How To Test The Ignition Coil Pack (Chrysler 2.0L, 2.4L)

This article will help you test and troubleshoot a misfire on your Chrysler (or Dodge or Eagle or Plymouth or Mitsubishi) 4 cylinder car or mini-van equipped with an ignition coil pack.

This article covers both styles of the Chrysler 4 cylinder coil pack used on all of the Chrysler, Dodge, Eagle and Mitsubishi (Eclipse only) cars and mini-vans. Both types of coil packs work the same and are tested in the same way.

On the left (box titled Applies To), you'll find a complete list of Chrysler, Dodge, Eagle, Plymouth, and Mitsubishi cars and mini-vans that use this type of coil pack ignition system. Also, if you need to test the 6 cylinder mini-van Chrysler coil pack (with the flat coil pack connector), click here: How To Test The Ignition Coil Packs Chrysler, Dodge, and Plymouth 3.3L V6 Engines.

You can find this tutorial in Spanish here: Cómo Probar La Bobina De Encendido DIS (Chrysler 2.0L, 2.4L) (at: autotecnico-online.com).

I've written several other tutorials that I think will also help you:

• Carbon Tracks Are A Common Cause Of Ignition Misfires.
• How To Test Misfire Codes (Chrysler 2.0L, 2.4L) (at: troubleshootmyvehicle.com).
• How To Test A Fuel Injector (Chrysler 2.0L, 2.4L) (at: troubleshootmyvehicle.com).
• How To Test The Engine Compression (Chrysler 2.0L, 2.4L) (at: troubleshootmyvehicle.com).
• How To Test The Crank Sensor (2.0L, 2.4L) (at: troubleshootmyvehicle.com).

Symptoms Of A Bad Chrysler Coil Pack

When the ignition coil pack or the spark plug wires are bad, your Chrysler (or Dodge or Eagle or Plymouth or Mitsubishi) vehicle will display one or more of the following symptoms:

1. The car idles rough and wants to stall (die).
2. When you accelerate the car, it has no power.
3. Really bad gas mileage.
4. The vehicle will not start.
5. The car will not run on all cylinders.
6. Misfire codes that are lighting up the check engine light on your instrument cluster.
   • P0300, P0301, P0302, P0303, P0304.
7. Rotten egg smell coming out of the tail-pipe.

What Tools Do I Need?

To successfully use this information to diagnose and troubleshoot your Chrysler (or Dodge or Eagle or Plymouth or Mitsubishi) four banger, you need a few specific tools. Don't worry, none of this stuff is expensive, here's the list:

1. A 12 Volt test light.
2. A multimeter.
3. An LED light.
   • To see what this tool looks like, click here: The LED Light Test Tool And How To Make One.
4. An HEI spark tester
   • This tool is a must have. To see what this tool looks like, click here: HEI Spark Tester.
5. Battery jump start cables.
6. Someone to help you crank the car.

The HEI spark tester is a must have tool to be able to troubleshoot and diagnose a bad coil pack on your Chrysler (or Dodge or Eagle or Plymouth or Mitsubishi) car.

Using the wrong tool or method will have you chasing a wrong diagnostic test conclusion and effectively wasting your time and money (don't have an HEI spark tester? Need to buy one? You can buy it here: OTC 6589 Electronic Ignition Spark Tester).

Circuit Descriptions Of The Chrysler Coil Pack Connector

The Chrysler coil pack connector has three wires coming out of it. No matter what the style of coil pack or the style of connector that connects to it, the circuit descriptions are the same.

1. Circuit labeled 1:
   • Switching Signal Circuit for Spark Plugs 2 and 3.
2. Circuit labeled 2:
   • Power (12 Volts) Circuit.
3. Circuit labeled 3:
   • Switching Signal Circuit for Spark Plugs 1 and 4.

You've probably noticed that there's no mention of the color of the wires of the three wires coming out of the connector, well the color is not important (to take advantage of the info in this article) as long as you're able to correctly identify the circuit by its number in the photos supplied.

Basic Operating Theory Of The Chrysler Coil Pack

The PCM (Powertrain Control Module=Fuel Injection Computer) is the one that controls the whole show in this type of ignition system since the 'ignition control module' function is handled by the PCM itself. So, in a nutshell, here's what happens when you turn the key to crank and start the car:

1. The engine starts to crank, inducing the crankshaft position (CKP) sensor to start producing its CKP signal.
2. The CKP signal, upon being received by the PCM along with other necessary sensor information, starts to do its little song and dance and sends back two different Switching signals (thru' separate circuits) to the ignition coil pack.
   • The coil pack is made up of two separate ignition coils. Each ignition coil within the coil pack has two towers that feed spark to two cylinders at the same time.
   • The term Switching signal describes the PCM's action of switching the Primary Current (12 Volts), flowing thru' each ignition coil within the coil pack, ON and OFF by interrupting their Ground path. It's this signal that makes the ignition coils fire spark.
   • Each ignition coil (that make up the coil pack) get their own switching signal from the PCM.
3. As each individual ignition coil, within the ignition coil pack, get their Switching signal, they then fire spark to two different cylinders at the exact same time (in what's known as the Waste Spark method).
   • One ignition coil within the coil pack fires spark to cylinders 1 and 4.
   • The other ignition coil that makes up the other part of the coil pack fires cylinders 2 and 3.

The only thing that you have to remember about the above information is that cylinders 1 and 4 are paired together, as are cylinders 2 and 3. And again, this just means that these paired cylinders get spark at the same time and from the same ignition coil within the ignition coil pack.

Precautions, Do's And Don'ts

Most of the testing that you'll be doing is with the engine cranking, so take all necessary safety precautions to keep your fingers, hands and entire self safe. Here are a few other tips and suggestions:

1. All of the coil pack tests in this article are ON CAR TESTS. Do not remove the ignition coil pack from the vehicle.
   • To make it easier to explain some of the tests or info in this article, the ignition coil pack has been photographed off of the car.
2. Do not use a regular spark plug instead of a spark tester to test for spark.
3. Do not remove the spark plug wire from the spark plug or the ignition coil while the engine is cranking to test for spark.
4. Start your diagnostic from TEST 1, do not skip around from test to test unless instructed to do so by the TEST you are currently on.
5. Do not use a test light where an LED light is called for.
6. Once again, use the recommended/indicated tools for all of your tests.