Home › Land Rover › 2014 › Range Rover Base › Repair and Diagnosis › General Information › DTC Index › Diagnostic Trouble Code Index DTC: Deployable TOWBAR Control Module (DTCM) -- Range Rover/L405 › Diagnostic Trouble Code Index DTC: Deployable TOWBAR Control Module (DTCM) › Description And Operation › DTC B1556-23: Deployable Side Step Button - Signal stuck low › Possible Causes