Home >> Land Rover >> 2021 >> Defender 90 First Edition >> 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