12 13... Normal oscillogram (M, S, W engines only)
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 BMW 540i, 2002 BMW 540i, 2001 BMW 540i, 2000 BMW 540i, and 1999 BMW 540i. However, it is still accessible from the selected car via links, so may be relevant.
- Start of ignition voltage peak
- Level of ignition voltage
- Level of combustion voltage
- Period of combustion
- Combustion curve characteristics
- Start of decay process
- Termination oscillations
Secondary voltage patterns, beside one another:
Evaluation of ignition voltage peaks at idle speed (this example shows an engine with 4 cylinders).
NOTE:
The display of ignition voltage spikes is approx. 20-25% lower than the real value.
The uniformity of all cylinders to each other is more important than the height of ignition voltage peaks.
Differences of 3000... 4000 V are permitted.
The uniformity of all cylinders to each other is more important than the height of ignition voltage peaks.
Differences of 3000... 4000 V are permitted.
Evaluation of ignition voltage peaks at increased speed of approx. 2000 RPM (this example shows an engine with 4 cylinders).
Secondary voltage diagrams, superimposed:
Evaluation of combustion characteristics curve and decay characteristics at idle speed (this example shows a 4-cylinder engine).
Secondary voltage diagrams, consecutive:
NOTE:
Only the major differences in the ignition voltage patterns are revealed by this method of comparison.
The identified fault must be allocated to the relevant cylinder using the secondary voltage representation forms next to/on top of each other.
The identified fault must be allocated to the relevant cylinder using the secondary voltage representation forms next to/on top of each other.