Home >> Land Rover >> 2021 >> Range Rover SVAutobiography Dynamic Blk. >> Repair and Diagnosis >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index DTC: Audio Amplifier Module (AAM) -- Range Rover/L405 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index - DTC: Audio Amplifier Module (AAM) (G2187165) >> DTC B13E7-13: Microphone 4 - Circuit open >> Possible Causes