Abstract:
An electronic anti-theft system and method is described herein. The system may inhibit the completion of vehicle theft, carjacking, as well as deter any unauthorized use of the vehicle. The system may include an input device and a microcontroller. The input device may communicate with an engine control module of a motor vehicle, wherein the engine control module controls an engine of the motor vehicle. The microcontroller may communicate with a door sensor of the vehicle and be able to detect when a door is opened. The microcontroller may include a door open circuit that can send a signal to the engine control module to disable the engine after a predetermined amount of time has lapsed in response to detecting that the door was opened. The microcontroller may disable the engine provided that a PIN is not received at the input device within the predetermined amount of time.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a vehicle security system and, more particularly, to an electronic anti-theft apparatus for preventing vehicle theft. 
       BACKGROUND 
       [0002]    Vehicle theft is often a problem in today&#39;s society. These thefts may result in a large cost to the owner and/or operator to replace a stolen vehicle not to mention any increased insurance costs. A number of vehicle security systems have been utilized in order to prevent such as loss. 
         [0003]    Theft of motor vehicles may require the thief to “hotwire” the vehicle before driving away. If the thief is unable to hotwire the motor vehicle or does not know how to hotwire the vehicle, the thief may resort to carjacking. Carjacking may be defined as the taking of a motor vehicle from the owner and/or operator by force, violence, or intimidation. In many carjackings weapons, such as knives or handheld firearms, may be used to coerce the owner to leave the vehicle. 
         [0004]    Carjackings may most frequently occur while the owner is driving the vehicle and is temporarily stopped, such as at a traffic light or stop sign. Carjackings, however, may also occur at other times, such as before the owner enters the vehicle. Once the thief gets the owner&#39;s keys, the vehicle may easily be taken. This type of scenario may often occur at a gas station or in a parking lot. Violent personal confrontations during a carjacking may leave the owner feeling helpless, frightened and violated. These confrontations may also leave the owner physically injured. 
         [0005]    Vehicle theft prevention devices may be utilized to prevent unauthorized access to and operation of a vehicle. Many typical theft prevention devices, however, are ineffective and have inherent drawbacks that may make them inefficient. Essentially, alarm systems do not work anymore. There is always an alarm going off somewhere, often by mistake, and unfortunately almost no one pays attention to the alarm. For example, often times these alarms may be activated by someone innocently bumping the car next to them in a parking lot. 
         [0006]    Other devices may include wheel locking devices. These wheel locking devices, however, may easily be removed by sawing or using Freon to break them off of the steering column. While these types of devices may provide a visible warning, they are really only effective after the vehicle is already parked and locked and not effective at all for carjacking situations when the vehicle owner is present. Situations where the vehicle owner is present are of most concern because this is when injury or loss of life may occur. 
         [0007]    Alternatively, vehicle tracking systems may be used to locate the stolen or carjacked vehicle. These types of tracking devices, however, can make no guarantees as to what type of condition the vehicle will be in if or when it is eventually located. Most often the vehicle may already be stripped of parts or damaged in other ways when the vehicle is located and retrieved. 
       SUMMARY 
       [0008]    An electronic anti-theft system is described herein. The electronic anti-theft system may include an input device and a microcontroller. The input device may be adapted to communicate with an engine control module of a motor vehicle, wherein the engine control module may be capable of controlling an engine of the motor vehicle. The microcontroller may be located within the input device, wherein the microcontroller may be adapted to communicate with the engine control module. 
         [0009]    The microcontroller may be adapted to communicate with a door sensor of the vehicle, wherein the microcontroller may be capable of detecting when a door is opened, such as the driver&#39;s side door. The microcontroller may also include a door open circuit that may be capable of sending a signal to the engine control module to disable the engine after a predetermined amount of time has lapsed in response to detecting that the door was opened. The microcontroller may also be operative to disable the engine provided that a predetermined input, such as a PIN, is not received at the input device within the predetermined amount of time, such as within approximately thirty seconds. 
         [0010]    A method of operating an electronic anti-theft system is also described. The method may include the step of engaging an input device with an engine control module of a motor vehicle. The input device may include a microcontroller capable of detecting when an engine of the motor vehicle has been started. The method may also include the step of receiving a predetermined input, such as a PIN, into the input device within a predetermined amount of time, such as thirty seconds, thereby activating an engine run circuit. The method may detect the opening of a driver&#39;s side door after receiving the PIN, thereby activating a door open circuit. The method may also include the steps of failing to receive the re-entry of the PIN within the predetermined amount of time, thereby activating an engine disrupt circuit, and disabling the engine for a specified amount of time by way of the engine disrupt circuit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Objects and advantages together with the operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein: 
           [0012]      FIG. 1  illustrates a side view of an electronic anti-theft system for a vehicle. 
           [0013]      FIG. 2  illustrates a partial perspective view of the electronic anti-theft system of  FIG. 1 . 
           [0014]      FIG. 3  illustrates a top perspective view of an input device of an electronic anti-theft system. 
           [0015]      FIG. 4  illustrates a partially exploded bottom perspective view of the input device of  FIG. 3 . 
           [0016]      FIG. 5  illustrates a circuit schematic of the electronic anti-theft system. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the invention. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the invention. Additionally, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something, and is not intended to indicate a preference. 
         [0018]    An electronic anti-theft system  10  (the “system  10 ”) is illustrated in  FIG. 1 . The electronic anti-theft system  10  may be of any appropriate shape, size, type or configuration. The system  10  may be utilized for any appropriate purpose. For example, the electronic anti-theft system  10  may be utilized to prevent any unauthorized use of a motor vehicle  12 . 
         [0019]    The electronic anti-theft system  10  may inhibit the completion of vehicle theft, carjacking, as well as deter any unauthorized use of the vehicle  12 . The system  10  may enhance the safety of the owner/operator in carjacking situations as well as increase the recoverability of the vehicle  12 . The system  10  may also be affordable, relatively simple to operate and may be used on any motor vehicle  12  that has an electronic ignition system  20 . 
         [0020]    The electronic anti-theft system  10  may be installed as an aftermarket accessory. The system  10  may go in any type of motor vehicle  12  that has an electronic ignition system  20 , such as a car, truck, motorcycle, boat and the like. The system  10  works regardless of whether the operator has a key or not. 
         [0021]    With reference to  FIGS. 2-4 , the electronic anti-theft system  10  may be operated by a small hand-held unit, such as an input device  30 . The electronic anti-theft system  10  may also include a circuit board  60 , at least one button and at least one light. The input device  30  may be of any appropriate shape, size, type or configuration, whereby information may be entered into the device  30  via a keypad, buttons, fingerprint, card swipe, scanner, voice command, and the like. In an exemplary embodiment, the input device  30  may be a keypad device. 
         [0022]    As illustrated in  FIGS. 3 and 4 , the input device  30  may be of a generally hollow square or rectangular configuration, whereby the input device  30  may include an upper housing  34  and a lower housing  36 . The upper housing  34  may be of any appropriate shape, size, type or configuration, such as of a generally square or rectangular shape. For example, the upper housing  34  may include walls extending approximately perpendicularly outward from the upper housing  34  to create a hollow opening. The upper housing  34  may be located at any appropriate position on the apparatus  10 , such as located above the lower housing  36 . 
         [0023]    The lower housing  36  may be of any appropriate shape, size, type or configuration, such as of a generally square or rectangular shape. For example, the lower housing  36  may be of a similar shape and size as that of the upper housing  34 . 
         [0024]    With reference to  FIG. 4 , the upper housing  34  and lower housing  36  may each include at least one mounting aperture, such as a plurality of mounting apertures  38 . For example, the upper housing  34  and lower housing  36  may each include a similar number of mounting apertures  38 , such as approximately four mounting apertures  38  each. The mounting apertures  38  may be of any appropriate shape, size, type or configuration, such as a generally circular shape. For example, the mounting apertures  38  may be located at an approximate corner location on the upper housing  34  and lower housing  36 , such that the mounting apertures  38  may be generally aligned with one another, such that any appropriate number and type of fasteners (not shown) may be utilized to secure the upper housing  34  to the lower housing  36 . 
         [0025]    The upper housing  34  and lower housing  36  may each include at least one post  40 . The posts  40  may be of any appropriate shape, size, type or configuration, such as of a generally cylindrical post  40 . The posts  40  may be located at any appropriate position on the upper housing  34  and lower housing  36 , such as adjacent the corners of the upper housing  34  and lower housing  36 . The posts  40  may aid in the assembly of the upper housing  34  and lower housing  36  together. 
         [0026]    The upper housing  34  may include any appropriate number of lighting apertures (not shown). For example, the upper housing  34  may include approximately two lighting apertures. The lighting apertures may be located at any appropriate position on the upper housing  34 , such as located towards a first end of the upper housing  34 . 
         [0027]    The input device  30  may include any appropriate number of lighting features. For example, as shown in  FIG. 3 , the input device  30  may include approximately two lighting features  44 ,  46 . The lighting features may be of any appropriate shape, size, type or configuration, such as light-emitting diodes (LEDs)  44 ,  46 . The LEDs  44 ,  46  may be of any appropriate color, whereby one may be a Green LED  44  and the other may be an Amber LED  46 . 
         [0028]    The input device  30  may include any appropriate number of button apertures (not shown). For example, the upper housing  34  may include approximately six button apertures. The button apertures may be located at any appropriate position on the upper housing  34 , such as located towards a second and opposite end of the upper housing  34  away from the lighting apertures. 
         [0029]    The input device  30  may include any appropriate number of buttons, such as a plurality of buttons  50 ,  52 ,  54 . For example, in a non-limiting example, the electronic anti-theft apparatus  10  may include six buttons  50 ,  52 ,  54 . 
         [0030]    The buttons  50 ,  52 ,  54  may be of any appropriate shape, size, type or configuration, such as of a generally square, circular, triangular shape or the like. For example, as shown in  FIG. 3 , the buttons  50 ,  52 ,  54  may be of a push button configuration. 
         [0031]    The buttons  50 ,  52 ,  54  may be utilized to control the electronic anti-theft system  10 . For example, two of the buttons  50 ,  52  may be programming mode buttons, whereby they may control the functions of the system  10 , such as an “ENTER” button  50  and a “CLEAR” button  52 . In addition, four of the buttons may be numeric digits buttons  54 , whereby they may correspond to numbers, such as 1, 2, 3 and 4. 
         [0032]    The input device  30  may include an output aperture  56 . The output aperture  56  may be of any appropriate shape, size, type or configuration, such as a generally square or rectangular shape. With reference to  FIGS. 3 and 4 , the output aperture  56  may be located at any appropriate position on the input device  30  such as at a first end of the input device  30 . 
         [0033]    The input device  30  may be secured or mounted in any appropriate manner to an interior of the vehicle  12 . With reference to  FIGS. 1 and 2 , in an exemplary embodiment, the input device  30  may be removably mounted onto a dashboard  26  of the vehicle  12  in any appropriate manner, such as by Velcro. Alternatively, the input device  30  may be placed within a cup holder or MP3 holder. 
         [0034]    The system  10  may engage an engine control module  14  of the vehicle in any appropriate manner. Referring to  FIG. 2 , the apparatus  10  may be operatively connected to the vehicle by any appropriate means, such as by way of a cable  32 . For example, the cable  32  may be engaged with the circuit board  60  of the input device  30 . That cable  32  may then be routed through an electrical rubber boot that runs beneath a steering column of the vehicle  12 , such as where the electrical harness may be located. The cable  32  may then run through the rubber boot through to the engine compartment of the vehicle  12  where the cable  32  may engage the systems of the vehicle  12 . For example, the system  10  may be powered by the battery  18  of the vehicle  12 . 
         [0035]    The cable  32  may be of any appropriate shape, size, type or configuration. In an exemplary embodiment, the cable  32  may be a six pin connector, whereby the wires may be soldered onto the circuit board  60 . The other end of the cable  32  may be connected to the vehicle circuits (not shown), such as the battery circuits, engine circuits, and vehicle courtesy light circuit, by way of a fuse box (not shown). 
         [0036]    For example, the fuse box may be located at any appropriate position in the vehicle  12 , such as where an ignition circuit and a door ajar circuit may be located. The fuse box may include a fuse that may provide power to the engine control module  14  of the vehicle  12 . In an exemplary embodiment, a microcontroller  62  on the circuit board  60  may control the fuse that provides power to the engine control module  14 . 
         [0037]    The input device  30  may include a switch  58 . The switch  58  may be of any appropriate shape, size, type or configuration, such as of a generally circular or rectangular shape. With reference to  FIG. 4 , the switch  58  may be located at any appropriate position on the input device  30 , such as located on a side of the input device  30 . The switch  58  may toggle or be selectable between two positions. 
         [0038]    As an alternative, the system  10  may also include a pressure sensor (not shown). The pressure sensor may be of any appropriate shape, size, type or configuration. The pressure sensor may be located at any appropriate position, such as under the driver&#39;s side seat. 
         [0039]    The circuit board  60  of the electronic anti-theft system  10  may be of any appropriate shape, size, type or configuration, such as a generally rectangular or square shaped printed circuit board  60 . With reference to  FIG. 4 , the circuit board  60  may be located within the input device  30 . The circuit board  60  may include any appropriate type or number of components and mechanisms to control the electronic anti-theft system  10 . For example, as illustrated in  FIG. 5 , the circuit board  60  may include a microcontroller  62 , keypad circuit  64 , LED circuit  66 , Engine Run circuit  68 , Engine Disrupt circuit  70 , Door Open circuit  72 , and audible alarm circuit  76 . 
         [0040]    The microcontroller  62  may be of any appropriate type or configuration, such that the microcontroller may be a small computer on a single integrated circuit including a processor core, memory, and programmable peripherals. Microcontrollers may be used in automatically controlled products and devices, such as automobile engine control systems and other embedded systems. With reference to  FIG. 5 , the microcontroller  62  may send out signals to operate a variety of the circuits  64 ,  66 ,  68 ,  70 ,  72 . For example, as illustrated in  FIG. 1 , some of these circuits  68 ,  70 ,  72  may interact with components of the vehicle  12 , such as the engine control module  14 , engine  16 , battery  18 , and ignition  20  components. 
         [0041]    The keypad circuit  64  may respond to the operator&#39;s commands via the buttons  50 ,  52 ,  54  to input a personal identification number (PIN) into the input device  30 . The PIN may be a secret numeric password shared between an operator and a system, such as the electronic anti-theft system  10 , which may be used to authenticate the operator to the system  10 . The operator may continue to operate the vehicle  12  only when the PIN entered matches with the PIN stored in the system  10 . The PIN may be of any appropriate amount of numeric digits, such as four, six, nine and the like. In an exemplary embodiment, the PIN may include four numeric digits. The LED circuit  66  may respond to certain buttons  50 ,  52 ,  54  being depressed in a predetermined order, such as during PIN entry, setting or re-setting of the PIN. 
         [0042]    The Engine Run circuit  68  may respond to the correct PIN entry to keep the vehicle  12  running. Conversely, the Engine Disrupt circuit  70  may respond to an incorrect PIN entry or lack of any PIN being entered, whereby the engine  16  may be shut down. 
         [0043]    The Door Open circuit  72  may respond to a correct PIN entry after the Engine Run circuit  68  has been activated and the door  22  has been opened. The circuit board  60  may also include a programmable header circuit  74 . The programmable header circuit  74  may be utilized for downloading software onto the microcontroller  62 . The audible alarm circuit  76  may send a signal to an audible alarm to instruct the alarm to begin emitting an audible sound. 
         [0044]    The electronic anti-theft system  10  may include at least one timer (not shown). For example, the system  10  may include any appropriate number of timers to operate, such as a first timer (not shown) and a second timer (not shown). The dual timers may be integrally located within the components of the circuit board  60 . For example, the dual timers may be located within the microcontroller  62 . The microcontroller  62  may include and operate a dual or two stage timer (not shown). The first timer may be used for transmitting an electric first signal after a first predetermined period of time after being electrically activated by a key (not shown) to operate the vehicle  12 . The second timer may be used for transmitting a second electric signal after a second predetermined period of time. 
         [0045]    The first timer may be the initializing timer. The initializing timer may begin the up count to a specific timed set point once current flow is detected through the counter located on the circuit board  60 . The amount of time may be a fixed set point for operator use, such as approximately thirty seconds. In an exemplary embodiment, the factory setting may be set at approximately thirty seconds, whereby the operator may have approximately thirty seconds to enter proper PIN before the Engine Disrupt circuit  70  may be activated and shut the engine  16  down. The first timer may be deactivated when the proper PIN is entered. 
         [0046]    If the proper PIN is not entered within the set time period, the microcontroller  62  may send a signal output to begin the up counter on the second timer. The second timer may begin a timed sequence of any appropriate timeframe, such as approximately two to four minutes, and may also energize a control relay (not shown) that may be located on the circuit board  60 . After the second timer counts down the approximate two to four minute timeframe, the second timer may send an output signal to reset the circuit board  60  back to the normal operation state and de-energize the control relay. This second timer sequence may begin again if the proper PIN is not entered within the predetermined amount of time after the engine  16  is started. 
         [0047]    The input device  30  may serve as the operator interface for the PIN selection and the re-programming of a new PIN, as needed. Once programmed and entered correctly, the PIN may stop and reset the up counter of the first timer to zero, whereby the circuit board  60  will remain de-energized in the normal state of operation. 
         [0048]    The power supply for the input device  30  may be the vehicles  12  twelve volt direct current (DC) power source for relay activation. The power may also supply a regulated 5 volt DC power source to the various components on the circuit board  60 . 
         [0049]    The battery  18  may be connected to the vehicle engine  16 . While running, the engine  16  may emit engine noise and vibrations that may ride on the DC circuit. This engine noise and vibrations may indicate to the microcontroller  62  that the engine  16  is running and that a PIN code needs to be entered. For example, the Engine Run circuit  68  may operate when the proper PIN code has been entered into the input device  30  within the specified time allowed, whereby this may result in a reset signal stopping and re-setting the up count of the first timer, thereby allowing the external circuit to remain uninterrupted. 
         [0050]    The Engine Disrupt circuit  70  may operate if the proper PIN code has not been entered into the input device  30  within the specified time, whereby the microcontroller  62  may break the external circuit continuity. The Engine Disrupt circuit  70  may shut the engine  16  down. For example, the Engine Disrupt circuit  70  may send a signal to the engine control module  14  of the vehicle system to remove power from the engine  16  and shut the engine  16  down. As an alternative, the pressure sensor located under the driver&#39;s side seat or the Door Open circuit  72  may trigger the first timer to begin the up counter to a predetermined set point. 
         [0051]    In a non-limiting example, if an operator enters the vehicle  12  and starts the vehicle  12  with a duplicate key, but does not have the PIN, the engine  16  will shut down for approximately two to four minutes and the vehicle  12  will not start. After approximately two to four minutes the vehicle  12  will be able to restart. 
         [0052]    The operator may operate the system  10  via the numeric digit buttons  54  (i.e., the 1 button, 2 button, 3 button and 4 button), two programming mode buttons (i.e., the ENTER button  50  and the CLEAR button  52 ) and the two LED indicating lamps (i.e., the Green LED  44  and the Amber LED  46 ). Also, the main circuit board  60  may respond to data inputs with corresponding flashes of the LED&#39;s to notify the user of data acceptance via the LED circuit  66 . 
         [0053]    The keypad circuit  64  and LED circuit  66  may respond to the operators input in setting the PIN. The Green LED  44  may be mounted at the top of the circuit board  60  and may flash a single pulse when data is entered for either normal PIN entry or re-programming a new PIN. The Amber LED  46  may be used to identify when the first timer has been activated with a one second flashing pulse. If the timer reaches the preset time allowed, then the Amber LED  46  may be lit up until the second timer is deactivated. The Amber LED  46  may be mounted directly next or adjacent to the Green LED  44 . An additional LED (not shown) may also be included for backlighting the buttons  50 ,  52 ,  54  of the input device  30 . 
         [0054]    The input device  30  may come with a default PIN that may be factory set. For example, the PIN may be a 4-digit PIN. To set the PIN, the CLEAR button  52  may be depressed and held until the Amber LED  46  lights up. When the Amber LED  46  lights up, the CLEAR button  52  may then be released, whereby the Amber LED  46  will go out. After the Amber LED  46  light goes out, the ENTER button  50  may be depressed for a period of time until the Green LED  44  lights up. For example, the ENTER button  50  should be depressed within approximately two seconds after the CLEAR button  52  is released. Failure to depress the ENTER button  50  during the appropriate timeframe may abort the default PIN setting. After the Green LED  44  lights up, the ENTER button  50  may be released, whereby the Green LED  44  may go out. The default PIN is now set. 
         [0055]    Each individual input device  30  may have a specific serial number and hard PIN code imbedded in the microcontrollers  62  ROM for master reset needs. This may act as a failsafe against operators forgetting their current PIN numbers. These serial numbers with encrypted PIN codes may be varied monthly along with daily security measures. 
         [0056]    Each input device  30  produced may be pre-set to a factory master reset code for initial installation and operation, which may be entered into the microcontroller  62  RAM and may not affect the master PIN code already stored in the ROM location. This PIN may be changed by performing the following steps: (1) Hold down both CLEAR button  52  and ENTER button  50  for approximately three seconds until the Green LED  44  goes solid. (2) Enter the current PIN code followed by the ENTER button  50 . This may ensure that the person re-programming the system is an authorized user. Once the correct PIN has been entered, the Green LED  44  may flash at one second interval awaiting the new code. (3) Enter the new PIN number followed by the ENTER button  50  and the Green LED  44  may go solid again for approximately three seconds before turning it off. Any wrong numbers entered during the programming may be corrected by depressing the CLEAR button  52  after the error has been entered. 
         [0057]    The operator may change the PIN at any time. For example, the operator may desire to change his/her PIN in order to allow someone else to use his/her vehicle without comprising the PIN or simply to use a new PIN. Changing the PIN may be accomplished while the engine  16  is running and should be performed while the vehicle  12  is legally and safely parked. In order to change the PIN, both the CLEAR button  52  and ENTER button  50  should be depressed until the Green LED  44  lights up. After the Green LED  44  lights up, the CLEAR button  52  and ENTER button  50  may be released. Next, the current PIN code may be entered followed by depressing the ENTER button  50 . 
         [0058]    After the current PIN has been entered, the Green LED  44  may flash, whereby a new PIN code may be entered followed by depressing the ENTER button  50 . The Green LED  44  may stop flashing and remain on for a predetermined amount of time, such as approximately three seconds, and then go off. If the operator depresses or inputs a wrong number, he/she may depress the CLEAR button  52  and then depress the correct number. 
         [0059]    In a non-limiting example, when power is first applied, the system  10  may be disabled for any predetermined amount of time, such as approximately ten seconds. After this ten second period, the Green LED  44  and Amber LED  46  may illuminate for a predetermined amount of time, such as approximately two seconds. After this two second period, the Green LED  44  and Amber LED  46  may go out, at which time the system  10  may be fully operational. 
         [0060]    After the engine  16  of the vehicle  12  is started, the operator may have approximately thirty seconds to enter the 4-digit PIN followed by depressing the ENTER button  50 . This approximate thirty second period of time may be indicated by the flashing of the Amber LED  46 . The audible alarm circuit  76  may send a signal to an audible alarm to instruct the alarm to begin emitting an audible sound approximately ten seconds before the Amber LED  46  stops flashing. For example, the audible alarm  76  may beep for approximately the last ten seconds that the Amber LED  46  flashes. 
         [0061]    Failure to enter the correct 4-digit PIN followed by depressing the ENTER button  50  within approximately thirty seconds may cause the engine  16  to shut down. In addition, the engine  16  may not start for an additional predetermined period of time, such as an approximately two minute or four minute period. This two to four minute period of time may be selectable via the switch  58  on the side of the input device  30 . 
         [0062]    If the correct 4-digit PIN is entered and followed by the operator depressing the ENTER button  50  within approximately thirty seconds, the engine  16  may operate as normal until it is turned off by the operator. As each PIN digit is depressed, the Green LED  44  may flash or temporarily light up to acknowledge that the respective numeric digit button  54  is being depressed. If the correct PIN has been entered, the Amber LED  46  may stop flashing and the Green LED  44  may light up for approximately three-quarters of a second after the ENTER button  50  is released. 
         [0063]    In normal operation, the system  10  may begin counting on power up sensed through current output from the microcontroller  62  to the first timer. The operator may then enter the proper PIN code followed by depressing the ENTER button  50 . Entry of the proper PIN may de-activate the Engine Disrupt circuit  70  and may permit normal mode of operation via the Engine Run circuit  68 . 
         [0064]    After failure to enter the correct PIN or failure to enter any PIN, the vehicle  12  may operate for a predetermined period of time. The objective of the time delay may be to cause the vehicle  12  to stall at a position remotely located from the point at which it was stolen. The time delay mechanism may permit the vehicle  12  to be started and driven from where it was stolen, only to later stall at some other location. The thief may abandon their plan to steal the vehicle  12  and look elsewhere. Once the vehicle  12  is disabled, and after waiting the predetermined period of time, such as two or four minutes, the engine  16  may be enabled by a specific combination of operator actions to allow the vehicle  12  to operate. 
         [0065]    The system  10  may have the flexibility to disable the vehicle  12  upon the automatic sensing of the opening of the driver&#39;s door  22 , such as while the engine  16  is running or upon a signal, such as a Door Open circuit  72 , transmitted by the system  10 . Under certain circumstances, when the door  22  is opened, a disablement sequence may start for disabling the engine  16  of the vehicle  12 . With reference to  FIG. 1 , the system  10  may interact with a courtesy light or door sensor  24 . 
         [0066]    As illustrated in  FIG. 1 , the door sensor  24  may be attached to the inside of the driver&#39;s side door  22 . The door sensor  24  may sense the opening of the door  22 . For example, when the door  22  opens, the door sensor  24  may output an opened door signal to the microcontroller  62 . For example, the door sensor  24  may be a wire connected to the vehicle&#39;s  12  existing pin switch (not shown). Most vehicles  12  may already include a pin switch for completing a circuit to illuminate a dome light. 
         [0067]    The electronic anti-theft system  10  may include a Door Open circuit  72 . The Door Open circuit  72  may operate when the driver side door  22  is opened after starting the vehicle  12  and initially entering the PIN. If the driver side door  22  is opened while the engine  16  is running, the PIN must be entered within a predetermined amount of time, such as approximately thirty seconds, in order to prevent the engine  16  from shutting down. During this timeframe, the Amber LED  46  may be flashing. In addition, the audible alarm circuit  76  may send a signal to the audible alarm to instruct the alarm to begin emitting an audible sound approximately ten seconds before the Amber LED  46  stops flashing. For example, the audible alarm  76  may beep for approximately the last ten seconds that the Amber LED  46  flashes. 
         [0068]    This Door Open circuit  72  may act as an anti-carjacking feature. If the operator knows that he/she is going to leave the vehicle  12  after starting the engine  16 , the operator may temporarily disable this Door Open circuit  72  for one “Engine Run” cycle. This “carjack override” feature may work for one Engine Run cycle. Once the engine has been turned off, this temporary override may re-set itself to normal operation. Deactivating the Door Open circuit  72  may be accomplished by following a disablement sequence. The operator may re-entering the correct 4-digit PIN prior to opening the door  22 . Re-entering the PIN may allow the operator to leave his/her vehicle  12  while it is running, whereby the engine  16  may not shut down. It is not recommended that any operator leave his/her vehicle  12  unattended with the engine  16  running, as doing so may unsafe as well as illegal in some cities and/or states. 
         [0069]    When the system  10  is in an override situation, the door  22  may be opened while the engine  16  is running without having to initiate the disablement sequence. This may permit the operator to exit the vehicle  12  and to allow the vehicle  12  to be left running, such as when the operator may clean the windshield or warm up the vehicle in cooler temperatures. 
         [0070]    In a non-limiting example, the operator may be stopped at a traffic light. While waiting for the traffic light to change, a carjacker may appear at the window and point a gun at the operator demanding that the operator give over the vehicle  12 . To end the confrontation, the operator may easily comply with the carjacker&#39;s demands knowing that the vehicle  12  may not get any more than approximately thirty seconds away. 
         [0071]    Although the embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present invention is not to be limited to the embodiments disclosed, but that the invention described herein is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter.