Home › Land Rover › 2021 › Defender 110 › Repair and Diagnosis › General Information › Specifications Index › Diagnostic Trouble Code Index DTC: Audio Amplifier Module (AAM) -- Defender/L663 › Diagnostic Trouble Code Index - DTC: Audio Amplifier Module (AAM) (G2804413) › Description And Operation › Audio Amplifier Module (AAM) › DTC U201B-56: Control Module Calibration Data #2 - Invalid/incomplete software component › Possible Causes