Home >> Land Rover >> 2021 >> Defender 90 X >> Repair and Diagnosis (Single Page) >> Quick Lookups >> Common Specs & Procedures >> 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 B1407-47: Trailer Module - Watchdog/Safety C failure >> Possible Causes