The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 26, 1995
Filed:
Jun. 14, 1994
Nippondenso Co., Ltd., Kariya, JP;
Abstract
In a vehicle diagnosis system in which a diagnosis unit is connected to a control unit, the control unit determines whether or not there is a code read request from the diagnosis unit. When there is the request, it further determines whether or not code erase is in execution. When code erase is not in execution, an abnormality code stored in the standby RAM region of its CPU is searched for and the result is transmitted to the diagnosis unit. When code erase is in execution, on the other hand, the data after code erase (no abnormality code) is transmitted to the diagnosis unit. Thus, during code erase operation, the abnormality data before erase is prevented from being transmitted to the diagnosis unit. Further, in case of a RAM value read request is made from a main CPU to other CPU in the controller, it is checked whether a requested address value from the main CPU to the other CPU agrees with the address value transmitted from the other CPU to the main CPU. When the address values agree, the flag XA4ANS is set. After a prescribed interval from this flag setting, the RAM value corresponding to the requested address are responsively sent out to the diagnosis unit. Therefore, transmission of erroneous information to the diagnosis unit can be prevented without fail.