I have a 2002 MB CLK 320 that recently ran out of refrigerant. The EC light remained on & no cold air was blowing. I learned (from the internet) that I could troubleshoot certain codes from my dashboard a/c screen. The code b241 confirmed the low refrigerant & no sensor malfunctions based upon the temperatures. I took the car to a simple QuikCar to have the refrigerant replaced. They said they could replace the refrigerant but could not get the EC light to turn off or the compressor to engage. They recommended I take it to MB so they could possible "re-set" some trouble codes? Took the car to MB yesterday. They said I have a small leak in my expansion tank line. Also commented that they could refill the refrigerant for me but didn't know how long it would remain. The overall work through MB was quoted at $1400! I want to know if this is something I can do at home. If I replace the line & have QuikCar replace the refrigerant, how do I re-set the "codes" to get the A/C to work?