Gm Global Technolgoy Operations, Inc.

Ronald A Lee

William M Murray

Phillip F McCauley

Thomas H Wilson

Ted M McQuinn

Robert T Niemczyk

William L McCoy

An apparatus and technique for fluid level determination in automatic transmissions. The invention employs an electronic control unit in association with an automatic transmission for a vehicle, the electronic control unit receiving data corresponding to transmission oil level, transmission oil temperature, engine speed, transmission speed, and transmission selected range. Upon determining that such data satisfies certain diagnostic tests, the level of transmission fluid within the transmission is determined and adjusted or otherwise normalized to ideal test conditions. The electronic control unit compensates an oil level signal for deviations in oil temperature from an optimum test temperature, and makes further compensation for deviations in engine speed and settling time at the time that the test data is acquired. Additionally, variations in oil density as a function of oil temperature are also compensated.

Apparatus and technique for fluid level determination in automatic

A position indication derived from the output signal of an engine demand device sensor is compensated for errors which tend to expand or contract the range of such output signal. The signal is compared to previously stored upper and lower reference values nominally corresponding to the limit positions of the demand device, and the position indication is derived in accordance with such comparison. The compensation is achieved by altering the previously stored upper and lower reference values at the initiation of each period of vehicle operation, in a sense to contract the range of output signals defined thereby, and by replacing the upper or lower reference values with the sensor output signal value during the ensuing period of vehicle operation if the sensor output signal value is greater or less than the upper or lower reference values, respectively.

Adaptively calibrated sensing mechanism for an engine demand device

Sportsman's grill

Portable grill

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Brownsburg, IN, United States of America

Ronald A Lee