GM Service Manual Online
For 1990-2009 cars only

Content Theft Deterrent (CTD) Alarm Mode Inoperative Except RPO UA2

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.

Circuit/System Description

The content theft deterrent (CTD) system is a software based system in which the body control module (BCM) actively monitors certain inputs to determine if unauthorized vehicle access is being attempted. Based on inputs such as the door ajar switches, and the Trunk ajar switch, the BCM determines whether a CTD alarm is warranted. If unauthorized access is being detected, the BCM will pulse the vehicle horn and flash the turn signals as a means of theft deterrent.

Reference Information

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Theft Deterrent System 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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Testing

  1. Ignition ON, while opening and closing each vehicle door, verify that the applicable scan tool door ajar switch parameter cycles between Door Closed and Door Ajar.
  2. If the scan tool parameter does not cycle between the specified values, refer to Door Ajar Indicator Malfunction .
  3. Ignition ON, while opening and closing the rear compartment lid open, verify the TRUNK AJAR switch parameter cycles between TRUNK AJAR and TRUNK CLOSED.
  4. If the scan tool parameter does not cycle between the specified values, refer to Trunk Release Inoperative .
  5. Completely lower the driver door window.
  6. Ignition OFF, arm the CTD system using the keyless entry system by pressing the transmitter LOCK button twice. Verify the scan tool CTD Status parameter displays Armed.
  7. If the parameter does not equal the specified value, refer to Keyless Entry System Inoperative .
  8. Without disarming the system, reach in through the open driver window, unlock and open the driver door. Verify the scan tool Content Theft Mode parameter displays Pre Alarm or Alarm.
  9. If the parameter does not equal the specified value, replace the BCM.
  10. With the door open, verify the vehicle horn is pulsing and the turn signal lamps are flashing.
  11. If the horn is not pulsing, refer to Horns Inoperative .
    If the turn signal lamps are not flashing, refer to Turn Signal Lamps and/or Indicators Malfunction .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming

Content Theft Deterrent (CTD) Alarm Mode Inoperative With RPO UA2

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.

Circuit/System Description

The content theft deterrent (CTD) system is a software based system in which the body control module (BCM) actively monitors certain inputs to determine if unauthorized vehicle access is being attempted. Based on inputs such as the door ajar switches, and the Trunk ajar switch, the BCM determines whether a CTD alarm is warranted. If unauthorized access is being detected, the BCM will pulse the vehicle horn, flash the turn signals, and sound the theft deterrent alarm as a means of theft deterrent.

Reference Information

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Theft Deterrent System Connector End Views

Description and Operation

Content Theft Deterrent (CTD) Description and Operation

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Testing

  1. Ignition ON, while opening and closing each vehicle door, verify that the applicable scan tool door ajar switch parameter cycles between Door Closed and Door Ajar.
  2. If the scan tool parameter does not cycle between the specified values, refer to Door Ajar Indicator Malfunction .
  3. Ignition ON, while opening and closing the rear compartment lid open, verify the TRUNK AJAR switch parameter cycles between TRUNK AJAR and TRUNK CLOSED.
  4. If the scan tool parameter does not cycle between the specified values, refer to Trunk Release Inoperative .
  5. Ignition OFF, disconnect the harness connector at the Hood Ajar Switch.
  6. Test for less then 1 ohm of resistance between the ground circuit terminal B and ground
  7. If greater than the specified range, test the ground circuit for an open/high resistance.
  8. Ignition ON, verify a test lamp between the signal circuit terminal A and ground.
  9. If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM.
  10. Test for infinite resistance between terminal A and terminal B of the hood ajar switch.
  11. If not the specified value replace the switch.
  12. Reconnect the harness connector at the hood ajar switch.
  13. Ignition OFF, arm the CTD system using the keyless entry system by pressing the transmitter LOCK button twice. Verify the scan tool CTD Status parameter displays Armed.
  14. If the parameter does not equal the specified value, refer to Keyless Entry System Inoperative .
  15. Ignition OFF, observe the intrusion sensor message display on the DIC. The message should switch between INTRUSION SENSOR ON and INTRUSION SENSOR OFF when arming and disarming.
  16. If not the specified value, refer to Intrusion Sensor Inoperative .
  17. Completely lower the driver door window.
  18. Ignition OFF, arm the CTD system using the keyless entry system by pressing the transmitter LOCK button twice.
  19. Without disarming the system, reach in through the open driver window, unlock and open the driver door. Verify the scan tool Content Theft Mode parameter displays Pre Alarm or Alarm.
  20. If the parameter does not equal the specified value, replace the BCM.
  21. With the door open, verify the vehicle horn is pulsing and the turn signal lamps are flashing.
  22. If the horn is not pulsing, refer to Horns Inoperative .
    If the turn signal lamps are not flashing, refer to Turn Signal Lamps and/or Indicators Malfunction .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming