Battery heating module failed. This resulted in small, hard to distinguish, ‘service vehicle’ icon to appear on the dash with no further information. This warning icon first appeared during a long drive, then went away on its own and eventually came back. This failure would eventually make charging, particularly in cold weather, impossible and potentially stranding the occupants. The servicing dealership has confirmed this failure and is attempting to replace the module. However, parts for this replacement seem to be unavailable with no current estimated arrival.