My '89 535i which sat in the garage with the engine/trans out all winter is now giving false messages on the SI readout. The messages which began about two weeks after I reassembled the car are for brake linings, oil level, and oil pressure sensor. I'm pretty sure that all three of these sensors could not have gone faulty in one week and I know for a fact that the brake lining sensors are intact. I've heard that in some BMW's there are batteries that can die in the instrument cluster. Can someone confirm this for this specific model? I have removed and dissassembled the instrument cluster but have not been able to locate any batteries. Any help will be sincerely appreciated.