Change battery to new and charged or use a new Alkaline 9V temporarily for a test. Apply voltage and make sure lower than 10V. Hit direction button, if it 2 dings again, or in a test you can't cycle past the first reset position (directions state how to do a reset). Chances are the engine has an ID conflict and needs reprograming.
Do inspect battery harness to make sure no corrosion on leads. G