GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

1

1

--

--

Ignition

1

1

--

--

Theft Deterrent Alarm Signal

1

1

1

--

Ground

--

1

--

--

1. Theft Deterrent Alarm Malfunction

Circuit/System Description

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

Reference Information

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

    •  Testing for Intermittent Conditions and Poor Connections
    •  Circuit Testing
    •  Wiring Repairs
    •  Connector Repairs

Scan Tool Reference

Control Module References for scan tool information.

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 10 ohms of resistance between the ground circuit terminal 4 and ground.
  3. If not within the specified range, test the low reference circuit for an open/high resistance.
  4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
  5. If not the specified range, test the circuit for a short to ground or an open/high resistance.
  6. Verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
  7. If not the specified range, test the circuit for a short to ground or an open/high resistance.
  8. Connect a test lamp between the control circuit terminal 3 and the B+ circuit terminal 2.
  9. Command the theft deterrent alarm ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  10. If the test lamp is always ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
    If the test lamp is always OFF, test the signal circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the BCM.
  11. If all circuits test normal, replace the theft deterrent alarm siren.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming