GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

ALC Status: The scan tool displays On/Off. When the ambient light level indicates low light level then the BCM will turn on the automatic light control (ALC) then the scan tool will display On.

Ambient Light Sensor: The scan tool displays the voltage reading of the ambient light sensor.

Backup Lamp Relay Command: The scan tool display On/Off. When the transmission is placed in the REVERSE position the scan tool displays On.

BPP Sensor: The scan tool displays Volts. The varied voltage from the BPP sensor is displayed on the scan tool.

Day/Night Status: The scan tool displays Day/Night. When the daylight conditions are present the scan tool will display Day.

Door Ajar Switch: The scan tool displays Closed or Open. When any passenger door is open, Open is displayed. When all of the passenger doors are closed, Closed is displayed.

Driver Door Ajar Switch: The scan tool displays Closed or Open. When the driver door is open, Open is displayed. When the driver door is closed, Closed is displayed.

DRL Status: The scan tool displays On/Off. When the ambient light level indicates daylight level then the scan tool will display ON.

Flash to Pass Switch : The scan tool displays Inactive/Active. When Flash to Pass switch is placed in the OFF position, the scan tool displays Inactive.

Front Fog Lamp Relay Command: The scan tool displays On/Off. When the fog lamps are placed in the ON position then the scan tool displays On.

Front Fog Lamp Switch: The scan tool displays Inactive/Active. When the fog lamp switch is in the OFF position the scan tool displays Off.

Hazard Lamp Switch: The scan tool displays Inactive/Active. When the hazard switch is placed in the ON position, the scan tool will display ON.

Headlamps OFF Switch: The scan tool displays On/Off. When the headlamp switch is placed in the OFF position, the scan tool displays On.

Headlamps ON Switch: The scan tool displays Inactive/Active. When the headlamp switch is placed in the ON position, the scan tool displays Active.

High Beam Relay Command: The scan tool displays On/Off. When the high beam headlamps are turned on, the scan tool displays On.

High Beam Select Switch: The scan tool displays Inactive/Active. When the high beam headlamps are turned on, the scan tool displays Active.

Inadvert Power CMD: The scan tool displays On/Off. When the inadvertent power is being commanded on by the BCM the scan tool displays On.

Inadvert Power Signal: The scan tool displays Inactive/Active. When the inadvertent power is being commanded on by the BCM the scan tool displays Active.

Interior Light Command: The scan tool displays Off or On. When the interior lights are commanded on, On is displayed. When the interior lights are commanded off, Off is displayed.

Interior Lights Dimmed: The scan tool displays the percentage of dimming that is commanded by the IP dimmer switch.

IP Dimmer Switch: The scan tool displays the position of the IP dimmer switch in volts.

Left Turn Signal Switch: The scan tool displays Inactive/Active. When the turn signal switch is placed in the LEFT position, the scan tool will display Active.

LF Turn Lamp/DRL Status: The scan tool displays On/Off. When the DRL lamps are commanded on by the BCM or the turn signal switch is placed in the LEFT position, scan tool displays On.

Low Beam Relay Command: The scan tool displays On/Off. When the headlamp are turned on, the scan tool displays On.

LR Turn Lamp/DRL Status: The scan tool displays On/Off. When the DRL lamps are commanded on by the BCM or the turn signal switch is placed in the LEFT position, scan tool displays On.

Park Brake Switch: The scan tool displays Off or On. When the park brake is disengaged, Off is displayed. When the park brake is engaged, On is displayed.

Park Lamp Relay CMD: The scan tool displays On/Off. When the park lamps are turned on, the scan tool will display On.

Park Lamp Switch: The scan tool displays On/Off. When the park lamp switch is placed in the ON position, the scan tool will display On.

RF Turn Lamp/DRL Status: The scan tool displays On/Off. When the DRL lamps are commanded on by the BCM or the turn signal switch is placed in the RIGHT position, scan tool displays On.

Right Turn Signal Switch: The scan tool displays Inactive/Active. When the turn signal switch is placed in the RIGHT position, the scan tool will display Active.

RR Turn Lamp/DRL Status: The scan tool displays On/Off. When the DRL lamps are commanded on by the BCM or the turn signal switch is placed in the RIGHT position, scan tool displays On.

Stop Lamp Relay Command: The scan tool displays On/Off. When the brakes are applied, the scan tool displays On.