STRANGE EZS PROBLEM

[GolfmkI]

Hello I am having a curious problem with one EZS

W209
2095450508
3k91d

Car is starting ok with both keys....
But only once!
I mean insert key everything ok but no second time allowed.
Even EZS dont energise the coil....


You should disconnect from bench and the connect again, this way works perfect with any key.

Read eeprom seems no HASH and FLASH seemed some bits altered so load a working 100% FLASH found in forum
But problem is exactly the same.

It works only the first time.

Do you think is HW PROBLEM?
I disassemble EZS before to :

Resolder mcu and of course check the mask of MCU

Any advice will be greatly appreciatted

[GolfmkI]

SOLVED!!

Seems like 3K91D is having some issues.

I managed to make work ok when HOT the mcu (quite similar as 2j74y audi problem) with air station

When processor is hot it works perfect any time.

FAILING AGAIN WHEN COLD

So seems I need other MCU or probably a used EZS FROM SCRAP

I have considered simply remove thread or erase it but i think IMHO someone could deserve these info.

MANY THANKS AGAIN