Home › Land Rover › 2017 › Range Rover Evoque SE Dynamic › Repair and Diagnosis › Quick Lookups › DTC Index › Diagnostic Trouble Code Index DTC: Automatic Temperature Control Module (ATCM) -- Range Rover EVOQUE/L538 › Diagnostic Trouble Code Index DTC: Automatic Temperature Control Module (ATCM) › Description And Operation › DTC B12B9-57: Auxiliary Heater Control Module - Invalid/incomplete software component › Possible Causes