GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Units Displayed

Typical Data Value

Ambient Light Sensor

Volts

Varies

Park Brake Switch

On/Off

Off

LCM Lights on Chime

On/Off

Off

Courtesy Switch

Inactive/Active

Inactive

Courtesy Ground

Present/Not Present

Present

Rt. Turning Signal Sw.

Inactive/Active

Inactive

Lt. Turning Signal Sw.

Inactive/Active

Inactive

Headlamp Switch

Inactive/Active

Inactive

Inadvert. Power Output

On/Off

Off

Front Fog Lamp Relay

On/Off

Off

Right Turn Signal

On/Off

Off

Left Turn Signal

On/Off

Off

Headlamp

On/Off

Off

Park lamps

On/Off

Off

Theater Dimming #1

On/Off

Off