The alarm siren monitors the alarm enable signal circuit and will sound an audible alarm when the body control module indicates a event has occurred that requires an alarm. The alarm siren also monitors its own voltage circuits independent of the body control module. In the event of the interruption of voltage to the alarm siren, the alarm will sound.

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Content Theft Deterrent (CTD) Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the Alarm Siren ON and OFF with a scan tool. Listen and feel for the relay to turn ON and OFF.

1. Ignition OFF, disconnect the horn relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the B+ circuit terminal 30 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, test or replace the horn relay.

4. Verify that a test lamp illuminates between the B+ circuit terminal 85 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, test or replace the horn relay.

5. Disconnect the harness connector at the alarm siren.
6. Test for less than 5 Ω between the ground circuit terminal A X2 and ground.

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

7. Connect the harness connector at the alarm siren.
8. Connect a 15 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the alarm siren is activated.

⇒	If the alarm siren does not activate, test the control circuit for an open/high resistance.If the circuit tests normal and the control circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test or replace the alarm siren.

9. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
10. Command the Alarm Siren ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the body control module.

⇒	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 body control module.

11. If all circuits test normal, test or replace the horn relay.

Relay Test

1. Ignition OFF, disconnect the content theft relay.
2. Test for 60 - 120 ohms between terminals 85 and 86.

⇒	If not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

4. Install a 15A fused jumper wire between relay terminal 85 and 12V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.