Home >> Land Rover >> 2015 >> LR4 HSE, AWD >> Repair and Diagnosis >> General Information >> DTC Index >> Diagnostic Trouble Code Index DTC: Automatic Temperature Control Module (ATC) -- LR4/L319 >> Diagnostic Trouble Code Index DTC: Automatic Temperature Control Module (ATC) >> Description And Operation >> DTC U0166-87: Lost Communication With Auxiliary Heater Control Module - Missing message >> Possible Causes