Self-diagnosis apparatus for vehicle

• US 5,590,040 A
• Filed: 08/17/1993
• Issued: 12/31/1996
• Est. Priority Date: 08/19/1992
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Takaba, Katsumi, Abe, Takahide
• Primary Examiner(s): Chin, Gary
• Assistant Examiner(s): Walker, Tyrone V.
• Application Number:
  US08/107,154
• Time in Patent Office: 1,232 Days
• Field of Search: 364/424.04, 364/424.03, 364/550, 364/551.01, 340/438, 340/439, 340/459, 340/635, 73/117.3, 377/13, 377/15, 377/16
• US Class Current: 701/35
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A self-diagnosis apparatus for vehicle capable of storing sufficient data useful for abnormality diagnosis includes a control unit having a CPU and RAM which can hold its stored contents even at the time of cut-off of an ignition key. The CPU receives diagnosis data necessary for analysis of the abnormality of an equipment at each predetermined period and judges whether or not the value of the diagnosis data exists in a predetermined region, in order to count up a counter of a predetermined storage region beforehand provided in the RAM corresponding to the judged region. The counting-up is stopped when the abnormality of an equipment is detected. In contrast with a method in which the value of diagnosis data is stored into the RAM as it is, the range of change of a lot of diagnosis data until the generation of abnormality can be stored with a small memory size.

Claims

1. A self-diagnosis apparatus for a vehicle for detecting and storing data of vehicle conditions, detecting a possible abnormality of equipment mounted on the vehicle, and for outputting stored data for diagnosis of the possible abnormality, said apparatus comprising:

a plurality of sensors each for detecting and outputting, during operation of equipment mounted on the vehicle, a value of a respective ones of predetermined parameters representative of vehicle operating conditions;

means for dividing a predetermined region of output values of each of said sensors into a plurality of subregions;

means for determining into which of said subregions values of each of the parameters output by the sensors fall;

memory means for storing data and for updating the stored data, said memory means including a plurality of storage regions corresponding in number to said subregions, each of said storage regions storing therein a period of time during which values of the parameters are in the subregion corresponding to the storage region, as determined by said determining means;

abnormality detecting means for detecting an abnormality of equipment; and

fixing means for causing said memory means to fixedly store data of said memory means when an abnormality is detected by said abnormality detecting means.

2. A self-diagnosis apparatus for a vehicle according to claim 1 wherein said condition detection means includes a plurality of sensors.

3. A self-diagnosis apparatus for a vehicle according to claim 1, wherein said memory means includes an abnormality storage region for storing the presence/absence of generation of an abnormality, and said fixing means includes setting means for storing the generation of an abnormality into said abnormality storage region when an abnormality is detected by said abnormality detecting means and inhibiting means for inhibiting the storage of said information into said memory means by judging whether the generation of an abnormality is stored in said abnormality storage region.

4. An apparatus according to claim 1, wherein said memory means comprises back-up RAMs.

5. An apparatus according to claim 1, wherein said each storage region stores the data of the length of time by additively storing data of the number of times values of the parameter fall within the corresponding subregion.

6. An apparatus according to claim 1, further including means for determining a trip period of the vehicle, wherein said memory means comprises a plurality of storage blocks each comprising said plurality of storage regions and storing data of time in current and past trip periods respectively.

7. A self-diagnosis apparatus for a vehicle according to claim 6, wherein said trip corresponds to one running period of the vehicle.

8. A self-diagnosis apparatus for a vehicle according to claim 7, wherein said trip corresponds to a period of time from the operation of an ignition switch of the vehicle into a turn-on position to the operation thereof into a turn-off position.

9. A self-diagnosis apparatus for a vehicle for detecting a possible abnormality of at least one equipment mounted on the vehicle, storing a vehicle condition at the time of generation of the possible abnormality and outputting the vehicle condition, said apparatus comprising:

vehicle condition detecting means for detecting, during operation of equipment mounted on the vehicle, a vehicle condition necessary for analyzing an abnormality of said equipment;

means for determining time duration periods during which said condition detecting means detects vehicle operation conditions to be in each of a plurality of predetermined operation regions in order to produce respective time information of said determined periods;

storage means including storage regions corresponding to said operation regions, each for storing therein a cumulative value of the respective time information, said storage means, connected to a battery mounted on the vehicle, being capable of holding the stored information in an off state of an ignition switch;

abnormality detecting means for detecting the abnormality of equipment mounted on the vehicle; and

fixing means for fixing information stored in said storing means when an abnormality of the equipment mounted on the vehicle is detected by said abnormality detecting means.

10. A self-diagnosis apparatus for a vehicle for detecting and storing data of vehicle conditions, detecting a possible abnormality of equipment mounted on the vehicle, and for outputting stored data for diagnosis of the possible abnormality, said apparatus comprising:

detection means for detecting, over a plurality of time periods during operation of equipment mounted on the vehicle, a value of at least one parameter representative of a vehicle condition necessary for diagnosis of an abnormality of said equipment;

means for dividing a predetermined region of values of the at least one parameter into a plurality of subregions;

measuring means for determining, during each of said time periods, a one of said plurality of subregions corresponding to the value of said parameter as detected by said detection means;

memory means for storing data and for updating the stored data, said memory means including a plurality of storage regions corresponding in number to said subregions, each of said storage regions storing therein a cumulative value of the number of time periods during which the value of the parameter is in the subregion corresponding to the storage region, as determined by said measuring means;

abnormality detecting means for detecting an abnormality of equipment; and

fixing means for causing said memory means to fixedly store data of said memory means when an abnormality is detected by said abnormality detecting means,

wherein said measuring means includes means for counting time periods during which said detection means detects a value of the parameter in the respective subregions.

11. A self-diagnosis apparatus for a vehicle for detecting and storing data of vehicle conditions, detecting a possible abnormality of equipment mounted on the vehicle, and for outputting stored data for diagnosis of the possible abnormality, said apparatus comprising:

a plurality of sensors each for detecting and outputting, during operation of equipment mounted on the vehicle, a value of a respective ones of predetermined parameters representative of vehicle operating conditions, said predetermined parameters including at least one of engine rotation speed, vehicle speed and throttle opening degree;

means for dividing a predetermined region of output values of each of said sensors into a plurality of subregions;

means for determining into which of said subregions values of the parameter of each said sensor fall;

memory means for storing data and for updating the stored data, said memory means including a plurality of storage regions corresponding in number to said subregions, each of said storage regions storing therein a period of time during which values of the parameters are in the subregion corresponding to the storage region, as determined by said determining means;

abnormality detecting means for detecting an abnormality of equipment; and

fixing means for causing said memory means to fixedly store data of said memory means when an abnormality is detected by said abnormality detecting means.

12. A self-diagnosis apparatus for a vehicle for detecting and storing data of vehicle conditions, detecting an abnormality of equipment mounted on the vehicle, and for outputting stored data for diagnosis of the detected abnormality, said apparatus comprising:

detection means for detecting, during operation of equipment mounted on the vehicle, a value of at least one parameter representative of a vehicle condition necessary for diagnosis of an abnormality of said equipment;

means for dividing a predetermined region of values of the at least one parameter into a plurality of subregions;

means for determining into which of said subregions values of the parameter fall within;

memory means for storing data and for updating the stored data for each trip of said vehicle, said memory means including a plurality of storage regions corresponding in number to said subregions, each of said storage regions storing therein on a real time basis a length of time during which values of the parameters are in the subregion corresponding to the storage region, as determined by said determining means;

abnormality detecting means for detecting an abnormality of equipment; and

fixing means for causing said memory means to fixedly store data of said memory means when an abnormality is detected by said abnormality detecting means.