Diagnosis

EWS system diagnosis capabilities are supported by the "EWS Electronic Immobilizer" diagnosis program (available on DIS tester).

The ability to select fault symptoms and run through the corresponding test modules makes diagnosis much easier.

The system also incorporates functions for verifying the validity of an available key (key test) and for cheking to ensure that the data in the EWS control unit correspond to those in the DME/DDE (EWS-DME/DDE data comparison).

In case of malfunction, proceed as follows:

• Connect the DIS tester to the diagnosis soket in the vehicle.
  
• Turn the ignition lock to position 2.
  
• Select the model series
  

For the E31/34/36 model series:

• On the page for "CONTROL UNIT Diagnosis" select the EWS control unit under "16 EWS ELECTRONIC IMMOBILIZER."
  
• Documentation is also available in the form of wiring and circuit diagrams on paper.
  

For the E38 model series:

• Enter vehicle identification. The "Diagnosis - Vehicle Identification" page then appears.
  
• Press the "Select function" button. Select the EWS system on the page for: Diagnosis of functions and component selection" for drive train or body.
  
• The test plan button provides further guidance through the diagnosis program.
  
• Select the "Documents" button for descriptions of operation, wiring diagrams, terminal assignments and installation locations of EWS components.