GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

1

Did you perform A Diagnostic System Check - Theft Deterrent?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

Perform the following to activate the CTD alarm mode:

  1. Open the driver's window.
  2. Lock the vehicle using the power door lock switch.
  3. Wait for the theft LED to transition from ON steady to flashing slowly.
  4. Reach in and unlock the driver's door.
  5. Open the driver's door.

Do all of the alarm mode functions activate, headlamps flash and horn pulses?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Are only the headlamps inoperative?

Go to Headlamps Inoperative - Low Beams in Lighting Systems

Go to Content Theft Deterrent (CTD) Alarm Mode Inoperative