How to troubleshoot a bad coil on a coil over plug system, using a scope and a low amp probe. There are other ways to isolate the problem. You can move the suspect coil to another cylinder and see if the misfire code moves with the coil. But this test is not always reliable.

Engine Performance Diagnostics chapter 1 pages 13-16/chapter 22 pages 10-19

symptoms 50

  • misfire
  • hesitation
  • check engine light with misfire codes
  • low power

fix 50

  • replace shorted ignition coil

test shown enh 50

  • how to measure ignition coil current from the fuse box
  • how to sync the coil patterns to identify specific cylinders
  • how to set up a lab scope for ignition coil primary current tests
  • what a shorted coil secondary waveform looks like

Tools used

  • scan tool
  • lab scope
  • low amp probe

end faq

Playlist

(Chapter 22) No Spark Troubleshooting, Ignition Coil & Module Testing

Related videos:

Ford 5.4 shorted coil primary winding and bad computer driver:

How to identify a shorted ignition coil (Honda):

How to test for a shorted ignition coil with a scope (Lexus):

How to test for a shorted ignition coil (Honda Distributor):

How to test for spark with a test light (GM distributor ignition system):

end faq


For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available as an eBook or paper book.

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