Home >> Land Rover >> 2017 >> Discovery SE >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Diagnostic Trouble Code Index DTC: TELEMATIC Control Module (TCU) -- Discovery/L462 >> Diagnostic Trouble Code Index DTC: Telematic Control Module (TCU) >> Description And Operation >> DTC B117A-01: Backup Microphone - General Electrical Failure >> Possible Causes