Help to solve this problem "EZS 639 545 01 08 fault turn ignition on mercedes vito

[electrones]

Hi friends

Today I went to see a mercedes vito that the key, does not turn the ignition "you know when to put the key in igniton "EZS", loose was a sound of Disarm, but now when to put key on ignition not happen anything. Maybe EZS is failing? EZL? key?
How to make an assessment to detect which one is failing?
Suggestions please

Thanks in advance

[smayer]

You hear a relay click inside ESL ? if yes replace ESL (just motor and mechanic parts, keep electronic board), if no check key.