Home >> Jaguar >> 2015 >> XKR-S 2D Convertible >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Diagnostic Trouble Code Index DTC: Speed Control Module (CCM) -- XK/X150 >> Diagnostic Trouble Code Index DTC: Speed Control Module (CCM) >> Description And Operation >> Speed Control Module [CCM] >> DTC U0421-81: Invalid Data Received from Suspension Control Module A - Invalid serial data received >> Possible Causes