Two problems related to turn signal have been reported for the 2001 BMW X5. The most recently reported issues are listed below.
Today I brought my BMW X5 to dealer because the warning light goes on and off indicating a problem with the rear brake lights. Dealer said that the bulb holder had failed because of excessive heat melting the bulb holder. Last September, I had a new bulb holder assembly replaced for the rear turn signal after the same warning light came on and was then told that the device failed because of excess heat, melting the bulb assembly. These would seem to be related problems and safety issues.
Front turn signal socket failure. First the right side failed, then a few weeks later the left. Dealer says this is a common problem. The units should be replaced via recall on all affected vehicles since this is a legally required safety feature.