How do I switch the processor oon an EIS ignition modular to match my vin # /key

Im trying to keep my cost down and due to the nature in which it would intermittently fail and then start. It seemed to start easier once the temperatures were brought up inside the vehicle. I assumed it was the EIS. Now that you mentioned this it very well good be the key Fob and I didn't realize it. Coupled with the fact that the key fobs other functions all worked correctly. I jumped to the conclusion that it was the EIS. The other functions quit working as well last night. What are the steps i need to take to aquire a new key fob and have it programmed and fully functional. I love this car but am on the verge of tearing out the motor and putting in a chevy motor. Just kidding but I am frustrated beyond belief there must be some other option for theft protection than locking the owners out. I want to believe that Mercedes-Benz Corporation has more integrity than to create a system that purposefully cost the consumer more money than needed. The Integrity shows in their craftsmanship but this issue has me baffled it must have been obvious from the first round of these problems.Fyi this is Pams fiance,my name is Scott and the car was purchased for me by my employer.I would have never purchased this vehicle ordinarily,now I dont want to drive anything else.Incredible driving experience,everyday.LOL

I understand your frustration. I am sure that Mercedes did not intend for these issues to occur, however this is just a result of what I call poorly and over engineered electronics. My honest opinion would be to have it 100% accurately diagnosed. I have people call me with different electrical issues daily. My concern is that you end up doing what most people do, and spend hundreds if not thousands of dollars on parts that will 'hopefully' fix it. My recommendation is that you have it properly diagnosed, it's worth paying one or two hundred dollars to make sure that you don't buy a thousand dollar immobilizer etc. that you don't need and can not return. Fyi most anti theft parts are non returnable because they are ordered to the VIN