Oscilloscope Pattern Diagnostics (Various Coil Manufacturers)
WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 2003 BMW Z8, 2003 BMW Z4, 2003 BMW X5, 2003 BMW M5, and 2003 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
If vehicle is equipped with Bremi, Beru, May and Christe or Bosch coil, evaluate ignition voltage peaks and decay characteristics at idle speed. See Fig 1. To evaluate combustion voltage characteristics at increased engine speeds of approximately 2500 RPM, See Fig 2-Fig 5 .