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.

Ambient Light Sensor

Exterior Lighting

Volts

Volts

Ambient Light Status

Exterior Lighting

Night/Day

Unknown/Invalid

--

Auto Hdlp. Disable Sw.

Exterior Lighting

Inactive/Active

--

Backup Lamps

Exterior Lighting

ON/OFF

OFF

Brake Applied Output Signal

Exterior Lighting

ON/OFF

OFF

Brake Applied Output Signal

Outputs

ON/OFF

OFF

Courtesy Lamp PWM Command

Interior Lighting

%

%

Courtesy Lamp Active Reason

Interior Lighting

ON/OFF

OFF

Dimming Control Reference

Interior Lighting

Volts

Volts

Dimming Control Signal

Interior Lighting

%

%

Dimming Control Signal

Interior Lighting

Volts

Volts

Flash to Pass Switch

Exterior Lighting

Inactive/Active

Inactive

Front Fog Lamp Relay Command

Exterior Lighting

ON/OFF

OFF

Front Fog Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Hazard Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Headlamp Switch

Exterior Lighting

Inactive/Active

Inactive

High Beam Relay Command

Exterior Lighting

ON/OFF

OFF

High Beam Select Switch

Exterior Lighting

Inactive/Active

Inactive

Incandescent Dimming PWM Command

Interior Lighting

%

%

LED Dimming PWM Command

Interior Lighting

%

%

Left Turn Signal Switch

Exterior Lighting

Inactive/Active

Inactive

LF Turn Signal

Exterior Lighting

ON/OFF

OFF

LR Turn Signal

Exterior Lighting

ON/OFF

OFF

Low Beam Relay Command

Exterior Lighting

ON/OFF

Inactive

Park Brake Switch

Inputs

Applied/Released

Released

Park Lamp Relay Command

Exterior Lighting

ON/OFF

OFF

Park Lamp Switch

Exterior Lighting

Inactive/Active

Inactive

Right Turn Signal Switch

Exterior Lighting

Inactive/Active

Inactive

RF Turn Signal

Exterior Lighting

ON/OFF

OFF

RR Turn Signal

Exterior Lighting

ON/OFF

OFF

Stop Lamp Relay Command

Exterior Lighting

ON/OFF

OFF

Valet Switch

Inputs

Inactive/Active

Inactive