Abstract: An engine controller capable of operating in both a torque governing mode and a speed governing mode simultaneously, and a method of operation whereby speed governing may be enabled and disabled while simultaneously providing a valid speed request signal to the controller is disclosed. A speed governor signal having an enabled state and a disabled state is generated external to the controller and monitored by the speed governor. A speed request signal is simultaneously monitored by the speed governor. The speed governor is operative to control the speed of the engine proportional to the speed request signal while the speed governor signal is in the enabled state. The speed governor is disabled by setting the speed governor signal into the disabled state. A torque governor may also be operational within the controller. The torque governor monitors a torque request signal which it uses to control a torque generated by the engine.