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15
EWS
Replacement Procedures
Keys
Up  to  6  additional  keys  may  be  ordered  as  replacement  keys.  The  EWS  II  control  module
is codeable for only 10 keys (4 delivered with vehicle and 6 replacement). 
EWS II Control Module
Replacement EWS II Control Modules must be ordered VIN specific.  EWS II modules con-
tain  the  VIN  and  coding  from  the  factory  to  recognize  the  key  codes.  Modules  from  other
vehicles will not recognize keys as being valid and not start the engine.
EWS II Control Modules store the Central Coding Key (ZCS) and the VIN. If the EWS II con-
trol module is replaced the system must be ZCS coded (SIB 61 02 96 and TRI 61 01 95).
The  EWS II  module  must  be  synchronized  with  the  DME  (aligned).  There  is  no  limit  to  the
number of times the ISN may be changed in the EWS II module.
DME Control Module 
The  DME  Control  Module  is  not  ordered  VIN  specific  and  must  be  programmed  during
replacement. The ISN from the new DME must
be  transferred  to  the  EWS II  module  using  the
DISplus or MoDic.
Key Activation
Keys that are lost or stolen may be deactivated
or  made  to  not  operate  the  starter  functions.
The  SERVICE FUNCTIONS  of  the  DISplus  or
MoDic  for  EWS II  contains  a  “Bar/Release
Code”  function  that  activates  and  deactivates
keys  of  the  EWS II.    Any  key  may  be  “Barred”
except  the  key  in  the  ignition  at  the  time  of
deactivation. The lost or stolen key can be iden-
tified by the identification of the remaining keys.
There  is  no  limit  to  the  number  of  times  a  key
can be activated/deactivated.
EWS II Update
Beginning MY 1997 E31 and E36 vehicles with manual transmissions were updated to include a clutch
pedal position switch.  The clutch switch signal is provided by a hall-effect sensor providing a high sig-
nal when the clutch is depressed.
Note: A “Barred” key will not start the engine, it
will still unlockthe vehicle. 
     
        
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18
EWS
Clutch Switch
A Hall-Effect Switch is added to the clutch system to inform the EWS III (3.2) control mod-
ule of clutch status. Input from the switch replaces the signal from the Trans Range Selector
Switch  on  manual  transmission  equipped  vehicles.  High  signal  status  indicates  the  clutch
is depressed and vehicle starting is allowed.
Principle of Operation
The starting sequence for the EWS III (3.2) is as follows:
• The key is inserted into the lock cylinder and switched “ON”.  The EWS III control mod-
ule is powered through KL R and sends a 125kHz AM signal to the ring antenna. The 
AM signal induces voltage in the key coil and powers up the transponder.
• Powered up, the key transponder sends the key identification code to the EWS III mod-
ule. The EWS III module verifies the key identification code and checks to see if the key
is enabled. If the key is correct and enabled, a password is sent to the transponder over
the 125kHz AM signal through the ring antenna.
• When the transponders accepts the password, it releases the changing code, which it 
received from the EWS III module during the last start-up operation, to the EWS III mod-
ule via the ring antenna.
• The EWS III module compares the changing code received from the transponder with 
the code stored in its memory and if they match the process is allowed to continue.
The EWS III module looks at the other inputs for correct status (e.g. Code function not
active, Transmission in P or N or clutch depressed, engine speed below specified RPM)
and energizes the the internal relay to begin starter operation.
• As the starter begins to operate, the EWS III module sends the ISN to the DME and if 
verified as correct by the DME, drive away protection is cancelled and injection and igni-
tion is enabled.   The EWS III module also sends a new changing code to the key 
transponder through the ring antenna.
Replacement Procedures
Keys
Up to 6 additional keys may be ordered as replacement keys. The EWS III (3.2) module is
codeable  for  only  10  keys  (4  delivered  with  vehicle  and  6  replacement).  The  keys  are
mechanically  matched  to  the  vehicle  with  the  lock  tumblers  and  electronically  matched  to
the EWS III (3.2) through unalterable coding. 
     
        
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EWS
DME Control Module
The DME Control Module has changed in that it is not the source of the ISN but now only
stores the “Rolling Code”.  It compares the “Codes” to those sent to it by the EWS III (3.3)
control module. The “Rolling Code Table” assigned to the DME must match the table in the
EWS III  (3.3)  module.  The  “Rolling  Code  Table  is  “burned”  into  the  DME  during  the  pro-
gramming of the DME and cannot be change once “burned”.
Transmission Range Selection Input
With  the  introduction  of  the  SKE  type  connectors  on  Transmission  Control  Modules  the
direct input from the Transmission Range Selector Switch is eliminated. The input for range
selection is now received from the AGS Control Module. 
On manual transmission vehicles clutch status is input directly into the DME.
Principle of Operation
The starting sequence of the EWS III (3.3) is as follows:
(Same as EWS III (3.2)
• The key is inserted into the lock cylinder and switched “ON”.  The EWS III (3.3) control
module is powered through KL R and sends a 125kHz AM signal to the ring antenna. 
The AM signal induces voltage in the key coil and powers up the transponder.
• Powered up, the key transponder sends the key identification code to the EWS III (3.3)
module. The EWS III (3.3) module verifies the key identification code and checks to see
if the key is enabled. If the key is correct and enabled, a password is sent to the 
transponder over the 125kHz AM signal through the ring antenna.
• When the transponders accepts the password, it releases the changing code which it 
received from the EWS III (3.3) module during the last start-up operation to the EWS III
(3.3) module via the ring antenna.
• The EWS III (3.3) module compares the changing code received from the transponder 
with the code stored in its memory and if they match the process is allowed to contin-
ue. The EWS III (3.3) module looks at the other inputs for correct status (e.g. Code func-
tion not active, Transmission in P or N or clutch depressed, engine speed below spec-
ified RPM) and energizes the the internal relay to begin starter operation.