GM Service Manual Online
For 1990-2009 cars only

Intelligent Switching Unit (ISU)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Door Switch

Central Locking

Open/Closed

Closed

Driver Door Switch

Central Locking

Released/ Applied

Applied

Hazard Lamp Switch

Lighting Data

On/Off

Off

Hood Open Switch

Central Locking

Active/Inactive

Inactive

Ignition 1

Miscellaneous Inputs

Off/On

On

Ignition 2

Miscellaneous Inputs

Off/On

On

Left Turn Signal Switch

Lighting Data

Active/Inactive

Inactive

Parking Lamps

Lighting Data

On/Off

Off

Right Turn Signal Switch

Lighting Data

Active/Inactive

Inactive

Tamper Status

Central Locking

Active/Inactive

Inactive

Trunk Open Switch

Central Locking

Open/Closed

Closed