GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Data Display

Units Displayed

Typical Data Value

Operating Conditions: Ignition in the ON position. Bright Light Applied to the DRL ambient light sensor. Park brake not set. Headlamp Switch in the OFF position. I/P lamp switch in the OFF position. Fog lamp switch in the OFF position.

Brake Apply Sensor

BCM Data

Volts

0 Volts

Stop Lamp Signal

Cruise Control Data

ON/OFF

OFF

Inputs

Flash to Pass Switch

Exterior Lighting

Inactive/Active

Inactive

Front Fog Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Headlamp Switch

Exterior Lighting

Inactive/Active

Inactive

High Beam Select Switch

Exterior Lighting

Inactive/Active

Inactive

Hazard Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Interior Light Switch

Inputs

ON/OFF

OFF

Interior Lights Power

Inputs

ON/OFF

OFF

Left Turn Signal Switch

Exterior Lighting

Inactive/Active

Inactive

Low Beam Switch

Inputs

ON/OFF

OFF

LR Door Open Switch

Inputs

ON/OFF

OFF

Right Turn Signal Switch

Exterior Lighting

ON/OFF

OFF

RF Door Lock Switch

Inputs

ON/OFF

OFF

RR Door Open Switch

Inputs

ON/OFF

OFF

Park Brake Switch

Inputs

Applied/Released

Released

Park Lamp Switch

Inputs

ON/OFF

OFF

Outputs

Backup Lamps

Exterior Lighting

ON/OFF

OFF

Front Fog Lamp Relay

Outputs

ON/OFF

OFF

Interior Lamp Output

Outputs

ON/OFF

OFF

Interior Lights Power

Outputs

ON/OFF

OFF

Instrumentation Backlight

Outputs

ON/OFF

OFF

LF Turn Signal

Exterior Lighting

ON/OFF

OFF

Low Beam Relay Command

Exterior Lighting

Inactive/Active

Inactive

LR Turn Signal

Exterior Lighting

ON/OFF

OFF

Park Lamp Relay Command

Exterior Lighting

ON/OFF

OFF

RF Turn Signal

Exterior Lighting

ON/OFF

OFF

RR Turn Signal

Outputs

ON/OFF

OFF

Bass Data

Ambient Light Sensor

Exterior Lighting

Volts

Volts

Ambient Light States

Exterior Lighting

Night/Day

Unknown/Invalid

--

Auto Hdlp. Disable Sw.

Exterior Lighting

Inactive/Active

--

Bass High During Learn

Bass Data

NO/YES

NO

Bass Learned

Bass Data

NO/YES

YES

Bass Low During Learn

Bass Data

NO/YES

NO

Bass Moved During Learn

Bass Data

NO/YES

NO

Bass Valid

Bass Data

NO/YES

YES

Brake Applied Output Signal

Outputs

ON/OFF

OFF

Brake Lamp

Bass Data

ON/OFF

OFF

Center Stop Lamp

Exterior Lighting

ON/OFF

--

Courtesy Lamp PWM Command

Interior Lighting

%

%

Courtesy Lamp Active Reason

Interior Lighting

ON/OFF

OFF

Current Position

Bass Data

Counts

0

Dimming Control Reference

Interior Lighting

Volts

Volts

Dimming Control Signal

Interior Lighting

%

%

Dimming Control Signal

Interior Lighting

Volts

Volts

Front Fog Lamp Relay Command

Exterior Lighting

ON/OFF

OFF

Incandescent Dimming

Interior Lighting

%

%

Learn in Progress

Bass Data

NO/YES

NO

Learned Home Position

Bass Data

Counts

0

LED Dimming PWM Command

Interior Lighting

%

%

Park Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Right Corner Lamp

Exterior Lighting

Inactive/Active

Inactive