N52T DME Fault CD9304: Diagnostic Hints for Bit-Serial Data Interface Communication. If there is a problem with communication on the Bit-serial data interface bus (BSD), the obvious symptoms are related to the oil service CBS functions. The DME must receive constant communication from the oil level sensor. Whenever this communication is disturbed, a fault is set and the following symptoms can be present: ? The remaining distance forecast to the next oil service is too short and not plausible in conjunction with the service history. ? The CBS engine oil service cannot be reset either in the Kombi or with the ISTA test plan. ? The engine oil level measurement is inactive and will not complete. The fault CD9304: Bit-serial data interface, signal: communication is stored in the DME. In addition, power management faults for undervoltage or overvoltage, as described in SI B12 12 13, could be stored as well. A faulty ignition coil may have damaged the DME; however, there is no DME fault code stored for te defective ignition coil.
