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.

Date of Patent:
Aug. 11, 1998

Filed:

Aug. 28, 1996
Applicant:
Inventors:

James Michael Hewelt, White Lake, MI (US);

Etsuko Muraji Stewart, Laingsburg, MI (US);

Assignee:

General Motors Corporation, Detroit, MI (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
731173 ; 123 4186 ;
Abstract

A positive crankcase ventilation system diagnostic applied in an automotive internal combustion engine with a pressure sensor disposed in the system for continuous sensing of system pressure while the engine is running in a steady state operating condition, with minimum and maximum sensed pressure values stored during each of repeated test periods. Pressure values exceeding a predetermined normal range over at least one test period indicate a leak or restriction condition in the system. Small differences in pressure values over test periods indicate sensor or electrical fault conditions. Fault conditions are logged and are indicated if persistent.


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