Home >> Jaguar >> 2018 >> XF S, AWD >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Diagnostic Trouble Code Index DTC: Restraints Control Module (RCM) -- XF/X260 >> Diagnostic Trouble Code Index DTC: Restraints Control Module (RCM) >> Description And Operation >> Restraints Control Module (RCM) >> DTC B0021-1A: Left Curtain Deployment Control 1 - Circuit resistance below threshold >> Possible Causes