Home › Land Rover › 2021 › Range Rover Evoque R-Dynamic S › Repair and Diagnosis › Quick Lookups › DTC Index › Diagnostic Trouble Code Index DTC: TELEMATIC Control Module (TCU) -- Range Rover EVOQUE/L551 › Diagnostic Trouble Code Index - DTC: TELEMATIC Control Module (TCU) (G2153768) › Description And Operation › TELEMATIC Control Module (TCU) › DTC U2109-91: Back-up Battery - Parametric › Possible Causes