Home >> Land Rover >> 2021 >> Defender 90 X >> Repair and Diagnosis (Single Page) >> General Information >> Specifications Index >> Diagnostic Trouble Code Index DTC: Trailer Control Module (TRM) -- Defender/L663 >> Diagnostic Trouble Code Index - DTC: Trailer Control Module (TRM) (G2445144) >> Description And Operation >> Trailer Control Module (TRM) >> DTC B1541-13: Trailer Socket Connection - Circuit open >> Possible Causes