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

  1. Open the driver and passenger windows.
  2. Unlock the doors using the power door lock switch or the keyless entry transmitter.
  3. Remove the keys from the ignition.
  4. Open the suspect door.
  5. Observe the courtesy lamps.

Does the courtesy lamps illuminate?

Go to Step 3

Go to Courtesy Lamps Inoperative in Lighting systems

3

  1. Open the driver and passenger windows.
  2. Unlock the doors using the power door lock switch or the keyless entry transmitter.
  3. Remove the keys from the ignition.
  4. Open the driver's door.
  5. Observe the theft LED.

Does the theft LED flash?

Go to Step 4

Go to Security Indicator LED Inoperative

4

  1. Lock the vehicle using one of the power door lock switches or the keyless entry transmitter.
  2. Observe the theft LED.

Does the theft LED change from flashing to on steady?

Go to Step 5

Go to Power Door Locks Inoperative - All Doors and Switches in Doors

5

  1. Close all of the doors.
  2. Important: Ensure that all the doors are closed. The Content Theft Deterrent System will not arm itself without all of the doors being closed.

  3. Observe the theft LED.

Does the theft LED begin to flash slowly in about 30 seconds?

Go to Step 6

Go to Courtesy Lamps Always On in Lighting Systems

6

  1. Reach in and unlock the driver's door manually.
  2. Open the driver's door.

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

Go to Step 7

Go to Step 8

7

Disarm the CTD system by inserting the door key into the driver door lock cylinder and rotate it to the unlock position, then try the passenger door lock cylinder.

Do all of the alarm mode functions stop?

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

Go to Content Theft Deterrent (CTD) Does Not Disarm with Key Lock

8

Do any of the alarm functions activate?

Go to Step 9

Go to Courtesy Lamps Inoperative in Lighting Systems

9

Do the horns pulse only?

Go to Lights Inoperative in Content Theft Deterrent (CTD) Alarm Mode

Go to Horn Inoperative in Content Theft Deterrent (CTD) Alarm Mode