GB2459775A

GB2459775A - Vehicle tampering detection system

Info

Publication number: GB2459775A
Application number: GB0907816A
Authority: GB
Inventors: Hiroyuki Yamada; Kouichi Masamura
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2008-05-09
Filing date: 2009-05-06
Publication date: 2009-11-11
Anticipated expiration: 2029-05-06
Also published as: GB2459775A8; GB0907816D0; GB2459775B; JP4518185B2; DE102009002911B4; DE102009002911A1; JP2009269527A

Abstract

A vehicle tampering detection system includes an on-off switch 13 turned on in response to a certain action taken on a vehicle. A harness 21 that connects a terminal 13a of the on-off switch 13 to a current source, a harness 22 connected to a terminal 13b of the on-off switch 13 and a harness 23 connected to the current source are provided. A tampering determination unit 11 that may be the current source which sends an electric current to the harness 21 and that determines whether the vehicle is tampered with based on a change in the state of the electric current passing through the harness 21, and a tampering determination unit 12 that may be the current source which sends an electric current to the harness 23 and that determines whether the vehicle is tampered with based on a change in the state of the electric current passing through the harness 23. A section 20, in which the harnesses 21, 22 and 23 are tied together in a bundle, is formed. The harnesses 21, 22 and 23 may be twisted together, may be the same colour and may have an opaque cover 20A.

Description

VEHICLE TAMPERING DETECTION SYSTEM

BACKGROUND OF THE INVENTION

1. Field of the Invention

[00011 The invention relates to a vehicle tampering detection system that determines that a vehicle is tampered with, if the state of electric current that passes through a wiring harness in the vehicle changes.

2. Description of the Related Art

[0002] Recently, development of technologies for preventing illicit actions such as vehicle thefts has been promoted (refer to, for example, Japanese Patent Application Publication No. 2001-71870 (JP-A-2001-71870) and Japanese Patent Application Publication No. 2000-219104 (JP-A-2000-219104)). JP-A-2001-71870 describes an alarm system that protects a vehicle from theft. According to JP-A-2001-71870, even if a certain alarm is disabled because an energizing circuit is short-circuited, the remaining alarm is operated reliably. In this way, a vehicle theft is prevented. JP-A-2000-219104 describes a vehicle antitheft system that includes control means for receiving a signal from a sensor that detects a change in the state of a certain portion of a vehicle, alarm means for issuing an alarm upon reception of an actuating signal from the control means, detection means for detecting at least one of an electrical break in a connection member that electrically connects the sensor, the control means and the alarm means to each other and a displacement of the connection member in the direction in which the connection member breaks, and auxiliary alarm means for issuing an auxiliary alarm when an electrical break of the connection member or a displacement of the connection member is detected. With this configuration, even if the connection member is broken, a vehicle theft or a theft of items in a vehicle compartment is discouraged.

[0003] As in the related technologies described above, even if a circuit is short-circuited or broken, an antitheft function is required to be continuously executed instead of being deactivated. FIGs. 6A to 6D show examples of the basic structure of a tampering detection system that detects tampering with a vehicle. The tampering detection systems in FIGs. 6A to 6D each include an on-off switch 3 that is turned on or off in response to a certain action taken on the vehicle, wiring harnesses 2 and 4, and a tampering determination unit 1 that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harnesses.

The tampering determination units 1 in FIGs. 6A and 6B each include a source circuit that sends an electric current to the wiring harness 2. The tampering determination units 1 in FIGs. 6C and 6D each include a sink circuit that takes in an electric current from the wiring harness 2.

[0004] With the structures shown in FIGs. 6A and 6C, when the tampering determination unit 1 detects a decrease in the electric current that passes through the wiring harness 2 while monitoring whether the vehicle is tampered with in the state where switch 3 is on, the tampering determination unit 1 determines that the switch 3 is turned off by the certain action taken on the vehicle. Then, the tampering determination unit 1 regards this action as tampering with the vehicle.

[000S] With the structures shown in FIGs. 6B and 6D, when the tampering determination unit 1 detects an increase in the electric current that passes through the wiring harness 2 while monitoring whether the vehicle is tampered with in the state where switch 3 is off, the tampering determination unit 1 determines that the switch 3 is turned on by the certain action taken on the vehicle. Then, the tampering determination unit 1 regards this action as tampering with the vehicle.

[0006] However, in the structure in FIG 6A, when an action for short-circuiting the wiring harness 2 to the ground is taken, even if the switch 3 is turned off after this action, a change in the electric current is not detected. Therefore, tampering with the vehicle is not detected. In the structure in FIG 6C, when an action for short-circuiting the wiring harness 2 to a power supply voltage is taken, even if the switch 3 is turned off after this action, a change in the electric current is not detected. Therefore, tampering with the vehicle is not detected. In each of the structures shown in FIG 6B and 6D, when an action for breaking the wiring harness 2 is taken, even if the switch 3 is turned on after this action, a change in the electric current is not detected. Therefore, tampering with the vehicle is not detected.

SUMMARY OF THE INVENTION

[0007] The invention provides a vehicle tampering detection system that reliably detects illicit actions taken on a vehicle including tampering with a wiring harness.

[0008] An aspect of the invention relates to a vehicle tampering detection system that includes: an on-off switch which is provided in a vehicle, an on-off state of which is changed in response to a certain action taken on the vehicle, and which includes a first connection portion and a second connection portion that are electrically connected to each other when the on-off switch is on and that are electrically disconnected from each other when the on-off switch is off; a first wiring harness that connects the first connection portion to a current source; a second wiring harness that is connected to the second connection portion; a third wiring harness that is connected to the current source; first determination means for determining that the vehicle is tampered with if the state of an electric current that passes through the first wiring harness changes from the state of the electric current that passes through the first wiring harness when the on-off switch is off, and/or for determining that the vehicle is tampered with if the state of an electric current that passes through the second wiring harness changes from the state of the electric current that passes through the second wiring harness when the on-off switch is off; and second determination means for determining that the vehicle is tampered with if the state of an electric current that passes through the third wiring harness changes from the state of the electric current that passes through the third wiring harness in the normal state. There is formed a section in which the first wiring harness, the second wiring harness and the third wiring harness are tied together in a bundle in such a manner that the first wiring harness, the second wiring harness and the third wiring harness are not distinguished from each other.

[0009] In the aspect of the invention described above, the current source that is connected to the first wiring harness and the current source that is connected to the third wiring harness may be arranged on the side of one end of the section, and the on-off switch may be arranged on the side of the other end of the section. The third wiring harness may be looped within the section.

[0010] In the aspect of the invention described above, the first wiring harness, the second wiring harness and the third wiring harness may be tied together in a bundle and covered with a cover within the section. The first wiring harness, the second wiring harness, and the third wiring harness may be the same in color.

[0011] In the aspect of the invention described above, the certain action may be opening of an openable body provided in the vehicle. In this case, the on-off state of the on-off switch may be changed by the opening of the openable body. The openable body may be a bonnet.

[0012] According to the aspect of the invention described above, it is possible to reliably detect illicit actions taken on the vehicle including tampering with the wiring harness.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The features, advantages and technical and industrial significance of this invention will be described in the following detailed description of example embodiments of the invention with reference to the accompanying drawings, wherein the same or corresponding portions will be denoted by the same reference numerals and wherein: FIG 1 is a view showing the structure of a vehicle tampering detection system according to the invention; FIG 2 is a view showing an example of a state in which wiring harnesses 21, 22 and 23 are tied together in a bundle within a cover 20A in such a manner that the wiring harnesses 21, 22 and 23 are not visually distinguished from each other; FIG 3 is a view showing the structure of a vehicle tampering detection system 100 according to a first embodiment of the invention; FIG 4 is a view showing the structure of a vehicle tampering detection system 200 according to a second embodiment of the invention; FIG 5 is a view showing the structure of a vehicle tampering detection system 300 according to a third embodiment of the invention; and FIGs. 6A to 6D are views showing examples of the basic structure of a tampering detection system that detects tampering with a vehicle.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0014] Hereafter, example embodiments of the invention will be described with reference to the accompanying drawings. FIG 1 is a view shàwing the structure of a vehicle tampering detection system according to the invention. The vehicle tampering detection system in FIG 1 includes an on-off switch 13 that is mounted in a vehicle, a wiring harness 21 that connects a terminal 13a of the on-off switch 13 to a current source, a wiring harness 22 that is connected to a terminal 13b of the on-off switch 13, a wiring harness 23 that is connected to a current source, a tampering determination unit 11 that is the current source which sends an electric current to the wiring harness 21 and that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 21, and a tampering determination unit 12 that is the current source which sends an electric current to the wiring harness 23 and that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 23.

[0015] The on-off switch 13 is, for example, a courtesy switch that is used to determine whether an openable body provided in the vehicle is open. Examples of the openable body include a bonnet (hood), a side door, a rear door, a boot lid, a sliding roof, a roof, a slide door, and a fuel lid. The openable body opens and closes in response of an operation performed by a person or based on a signal that indicates the operation.

[0016] When the openable body is opened, the on-off switch 13 is turned on. When the openable body is closed, the on-off switch 13 is turned off. When the openable body is kept open, the on-off switch 13 is kept on. When the openable body is kept closed, the on-off switch 13 is kept off. FIG 1 shows the state in which the on-off switch 13 is off.

[0017] The terminals 13a and 13b are provided in the on-off switch 13 and serve as connection portions to which the wiring harnesses are electrically connected. The terminals 13a and 13b are electrically connected to each other when the on-off switch 13 is on, and electrically disconnected from each other when the on-off switch 13 is off.

[0018] The wiring harness 21 connects the tampering determination unit 11, which is the current source, and the terminal 13a of the on-off switch 13 to each other. An electric current from the tampering determination unit 11 passes through the wiring harness 21. The wiring harness 22 connects the terminal 13b of the on-off switch 13 to the ground. An electric current from the on-off switch 13, which is on, passes through the wiring harness 22. The wiring harness 23 connects the tampering determination unit 12, which serves as the current source, to the ground. An electric current from the tampering determination unit 12 passes through the wiring harness 23.

[0019] The tampering determination unit 11 includes, for example, a source circuit that has first current detection means. The first current detection means detects a current value of the electric current that passes through the wiring harness 21 and a change in the current value with the use of a resistance arranged between and in series with a constant-voltage source and the wiring harness 21. When the tampering determination unit 11 determines that the electric current that passes through the wiring harness 21 is equal to or higher than a predetermined first current threshold value (for example, a value that is slightly higher than zero), the tampering determination unit 11 may determine that the on-off switch 13 is turned on. When the tampering detennination unit 11 determines that the electric current that passes through the wiring harness 21 is equal to or lower than a predetermined second current threshold value (for example, zero or a value that is slightly higher than zero), the tampering determination unit 11 may determine that the on-off switch is turned off.

[0020] When the tampering determination unit 11 is placed in the tampering detection mode, in which the tampering detection function is activated, while the on-off switch 13 is off (that is, while the openable body is closed), if the state of electric current that passes through the wiring harness 21 changes from the state of electric current that passes through the wiring harness 21 when the on-off switch 13 is off, the tampering determination unit 11 determines that the vehicle is tampered with. That is, if the state of electric current that passes through the wiring harness 21 is changed when the openable body is closed and the tampering determination unit 11 is placed in the tampering detection mode, the tampering determination unit 11 determines that the change occurs because the vehicle is tampered with.

[0021] For example, when the openable body is closed and the tampering determination unit 11 is placed in the tampering detection mode, if the electric current that passes through the wiring harness 21 becomes higher than the electric current that passes through the wiring harness 21 when the on-off switch 13 is off (higher than zero, when electric loads other than an electric load shown in FIG 1 are not connected to the wiring harness 21), the tampering determination unit 11 determines that the on-off switch 13 is turned on and the vehicle is tampered with by opening the openable body. When the openable body is closed and the tampering determination unit 11 is placed in the tampering detection mode, if the electric current that passes through the wiring harness 21 becomes higher than the electric current that passes through the wiring harness 21 when the on-off switch 13 is off, the tampering determination unit 11 may determine that the vehicle is tampered with by causing electric leakage from the wiring harness 21 (for example, the vehicle is tampered with by short-circuiting the wiring harness 21 to the ground).

[0022] The tampering determination unit 12 includes, for example, a source circuit that has second current detection means. The second current detection means detects a current value of the electric current that passes through the wiring harness 23 and a change in the current value using a resistance that is arranged between and in series with a constant voltage source and the wiring harness 23. When the tampering determination unit 12 determines that the electric current that passes through the wiring harness 23 becomes equal to or lower than a predetermined third current threshold value (for example, zero or a value that is slightly higher than zero), the tampering determination unit 12 may determine that the wiring harness 23 is broken.

[0023J When the tampering determination unit 12 is placed in the tampering detection mode, in which the tampering detection function is activated, while the on-off switch 13 is off (that is, while the openable body is closed), if the state of electric current that passes through the wiring harness 23 changes from the state of electric current that passes through the wiring harness 23 in the normal state, the tampering determination unit 11 determines that the vehicle is tampered with. That is, if the state of electric current that passes through the wiring harness 23 is changed when the openable body is closed and the tampering determination unit 12 is placed in the tampering detection mode, the tampering determination unit 12 determines that the change occurs because the vehicle is tampered with.

[0024] For example, when the openable body is closed and the tampering determination unit 12 is placed in the tampering detection mode, if the electric current that passes through the wiring harness 23 becomes lower than the electric current that passes through the wiring harness 23 in the normal state in which a constant electric current flows, the tampering determination unit 12 determines that the vehicle is tampered with by breaking the wiring harness 23.

[0025] The wiring harness 21, the wiring harness 22 and the wiring harness 23 are tied together in a bundle within a section 20 in such a manner that these wiring harnesses 21, 22 and 23 are not visually distinguished from each other. That is, it is not possible to visually distinguish a certain wiring harness from the other wiring harnesses among the wiring harnesses tied together in a bundle. For example, if multiple wiring harnesses are twisted together into a bundle, like a twist pair, it difficult to visually identify each wiring harness.

[0026] FIG 2 is a view showing an example in which the wiring harnesses 21, 22 and 23 are tied together in a bundle within a cover 20A so that these wiring harnesses 21, 22 and 23 cannot be visually distinguished from each other. The portions of the wiring harnesses 21, 22 and 23, which are within the section 20 in FIG 1, are covered with the cover 20A. Examples of the cover 20A include a tape, a corrugated tube, a sumi-tube, a nishi-tube, and a spiral tube. An opaque cover is better than a transparent cover as the cover 20A, because using an opaque cover makes it more difficult to distinguish the multiple wiring harnesses tied together in a bundle from each other. When a tape is used as the cover 20A, the tape is wound around the wiring harnesses 21, 22 and 23 so that these wiring harnesses 21, 22 and 23 are not visually distinguished from each other from the outside. When a tube is used as the cover 20A, the wiring harnesses 21, 22 and 23 are covered with the tube so that these wiring harnesses 21, 22 and 23 are not visually distinguished from each other from the outside. Covering the wiring harnesses 21, 22 and 23 with a tape or a tube makes it difficult todistinguish the multiple wiring harnesses from each other and makes it easier to tie the multiple wiring harnesses together in a bundle.

[0027] Tying the wiring harnesses 21, 22 and 23 that are the same in color together in a bundle makes it difficult to distinguish these wiring harnesses from each other.

Covering the, multiple wiring harnesses that are the same in color with the cover 20A shown in FIG 2 makes it more difficult to distinguish these wiring harnesses from each other.

[00281 Because the section 20, in which the wiring harnesses 21, 22 and 23 are tied together in a bundle so that the wiring harnesses 21, 22 and 23 are not distinguished from each other, is formed as described above, even if an attempt to tamper with the wiring harness is made, for example, an attempt to short-circuit the wiring harness to the ground or an attempt to break the wiring harness is made, such an attempt is detected.

Therefore, the antithelt function is not deactivated. As a result, it is possible to reliably prevent tampering with the vehicle such as tampering with the wiring harness and illicit opening of the openable body. That is, because the wiring harnesses that are different in routing destination are tied together in a bundle as shown in FIG 2, it is not possible to identify each wiring harness. Therefore, even if an attempt to deactivate the antitheft function is made, tampering with the wiring harness is discouraged.

[0029] For example, if a wiring harness is cut off at a portion within the cover 20A in FIG 2, which of the wiring harnesses 21, 22 and 23 is cut off is not predicted.

Therefore, if the wiring harness that is cut off at a portion within the cover 20A is the wiring harness 23, the tampering determination unit 12 detects a change in the electric current, and determines that the wiring harness 23 is tampered with (Cut off).

[0030] Similarly, if a wiring harness is short-circuited to the ground at a portion within the Cover 20A, which of the wiring harnesses 21, 22 and 23 is short-circuited to the ground is not predicted. Therefore, if the wiring harness that is short-circuited to the ground at a portion within the cover 20A is the wiring harness 21, the tampering determination unit 12 detects a change in the electric current and determines that the vehicle is tampered with. As a matter of course, even if the switch 13 is turned on due to illicit opening of the openable body when the tampering determination unit 11 is placed in the tampering detection mode, the tampering detennination unit 11 detects a change in the electric current and determines that the vehicle is tampered with.

[0031] FJXI 2 shows an example in which three wiring harnesses 21, 22 and 3, which extend without being looped, are tied together in a bundle in such a manner that these wiring harnesses 21, 22 and 23 are not distinguished from each other.

Alternatively, the wiring harnesses 21, 22 and 23 may be tied together in a bundle within the cover 20A while at least one of the wiring harnesses 21, 22 and 23 is looped so that the wiring harnesses 21, 22 and 23 are not distinguished from each other. It is more difficult to distinguish these wiring harnesses 21, 22 and 23 from each other in this case than in the case where non of the wiring harnesses 21, 22 and 23 is looped within the cover 20A. For example, the wiring harness 23 may be looped once within the cover 20A, that is, four wiring harnesses may be tied together in a bundle within the cover 20A, so that the wiring harnesses are not distinguished from each other. The wiring harness may be looped within the cover 20A once. Alternatively, the wiring harness may be looped within the cover 20A twice or more.

[0032] Vehicle tampering detection systems according to the example embodiments of the invention will be described below. These vehicle tampering detection systems have the configurations described above. In the example embodiments of the invention described below, the same configurations as those in the above description will be denoted by the same reference numerals as those used in the above description, and

description thereof will be omitted or simplified.

[0033] FIG 3 is a view showing the structure of a vehicle tampering detection system 100 according to a first embodiment of the invention. The vehicle tampering detection system 100 includes a security electronic control unit (ECU) 10 that includes the tampering determination units 11 and 12 that are able to detect illicit opening of a bonnet (hood) that covers the space in which a vehicle engine is housed. The electronic control unit 10 controls the tampering determination units 11 and 12 with the use of a microcomputer 14. The ECU 10 is provided in such a location that the ECU 10 is neither reached nor seen from the outside of, for example, a vehicle compartment. More specifically, the ECU 10 is provided below a seat or in a console. The on-off switch 13 corresponds to a hood courtesy switch. The hood courtesy switch 13 that is used to determine whether the hood is open is provided in an engine room in such a manner that the hood courtesy switch 13 is not seen from the outside of the vehicle when the hood is closed.

[0034] The vehicle tampering detection system 100 includes the hood courtesy switch 13, the wiring harness 21 (21a, 21b) that connects the terminal 13a of the hood courtesy switch 13 to the ECU 10, the wiring harness 22 (22a, 22b) that is connected to the terminal 13b of the hood courtesy switch 13, the wiring harness 23 (23a, 23b, 23c) that is connected to the ECU 10, and the ECU 10 that is the current source. The ECU 10 includes the tampering determination unit 11 that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 21 connected to the terminal lOa, and the tampering determination unit 12 that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 23 connected to the terminal lOb.

In addition, the wiring harness 21, the wiring harness 22, and the wiring harness 23 are tied together in a bundle within the section 20 so that these wiring harnesses 21, 22 and 23 are not distinguished from each other.

[0035) The ECU 10 and the hood courtesy switch 13 are arranged in such a manner that the Section 20 is interposed between the ECU 10 and the hood courtesy switch 13.

On one side of the section 20 (on the left side of the section 20 in FIG 3), the ECU 10 to which the wiring harnesses 21 and 23 are connected is provided. On the other side of the section 20 (on the right side of the section 20 in FIG 3), the hood courtesy switch 13 is provided.

[0036] When a vehicle wiring harness-side connector 31 and a courtesy switch-side connector 32 are connected to each other, the wiring harnesses routed from the vehicle compartment side (hereinafter, referred to as "vehicle compartment-side harnesses") and the wiring harnesses routed from the engine room side (hereinafter, referred to as "switch-side harnesses") are electrically connected to each other. The vehicle compartment-side harnesses include the wiring harness 21a electrically connected to the tampering determination unit 11 via the terminal lOa of the ECU 10, the wiring harness 23a electrically connected to the tampering determination unit 12 via the terminal lOb of the ECU 10, the wiring harness 23c connected to the ground, and the wiring harness 22b connected to the ground. The switch-side harnesses include the wiring harness 21b that connects the wiring harness 21a and the terminal 13a to each other, the wiring harness 22a that connects the wiring harness 22b and the terminal 13b to each other, and the wiring harness 23b that connects the wiring harness 23a and the wiring harness 23c to each other. When the connectors 31 and 32 are connected to each other, the wiring harnesses are connected to each other, as shown in FIG 3.

[00371 The upstream-side end portion of the wiring harness 23 is connected to the tampering determination unit 12 that is on the current source side (upstream side). The wiring harness 23 connected to the tampering determination unit 12 is looped once within the section 20 and then connected to the ground. If the wiring harness 23 is looped once, the downstream-side end portion of the wiring harness 23 that extends from the tampering determination unit 12 on the upstream side may be positioned on the upstream side on which the upstream-side tampering determination unit 12 is arranged, not on the side on which the courtesy switch 13 is arranged. If the position at which the downstream-side end portion of the wiring harness 23 is connected to the ground is on the side on which the courtesy switch 13 is arranged, the other wiring harnesses 21 and 22 are more easily identified using the wiring harness 23 that is connected to the ground as a clue. Especially, the wiring harness is more easily accessed and seen from the outside of the vehicle body and therefore the wiring harness is more easily identified when the downstream-end portion of the wiring harness 23 is connected to the ground at a position on the engine room side on which the courtesy switch 13 is arranged, than when the downstream-end portion of the wiring harness 23 is connected to the ground at a position on the vehicle compartment side. Accordingly, as described above, if the wiring harness is looped once, the wiring harness is less prone to be identified.

[0038] FIG 4 is a view showing the structure of a vehicle tampering detection system 200 according to a second embodiment of the invention. The same portions as those in FIG 3 will not be described below. The downstream-side end portion of the wiring harness 23 is electrically connected to the wiring harness 22 (switch-side hariiess 22a which is accessed more easily) and then connected to the ground. With the structure in FIG 4, it is possible to ensure the above-described security function according to the invention, and to make the volume of the required wiring harnesses smaller than that in FIG 3.

[0039] FIG 5 is a view showing the structure of a vehicle tampering detection system 300 according to a third embodiment of the invention.

[0040] The vehicle tampering detection system 300 includes the hood courtesy switch 13, the wiring harness 21 (21a, 21b) that connects the terminal 13a of the hood courtesy switch 13 and a current source 30 to each other, the wiring harness 22 (22a, 22b) that is connected to the terminal 13b of the hood courtesy switch 13, the wiring harness 23 (23a, 23b, 23c) connected to the current source 30, and the ECU 10 arranged downstream of the current source 30. The ECU 10 includes the tampering determination unit 11 that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 22, and the tampering determination unit 12 that determines whether the vehicle is tampered with based on a change in the state of electric current that passes through the wiring harness 23.

The wiring harness 21, the wiring harness 22 and the wiring harness 23 are tied together in a bundle within the section 20.

[00411 The tampering determination unit 11 includes, for example, a sink circuit that has third current detection means. The third current detection means detects a current value of the electric current that passes through the wiring harness 22 and a change in the current value with the use of a resistance that is interposed between and in series with the ground and the wiring harness 22. As in the case of the source circuit described above, the third current detection means determines whether the on-off switch 13 is on by comparing the electric current that passes through the wiring harness 22 and the electric current threshold value with each other. As in the case of the source circuit described above, the tampering determination unit 11 determines whether the vehicle is tampered with.

GO42] The tampering determination unit 12 includes, for example, a sink circuit'that has fourth current detection means. The fourth current detection means detects a current value of the electric current that passes through the wiring harness 23 and a change in the current value with the use of a resistance that is interposed between and in series with the ground and the wiring harness 23. As in the case of the source circuit described above, the fourth current detection means determines whether the wiring harness 23 is broken by comparing the electric current that passes through the wiring harness 23 and the electric current threshold value with each other. As in the case of the source circuit described above, the tampering determination unit 11 determines whether the vehicle is tampered with.

[0043] The upstream-side end portion of the wiring harness 23 is connected to the current source 30 that is on the vehicle compartment side. The wiring harness 23 connected to the current source 30 is looped once within the section 20 and then connected to the ECU 10 on the downstream side. When the wiring harness 23 is looped once, the downstream-side end portion of the wiring harness 23 that extends from the current source 30 may be positioned on the downstream side on which the upstream-side tampering determination unit 12 is arranged, not on the side on which the courtesy switch 13 is arranged. That is, as in the case described above, if the wiring harness 23 is looped once within the section 20, the wiring harness is less prone to be identified.

[0044] According to the embodiments of the invention described above, it is possible to reliably detect illicit actions taken on the vehicle including tampering with the wiring harness. As a result, it is possible to enhance the antitheft function. There is a space in an engine room. Therefore, a wiring harness in the engine room is easily accessed from the outside of the vehicle body. Accordingly, measures need to be taken to hide the wiring harness, for example, a steel plate needs to be provided to hide the wiring harness.

However, with the structures described above, it is possible to eliminate or reduce the work for providing or processing a steel plate used to hide a wiring harness. If, for example, a steel plate used to hide the wiring harness is no longer necessary, the vehicle weight is reduced. As a matter of course, if such a steel plate is provided, the antitheft function is further enhanced.

[0045] While the invention has been described with reference to example embodiments thereof, it is to be understood that the invention is not limited to the example embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements within the scope of the invention.

[0046] For example, electric currents are supplied to the two wiring harnesses 21 and 23 from the common current source. Alternatively, electric currents may be supplied to the two wiring harnesses 21 and 23 from different current sources. These current sources may be provided at different locations. In the embodiments of the invention described above, the tampering determination units 11 and 12 are embedded in the ECU 10. Alternatively, the tampering determination units 11 and 12 may be provided in another location.

Claims

CLAIMS: 1. A vehicle tampering detection system, characterized by comprising: an on-off switch (13) which is provided in a vehicle, an on-off state of which is changed in response to a certain action taken on the vehicle, and which includes a first connection portion (13a) and a second connection portion (13b) that are electrically connected to each other when the on-off switch (13) is on and that are electrically disconnected from each other when the on-off switch (13) is off; a first wiring harness (21) that connects the first connection portion (13a) to a current source; a second wiring harness (22) that is connected to the second connection portion (13 b); a third wiring harness (23) that is connected to the current source; first determination means (11) for determining that the vehicle is tampered with if a state of an electric current that passes through the first wiring harness (21) changes from the state of the electric current that passes through the first wiring harness (21) when the on-off switch (13) is off, and/or for determining that the vehicle is tampered with if a state of an electric current that passes through the second wiring harness (22) changes from the state of the electric current that passes through the second wiring harness (22) when the on-off switch (13) is off; and second determination means (12) for detennining that the vehicle is tampered with if a state of an electric current that passes through the third wiring harness (23) changes from the state of the electric current that passes through the third wiring harness (23) in a normal state, wherein there is formed a section (20) in which the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are tied together in a bundle in such a manner that the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are not distinguished from each other.
2. The vehicle tampering detection system according to claim 1, wherein the current source that is connected to the first wiring harness (21) and the current source that is connected to the third wiring harness (23) are arranged on a side of one end of the section (20), and the on-off switch (13) is arranged on a side of the other end of the section (20).
3. The vehicle tampering detection system according to claim 1 or 2, wherein the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are twisted with each other.
4. The vehicle tampering detection system according to any one of claims 1 to 3, wherein the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are tied together in a bundle while at least one of the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) is looped at least once within the section (20).
5. The vehicle tampering detection system according to claim 4, wherein the wiring harness that is looped within the section (20) is the third wiring harness (23).
6. The vehicle tampering detection system according to any one of claims 1 to 5, wherein the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are tied together in a bundle and covered with a cover (20A) within the section (20).
7. The vehicle tampering detection system according to claim 6, wherein the cover (20A) is opaque.
8. The vehicle tampering detection system according to any one of claims 1 to 7, wherein the first wiring harness (21), the second wiring harness (22) and the third wiring harness (23) are the same in color.
9. The vehicle tampering detection system according to any one of claims 1 to 8, wherein the first determination means (11) and the second determination means (12) each have a source circuit.
10. The vehicle tampering detection system according to any one of claims 1 to 8, wherein the first determination means (11) and the second determination means (12) each have a sink circuit.
11. The vehicle tampering detection system according to any one of claims 1 to 10, wherein: the certain action is opening of an openable body provided in the vehicle; and the on-off staie of the on-off switch (13) is changed by the opening of the openable body.
12. The vehicle tampering detection system according to claim 11, wherein the openable body is a bonnet.