For 1990-2009 cars

Important: Before attempting to diagnose the intrusion sensor, ensure that the intrusion sensor is ENABLED, via the intrusion sensor defeat switch.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Theft Deterrent System Schematics Connector End View Reference: Theft Deterrent System Connector End Views DEFINITION: After arming, the Content Theft Deterrent (CTD) system does not enter alarm mode when there is motion inside the vehicle.
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn OFF the ignition.
2. Disconnect the intrusion sensor harness connector.
3. Probe the intrusion sensor battery positive voltage circuit at the intrusion sensor harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 7

3 | With a DMM, measure the voltage of the intrusion sensor alarm on signal circuit at the intrusion sensor harness connector. Is the voltage near the specified value? | B+ | Go to Step 4 | Go to Step 5
4 | Test the intrusion sensor armed signal circuit for a short to ground, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6
5 | Test the intrusion sensor alarm on signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9
6 | Inspect for a loose or poor connection at the harness connector of the intrusion sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8
7 | Repair the intrusion sensor battery positive voltage circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 11 | --
8 | Replace the intrusion sensor. Refer to Intrusion Sensor Inoperative . Did you correct the condition? | -- | Go to Step 11 | Go to Step 9
9 | Inspect for a loose or poor connection at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10
10 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | --
11 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2