Home › Land Rover › 2021 › Defender 90 First Edition › Repair and Diagnosis › General Information › Specifications Index › Diagnostic Trouble Code Index DTC: Transmission Control Module (TCM) -- Defender/L663 › Diagnostic Trouble Code Index - DTC: Transmission Control Module (TCM) (G3187879) › Description And Operation › Transmission Control Module (TCM) - 8HP70/45 Transmissions › DTC U0302-57: Software Incompatibility with Transmission Control Module - Invalid/incomplete software component › Possible Causes