Hey guys. My check engine light came on the other day while I was driving and stayed on. My gas cap wasnt open. So I took it to an authorized Mercedes shop. I have good experience here, they gave me some good prices on tires and they serviced my car at 76k. They tried to explain to be what was wrong but I didn't really understand, all I know is that its something with Tranny Shift Module. Here are the part numbers and prices they would charge me. 1402700861 $285 plus 2022670824 $488 plus $225 for 2 1/2 hours of labor. It all comes out to be just under $1,000. The guy said its some what of a serious problem because eventually the car wont start because it will think its in 1st or 2nd gear. I really dont understand whats going on so I thought I just run it by you guys. So if you could just look into this and help me out (AGAIN) I would really appreciate it. Thanks!