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

{accordionfaq faqid=accordion15 faqclass="dotluvfaq help2 aligncenter headerbackground headerborder contentbackground contentborder round7" active=item0}


(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

{accordionfaq faqid=accordion3 faqclass="darkhivefaq defaulticon headerbackground headerborder contentbackground contentborder round5" active=item0}

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.

Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium. There is a 14 day free trial.

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!