The codes are an important part of the EWS system. It is essential that the codes be matched correctly when either the EWS control unit or the engine control unit (DME/DDE) is replaced, as it will otherwise be impossible to start the engine.
Procedure:
The first step in the encoding procedure is to read out the data from the defective EWS control unit before removing it from the vehicle for replacement.
The data from the defective EWS control unit are then transfered to the DIS tester or MoDiC for temporary storage. These data are then entered into the new EWS control unit once it has been installed.
Important!
It is essential that this sequence (read the data from the defective component - installation of new unit - transfer the data to the new unit) be strictly observed whenever an EWS control unit is replaced!
If the defective EWS control unit is no longer capable of supporting communications, then it will be necessary to enter the VIN and the central key code (ZCS) by hand. It will then be impossible to read any remaining customer service data from the old EWS unit; these data will be lost.
The code is entered after replacement of the engine control unit.
The engine control unit is automatically calibrated to match the EWS control unit during programming.