GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF/Vehicle in PARK/Headlamps in AUTO

Ambient Light

Data

DARK/LIGHT

LIGHT (DRL ON) DARK (AHL ON)

Ambient Light Sensor

Data

Volts

4.7 Volts Maximum Light to 1.0 Volt Maximum Dark

Auto Headlamps

Input 2

ACTIVE/INACTIVE

INACTIVE (in LIGHT state)

Auto Learn Timer

Security Data

Seconds

0-600

Battery Voltage

Data

Volts

Varies

Battery Voltage

Security Data

Volts

Varies

Cargo Lamp Switch

Input 1

ON/OFF

OFF

Chime

Outputs

None/Headlamp/Turn Signal/Key-In-Ignition/Seatbelt/Park Brake

None

Content Theft Lamp

Security Data

ON/OFF

OFF

Content Theft State

Security Data

ON/OFF

OFF

Courtesy Lamp Relay

Input 2

ON/OFF

OFF

Courtesy Lamp Relay

Outputs

ON/OFF

OFF

Courtesy Lamp Timer

Data

Seconds

0 Seconds

DRL Relay

Outputs

ON/OFF

ON (in LIGHT state)

Dimming

Outputs

ACTIVE/INACTIVE

INACTIVE (park lamps OFF)

Dimming Potentiometer

Data

Volts

Varies

Dimming Potentiometer Input

Input 2

ACTIVE/INACTIVE

ACTIVE

Dome Lamp Switch

Input 2

ON/OFF

OFF

Dome Override Switch

Input 2

ON/OFF

OFF

Door Key Switch

Security Data

ACTIVE/INACTIVE

ACTIVE

Door Lock Relay

Outputs

ON/OFF

OFF

Door Lock Relay Feedback

Input 1

ON/OFF

OFF (relay not energized)

Driver Door Jamb Switch

Input 1

ACTIVE/INACTIVE

ACTIVE (door open)

Driver Door Unlock Relay

Outputs

ON/OFF

OFF

Flash to Pass Switch

Input 2

ON/OFF

OFF

Front Fog Lamp Relay

Outputs

ON/OFF

OFF

Front Fog Lamp Switch

Input 2

ON/OFF

OFF

Headlamp Power Relay

Outputs

ON/OFF

OFF (in LIGHT state)

Headlamp Relay Feedback

Input 2

ON/OFF

OFF (in LIGHT state)

High Beam Input

Data

Volts

12.2 - Low Beams 0.8 - High Beams

High Beam Switch

Input 2

ON/OFF

OFF

Horn Relay

Outputs

ON/OFF

OFF

Ignition 1

Input 1

ACTIVE/INACTIVE

ACTIVE

Ignition 3

Input 1

ACTIVE/INACTIVE

ACTIVE

Ignition 1

Security Data

ACTIVE/INACTIVE

ACTIVE

Ignition 3

Security Data

ACTIVE/INACTIVE

ACTIVE

Ignition Power Mode

Input 1

OFF/RUN/CRANK/ UNKNOWN

RUN

Inadvertent Power Relay

Outputs

ON/OFF

ON

Inadvertent Power Timer

Data

Seconds

2400 Seconds

Interior Lighting Mode

Outputs

None/Interior/Illuminated Entry/Exit Lighting/Remote Illuminated

Interior

Julian Date of Build

Module Information 1

Numeric

Varies

Key-In-Ignition

Input 1

YES/NO

YES

Last RFA Comd. Since Wake-Up

Input 1

None/Lock/Unlock/Panic/Manual Resynch/Fob Program/Diag Acknowledge/Diag Request

Unlock

Left Turn Signal

Input 2

ON/OFF

OFF

Lighting Calibration Number

Module Information 2

Numeric

Varies

Lighting Suffix

Module Information 2

2 Letters

Varies

Manufacture Enable Counter

Module Information 1

0-255

0

Module Part Number

Module Information 1

Numeric

Varies

Park Brake Switch

Input 1

SET/RELEASED

RELEASED (park brake not set)

Park Lamp Relay

Outputs

ON/OFF

OFF (in LIGHT state)

Park Lamps

Input 2

ON/OFF

ON

Passenger Door Jamb

Input 1

ACTIVE/INACTIVE

ACTIVE (door open)

Passenger Door Unlock Input

Input 1

ACTIVE/INACTIVE

INACTIVE

Passenger Door Unlock Relay

Outputs

ON/OFF

OFF

Passlock™ Code

Security Data

Open/Short/Tamper/Numeric

Valid Code 1-10

Passlock™ Data Voltage

Security Data

Volts

0.86-4.28 Volts

Passlock™ State

Security Data

Ignition Off/Tamper/Fail Enable/Fail Enable Dec/Seedkey Lrn Pend/Seedkey Learn/Auto Learn Pend/Learn Passlock™/Monitor Passlock™/Normal Decision/Auto Learn

Monitor Passlock™

Puddle Lamp Relay

Outputs

ON/OFF

OFF

Rear Fog Lamp Relay

Outputs

ON/OFF

OFF

Reminder Calibration Number

Module Information 2

Numeric

Varies

Reminder Suffix

Module Information 2

2 Letters

Varies

RFA Message Since Wake-Up

Input 1

NONE/PANIC/Active Unlock Fob# /Active Lock/Prog Mode Cancel/Prog Successful/Prog Mode Ack/Manual Resync

Actv Unlock Fob#

RAP Calibration Number

Module Information 2

Numeric

Varies

RAP Relay

Outputs

ON/OFF

ON

RAP Relay Feedback

Input 1

ON/OFF

ON

RAP Suffix

Module Information 2

2 Letters

Varies

RAP Timer

Data

Seconds

1198 Seconds

Right Turn Signal

Input 2

ON/OFF

OFF

Seatbelt Buckled

Input 1

YES/NO

YES (driver seatbelt buckled)

Security Calibration Number

Module Information 2

Numeric

Varies

Security Lamp State

Security Data

ON/OFF/FLASHING

OFF

Security Suffix

Module Information 2

2 Letters

Varies

Side Door Jamb Switch

Input A

ACTIVE/INACTIVE

ACTIVE (door open)

Software Design Suffix

Module Information 1

2 Letters

Varies

Software Part Number

Module Information 1

Numeric

Varies

Transmission Preference

Input 1

ON/OFF

OFF

Tamper Timer

Security Data

Seconds

0-600

VCM/PCM Fail Enable

Security Data

YES/NO

NO

VCM/PCM Fuel Continue

Security Data

YES/NO

YES

VCM/PCM Learn Timer

Security Data

ACTIVE/INACTIVE

INACTIVE

Vehicle Speed

Data

MPH

0

VTD Fuel Disable

Security Data

ACTIVE/INACTIVE

INACTIVE

VTD Fuel Disable Until Ignition Off

Security Data

YES/NO

NO

VTD Password Learn Mode

Security Data

ACTIVE/INACTIVE

INACTIVE