Method and system for determining a driveline ratio for a powertrain having an auxiliary transmission

Abstract

A method for determining a driveline ratio for a powertrain having an auxiliary transmission is provided and includes identifying a transmission gear ratio, measuring a transmission output speed, and measuring an auxiliary transmission output speed. An auxiliary transmission gear ratio is identified by comparing the transmission output speed to the auxiliary transmission output speed when the powertrain is in motion. The auxiliary transmission gear ratio is identified from a switch when the powertrain is at rest. An auxiliary transmission module has an auxiliary transmission in communication with a controller. The controller is configured to identify an auxiliary transmission gear ratio, and limit an engine torque command to limit the auxiliary transmission output torque. The engine torque command is limited if the output torque exceeds a predetermined value and if the auxiliary transmission is in a reducing gear ratio.

Dependencies are inferred from the claim text.