Home >> Land Rover >> 2023 >> Range Rover Velar HST >> Repair and Diagnosis >> Quick Lookups >> DTC Index >> Diagnostic Trouble Code Index DTC: Audio Amplifier Module (AAM) -- Range Rover Velar/L560 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index - DTC: Audio Amplifier Module (AAM) (G2739084) >> U0400-81: Invalid data received - Invalid serial data received >> Possible Causes