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. IP Lamp switch in the OFF position. Fog lamp switch in the OFF position.

Ambient Light Sensor

Data

Volts

2.1 volts

Ambient Light Sensor Re

Outputs

ON/OFF

ON

Backup Lamp Relay

Outputs

Active/Inactive

Inactive

Courtesy Lamp Switch

Inputs

Active/Inactive

Inactive

Dimming Switch

Data

Volts

0

DRL Relay

Outputs

Off/On

On

Fog Lamp Relay

Outputs

Off/On

Off

Fog Lamp Switch

Inputs

Active/Inactive

Inactive

Headlamp Relay

Outputs

Off/On

Off

Headlamp Switch

Inputs

Active/Inactive

Inactive

Hi Beam On Switch

Inputs

Active/Inactive

Inactive

Park Lamp Relay

Outputs

Off/On

Off

Park Break Switch

Inputs

Off/On

Off

Surveillance Mode Switch

Inputs

Inactive/Active

Inactive

Theater Dim 1 Ground

Inputs

Inactive/Active

Inactive

Theater Dim 2 Ground

Inputs

Inactive/Active

Inactive

Theater Dimming

Outputs

Off/On

Off