Theft Deterrent Alarm Inoperative

Theft Deterrent Alarm Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

Circuit/System Description

The theft deterrent alarm siren is part of the Content Theft Deterrent (CTD) System. The CTD system is an internal function of the body control module (BCM) which utilizes class 2 serial data and various switch input information to perform CTD functions. When the BCM detects an unauthorized entry, it will activate the horns, exterior lamps, and the theft deterrent siren (UA2 RPO).

Circuit/System Verification

With a scan tool, command the alarm siren ON. Alarm siren should sound.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the theft deterrent alarm siren.
2. Ignition OFF, test for less then 1 ohms of resistance between the theft deterrent alarm siren ground circuit terminal 4 and ground.

• If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp does not illuminate between the ignition 1 voltage circuit terminal 1 and ground.

• If the test lamp illuminates, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, test circuit for a short to ground. If the circuit tests normal, replace the BCM.

5. Connect a test lamp between the control circuit terminal 3 and the B+ circuit terminal 2.
6. Command the alarm siren ON with a scan tool. The test lamp should switch from OFF to ON when commanding the alarm siren ON.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

7. If all circuits test normal, test or replace the theft deterrent alarm siren.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Refer to Programming and Relearning.Programming and Relearning