2013 Chevrolet Volt Owner Manual - Page 212

9-26 Driving and Operating When FMM is needed, the FMM Request screen appears on the center stack display at vehicle start. start. An EMM Notification screen will appear in the center stack display. Fuel Maintenance Mode (FMM) Fuel Maintenance Mode (FMM) tracks average fuel age. Old fuel can cause engine problems. If low engine usage causes average fuel age to exceed approximately one year, FMM will run the engine to use up the old fuel. The engine will run until enough fresh fuel is added to bring the average fuel age into an acceptable range. Allowing more old fuel to be used up by FMM and adding a larger amount of fresh fuel will maximize the length of time before another fuel maintenance mode is needed. During FMM the engine may turn on and off. If the vehicle shuts off during EMM, it will restart the next time the vehicle is driven. A message displays to indicate that EMM is active. If EMM is required and the fuel level is low, EMM may eventually empty the fuel tank if fuel is not added. This will result in reduced, or no power. An adequate fuel level must be maintained in the vehicle to keep it operational. See Propulsion Power Messages on page 5‑49. If Yes is selected, FMM will begin. FMM will automatically continue at each vehicle start until fresh fuel is added. If No is selected, the FMM Request screen will appear when the vehicle is next started. The FMM request can be delayed for only one day.