I recently bought a relatively cheap hantek oscilloscope off of amazon so that I can test some of the sensors more precisely, But now I'm curious.

Can a T-pin be backprobed into the coil pack of the spark plug wires and grounded to the frame or spark plug somehow to test for a misfire, or is that not safe considering the voltage coming out of the pack... I havent seen anything about this online, I've just seen ways to check the spark with high end obd scanners.

1 Answer 1



If you don't have 'coil on plug signal probe' you can measure the coil induced magnetic field in conjunction with for example the ignitor's trigger signal. Although, this can only be done if your scope is sensitive enough.

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Most COP are either 3 or 4 wire.

One will be your 12V, ground (return), ignition trigger and ECM signal feedback (optional).

On your scope connect your black probe to the battery NEG. terminal, CH1 will go to the ignition trigger and CH2 will be simply placed on top the ignition coil.

Zoomed in you will be able to see your coil charge time and spark duration.

Good running engine should have at least 1.2ms spark duration.

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Hope that helps.

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