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:
May. 04, 2004
Filed:
Apr. 08, 2002
Ronald A Reese, II, Goodrich, MI (US);
Gary M Pallach, Chesterfield, MI (US);
Gary D. Dawson, Rochester, MI (US);
David P. Ploucha, Ann Arbor, MI (US);
Susan A. Aldridge, Linden, MI (US);
DaimlerChrysler Corporation, Auburn Hills, MI (US);
Abstract
A method is provided for testing a thermostat in a motor vehicle. The method includes an engine warm-up model and a thermostat diagnostic. The engine warm-up model predicts the temperature that the engine coolant temperature should be equal to at a given time after start-up. This is based on the engine coolant temperature at start-up, ambient air temperature, and how the vehicle is driven subsequent to start-up. This predicted engine coolant temperature is compared to the actual engine coolant temperature as read by an engine coolant temperature sensor. The error between the predicted engine coolant temperature and the actual engine coolant temperature is calculated and integrated over time. The thermostat diagnostic runs at a pre-selected temperature after start-up and compares the integrated error to a predetermined threshold value. Depending upon the results of the comparison, a pass, fail, or inconclusive condition is determined.