GM Service Manual Online
For 1990-2009 cars only
Table 1: Body Control Module (BCM)
Table 2: Driver Door Module (DDM)
Table 3: Headlamp Control Module
Table 4: HVAC
Table 5: Instrument Panel Controller (IPC)

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON Engine OFF/Doors, Trunk and Hood Closed/No Switches ON/Vehicle in PARK or NEUTRAL

ALC Switch

Exterior Lamps

Off/On

Varies with light level

Backup Lamp Relay Command

Exterior Lamps

Off/On

Off

BPP Sensor

Exterior Lamps

Volts

Varies

BPP Sensor Learn Home Position

Exterior Lamps

Counts

Varies

BPP Sensor Learn in Progress

Exterior Lamps

No/Yes

No

BPP Sensor High During Learn

Exterior Lamps

No/Yes

No

BPP Sensor Low During Learn

Exterior Lamps

No/Yes

No

BPP Sensor Move During Learn

Exterior Lamps

No/Yes

No

BPP Sensor Reference Signal

Exterior Lamps

Volts

5 Volts

BPP Sensor Status Unlearned

Exterior Lamps

No/Yes

No

Day/Night Status

Exterior Lamps

Day/Night

Varies with light level

DRL Status

Exterior Lamps

Off/On

Varies with light level

Flash to Pass Switch

Exterior Lamps

Inactive/Active

Inactive

Fog Lamp Relay CMD

Exterior Lamps

Off/On

Off

Front Fog Lamp Switch

Exterior Lamps

Inactive/Active

Inactive

Hazard Lamp Switch

Exterior Lamps

Inactive/Active

Inactive

Headlamps OFF Switch

Exterior Lamps

Off/On

On

Headlamps ON Switch

Exterior Lamps

Inactive/Active

Inactive

High Beam Relay Command

Exterior Lamps

Off/On

Off

High Beam Select Switch

Exterior Lamps

Inactive/Active

Inactive

IGN Mode Switch Dimming CMD

Interior Lamps

Off/On

Off

Inadvert Power CMD

Interior Lamps

Off/On

Off

Inadvert Power Signal

Interior Lamps

Inactive/Active

Inactive

Left Turn Signal Switch

Exterior Lamps

Inactive/Active

Inactive

LF Door Ajar Switch

Interior Lamps

Closed/Open

Closed

LF Turn/Hazard Lamp Command

Exterior Lamps

Off/On

Off

LF Turn Lamp/DRL Status

Exterior Lamps

Off/On

Off

Low Beam Relay Command

Exterior Lamps

Off/On

Off

LR Turn/Hazard Lamp Command

Exterior Lamps

Off/On

Off

LR Turn Lamp/DRL Status

Exterior Lamps

Off/On

Off

Park Lamp Relay CMD

Exterior Lamps

Off/On

Off

Park Lamp Switch

Exterior Lamps

Off/On

Off

Rear Fog Lamp Relay CMD

Exterior Lamps

Off/On

Off

Rear Fog Lamp Switch

Exterior Lamps

Inactive/Active

Inactive

RF Door Ajar Switch

Interior Lamps

Closed/Open

Closed

RF Turn/Hazard Lamp Command

Exterior Lamps

Off/On

Off

RF Turn Lamp/DRL Status

Exterior Lamps

Off/On

Off

Right Turn Signal Switch

Exterior Lamps

Inactive/Active

Inactive

RR Turn/Hazard Lamp Command

Exterior Lamps

Off/On

Off

RR Turn Lamp/DRL Status

Exterior Lamps

Off/On

Off

Stop Lamp Relay Command

Exterior Lamps

Off/On

Off

Stop Lamp Status

Exterior Lamps

Off/On

Off

Theater Dimming Command

Interior Lamps

Off/On

Off

Trunk Release Switch

Interior Lamps

Inactive/Active

Inactive

Driver Door Module (DDM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON Engine OFF/Doors, Trunk and Hood Closed/No Switches ON/Vehicle in PARK or NEUTRAL

Door Switch Backlight

Data

0%

0%

Exterior Courtesy Lamp

Data

Off/On

Off

Headlamp Control Module

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, with the engine OFF transmission shift lever in the PARK position all lighting turned OFF all doors closed

AFS Disable Indication

Data/Inputs

Off/On

Off

Auto Headlamp Status

Data/Inputs

Off/On

On

Auto Hdlp. Signal Present

Data/Inputs

Yes/No

Yes

Base Model Part Number

Module ID Information

Number

Varies

Component Serial No. 13-16

Module ID Information

Number

13-16th Digit

End Model Part Number

Module ID Information

Number

Varies

Headlamp Control Motor Status

Data/Inputs

Off/Active/Hold/Homing/Forward/Disabled/Invalid

Active

Headlamp Signal

Data/Inputs

High Beams/Low Beams

Low Beams

Ignition 1

Data/Inputs

Active/Inactive

Active

Julian Date Of Build

Module ID Information

Number

Varies

Left Hdlp. Motor Position

Data/Outputs

Counts

Varies

Right Hdlp. Motor Position

Data/Outputs

Counts

Varies

Software Part Number

Module ID Information

Number

Varies

Year Model Built

Module ID Information

Number

Varies

HVAC

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON Engine OFF/Doors, Trunk and Hood Closed/No Switches ON/Vehicle in PARK or NEUTRAL

Ambient Light Sensor

Data

Counts

Varies

Instrument Panel Controller (IPC)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON Engine OFF/Doors, Trunk and Hood Closed/No Switches ON/Vehicle in PARK or NEUTRAL

Dim Down Switch

Data

Inactive/Active

Inactive

Dim Up Switch

Data

Inactive/Active

Inactive

Dome Lamp Switch

Data

Off/On

Off

Front Fog Indicator Command

Data

Off/On

Off

High Beam Indicator Command

Data

Off/On

Off

Left Turn Signal

Data

Off/On

Off

Park Lamps Signal

Data

Off/On

Off

Rear Fog Indicator Command

Data

Off/On

Off

Right Turn Signal

Data

Off/On

Off