I have a 91 318i. It sat for about 3 months between my son parking it now that he has his 95 318is and my daughter starting to use it because she needed a car. The battery had drained enough that when I went to start it, it wouldn't start so I put the battery charger to it. That worked fine. The battery charged up and the car worked, but my son pointed out that I would need to reenter the radio code to get that working. I did this and it worked fine. turned off the car, etc. When my daughter then took the car (she was driving about 8 miles away) the radio worked and all was well, but when she got back in the car a couple hours later, she called and asked me for the radio code because the radio was showing CODE. I told her where to find it but she couldn't get it to "take." When she got back home, I noticed that not only was the radio code not taking, but the clock module had reset itself. I set the clock and when I turned off and turned on the car again, it was back to 12:00 and wanted the radio CODE. I can't get the radio to accept the code and work and the clock keeps reseting. (And we tried the "turn on the car for 65+ minutes with the radio off" trick, but that didn't do any good.) Any thoughts where to begin looking?