One problem related to ignition module has been reported for the 2001 BMW 325. The most recently reported issues are listed below.
Purchased the car used, in January 2011, with approximately 110,000 miles. Vehicle had several stored engine codes, po0300,171,174,1345,1351,1353; mostly relating to oxygen sensors and the maf. All engine hoses, the maf, all 4 oxygen sensors and the ignition coil packs were replaced by a certified mechanic. Within 2 months of normal driving, all codes had returned. Mechanic is unable to determine the points of failure for these issues and BMW denies any existing problem the passenger side airbag light, turns on and off, randomly, whether someone is sitting there, or not. Failure of the sensor could cause the ab not to deploy during an accident, causing serious, if not fatal, injury. BMW is aware of the issue, does not replace/repair. Door lock/window/windshield wiper control module, known as gm5, fails randomly and often. It has failed several times, while I was in the car. Since it disables the door locks and windows, I was trapped in my car for several minutes. Thankfully, I had the window rolled down far enough to pass my keys to someone on the outside, so they could unlock the door. In an accident, passengers could be stuck, keeping emergency workers from giving them medical attention, in a timely fashion. BMW is fully aware of the problem, but denies it's existence. I also receive random exterior light out warnings, on the dash. Usually, it's both taillights, but more frequently, it is the driver side light sensor, that fails, though the light is actually working, just fine.