A system for braking a vehicle includes a transmission having a plurality of gear sets for establishing a plurality of forward and reverse gear ratios and an actuator for changing the gear ratios. The system also includes a plurality of sensors for detecting a plurality of vehicle operating parameters and an auxiliary brake for reducing a speed of the vehicle. A controller having a processor configured to receive a plurality of output signals from the plurality of sensors has control logic for activating one of the actuator and the auxiliary brake based on the received output signals. A method for operating the system for braking is also provided. The method includes determining road grade, determining an acceleration of the vehicle, determining an activation status of the primary brake, determining a position of the throttle, determining whether extra braking is and activating the auxiliary brake based on the extra braking determination.