Home >> Land Rover >> 2021 >> Discovery S >> Repair and Diagnosis (Single Page) >> Quick Lookups >> DTC Index >> Diagnostic Trouble Code Index: Transmission Control Switch (TCS) -- Discovery/L462 >> General Information >> Description And Operation >> Diagnostic Trouble Code Index: Transmission Control Switch (TCS) (G2016133) >> DTC U0028-88: Vehicle Communication Bus A - Bus off >> Possible Causes