Vehicle anti-theft device having back-up means should the ECU fail, but preventing theft if the ECU was intentionally damaged

• US 5,561,332 A
• Filed: 06/07/1995
• Issued: 10/01/1996
• Est. Priority Date: 06/10/1994
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Udo, Hiroshi, Kobayashi, Sadao, Funakoshi, Hiroshi
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Elms, Richard T.
• Application Number:
  US08/487,328
• Time in Patent Office: 482 Days
• Field of Search: 307/9.1-10.6, 180/287, 123/198 DB, 123/198 DC, 123/198 B, 340/426, 340/441, 340/825.32, 340/825.34, 340/825.69, 340/825.72, 364/424.01, 364/424.05
• US Class Current: 307/10.5
• CPC Class Codes: B60R 25/04 operating on the propulsion system, e.g. engine or drive motor
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user

Abstract

This invention relates to an anti-theft device for an engine-driven vehicle having a control unit for controlling either of the supply of fuel to an engine and the ignition timing of this fuel, and a back-up mechanism acting for the control unit when the control unit is damaged. It is determined whether or not the control unit has functioned appropriately when the engine is started up, and if it is determined that it has not, the function of the back-up mechanism is prohibited. Hence, the engine will not start and theft of the vehicle is prevented even if, for example, the control unit is deliberately damaged and an attempt is made to start the engine. However, the back-up mechanism does function if the control unit develops a fault while the vehicle is running, and the vehicle therefore continues to run.

Claims

1. An anti-theft device for an engine-driven vehicle comprising:

a control unit for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel,

back-up means acting for said control unit when said control unit is damaged,

means for determining whether or not said control unit has functioned appropriately when said engine is started up, and

means for prohibiting the function of said back-up means when said control unit has not functioned appropriately when said engine is started up.

2. An anti-theft device for an engine-driven vehicle comprising:

a control unit for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel,

back-up means acting for said control unit when said control unit is damaged,

first means for storing an identifying code provided inside said control unit,

second means for storing an identifying code, said second means provided outside said control unit,

means for verifying whether or not said identifying codes stored in said first and second storing means are identical when said engine is started up,

means for preventing engine start-up when said identifying codes are not identical,

means for retaining a verification result of whether or not said identifying codes are identical, and

means for prohibiting a function of said back-up means when said verification result shows said identifying codes are not identical.

3. An anti-theft device as defined in claim 2, wherein said retaining means comprises means for coding said verification result, means for decoding said code, and means for retaining said decoded result.

4. An anti-theft device as defined in claim 3, wherein said code decoding means, said decoded result retaining means and said prohibiting means are formed in a one-piece construction with said back-up means.

5. An anti-theft device as defined in claim 2, wherein said retaining means retains a verification result also after said engine stops.

6. An anti-theft device for an engine-driven vehicle comprising:

a starter means for starting said engine,

a control unit for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel,

back-up means acting for said control unit when said control unit is damaged,

means for detecting a rotation of said engine,

means for detecting whether or not said starter means is operating,

means for prohibiting a function of said back-up means when said rotation is not detected, and

means for prohibiting the function of said backup means while said starter means is operating.

7. An anti-theft device for an engine-driven vehicle comprising:

a starter means for starting said engine,

a control unit for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel by outputting a control signal,

means for outputting a rotation signal corresponding to a predetermined rotation angle of said engine,

back-up means for outputting a control signal based on said rotation signal when said control unit is damaged for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel,

first means for storing an identifying code provided inside said control unit,

second means for storing an identifying code, said second means provided outside said control unit,

means for verifying whether or not said identifying codes stored in said first and second storing means are identical when said engine is started up,

means for preventing engine start-up when said identifying codes are not identical,

means for detecting whether or not said starter means is operating,

means for prohibiting a function of said back-up means when said rotation signal is not detected, and

means for prohibiting the function of said back-up means while said starter means is operating.

8. An anti-theft device as defined in claim 7, wherein said starter means operation detecting means comprises a starter switch for continuously outputting an ON signal while said starter means is operating, said two prohibiting means comprise a NOT circuit for inverting the output signal from said starter switch and an AND circuit for outputting a signal corresponding to an overlapping part of said inverted signal and said rotation signal, and said back-up means functions according to the output signal from said AND circuit.

9. An anti-theft device as defined in claim 7, wherein said starter means operation detecting means comprises a starter switch for continuously outputting an ON signal while said starter means is operating, said two prohibiting means comprise a NOT circuit for inverting the output signal from said starter switch, and an AND circuit for outputting a signal corresponding to an overlapping part of the signal output by said back-up means and the signal output by said NOT circuit as said control signal.

10. An anti-theft device for an engine-driven vehicle comprising:

a starter means for starting said engine,

means for supplying fuel to said engine according to an input injection signal,

means for igniting said fuel inside said engine according to an input ignition signal,

a control unit for controlling at least one of either said fuel supplying means or igniting means by outputting a control signal,

means for outputting a rotation signal corresponding to a predetermined rotation angle of said engine,

back-up means for outputting a control signal based on said rotation signal when said control unit is damaged for controlling at least one of either said fuel supplying means or igniting means,

first means for storing an identifying code provided inside said control unit,

second means for storing an identifying code, said second means provided outside said control unit,

means for verifying whether or not said identifying codes stored in said first and second storing means are identical when said engine is started up,

means for preventing engine start-up when said identifying codes are not identical,

means for detecting whether or not said starter means is operating,

means for prohibiting a function of said back-up means when said rotation signal is not detected, and

means for prohibiting the function of said back-up means while said starter means is operating.

11. An anti-theft device for an engine-driven vehicle comprising:

a starter means for starting said engine,

a control unit for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel by outputting a control signal,

an ignition switch for activating said control unit when said switch is changed over from OFF to ON,

means for outputting a rotation signal corresponding to a predetermined rotation angle of said engine,

back-up means for outputting a control signal based on said rotation signal when said control unit is damaged for controlling at least one of either a supply of fuel to said engine or an ignition timing of said fuel,

means for detecting whether or not said ignition switch has been changed over from OFF to ON,

means for prohibiting engine start-up when said ignition switch has been change over from OFF to ON,

first means for storing an identifying code provided inside said control unit,

second means for storing an identifying code, said second means provided outside said control unit,

means for verifying whether or not said identifying codes stored in said first and second storing means are identical when said ignition switch is changed over from OFF to ON,

means for releasing prohibition of engine start-up by said prohibiting means when said identifying codes are identical,

means for detecting whether or not said starter means is operating,

means for prohibiting a function of said back-up means when said rotation signal is not detected, and

means for prohibiting the function if said back-up means while said starter means is operating.