Some 2016 Model Year Fusion, MKZ and C-MAX Hybrid Electric Vehicles(HEV) vehicles equipped with 2.0L DOHC Gas/Electric engines may exhibit MIL On with Diagnostic Trouble Code P0137(O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2) in Powertrain Control Module(PCM) memory and U3003 (Battery Voltage) in Battery Energy Control Module(BECM) memory due to low battery voltage. Perform Battery diagnostic tests referenced in Workshop Manual Section 414-01 Battery, Mounting and Cables-Diagnosis and Testing. After repairs for low voltage concern are repaired, clear Diagnostic Trouble Codes. If DTC P0137 and U3003 do not repeat return vehicle to the Customer. If DTC P0137 repeats perform Powertrain Control and Emissions Manual(PCED) diagnostic DW. Engineering is currently investigating this concern.