I will show you how to troubleshoot the entire ignition system, including cam and crank signals, ECU to igniter control and igniter to ignition coil control using a simple test light. A follow up test will be done with a small single channel lab scope, showing yet another way to verify the same condition.

Engine Performance Diagnostics chapter 22

Topics discussed


  • no start


  • replace faulty ignition coil

test shown

  • how to test for spark and injector pulse with an incandescent test light
  • using injector pulse as a guide for good cam and crank signals
  • how to test for igniter control of the ignition coil
  • how to isolate the ignition coil to test the igniter itself
  • how to perform a primary coil current ramp test with a lab scope (uScope) and an inductive low amp probe

Tools used

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

Related videos:

How to troubleshoot a no spark condition with a test light (Subaru):


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


2004 Saturn Ion 2.2 misfire, no spark from one coil, bad ignition module:


Ignition coil-module test with test light (a free SD Premium video):


Misfire case study featuring a uScope by AESwave.com:


What does an open plug wire look like on a lab scope (uScope):


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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!