Control system for vehicular power plant including automatic transmission and exhaust brake

摘要

A control system for a vehicular power plant including an automatic transmission and an exhaust brake. The exhaust brake includes a butterfly valve movably disposed in an exhaust pipe. The control system is comprised of a control unit which is supplied with a signal representative of an engine brake condition and is adapted to generate a signal commanding an automatic downshift of the automatic transmission. Under the operation of the control unit, the exhaust brake is temporarily put into an inoperative condition in response to both the detected engine brake condition and the downshift command.