My independent MB Specialist has diagnosed a bad ECM for my 2000 E 320 4-Matic Wagon. Cylinders 4 & 5 are not firing (no spark) and working backwards all indications point to the ECM. He also stated that no codes are being generated. My questions are: 1) Are authorized MB Dealers the only source to program or reprogram the ECM? 2) Can the ECM be programmed with-out taking the car to the dealer? 3) How much does it cost to re-program the ECM (the ECM is $200 from a used parts supplier)? 4) My wife has my truck while her car is broken and I want it back. Thanks for any suggestions.