How to Reset the Service Light in a BMW E34
- 1). Turn the ignition off. Open the hood.
- 2). Twist open the cap of the data link connecter, located directly in front of the engine.
- 3). Bend the paper clip into a "U" shape. Insert one end of the paper clip into port #7. Insert the other end into port #19. Each port has a small number next to it.
- 4). Turn the ignition switch to "ON" without starting the engine.
- 5). Remove the paper clip from both ports after the ignition has been on for five seconds.
- 6). Replace the cap to the data link connector.
- 7). Turn the ignition off.
Source...