alarm problem, 98 mercedes e-320

So far i understand it is for the locks and the alarm (the car is not mine it is a friend whose English is not good enough for the forum). In the same area where the fuse box with the only  relay sits is a "CPU" box too. When he removed the relay and reinstated it all the sit functions and door lock function and the signal all started to work on the driver side, but the same time seat function and the window on the passenger side don't function. He tried a new relay but that didn't help any more. He is going to get in a day or two a used "cpu" box to try out. The alarm is too very unstable specially on the turns. (Sorry I call it a CPU may be it is a kind of computer). Thanks for taking interest to help me! I hope I will hear from you more! My electronic knowledge is not so good either- i know a little bit about DC and diodes, was working to build a automatic battery charger for many years ago, this year I will be 80 years old. Thanks so far!