Home › Jaguar › 2014 › XF Base › Repair and Diagnosis › Quick Lookups › DTC Index › Diagnostic Trouble Code: Adaptive Speed Control Module (ASCM) -- XF/X250 › Diagnostic Trouble Code (DTC) Index DTC: Adaptive Speed Control Module (ASCM) › Description And Operation › DTC U0423-81: Invalid Data Received From Instrument Panel Control Module - Invalid serial data received › Possible Causes