Specifications

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Testing Testing Immobilizer (EWS) Systems
Up to 6 additional keys may be ordered as replacement keys. The EWS II control module accepts
codes for only 10 keys (4 delivered with vehicle and 6 replacement).
1— Transmitter/receiver module
2— DME control module
3— EWS II control module
4— Vehicle key
5— Ring antenna
Figure 4-8 EWS II components
EWS II Starting Procedure
When the key is inserted into the lock cylinder and switched on, the transmitter/receiver module is
powered. The key coil and transponder chip are also powered by the induced voltage.
Data now transfers between the transponder chip and EWS II control module as follows:
1. The key identification code stored in the key is sent to the transmitter/receiver module.
2. The transmitter/receiver module converts the amplitude modulated signal to a digital signal
containing the same identification code. The code is sent to the EWS Control Module over a
data link, such as a K Bus.
3. The EWS II control module must recognize the code as valid for engine starting to continue.
4. Once the identification code is accepted as valid, the EWS II sends the digital password to the
transmitter/receiver module.
5. The transmitter/receiver module converts the signal into AM and sends it to the transponder.
6. If the transponder accepts the received password as valid, starting continues.
7. With acceptance of the password, the transponder releases the changing code.
8. The code is converted to a digital changing code and sent to the EWS control module.
9. If the code is valid, the EWS control module accepts the key as valid.
10. The EWS II activates the internal starter relay and the starter circuit is energized.
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