Home >> Land Rover >> 2017 >> Discovery Sport SE >> Repair and Diagnosis >> General Information >> DTC Index >> Diagnostic Trouble Code Index DTC: Adaptive Speed Control Module (ASCM) -- Discovery Sport/L550 >> Diagnostic Trouble Code Index DTC: Adaptive Speed Control Module (ASCM) >> Description And Operation >> DTC U0028-88: Vehicle Communication Bus A - Bus off >> Possible Causes