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. 16, 2003
Filed:
Feb. 13, 2002
Keiji Wakahara, Inazawa, JP;
Toshio Kondo, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
Even after initiation of a fuel cutting operation, an estimated coolant temperature value is continuously renewed based on an engine operating state until a predetermined time period elapses. Thus, an increase in the coolant temperature during the fuel cutting operation can be estimated. Furthermore, overestimation of the increase in the coolant temperature during the fuel cutting operation can be avoided since the renewal of the estimated coolant temperature after the elapse of the predetermined time period is prohibited. In this way, possible deterioration of coolant temperature estimation accuracy caused by the fuel cutting operation can be minimized, allowing more accurate coolant temperature estimation. As a result, when abnormality of a thermostat is judged based on a difference between an actual coolant temperature and the estimated coolant temperature value, misjudgment of a normal thermostat as an abnormal thermostat can be prevented.