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:
Jun. 20, 2000
Filed:
Jul. 09, 1998
Nissan Motor Co. Ltd., Yokohama, JP;
Abstract
An electronic transmission control system having a fail-safe system for an automotive vehicle with a continuously variable automatic transmission whose speed-change ratio is changeable continuously depending on vehicle speed and engine load, comprises a hydraulic modulator producing at least a regulated line pressure necessary to adjust the speed-change ratio hydraulically, a desired speed-change ratio arithmetic processing section for calculating a desired speed-change ratio based on the vehicle speed and the engine load, and a desired line pressure arithmetic processing section for calculating a desired line pressure based on the desired speed-change ratio and the engine load. Also provided is a fail-safe section comprises a comparing portion for comparing the desired line pressure to a predetermined line pressure threshold above which the desired line pressure is within an unreasonably high line pressure zone, a decision portion for deciding on the basis of a result of comparison of the comparing portion whether the desired line pressure is above the predetermined line pressure threshold, and a speed-change ratio retaining portion for retaining the speed-change ratio of the continuously variable automatic transmission unchanged, when the desired line pressure exceeds the predetermined line pressure threshold.