Granted Patent
Utility
US 6,550,316 · App. 09/967,542
Engine off natural vacuum leakage check for onboard diagnostics
Inventors:
Kevin C. Wong, William Western
Patented Case
View Patent ↗
Granted: Apr 22, 2003
Filed: Oct 1, 2001
Inventors
Kevin C. Wong
William Western
Assignee (at issue)
General Motors LLC
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.