EGR valve maintenance method
AssigneeGeneral Motors Corporation
InventorsPaul Alan Bauerle, Robert Francis Semrau, John Norman Stockbridge
Life of this patent
Estimating the term…
Abstract
A maintenance method for periodically maintaining the operating condition of an exhaust gas recirculation valve for controlling recirculation of internal combustion engine exhaust gas from an exhaust gas path to an engine intake air path in which the valve is periodically driven to a maximum open position and then back to an initial position, such as a closed position when engine operating conditions are such that there is no driveability or emissions penalty associated with such valve maintenance and when sufficient battery drive voltage is available to drive the valve as required for maintenance thereof.
Claims6
In an internal combustion engine having an engine exhaust gas recirculation path with an electrically controlled recirculation valve therein for controlling the volume of exhaust gas recirculated through the recirculation path, a valve maintenance method comprising the steps of:
- sensing an engine power-up condition;
- referencing a predetermined valve drive command corresponding to a substantially fully open valve position upon sensing the engine power-up condition;
- applying the predetermined valve drive command to the valve upon sensing the engine power-up condition;
- sensing a predetermined termination condition;
- and
- reducing the predetermined valve drive command toward a predetermined minimum command upon sensing the predetermined termination condition.
Dependencies are inferred from the claim text.