Home >> Land Rover >> 2015 >> LR4 HSE, AWD >> Repair and Diagnosis >> General Information >> DTC Index >> Diagnostic Trouble Code Index DTC: Restraints Control Module (RCM) -- LR4/L319 >> Diagnostic Trouble Code Index DTC: Restraints Control Module (RCM) >> Description And Operation >> DTC B0021-12: Left Curtain Deployment Control 1 - Circuit short to battery >> Possible Causes