GM Service Manual Online
For 1990-2009 cars only

Data Display

Use a scan tool to display the BCM data. This information assists in determining whether the BCM is operating properly and whether the BCM is sending or receiving the proper data to and from a particular system. The BCM uses data received from other systems in order to carry out some functions. Therefore, if the BCM receives the incorrect data from another system, the BCM may function improperly. Use the scan tool in order to review the data from systems that interact with the BCM.

Displayed Input Status

The scan tool also displays the BCM input status. Select the BCM input status display in order to display the data and determine if the switched inputs can be properly interpreted. The display also indicates if the input has changed states. For example, when a door is closed, the scan tool displays the input status of the door ajar switch as INACTIVE. When the door is open, the scan tool reads ACTIVE. Use this kind of information when diagnosing a malfunction associated with a particular BCM input or an input that is shared with another system.

Cycle Outputs

Use a scan tool in order to cycle the BCM output functions. When the BCM output cycling is selected, the scan tool can command the BCM to cycle an output. This feature can be used to determine if the BCM is able to cycle an output regardless of the inputs or any specific program instructions. Once a test is selected, the scan tool will command the BCM to energize the selected output. The scan tool then displays the status of the selected output. The displayed information represents only what was BCM commanded, not what action was actually taken. Check if the BCM is actually preforming each of the selected output functions.

BCM Scan Tool Data List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Doors, Hatch/Trunk and Hood Closed/No Switches On or Pressed/Vehicle in Park

Controller Part Number

Module Info 1

Part Number

Varies

EEPROM Calibration ID

Module Info 1

Calibration Number

0-255

Varies

Hardware Version

Module Info 2

Version Number

0-255

Varies

Software Major Version

Module Info 2

Version Number

0-255

Varies

Software Minor Version

Module Info 2

Version Number

0-255

Varies

Calibration Version

Module Info 2

Version Number

0-255

Varies

Battery Volts

Data

0-16.0 Volts

Battery Voltage

PassKey Resister Signal

Data

0-5.0 Volts

Varies

PRNDL Illumination

Data

0-100%

Varies with Dimming Level

HVAC Bulb Illumination

Data

0-100%

Varies with Dimming Level

Console Switch Illumination

Data

0-99.9%

Varies with Dimming Level

Fog Light Illumination

Data

0-100%

Varies with Dimming Level

Ignition 1

Input Data 1

On/Off

On

Ignition 2

Input Data 1

On/Off

On

Ignition 3

Input Data 1

On/Off

On

Key In Ignition

Input Data 1

Active/Inactive

Active

Key Out of Ignition

Input Data 1

Active/Inactive

Varies

Current Power Mode

Input Data 1

Power Mode

Run

Inadvertent Load Monitor

Input Data 1

Active/Inactive

Inactive

Theft Deterrent State

Input Data 1

Current State

Varies

PASS-Key State

Input Data 1

Current State

Monitor PassKey

Front Fog Light Switch

Input Data 1

Active/Inactive

Inactive

Rear Fog Light Switch

Input Data 1

On/Off

Off

Right Turn Signal Monitor

Input Data 1

Active/Inactive

Inactive

Right Turn Signal Relay

Input Data 1

Active/Inactive

Inactive

Left Turn Signal Monitor

Input Data 1

Active/Inactive

Inactive

Left Turn Signal Relay

Input Data 1

Active/Inactive

Inactive

Backup Light Request

Input Data 1

Yes/No

No

Driver Door Ajar Switch

Input Data 2

Open/Closed

Closed

Passenger Door Ajar Switch

Input Data 2

Open/Closed

Closed

Hood Ajar (export)

Input Data 2

Open/Closed

Closed

Hatch/Trunk Ajar Switch

Input Data 2

Open/Closed

Closed

Hatch/Trunk Release Switch

Input Data 2

Active/Inactive

Inactive

Tonneau Ajar Switch

Input Data 2

Open/Closed

Closed

Tonneau Release Switch

Input Data 2

Active/Inactive

Inactive

Column Lock State

Input Data 2

Current State

Ignition On Unlocked

Column Feedback

Input Data 2

Active/Inactive

Active

Column Lock/Unlock A

Input Data 2

Active/Inactive

Inactive

Column Lock/Unlock B

Input Data 2

Active/Inactive

Inactive

Horn Relay Feedback

Input Data 2

Active/Inactive

Inactive

TCS Switch

Input Data 2

Active/Inactive

Inactive

HVAC Rear Defogger Switch

Input Data 2

Active/Inactive

Inactive

Rear Defogger Relay

Input Data 2

Active/Inactive

Inactive