ELECTRIC SHIFT APPARATUS AND CONTROL SYSTEM THEREFOR

摘要

An electronic control system for a motor vehicle automatic transmission assembly of the type including an automatic transmission and a transfer case connected to the output of the automatic transmission. The automatic transmission has a mode select shaft to position the transmission in its various shift modes and includes a plurality of serially arranged planetary gear sets which are selectively engagable to provide the various shift modes of the transmission including the various forward speeds of the transmission. Solenoid valves are provided to control each planetary gear set so as to provide a direct drive or a speed reduction through that gear set. The invention control system includes a push-button module positioned in the passenger compartment of the motor vehicle providing input signals to a microprocessor. The microprocessor generates a first set of command signals for shifting the transmission between its various shift modes in response to operator selection of a particular push-button, a further set of command signals to automatically shift the transmission between its various forward speeds with the transmission in a forward drive mode, and a further set of command signals to shift the transfer case between its various drive modes in response to operator selection of a push-button corresponding to a transfer case shift mode.