Envoy 2WD L6-4.2L (2008)
Alarm Module: Testing and Inspection
Content Theft Deterrent Malfunction
Content Theft Deterrent Malfunction
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection/Initial Inspection and
Diagnostic Overview/Diagnostic System Check - Vehicle
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Review Strategy Based Diagnosis for an overview of the diagnostic approach.
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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 liftgate ajar switch, the BCM
determines whether a CTD alarm is warranted. If unauthorized access is being detected, the BCM will pulse the horn and flash the exterior lamps as a
means of theft deterrence.
Circuit/System Verification
1. Individually open and close each vehicle door while observing the door ajar indicator/message. The indicator/message should accurately transition
between the door ajar and door closed state when each door is opened and closed.
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If the door ajar indicator/message does not properly transition when each door is opened and closed, refer to Door Ajar Indicator Malfunction.
See: Body and Frame/Locks/Testing and Inspection/Symptom Related Diagnostic Procedures/Door Ajar Indicator Malfunction
2. Open and close the liftgate while observing the liftgate ajar indicator/message. The indicator/message should accurately transition between the
liftgate ajar and liftgate closed state when the trunk is opened and closed.
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If the liftgate ajar indicator/message does not properly transition when the liftgate is opened and closed, refer to Liftgate/Liftgate Window Ajar
Indicator Malfunction.
3. Insert the vehicle key into the driver door key cylinder and rotate the cylinder between the lock and unlock positions. Verify the scan tool Door
Key Cyl. Unlock Switch parameter cycles between Idle and Unlock.
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If the scan too parameter does not cycle between the specified parameters, refer to Content Theft Deterrent (CTD) Does Not Disarm with Key
Lock. See: Content Theft Deterrent (CTD) Does Not Disarm with Key Lock
4. Completely lower the driver door window and close all vehicle doors.
5. 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.
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If the parameter does not equal the specified value, refer to Keyless Entry System Inoperative. See: Accessories and Optional
Equipment/Antitheft and Alarm Systems/Keyless Entry/Testing and Inspection/Symptom Related Diagnostic Procedures/Keyless Entry System
Inoperative
6. Without disarming the system, reach in through the open driver window, unlock and open the driver door. Verify the scan tool CTD Status
parameter displays Alarm Active.
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If the parameter does not equal the specified value, replace the BCM.
7. With the door open, verify the vehicle horn is pulsing and the exterior lamps are flashing.
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If the horn is not pulsing, refer to Horns Malfunction. See: Lighting and Horns/Horn/Testing and Inspection/Symptom Related Diagnostic
Procedures/Horns Malfunction
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If the exterior lights are not flashing, refer to Headlamps Malfunction. See: Lighting and Horns/Testing and Inspection/Symptom Related
Diagnostic Procedures/Headlamps Malfunction
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
