I believe most of the data is stored in both MCUs. Personally I have never luck to clone one. There are different speculations for what is stored in which MCU, but these type EIS is extremely hard to clone or change data inside. 0D69J, 1D69J and I have seen one other mask once or twice(and was not able to read it). So let's start with the first type EIS introduced in 1998 for the W202, W208 and W210 models. It is good to have a similar EIS handy to make comparisons on the board, the current it draws and eventually to swap the EEprom.

I use AK500 to verify each key I renew is a functional and the IR circuit works. Make sure the key you programmed is fully functional. This way you will know if a subsequent failure has occured after your intervention or before. Even if there is no original working key another key can be inserted to verify the correct function. Before even starting any work on the EIS connect to a power supply and test the function. First thing is always to read and back-up the EEprom data. After reading the dump from EIS always run it thru SKC to verify the corectness. Also the beahviour thru different stages can be observed-when inserting the key, when it goes to sleep, etc Closely monitoring the current EIS is drawing helps evaluate the condition. Always connect the EIS for testing to a bench power supply with display for the current. Regardless of how many times you did this job, it will byte you later if you cut corners I am sure many people will add knowledge to this thread.Ī few simple rules have helped me to be successfull most of the time: Here is my short, but hopefully usefull manual I wrote for most Mercedes Motorola EIS diagnostic and repair.My experience is not decades, but I made keys and repairs to 100s of them.

Bypass eis mercedes