Home › Jaguar › 2018 › XE S, RWD › Repair and Diagnosis › Quick Lookups › DTC Index › Diagnostic Trouble Code Index DTC: TELEMATIC Control Module (TCU) -- XE (X760) › Diagnostic Trouble Code Index DTC: TELEMATIC Control Module (TCU) › Description And Operation › Telematics Control Module (TCU) › DTC U2109-09: Back-up Battery - Component failures › Possible Causes