No Spark Caused by a Shorted Ignition Coil
This 1997 Chrysler Sebring with a 2.5 liter came in as a no start. The basic checks revealed a no spark condition. Instead of checking for a good cam and crank signal I pulled the distributor cap off to check spark right at the coil that is located in the distributor housing. With my spark tester hooked up to the coil I used my scan tool to actuate the coil spark test. I still did not have spark so I now know that I either have a coil, power, ground, or signal problem. I checked the power supply and had 12v. I than checked the signal from PCM.The PCM signal triggers a transistor in the distributor to fire the coil. Instead of using a test light like I do with other Chrysler’s, where the PCM coil driver is the actual ground for the coil, I used my logic probe. With the logic probe I could see that the PCM was attempting to fire the coil. I now knew I had a bad coil but did a current test to confirm my belief. The current test revealed a shorted coil, which you can see by how the amperage jumps straight up instead of having a nice even slope. I tested the new used coil to make sure it worked before I installed it. With every thing back in place the Sebring pop right off. Having the ability to see amperage in work really makes life easier.
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