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 sensor indicates low light level the body control module (BCM) will turn the automatic light control (ALC) ON and the scan tool will display On.

Ambient Light Sensor: The scan tool displays Volts. The ambient light sensor voltage will vary depending on the outside lighting conditions.

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

Battery Voltage Signal: The scan tool displays Volts. This is the current battery voltage at the BCM.

BPP Sensor: The scan tool displays Volts. The varied voltage from the brake pedal position (BPP) sensor is displayed on the scan tool.

BPPS Learn Home Position: The scan tool displays Counts. The brake pedal home position is displayed as Counts.

BPPS Ratio: The scan tool displays Counts. The varied voltage from the brake pedal position (BPP) sensor is displayed on the scan tool as counts.

BPPS Status: The scan tool displays Learned/Unlearned. If the BPP sensor is not programmed, the scan tool displays Unlearned.

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

DRL Status: The scan tool displays On/Off. When the ambient light sensor indicates outside light conditions are bright, the scan tool will display On indicating the daytime running lamps (DRLs) are active.

Flash to Pass Switch: The scan tool displays Inactive/Active. When the 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 lamp switch is placed in the ON position, 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 Off/On. When the hazard switch is placed in the ON position, the scan tool will display On.

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

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

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.

I/P Dimmer Switch: The scan tool displays Volts. When the instrument panel (I/P) dimmer switch is rotated from HIGH to LOW, the scan tool displays the change in Volts.

Inadvertent Power Cmd.: The scan tool displays On/Off. When the inadvertent power is being commanded ON by the BCM, the scan tool displays On.

Inadvertent 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 On/Off. When the interior courtesy lamps are ON, the scan tool will display On.

Interior Lights Dimmed Command: The scan tool displays On/Off. When the interior courtesy lamps are being dimmed, the scan tool will display On.

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

LF Turn/Hazard Lamp Command: The scan tool displays On/Off. When the turn signal is place in the LEFT position, the scan tool displays On.

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, the 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/Hazard Lamp Command: The scan tool displays On/Off. When the turn signal is place in the LEFT position, the scan tool displays On.

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

Park Brake Switch: The scan tool displays Active/Inactive. When the park brake is applied the scan tool will display Active.

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/Hazard Lamp Command: The scan tool displays On/Off. When the turn signal is place in the right position, the scan tool displays 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, the scan tool displays On.

RR Turn/Hazard Lamp Command: The scan tool displays On/Off. When the turn signal switch is placed in the right position, the scan tool displays On.

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

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