1999-2001 Coil Pack Diagnostic Tests (Chrysler 3.3L)

This tutorial is a step by step testing guide to diagnose and troubleshoot a misfire condition and/or a bad ignition coil pack on the 1999-2001 3.3L V6 equipped Chrysler (Dodge and Plymouth) mini-vans.

NOTE: There are two other ignition coil pack test tutorial:

This first section contains a lot of important information that will help you to successfully diagnose the coil pack on your Chrysler (or Dodge and Plymouth) mini-van.

En Español You can find this tutorial in Spanish here: Cómo Probar La Bobina De Encendido (1999-2001 3.3L Chrysler) (at: autotecnico-online.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) mini-van 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, P0305, P0306.
  7. Rotten egg smell coming out of the tail-pipe.

Where To Buy The Ignition Coil And Save

The following links will help you comparison shop for the ignition coil pack:

Not sure if the above ignition coils fit your particular vehicle? Don't worry, once you get to the site they'll make sure it fits by asking you the specifics of your vehicle. If they don't fit, they'll find you the right ones.

What Tools Do I Need?

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

  1. A 12 Volt automotive test light.
  2. A multimeter (don't have a digital multimeter? Need to buy one? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing).
  3. A LED light.
  4. An 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) mini-van. Using the wrong tool or method will have you chasing a wrong diagnostic test conclusion and effectively wasting your time and money.

Coil Pack Circuit Descriptions

1999-2001 Coil Pack Diagnostic Tests (Chrysler 3.3L) 1999-2001 Coil Pack Diagnostic Tests (Chrysler 3.3L)

It's important to know what the four wires coming out of the Chrysler coil pack connector do and below you'll learn the circuit descriptions of each.

  • Circuit labeled 1:
    • Switching Signal Circuit for spark plugs 3 and 6.
  • Circuit labeled 2:
    • Switching Signal Circuit for spark plugs 1 and 4.
  • Circuit labeled 3:
    • Power (12 Volts) Circuit
  • Circuit labeled 4:
    • Switching Signal Circuit for spark plugs 2 and 5.

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

1999-2001 Coil Pack Diagnostic Tests (Chrysler 3.3L)

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 crankshaft position sensor starts to create its CKP signal, as the engine cranks.
  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 activates the Auto Shut Down (ASD) Relay and decides which ignition coil (within the coil pack assembly) to fire. It does this by sending the coil pack three different Switching signals (thru' separate circuits)
    • 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.
    • The ASD Relay is the one that powers the coil pack and this only happens with the engine cranking or running. The ASD Relay will not power up the coil pack with just the key in the ON position (and engine OFF).
  3. The coil pack is made up of three separate and individual ignition coils, therefore each one gets its own switching signal from the PCM. Each ignition coil within the coil pack has two towers that feed spark to two cylinders at the same time.
    • One ignition coil within the coil pack fires spark to cylinders 3 and 6.
    • One ignition coil fires cylinders 1 and 4.
    • The other ignition coil fires cylinders 2 and 5.
  4. 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).

To test the Chrysler ignition coil (for these specific 3.3L Chrysler engines this article covers) the only thing that you have to worry about is knowing that two cylinders get spark at the exact same time (#3 and #6, #1 and #4, #2 and #5) from separate ignition coils within the coil pack assembly.

Precautions, Do's And Don'ts

The tests you're about to learn are pretty simple and easy but, since most of them are done with the engine cranking, you need to be alert and on your toes. 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.
  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. It's important that you start your diagnostic from TEST 1, do not skip around from test to test unless specifically instructed to do so by the TEST you are currently on.
  5. Do not use a 12 Volt test light where an LED light is called for.
  6. Once again, use the recommended/indicated tools for all of your tests.