Boots – shoes – and leggings
Patent
1994-04-07
1996-04-09
Chin, Gary
Boots, shoes, and leggings
36442404, 36443101, 36455101, 340438, F02D 4500
Patent
active
055067735
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a self-diagnosing apparatus for motor vehicles which stores diagnostic data necessary for analyzing malfunctions of instruments installed in such motor vehicle.
BACKGROUND ART
At the present time the construction of motor vehicles has become remarkably electronic. Instruments, including, among other things, the engine, installed in each section of a motor vehicle are interconnected via a control computer so that complex operations can be performed.
In such a case, even if a malfunction of a certain single installed instrument is detected, often the true cause cannot be determined because of the interrelationship with other installed instruments unless a wide range of data (diagnostic data) indicating the state of the motor vehicle at the time the malfunction is detected is collected. Also, after a temporary malfunction, there is a possibility that the malfunction will be corrected naturally. Further, often this temporary malfunction is a sign that a complete failure will occur; however, it is quite difficult to find the cause thereof by performing an inspection after getting out of the motor vehicle.
Accordingly, a self-diagnosing apparatus is proposed in Japanese Patent Laid-Open No. 62-142849, in which diagnostic data from each section of a motor vehicle is updated and stored in a memory where the contents are stored at specified intervals even when the power supply is shut down; updating of the contents of the memory being inhibited (frozen) after a malfunction of the installed instrument is detected, so that the cause of the malfunction can be determined accurately after getting out of the motor vehicle.
An apparatus is proposed in Japanese Patent Laid-Open No. 3-92564, in which control programs in addition to the diagnostic data are stored in the memory in order to determine the cause of a malfunction more accurately.
In the above-described conventional apparatuses, since the above-mentioned diagnostic data is stored by a microcomputer operation, it takes some time, though slight, from when a malfunction is detected until data is frozen. If the ignition switch is turned off between the time of malfunction detection and freezing the data, the microcomputer stops its processing, and the diagnostic data obtained before the ignition switch has been turned off is not frozen. Therefore, the diagnostic data is reset to an initial state when the ignition switch is turned on again to start the control program, making it impossible to analyze the malfunction, which is problematical. Also, if the diagnostic data obtained when a malfunction is detected again after the ignition switch is turned on again is frozen despite the first detection of the malfunction before the ignition switch has been turned off, diagnostic data (data obtained when the ignition switch is turned on again) different from that when the first malfunction has occurred, will be output. As a result, there is a risk that the cause of the malfunction will be analyzed erroneously, or it will become impossible to investigate the cause of the malfunction.
In the above-described conventional apparatuses, the diagnostic data is stored and updated in the memory at regular intervals up to the time a malfunction occurs. This storing and updating becomes a burden depending upon the computing speed of the CPU, and it is conceivable that the diagnostic data is stored and frozen only after the occurrence of the malfunction is detected.
However, there is a problem in that if the ignition switch is turned off during the time from when the malfunction is detected until when all the diagnostic data is completely stored, since non-updated erroneous data remains, new and old data are present when the diagnostic data is output, causing an erroneous analysis of the malfunction. To prevent this erroneous analysis, it is conceivable that a main relay for supplying power to the CPU for some time after the ignition switch has been turned off is disposed. This results in increased cost because of the addition of hardwa
REFERENCES:
patent: 4307455 (1981-12-01), Juhasz et al.
patent: 4635214 (1987-01-01), Kasai et al.
patent: 5173856 (1992-12-01), Purnell et al.
patent: 5191529 (1993-03-01), Ramsey et al.
patent: 5227766 (1993-07-01), Endo
patent: 5276619 (1994-01-01), Ohara et al.
patent: 5388045 (1995-02-01), Kamiya et al.
Abe Takahide
Abeta Takehiro
Takaba Katsumi
Chin Gary
Nippondenso Co. Ltd.
LandOfFree
Self-diagnosing apparatus for motor vehicles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Self-diagnosing apparatus for motor vehicles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Self-diagnosing apparatus for motor vehicles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-143269