GM Service Manual Online
For 1990-2009 cars only

Theft System Description and Operation

The theft deterrent system on this vehicle is comprised of 2 separate systems, the vehicle theft deterrent (VTD) system and the content theft deterrent (CTD) system. The VTD system prevents drive away theft by keeping the vehicle from starting. The CTD system is the vehicle alarm system which discourages unauthorized entry into the vehicle. These system are described and diagnosed separately within this section.

SECURITY Telltale

The SECURITY Telltale on the message center is controlled by both the VTD system and the CTD system. The SECURITY telltale is a part of the reconfigurable message center on the instrument cluster. The SECURITY telltale is controlled by the body control module through the class 2 data line.

The VTD system contained in the BCM commands the instrument cluster to control the SECURITY telltale only when the ignition switch is ON. The VTD system uses the telltale as a malfunction indicator.

Theft Lock Radio (If Applicable)

Refer to Diagnostic Starting Point - Entertainment in Entertainment.

VTD Description and Operation

Refer to Vehicle Theft Deterrent (VTD) Description and Operation for the appropriate description and operation.