Home >> Land Rover >> 2021 >> Defender 110 S >> Repair and Diagnosis >> General Information >> Specifications Index >> Diagnostic Trouble Code Index DTC: Gateway Module (GWM) -- Defender/L663 >> Diagnostic Trouble Code Index: Gateway Module (GWM) (G2801686) >> Description And Operation >> Gateway Module (GWM) >> DTC U0064-88: Vehicle Communication Bus E - Bus off >> Possible Causes