Home >> Land Rover >> 2017 >> Discovery Sport SE >> Repair and Diagnosis >> Quick Lookups >> 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 C0078-61: Tire Diameter - Signal calculation failure >> Possible Causes