Can Someone Explain the Anti-Theft System to Me?
#1
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Can Someone Explain the Anti-Theft System to Me?
What it does, how it operates, when it activates, how the car knows it is being stolen, what it does when it is stolen, you know that kind of stuff.
I have a y2k coupe.
Thanks in advance
I have a y2k coupe.
Thanks in advance
#2
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2023 C5 of the Year Finalist - Unmodified
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Courtesy GM
Document ID# 675948
2002 Chevrolet Corvette
________________________________________
Theft Systems Description and Operation
The theft deterrent system on this vehicle is comprised of two separate systems, the vehicle theft deterrent (VTD) system and the content theft deterrent (CTD) system. VTD prevents drive away theft by keeping the vehicle from starting. CTD is the vehicle alarm system which discourages unauthorized entry into the vehicle. These systems are described and diagnosed separately within this section.
Security Indicator
The security indicator on the instrument cluster is controlled by both the VTD system and the CTD system. The security indicator is displayed on the instrument cluster. The indicator is controlled by the instrument cluster when commanded by the theft deterrent controller module via the class 2 serial data line.
• The VTD system commands the instrument cluster to control the indicator only when the ignition switch is ON. The VTD System uses the indicator as a malfunction indicator.
• The CTD system commands the instrument cluster to control the indicator only when the ignition switch is OFF. The CTD System uses the indicator to identify system status.
Keyless Entry System (w/AU0)
The keyless entry system functions interact with the content theft deterrent system but is diagnosed as a stand-alone system. Refer to Keyless Entry System Description and Operation in Keyless Entry.
Radio with Theftlock
The theft deterrent system does not interact with radio theft lock equipped vehicles. Radio theft lock is diagnosed as a stand-alone system. Refer to Radio/Audio System Description and Operation in Entertainment.
CTD/VTD Description and Operation
• For content theft Deterrent (CTD) information, refer to Content Theft Deterrent (CTD) Description and Operation .
• For vehicle theft deterrent (VTD) information, refer to Vehicle Theft Deterrent (VTD) Description and Operation .
________________________________________
Document ID# 675948
2002 Chevrolet Corvette
Keyless Entry System Description and Operation
The keyless entry system is a supplementary vehicle entry device. Radio frequencies or discharged batteries may disable the system.
Keyless entry allows you to operate the following components:
• The door locks
• The rear compartment lid release
• The illuminated entry lamps
• The panic alarm (instant alarm)
The keyless entry system has the following main components:
• The transmitters
• The remote control door lock receiver (RCDLR)
When you press a button on a transmitter, the transmitter sends a signal to the remote control door lock receiver. The RCDLR interprets the signal and activates the requested function via a class 2 message over the serial data line.
Unlock Driver's Door Only
Momentarily press the UNLOCK button in order to perform the following functions:
• Unlock the driver door only.
• Illuminate the interior lamps when the ambient light is low for approximately 30 seconds or until a door is opened.
• Illuminate the exterior lights for approximately 30 seconds or until a door is opened (if selected ON in personalization).
• Disarm the content theft deterrent (CTD) system (if equipped).
• Recall the memory seat, the memory mirror, and the telescopic steering column (if equipped) positions for that driver.
• Recall the temperature, the fan speed, and the mode settings for the comfort control for that driver.
• Recall the radio presets, tone volume, playback mode (AM/FM, tape or CD), last displayed station, compact disc position, and tape direction for that driver.
Unlock All Doors (Second Operation)
Momentarily press the UNLOCK button a second time (within 2 seconds of the first press) in order to perform the following functions:
• Unlock the remaining doors.
• Illuminate the interior lamps when the ambient light is low for approximately 30 seconds or until a door is opened.
• Illuminate the exterior lights for approximately 30 seconds or until a door is opened (if selected ON in personalization).
• Disarm the content theft deterrent (CTD) system (if equipped).
Lock All Doors
Press the LOCK button in order to perform the following functions:
• Lock all of the doors.
• Immediately turn off the interior lamps.
• Flash the park lamps (if selected ON in personalization).
• Chirp the horn (if selected ON in personalization).
• Arm the content theft deterrent (CTD) system.
Rear Compartment Lid Release
If the vehicle transaxle is in PARK or NEUTRAL and the ignition is in the OFF position, a single press of the rear compartment release button will open the rear compartment lid. The interior lamps will not illuminate.
Alarm
A single press of the panic button performs the following functions:
• Illuminates the interior lamps.
• Flashes the headlamps (if turned ON in personalization).
• Pulses the horn for 30 seconds or until one of the following conditions is met:
The panic button is pressed again.
The ignition switch is turned to the RUN position with a valid key.
The vehicle is unlocked with the key.
Keyless Entry Personalization
The exterior lamps and the horn chirp may be personalized as part of the remote activation verification feature. The headlamps may be personalized as part of the keyless entry alarm feature. For mode descriptions and programming instructions, refer to Driver Personalization in Personalization.
Rolling Code
The keyless entry system uses rolling code technology. Rolling code technology prevents anyone from recording the message sent from the transmitter and using the message in order to gain entry to the vehicle. The term "rolling code" refers to the way that the keyless entry system sends and receives the signals. The transmitter sends the signal in a different order each time. The transmitter and the RCDLR are synchronized to the appropriate order. If a programmed transmitter sends a signal that is not in the order that the RCDLR expects, then the keyless entry system will not function.
________________________________________
Document ID# 659075
2002 Chevrolet Corvette
Document ID# 676808
2002 Chevrolet Corvette
________________________________________
Content Theft Deterrent (CTD) Description and Operation
The CTD system (when armed) is designed to deter vehicle content theft by pulsing the horns and exterior lamps for approximately two minutes when an unauthorized vehicle entry is detected. The CTD system also disables engine starting when an unauthorized entry is detected.
An unauthorized entry can be any of the following with the CTD system armed:
• Forced entry into the passenger compartment.
• When any door is opened without being unlocked by using the key to unlock the drivers door or the UNLOCK command from a Keyless Entry Transmitter. On vehicles equipped with option code VE1, when any door is opened without being unlocked by using the key to unlock either of the front doors.
• Forced entry into the rear compartment.
The components of the system are:
• Remote Control Door Lock Receiver (RCDLR), if equipped
• Body Control Module
• Door Ajar Switches (including hatch ajar switch)
• Ignition Lock Cylinder
• Drivers Door Key Switch (W/O VE1)
• Front Door Key Switches (W/VE1)
• Power Door Lock Switches
Arming the CTD System
Use the following procedure in order to arm the system:
1. Place the shift lever in P (park).
2. Turn OFF the ignition.
3. Open any door.
Important
The system is not armed if the doors are locked manually, the power door lock switch or keyless entry transmitter (if equipped) must be used to arm the CTD system.
4. Lock the doors with the power door lock switch or the LOCK button on the transmitter (if equipped). The system is in standby mode and will not start the arming timer until all doors are closed.
5. The system will arm approximately 30 seconds from the time that the last door is closed. This delay is shown by the SECURITY indicator ON STEADY. When the indicator transitions to OFF, the system is armed.
Locking the Vehicle Without Arming the CTD System
Locking the vehicle may be accomplished without arming the CTD system. Use of the manual door locks or using the key to lock the doors will lock the vehicle but will not arm the CTD system.
Disarming an Armed System/Silencing an Alarm
If system arming has been requested by the power door lock switch or the transmitter, it must be disarmed.
Important
Using the power door unlock switch or manually unlocking the doors does not disable the CTD arm mode. Also, disconnecting the battery or pulling fuses does not disable the arm mode, since the BCM stores the CTD mode status in memory.
• To disarm the CTD system in standby mode (SECURITY indicator flashing and door(s) open), perform one of the following:
Press either power door unlock switch.
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position.
• To disarm the CTD system in the armed mode:
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position
• To disarm the CTD system when activated (alarming mode).
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position.
CTD Circuit Description
The following is a description of each component used in the CTD system:
Remote Control Door Lock Receiver (RCDLR)
The keyless entry system can arm and disarm the CTD system. When the remote control door lock receiver (RCDLR) receives a door lock or unlock signal from the transmitter, the RCDLR sends a class 2 message to the body control module (BCM) to perform the appropriate arm/disarm functions.
Body Control Module (BCM)
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 activates the horns and exterior lamps. The BCM has five basic modes (disarmed, standby, delayed, armed, and alarm) for operating the CTD system. The different modes are described below.
1. When the CTD system is in the disarmed mode, ignition is OFF and any door is open, the BCM commands the instrument cluster to flash the SECURITY indicator via the class 2 serial data circuit. The BCM has the CTD system in the disarmed mode until the following conditions are detected:
o Ignition key turned to the OFF position.
o Any door open.
o Doors locked by either the power door lock switch or the LOCK button on the transmitter (if equipped).
2. The BCM enters the standby mode when the above conditions are detected. In standby mode, the BCM commands the SECURITY indicator to illuminate ON steady. If all the doors are closed and the LOCK button on the transmitter (if equipped) is used, the BCM enters the delayed mode.
3. When the last door is closed, the BCM remains in the delayed mode for 30 seconds. In delayed mode the BCM commands the SECURITY indicator to illuminate ON steady.
4. After 30 seconds, the BCM enters the armed mode. In armed mode, the BCM commands the SECURITY indicator OFF. Any forced entry activates the alarm mode.
5. When the BCM detects a forced entry, the BCM enters the alarm mode. The BCM activates exterior lamps for 2 minutes and the horns for 30 seconds. This is followed by a three minute time-out of the horns, with the horns no longer active. If no new intrusions are detected during the time-out, the horns remain inactive. The system must be disarmed or the intrusion condition removed after the time-out for the system to exit alarm mode.
Door Ajar Switches
The door ajar switches are an internal function of the door latches. The CTD system uses the door ajar switches as one method to activate the alarm. The body control module (BCM) monitors all door ajar switches via a discrete input from each door ajar switch, including the rear compartment. If the BCM receives a ground signal from a door ajar switch or hatch/trunk ajar switch when the CTD system is armed, the BCM activates the alarm.
Ignition Lock Cylinder
The ignition lock cylinder contains contact terminals that mate with the resistor pellet in the ignition key when the ignition key is inserted into the lock cylinder. When the correct ignition key is inserted into the lock cylinder, the BCM will either silence an alarming system or disarm a system in standby mode.
Drivers Door Key Switch
The drivers door key switch is an internal function of the driver door latch. The door key switch use's a discrete input to the BCM. The BCM utilizes this input to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.
Front Door Key Switches (W/VE1)
The door key switches are an internal function of the driver and passenger door latches. The door key switches use a discrete input to the BCM. The BCM utilizes each of these inputs to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.
Power Door Lock Switches
The power door lock switches are used to either arm or disarm the CTD system. Pressing the lock position will cause the CTD to arm after all doors are closed and the 30 second delay period has elapsed. Pressing the unlock position with the CTD system in any mode except ARMED will cause the CTD system to enter the disarm mode.
Important
The CTD system can be armed with the windows or sunroof open.
Inputs
The BCM monitors the following inputs:
• Driver and passenger door ajar switches (including hatch ajar switch)
• Driver and passenger power door lock/unlock switches
• Ignition lock cylinder input
• Drivers door key switch (W/O VE1)
• Front door key switches (W/VE1)
• Transmitter LOCK/UNLOCK buttons, class 2 message from the Remote Control Door Lock Receiver (RCDLR), if equipped
Outputs
The BCM controls the following :
• Theft deterrent relay
• The horn relay
• The exterior lights
________________________________________
Document ID# 676808
2002 Chevrolet Corvette
Document ID# 677002
2002 Chevrolet Corvette
________________________________________
Vehicle Theft Deterrent (VTD) Description and Operation
PASS-Key System
The personal automotive security system (PASS-Key®) is standard equipment on the vehicle. The system is designed to prevent vehicle theft by disabling the engine unless an ignition key with a specific electrical resistance is used in the ignition cylinder. The PASS-Key® system and the content theft deterrent system operate separately.
There are 15 different ignition key resistance values. Of the 15 different resistance values, or key codes available, only one will work with each body control module (BCM). Once the key code is programmed into the BCM, the code is stored in non-volatile memory.
The PASS-Key® system prevents the engine from starting by controlling the theft deterrent relay and the powertrain control module (PCM) fuel enable input. If the PCM does not sense the proper fuel enable signal, fuel will not be provided to the engine.
If the wrong resistance value is sensed when the ignition switch is in the RUN position, the BCM will not ground the theft deterrent relay control circuit and will not provide the fuel enable signal for approximately three minutes. The engine is prevented from starting and discourages a thief from trying key codes or resistance values at random.
If the correct resistance value is sensed when the ignition switch is in the RUN position, the BCM will ground the theft deterrent relay control circuit and enable fuel delivery. The engine will start normally.
If the PASS-Key® system detects an open or short to ground when the ignition switch is in the RUN position, the BCM will default to fail enable mode. Fail enable occurs when the proper key resistance is sensed before the open short to ground occurs. Fail enable will illuminate the security indicator lamp and allow the operator to stop and start the vehicle until the problem is corrected. The PASS-Key® system includes the following components:
• Ignition key
• Ignition cylinder
• Body control module (BCM)
• Theft deterrent relay
• Powertrain control module (PCM)
• SECURITY indicator
Ignition Key
The ignition key is a typical square ignition key blank with an imbedded resistor. The key blank and resistor are not serviceable separately. There are 15 different resistance values. The ignition key also has mechanical cuts similar to non-PASS-Key® ignition keys.
Ignition Cylinder
The ignition cylinder contains a set of electrical contacts used to measure the resistor in the ignition key. When the ignition key is inserted into the lock cylinder, the resistor in the key makes contact with the electrical contacts inside the ignition cylinder.
Body Control Module
The Body Control Module (BCM) contains the theft deterrent system logic. The BCM reads the key code from the ignition cylinder when the ignition is turned to the START position. If the code is correct, the BCM will enable the theft deterrent relay and will send a fuel enable signal to the PCM via the class 2 serial data circuit.
If the BCM receives the wrong code, the BCM will immediately go into tamper mode. The tamper mode will lock-out the vehicle starter and fuel injectors for 3 minutes. The SECURITY indicator will flash while the BCM is in tamper mode.
Theft Deterrent Relay
The theft deterrent relay is used to prevent the engine from cranking if the correct resistance is not sensed at the ignition key. It prevents the engine from cranking by opening the circuit to the starter solenoid.
Powertrain Control Module
The PCM communicates with the BCM over the Class 2 serial data circuit. When the BCM enters tamper mode, it sends a Class 2 message to the PCM in order to disable the fuel injection system. If the BCM receives the expected ignition code, the BCM sends a class 2 message to the PCM in order to enable the fuel injection system. The PCM then allows the vehicle to start.
SECURITY Indicator
The SECURITY indicator is located on the instrument cluster. The SECURITY indicator is controlled by the BCM via the class 2 serial data circuit.
________________________________________
Document ID# 677002
2002 Chevrolet Corvette
Courtesy GM
Document ID# 675948
2002 Chevrolet Corvette
________________________________________
Theft Systems Description and Operation
The theft deterrent system on this vehicle is comprised of two separate systems, the vehicle theft deterrent (VTD) system and the content theft deterrent (CTD) system. VTD prevents drive away theft by keeping the vehicle from starting. CTD is the vehicle alarm system which discourages unauthorized entry into the vehicle. These systems are described and diagnosed separately within this section.
Security Indicator
The security indicator on the instrument cluster is controlled by both the VTD system and the CTD system. The security indicator is displayed on the instrument cluster. The indicator is controlled by the instrument cluster when commanded by the theft deterrent controller module via the class 2 serial data line.
• The VTD system commands the instrument cluster to control the indicator only when the ignition switch is ON. The VTD System uses the indicator as a malfunction indicator.
• The CTD system commands the instrument cluster to control the indicator only when the ignition switch is OFF. The CTD System uses the indicator to identify system status.
Keyless Entry System (w/AU0)
The keyless entry system functions interact with the content theft deterrent system but is diagnosed as a stand-alone system. Refer to Keyless Entry System Description and Operation in Keyless Entry.
Radio with Theftlock
The theft deterrent system does not interact with radio theft lock equipped vehicles. Radio theft lock is diagnosed as a stand-alone system. Refer to Radio/Audio System Description and Operation in Entertainment.
CTD/VTD Description and Operation
• For content theft Deterrent (CTD) information, refer to Content Theft Deterrent (CTD) Description and Operation .
• For vehicle theft deterrent (VTD) information, refer to Vehicle Theft Deterrent (VTD) Description and Operation .
________________________________________
Document ID# 675948
2002 Chevrolet Corvette
Keyless Entry System Description and Operation
The keyless entry system is a supplementary vehicle entry device. Radio frequencies or discharged batteries may disable the system.
Keyless entry allows you to operate the following components:
• The door locks
• The rear compartment lid release
• The illuminated entry lamps
• The panic alarm (instant alarm)
The keyless entry system has the following main components:
• The transmitters
• The remote control door lock receiver (RCDLR)
When you press a button on a transmitter, the transmitter sends a signal to the remote control door lock receiver. The RCDLR interprets the signal and activates the requested function via a class 2 message over the serial data line.
Unlock Driver's Door Only
Momentarily press the UNLOCK button in order to perform the following functions:
• Unlock the driver door only.
• Illuminate the interior lamps when the ambient light is low for approximately 30 seconds or until a door is opened.
• Illuminate the exterior lights for approximately 30 seconds or until a door is opened (if selected ON in personalization).
• Disarm the content theft deterrent (CTD) system (if equipped).
• Recall the memory seat, the memory mirror, and the telescopic steering column (if equipped) positions for that driver.
• Recall the temperature, the fan speed, and the mode settings for the comfort control for that driver.
• Recall the radio presets, tone volume, playback mode (AM/FM, tape or CD), last displayed station, compact disc position, and tape direction for that driver.
Unlock All Doors (Second Operation)
Momentarily press the UNLOCK button a second time (within 2 seconds of the first press) in order to perform the following functions:
• Unlock the remaining doors.
• Illuminate the interior lamps when the ambient light is low for approximately 30 seconds or until a door is opened.
• Illuminate the exterior lights for approximately 30 seconds or until a door is opened (if selected ON in personalization).
• Disarm the content theft deterrent (CTD) system (if equipped).
Lock All Doors
Press the LOCK button in order to perform the following functions:
• Lock all of the doors.
• Immediately turn off the interior lamps.
• Flash the park lamps (if selected ON in personalization).
• Chirp the horn (if selected ON in personalization).
• Arm the content theft deterrent (CTD) system.
Rear Compartment Lid Release
If the vehicle transaxle is in PARK or NEUTRAL and the ignition is in the OFF position, a single press of the rear compartment release button will open the rear compartment lid. The interior lamps will not illuminate.
Alarm
A single press of the panic button performs the following functions:
• Illuminates the interior lamps.
• Flashes the headlamps (if turned ON in personalization).
• Pulses the horn for 30 seconds or until one of the following conditions is met:
The panic button is pressed again.
The ignition switch is turned to the RUN position with a valid key.
The vehicle is unlocked with the key.
Keyless Entry Personalization
The exterior lamps and the horn chirp may be personalized as part of the remote activation verification feature. The headlamps may be personalized as part of the keyless entry alarm feature. For mode descriptions and programming instructions, refer to Driver Personalization in Personalization.
Rolling Code
The keyless entry system uses rolling code technology. Rolling code technology prevents anyone from recording the message sent from the transmitter and using the message in order to gain entry to the vehicle. The term "rolling code" refers to the way that the keyless entry system sends and receives the signals. The transmitter sends the signal in a different order each time. The transmitter and the RCDLR are synchronized to the appropriate order. If a programmed transmitter sends a signal that is not in the order that the RCDLR expects, then the keyless entry system will not function.
________________________________________
Document ID# 659075
2002 Chevrolet Corvette
Document ID# 676808
2002 Chevrolet Corvette
________________________________________
Content Theft Deterrent (CTD) Description and Operation
The CTD system (when armed) is designed to deter vehicle content theft by pulsing the horns and exterior lamps for approximately two minutes when an unauthorized vehicle entry is detected. The CTD system also disables engine starting when an unauthorized entry is detected.
An unauthorized entry can be any of the following with the CTD system armed:
• Forced entry into the passenger compartment.
• When any door is opened without being unlocked by using the key to unlock the drivers door or the UNLOCK command from a Keyless Entry Transmitter. On vehicles equipped with option code VE1, when any door is opened without being unlocked by using the key to unlock either of the front doors.
• Forced entry into the rear compartment.
The components of the system are:
• Remote Control Door Lock Receiver (RCDLR), if equipped
• Body Control Module
• Door Ajar Switches (including hatch ajar switch)
• Ignition Lock Cylinder
• Drivers Door Key Switch (W/O VE1)
• Front Door Key Switches (W/VE1)
• Power Door Lock Switches
Arming the CTD System
Use the following procedure in order to arm the system:
1. Place the shift lever in P (park).
2. Turn OFF the ignition.
3. Open any door.
Important
The system is not armed if the doors are locked manually, the power door lock switch or keyless entry transmitter (if equipped) must be used to arm the CTD system.
4. Lock the doors with the power door lock switch or the LOCK button on the transmitter (if equipped). The system is in standby mode and will not start the arming timer until all doors are closed.
5. The system will arm approximately 30 seconds from the time that the last door is closed. This delay is shown by the SECURITY indicator ON STEADY. When the indicator transitions to OFF, the system is armed.
Locking the Vehicle Without Arming the CTD System
Locking the vehicle may be accomplished without arming the CTD system. Use of the manual door locks or using the key to lock the doors will lock the vehicle but will not arm the CTD system.
Disarming an Armed System/Silencing an Alarm
If system arming has been requested by the power door lock switch or the transmitter, it must be disarmed.
Important
Using the power door unlock switch or manually unlocking the doors does not disable the CTD arm mode. Also, disconnecting the battery or pulling fuses does not disable the arm mode, since the BCM stores the CTD mode status in memory.
• To disarm the CTD system in standby mode (SECURITY indicator flashing and door(s) open), perform one of the following:
Press either power door unlock switch.
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position.
• To disarm the CTD system in the armed mode:
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position
• To disarm the CTD system when activated (alarming mode).
Use the key to unlock drivers door. Vehicle's equipped with option code VE1, use the key to unlock either front door.
Press the UNLOCK button on the transmitter (if equipped).
Insert a valid key into the ignition and switch to the ON position.
CTD Circuit Description
The following is a description of each component used in the CTD system:
Remote Control Door Lock Receiver (RCDLR)
The keyless entry system can arm and disarm the CTD system. When the remote control door lock receiver (RCDLR) receives a door lock or unlock signal from the transmitter, the RCDLR sends a class 2 message to the body control module (BCM) to perform the appropriate arm/disarm functions.
Body Control Module (BCM)
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 activates the horns and exterior lamps. The BCM has five basic modes (disarmed, standby, delayed, armed, and alarm) for operating the CTD system. The different modes are described below.
1. When the CTD system is in the disarmed mode, ignition is OFF and any door is open, the BCM commands the instrument cluster to flash the SECURITY indicator via the class 2 serial data circuit. The BCM has the CTD system in the disarmed mode until the following conditions are detected:
o Ignition key turned to the OFF position.
o Any door open.
o Doors locked by either the power door lock switch or the LOCK button on the transmitter (if equipped).
2. The BCM enters the standby mode when the above conditions are detected. In standby mode, the BCM commands the SECURITY indicator to illuminate ON steady. If all the doors are closed and the LOCK button on the transmitter (if equipped) is used, the BCM enters the delayed mode.
3. When the last door is closed, the BCM remains in the delayed mode for 30 seconds. In delayed mode the BCM commands the SECURITY indicator to illuminate ON steady.
4. After 30 seconds, the BCM enters the armed mode. In armed mode, the BCM commands the SECURITY indicator OFF. Any forced entry activates the alarm mode.
5. When the BCM detects a forced entry, the BCM enters the alarm mode. The BCM activates exterior lamps for 2 minutes and the horns for 30 seconds. This is followed by a three minute time-out of the horns, with the horns no longer active. If no new intrusions are detected during the time-out, the horns remain inactive. The system must be disarmed or the intrusion condition removed after the time-out for the system to exit alarm mode.
Door Ajar Switches
The door ajar switches are an internal function of the door latches. The CTD system uses the door ajar switches as one method to activate the alarm. The body control module (BCM) monitors all door ajar switches via a discrete input from each door ajar switch, including the rear compartment. If the BCM receives a ground signal from a door ajar switch or hatch/trunk ajar switch when the CTD system is armed, the BCM activates the alarm.
Ignition Lock Cylinder
The ignition lock cylinder contains contact terminals that mate with the resistor pellet in the ignition key when the ignition key is inserted into the lock cylinder. When the correct ignition key is inserted into the lock cylinder, the BCM will either silence an alarming system or disarm a system in standby mode.
Drivers Door Key Switch
The drivers door key switch is an internal function of the driver door latch. The door key switch use's a discrete input to the BCM. The BCM utilizes this input to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.
Front Door Key Switches (W/VE1)
The door key switches are an internal function of the driver and passenger door latches. The door key switches use a discrete input to the BCM. The BCM utilizes each of these inputs to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.
Power Door Lock Switches
The power door lock switches are used to either arm or disarm the CTD system. Pressing the lock position will cause the CTD to arm after all doors are closed and the 30 second delay period has elapsed. Pressing the unlock position with the CTD system in any mode except ARMED will cause the CTD system to enter the disarm mode.
Important
The CTD system can be armed with the windows or sunroof open.
Inputs
The BCM monitors the following inputs:
• Driver and passenger door ajar switches (including hatch ajar switch)
• Driver and passenger power door lock/unlock switches
• Ignition lock cylinder input
• Drivers door key switch (W/O VE1)
• Front door key switches (W/VE1)
• Transmitter LOCK/UNLOCK buttons, class 2 message from the Remote Control Door Lock Receiver (RCDLR), if equipped
Outputs
The BCM controls the following :
• Theft deterrent relay
• The horn relay
• The exterior lights
________________________________________
Document ID# 676808
2002 Chevrolet Corvette
Document ID# 677002
2002 Chevrolet Corvette
________________________________________
Vehicle Theft Deterrent (VTD) Description and Operation
PASS-Key System
The personal automotive security system (PASS-Key®) is standard equipment on the vehicle. The system is designed to prevent vehicle theft by disabling the engine unless an ignition key with a specific electrical resistance is used in the ignition cylinder. The PASS-Key® system and the content theft deterrent system operate separately.
There are 15 different ignition key resistance values. Of the 15 different resistance values, or key codes available, only one will work with each body control module (BCM). Once the key code is programmed into the BCM, the code is stored in non-volatile memory.
The PASS-Key® system prevents the engine from starting by controlling the theft deterrent relay and the powertrain control module (PCM) fuel enable input. If the PCM does not sense the proper fuel enable signal, fuel will not be provided to the engine.
If the wrong resistance value is sensed when the ignition switch is in the RUN position, the BCM will not ground the theft deterrent relay control circuit and will not provide the fuel enable signal for approximately three minutes. The engine is prevented from starting and discourages a thief from trying key codes or resistance values at random.
If the correct resistance value is sensed when the ignition switch is in the RUN position, the BCM will ground the theft deterrent relay control circuit and enable fuel delivery. The engine will start normally.
If the PASS-Key® system detects an open or short to ground when the ignition switch is in the RUN position, the BCM will default to fail enable mode. Fail enable occurs when the proper key resistance is sensed before the open short to ground occurs. Fail enable will illuminate the security indicator lamp and allow the operator to stop and start the vehicle until the problem is corrected. The PASS-Key® system includes the following components:
• Ignition key
• Ignition cylinder
• Body control module (BCM)
• Theft deterrent relay
• Powertrain control module (PCM)
• SECURITY indicator
Ignition Key
The ignition key is a typical square ignition key blank with an imbedded resistor. The key blank and resistor are not serviceable separately. There are 15 different resistance values. The ignition key also has mechanical cuts similar to non-PASS-Key® ignition keys.
Ignition Cylinder
The ignition cylinder contains a set of electrical contacts used to measure the resistor in the ignition key. When the ignition key is inserted into the lock cylinder, the resistor in the key makes contact with the electrical contacts inside the ignition cylinder.
Body Control Module
The Body Control Module (BCM) contains the theft deterrent system logic. The BCM reads the key code from the ignition cylinder when the ignition is turned to the START position. If the code is correct, the BCM will enable the theft deterrent relay and will send a fuel enable signal to the PCM via the class 2 serial data circuit.
If the BCM receives the wrong code, the BCM will immediately go into tamper mode. The tamper mode will lock-out the vehicle starter and fuel injectors for 3 minutes. The SECURITY indicator will flash while the BCM is in tamper mode.
Theft Deterrent Relay
The theft deterrent relay is used to prevent the engine from cranking if the correct resistance is not sensed at the ignition key. It prevents the engine from cranking by opening the circuit to the starter solenoid.
Powertrain Control Module
The PCM communicates with the BCM over the Class 2 serial data circuit. When the BCM enters tamper mode, it sends a Class 2 message to the PCM in order to disable the fuel injection system. If the BCM receives the expected ignition code, the BCM sends a class 2 message to the PCM in order to enable the fuel injection system. The PCM then allows the vehicle to start.
SECURITY Indicator
The SECURITY indicator is located on the instrument cluster. The SECURITY indicator is controlled by the BCM via the class 2 serial data circuit.
________________________________________
Document ID# 677002
2002 Chevrolet Corvette
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TXWMH (11-10-2015)
#4
Racer
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Thank you very much.
This has to be one of the best and most detailed responses I have ever received and I am glad I asked it because now I know my vette is well protected. I have printed this out for future reference
This has to be one of the best and most detailed responses I have ever received and I am glad I asked it because now I know my vette is well protected. I have printed this out for future reference
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Great info, DeeGee.
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Professional thieves will usually tow/flatbed a Vette. Nobody cares if the alarm is blaring as obviously the owner is having car trouble. Some thieves copy the VIN and get a duplicate set of keys made for the car by somebody at a dealership.
Joy riders will not be able to take the car unless you leave your keys in the car.
Bill
Joy riders will not be able to take the car unless you leave your keys in the car.
Bill
#12
Melting Slicks
It is very easy to break into a Corvette without setting off the factory alarm. Once inside it is a simple process of elimination to defeat the VATS system and start the car and can be done quickly.
The major weakness is that the alarm can be disarmed by turning the door cylinder. So if anything is used to turn the cylinder, including force, then the alarm thinks the key was used and disarms the alarm. Then the thief has all the time he needs to steal the car.
It is why I have an aftermarket alarm on my car. It in the end will not defeat a determined pro but it might make him look at your's to steal instead of mine.
The major weakness is that the alarm can be disarmed by turning the door cylinder. So if anything is used to turn the cylinder, including force, then the alarm thinks the key was used and disarms the alarm. Then the thief has all the time he needs to steal the car.
It is why I have an aftermarket alarm on my car. It in the end will not defeat a determined pro but it might make him look at your's to steal instead of mine.
#13
Race Director
Short Version:
1-Safety off.
2-Take aim.
3-Squeeze trigger.
4- Repeat step 3 if you're a bad shot.
1-Safety off.
2-Take aim.
3-Squeeze trigger.
4- Repeat step 3 if you're a bad shot.
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zdeckich (09-24-2015)
#16
Melting Slicks
Basic, effective theft protection IMO
1) Lojack/Onstar
2) Hidden kill switch in line with starter or fuel pump (where you put it is up to you
I wouldn't rely on the GM system alone.