Hello, i have been trying to solve this issue for a few days, reading the Bentley manual and scowering through forums but have not crashed in to a solution. The car in question, a 2000 330xi wagon, automatic, has been sitting for five weeks, started every second week. Now, at the latest start, the instrument cluster went nuts. Tacho didnt work, temp gauge was pegged in hot, obc was dark and abs, dsc, and handbrake lights were lit. We decided to read the obd2 codes, and it showed p0600, serial communication link malfunction. I read about it, and found a few solutions which i have tried, with no luck; cleaning out the ecu connectors, restarting the ecu by unplugging the battery, checking visible sensor connectors , wires and i checked all fuses, none were damaged. Then i decided to replace the battery, which brought the obc to life and now i can see that my transmission is in failsafe mode too. What else can i try before i take it to a technician and pay myself sick? Im open to every trick in the book!!