GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

ALC Switch: 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.

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.

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

BPP Sensor Learn in Progress: The scan tool displays No/Yes. When the BPP Sensor is being reprogrammed, the scan tool displays Yes.

BPP Sensor High During Learn: The scan tool displays No/Yes. If the BPP sensor is shorted high during reprogramming, the scan tool will display Yes.

BPP Sensor Low During Learn: The scan tool displays No/Yes. If the BPP sensor is shorted low during reprogramming, the scan tool will display Yes.

BPP Sensor Move During Learn : The scan tool displays No/Yes. If the BPP sensor is moved during reprogramming, the scan tool will display Yes.

BPP Sensor Reference Signal: The scan tool displays Volts. The 5-volt reference voltage is displayed.

BPP Sensor Status Unlearned: The scan tool displays No/Yes. If the BPP sensor is not programmed then the scan tool displays Yes.

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

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.

Fog Lamp Relay CMD: 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.

IGN Mode Sw Dimming CMD: The scan tool displays On/Off. When the ignition switch dimming is commanded on, the scan tool displays On.

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.

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 Door Ajar Switch: The scan tool displays Closed/Open. When the LF door is opened, the scan tool displays Open.

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, 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 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 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.

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

Rear Fog lamp Switch: The scan tool displays inactive / active. When the rear fog lamp switch is in the OFF position the scan tool displays Off.

RF Door Ajar Switch: The scan tool displays Closed/Open. When the RF door is opened, the scan tool displays Open.

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

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.

Stop Lamp Status : The scan tool displays On/Off. When the stop lamps are applied, the scan tool displays On.

Theater Dimming Command: The scan tool displays On/Off. When the theater dimming is commanded on by the BCM, the scan tool displays On.

Trunk Release Switch: The scan tool displays Inactive/Active. When the trunk release switch is pressed, the scan tool displays Active.

Driver Door Module (DDM)

Door Switch Backlight: The scan tool displays a percentage of intensity. When the dimmer switch is full bright the scan tool will display 100 percent.

Exterior Courtesy Lamp: The scan tool displays On/Off. When the door is open , the BCM commands the exterior lamps on, the scan tool displays On.

Headlamp Control Module

AFS Disable Indication: The scan tool displays Off or On. Indicates the status of the adaptive forward lighting system (AFS).

Auto Headlamp Status: The scan tool displays Off or On. Indicates the state of the headlamps switch when placed in the AUTO position.

Auto Hdlp. Signal Present: The scan tool displays Yes or No. Indicates the state of the headlamps switch when placed in the AUTO position.

Component Serial No. 13-16: The scan tool displays the third partition of the door module serial number.

Headlamp Control Motor Status: The scan tool displays Off/Active/Hold/Homing/Forward/Disabled/Invalid. Indicates the status of the headlamp control motors input.

Headlamp Signal: The scan tool displays High Beams or Low Beams. Indicates the state of the high and low beam headlamp signals.

Ignition 1: The scan tool displays Active or Inactive. Indicates the state of the ignition 1 voltage input.

Julian Date Of Build: The scan tool displays a number representing the day of the year the module selected was built.

Left Hdlp. Motor Position: The scan tool displays Counts. This is the value that represents how much the headlamps are being moved to the left position.

Right Hdlp. Motor Position: The scan tool displays Counts. This is the value that represents how much the headlamps are being moved to the right direction.

Software Part Number: The scan tool displays the part number for the current level software.

Year Module Built: The scan tool displays the four digit year of build for the module selected.

HVAC

Ambient Light Sensor: The scan tool displays Counts. When the ambient light level increases are decreases, the scan tool display will change the counts displayed.

Instrument Panel Controller (IPC)

Dim Down Switch: The scan tool displays Inactive/Active. When the dimmer switch is commanding The interior lamps dim down, the scan tool displays Active.

Dim Up Switch: The scan tool displays Inactive/Active. When the dimmer switch is commanding The interior lamps dim up, the scan tool displays Active.

Dome Lamp Switch: The scan tool displays On/Off. When the dome lamps are commanded on, the scan tool displays On.

Front Fog Indicator Command: The scan tool displays On/Off. When the front fog lamp indicator is commanded on, the scan tool displays On.

High Beam Indicator Command: The scan tool displays On/Off. When the high beam indicator is commanded on the scan tool displays On.

Left Turn Signal: The scan tool displays On/Off. When the left turn lamps are commanded on, the scan tool displays On.

Park Lamps Signal: The scan tool displays On/Off. When the park lamps are commanded on, the scan tool displays On.

Rear Fog Indicator Command: The scan tool displays On/Off. When the rear fog lamp indicator is commanded on, the scan tool displays On.

Right Turn Signal: The scan tool displays On/Off. When the right turn lamps are commanded on, the scan tool displays On.