Abstract: A vehicle computer system controls downhill speed of a vehicle having a cruise control and an engine retarder. The system receives a request to increase engine retarder demand. In response, the system increases an engine retarder demand setting and, if cruise control is active, decreases a downhill speed control (DSC) cruise control offset. The engine retarder system may automatically activate to reduce the vehicle speed to a cruise control set speed plus the DSC cruise control offset. In an embodiment, the request to increase engine retarder demand is generated in response to operator input via an engine retarder demand input device (e.g., a steering-column-mounted control stalk). The system may also receive a request to decrease engine retarder demand in the engine retarder of the vehicle. In response, the system decreases the engine retarder demand setting and, if cruise control is active, increases the DSC cruise control offset.

Abstract: A vehicle computer system controls downhill speed of a vehicle having a cruise control system and an engine retarder system. The system receives a request to increase engine retarder demand. In response, the system increases an engine retarder demand setting and, if cruise control is active, decreases a downhill speed control (DSC) cruise control offset. The engine retarder system may automatically activate to reduce the vehicle speed to a cruise control set speed plus the DSC cruise control offset. In an embodiment, the request to increase engine retarder demand is generated in response to operator input via an engine retarder demand input device (e.g., a steering-column-mounted control stalk). The system may also receive a request to decrease engine retarder demand in the engine retarder system of the vehicle. In response, the system decreases the engine retarder demand setting and, if cruise control is active, increases the DSC cruise control offset.