Hello,

I have a w212 2010 220 CDI and lately, the key has started giving me problems. When the engine is hot, the key does not work. The key cannot turn on the instrument cluster, or crank and engine.
I emphasize that the key opens and closes the doors normally, but it cannot start the car. After 10-15 minutes that the car cools down, the key works and the car starts. 1 week ago, I changed the EIS module but the problem remains.

 

First, the door lock-unlock and ignition switch are completely different key functions and have no relation to each other. If you don't know this, then I wonder why you spent money to replace the EIS module. Who talked you into replacing the EIS module? Replacing the EIS is the LAST thing you should do.

I assume you haven't tried using the second key fob?

For the price of the EIS module, I suspect you could have bought 2-3 OBD2 diagnostic tools, that could actually tell you why the car will not start when hot.

 

check codes.
My $49 HT200, what is sibling to AP200 has very nice troubleshooting page to inspect why the car is not starting.

 

Thanks for reply,

I don't have another key. A month ago, I went to a service center and after diagnostics, he told me that the EIS module had to be changed because it has a limited number of ignitions.
The problem is that when I place the key, I don't hear the sound of the steering wheel unlocking and when I turn the key to turn it on, no light appears in the instrument cluster. When this happens, I have to wait for the car to cool down and then start the engine.

As for the obd2 scanner, which variant would be more suitable?
In fact, I have a OBD2 but it is only for the VAG group and I am not very informed about the scanners for Mercedes since got the w212 5 months ago.
Thank you,
Mario

 

One of the old ***** cars my dad had back in time suffered from a similar problem and it was not a Mercedes-Benz . We had to wait more than 15 minutes to get it fired up . It turned out to be a fuel pressure problem . My old Jaguar had long cranks to getting it started up as well .

 

Don't hold back get yourself a scanner to hopefully read your faults.

This sounds like a bad SAM relay... poke around to swap similar cubes.

 

The most likely problem is the key. Whoever changed your EIS, did they installed a new one or used???