Does anyone have a suggestion a simple method how I can find out when the factory controller decides it detected knock?

I assume it could be done by monitoring sudden changes in ignition timing, but I think it would be difficult to set up a scope trig condition for that.

What I want is to monitor the knock microphone using an oscilloscope and have it trig on knock detection. Then the scope can do an FFT analysis of the stored trace. Or save it on a USBstick for later analysis. But if it is not known that the sample is taken during a knock condition, it will not be of much help.

There's also a limitation on the depth of a trace that means it can either take a short duration high bandwidth trace, or a long duration low bandwidth trace. So logging a run with one channel on the microphone, one on the ignition and a the remaining 2 on the crank + cam sensors for later finding out where the ignition retard is will be a shot in the dark.

MembersPage/PhatBob Try using the method of calculating knock frequency as suggested in the MembersPage/PhatBob/UserGuide (updated 7 Nov 2006).

Knock Sensor Question


(Question from ESjaavik: On my V3.3 Sn:399 board the knock chip inputs seems to end in a 3pin header and not EC18? Am I missing something?)

MembersPage/PhatBob The picture shows the wiring for new units as delivered from the webshop with the Knock chip option. You will need to connect you knock sensor to the correct pins on the header - OR, connect your knock sensor input to the EC18pins shown above.