp Relay Command

Exterior Lighting

Off/On

Off

Front Fog Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Hazard Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Headlamp Switch

Exterior Lighting

Inactive/Active

Inactive

High Beam Relay Command

Exterior Lighting

Off/On

Off

High Beam Select Switch

Exterior Lighting

Inactive/Active

Inactive

Incandescent Dimming PWM Cmd.

Interior Lighting

Percent

0%

LED Dimming PWM Cmd.

Interior Lighting

Percent

0%

Left Turn Signal Switch

Exterior Lighting

Inactive/Active

Inactive

LF Turn Signal

Exterior Lighting

Off/On

Off

LR Turn Signal

Exterior Lighting

Off/On

Off

Low Beam Relay Command

Exterior Lighting

Off/On

Off

Park Brake Switch

Inputs

Released/Applied

Released

Park Lamp Relay Cmd.

Exterior Lighting

Off/On

Off

Park Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Right Turn Signal Switch

Exterior Lighting

Inactive/Active

Inactive

RF Turn Signal

Exterior Lighting

Off/On

Off

RR Turn Signal

Exterior Lighting

Off/On

Off

Stop Lamp Sw. Status

Exterior Lighting

Counts

1023 Counts

Stop Lamp Relay Command

Exterior Lighting

Off/On

Off

Driver Door Switch

Scan Tool Parameter

Data Display

Units Displayed

Typical Data Value

Operating Conditions: Ignition in the ON position, bright light applied to the ambient light sensor, park brake not set, headlamp switch in the OFF position, dome lamp switch in the OFF position, fog lamp switch in the OFF position, and all doors closed.

Driver Door Open Sw.

Inputs

Inactive/Active

Inactive

Memory Switch Backlight

Outputs

Percent

0%

Window Switch Backlight

Outputs

Percent

0%

Export Body Control Module (XBCM)

Scan Tool Parameter

Data Display

Units Displayed

Typical Data Value

Operating Conditions: Ignition in the ON position, bright light applied to the ambient light sensor, park brake not set, headlamp switch in the OFF position, dome lamp switch in the OFF position, fog lamp switch in the OFF position, all doors closed, and trailer harness disconnected.

Battery Voltage

Data Display

Volts

Varies

Rear Fog Lamp Relay Cmd.

Data Display

Off/On

Off

Rear Fog Lamp Switch

Data Display

Inactive/Active

Inactive

Trailer Left Bulb Out Signal

Data Display

Counts

0 Counts

Trailer Right Bulb Out Signal

Data Display

Counts

0 Counts

Trailer Detection Input

Data Display

Off/On

Off

Trailer Fog Lamp Relay Cmd.

Data Display

Off/On

Off

Passenger Door Switch

Scan Tool Parameter

Data Display

Units Displayed

Typical Data Value

Operating Conditions: Ignition in the ON position, bright light applied to the ambient light sensor, park brake not set, headlamp switch in the OFF position, dome lamp switch in the OFF position, fog lamp switch in the OFF position, and all doors closed.

Memory Switch Backlight

Outputs

Percent

0%

Passenger Door Open Sw.

Inputs

Inactive/Active

Inactive

Window Switch Backlight

Outputs

Percent

0%