GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

Connector End View Reference: Theft Deterrent System Connector End Views

DEFINITION: The CTD system does not disarm when the vehicle is unlocked with the key.

1

Did you perform the Theft Deterrent Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Disconnect the suspect door key cylinder switch.
  2. Turn ON the ignition.
  3. Connect a test lamp between the unlock control circuit of the door key cylinder switch and a good ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 4

3

  1. Disconnect the suspect door key cylinder switch.
  2. Connect a test lamp between the unlock ground circuit of the door key cylinder switch and battery voltage.

Does the test lamp illuminate?

Go to Step 7

Go to Step 5

4

Test the control circuit of the door key cylinder switch input for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Test the ground circuit of the door key cylinder switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Inspect for a poor connection at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

7

Inspect for a poor connection at the harness connector of the suspect door key cylinder switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

8

Replace the suspect door key cylinder switch. Refer to Door Lock Cylinder Replacement in Doors.

Did you complete the repair?

Go to Step 10

--

9

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 10

--

10

  1. Reconnect any connectors that were removed for testing.
  2. Attempt to arm the CTD system. Refer to Content Theft Deterrent (CTD) Description and Operation .
  3. Simulate an intrusion.

Did you correct the condition?

System OK

Go to Diagnostic System Check - Theft Deterrent