My car's service manual shows this for the ignition coils:
What is the ICM? Related to https://mechanics.stackexchange.com/a/2850/31, is there a way to check the coils to see if they are working correctly?
2003 Honda Civic EX D17A2 1.7L SOHC engine
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Honda Coil Over Plug setups have three wires. As mentioned they have an internal Ignition Control Module. Pins 1 & 2 are power and ground while pin 3 is the control signal from the Electronic Control Module.
You can test coil resistance with a multimeter.
How to Test an Ignition Coil with a Multimeter
You can also check the primary coil with a digital storage oscilloscope and a low amp inductance probe by observing the primary coil waveform.
This is known good ignition coil waveform from an 09 Accord 2.4 that uses the same style ignition coil.
Generally when observing waveforms problems on the primary coil will affect the secondary coil and vice versa.
As paulster2 mentioned you could also check ignition coil performance with a misfire code by swapping the suspect ignition coil, resetting codes and waiting for another code to show up.
Or by again swapping the suspect ignition coil and observing misfire counters with a scan tool.
