The ignition system on your 2.4L minivan is a "waste spark" type ignition system. The ignition coil pack at the heart of it can easily be tested with a basic hand tools.
In this tutorial I'll show you how. You'll easily find out if the ignition coil pack is causing an cylinder misfire issue or an engine no-start problem.
Contents of this tutorial:
- Symptoms Of A Bad Ignition Coil.
- What Tools Do I Need?
- Waste Spark Ignition System Basics.
- TEST 1: Checking All Four Spark Plug Wires For Spark.
- TEST 2: Testing For Spark At The Ignition Coil Pack.
- TEST 3: Testing For Spark At The Ignition Coil Pack (Paired Cylinders).
- TEST 4: Testing For Spark At The Ignition Coil Pack (Non-Paired Cylinders).
- TEST 5: Making Sure The Coil Pack Is Getting 12 Volts.
- TEST 6: Checking The Activation Signal For Cylinders 1 And 4.
- TEST 7: Checking The Activation Signal For Cylinders 2 And 3.
- TEST 8: Making Sure The Ignition Coil Pack Is Getting Its Activation Signals.
- Other Possible Misfire Causes.
You can find this tutorial in Spanish here: Cómo Probar La Bobina De Encendido (2.4L Caravan, Grand Caravan, Voyager, Grand Voyager) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 2.4L Chrysler Voyager: 2000, 2001, 2002, 2003.
- 2.4L Dodge Caravan: 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007.
- 2.4L Dodge Grand Caravan: 1996, 1997.
- 2.4L Plymouth Voyager: 1996, 1997, 1998, 1999, 2000.
- 2.4L Plymouth Grand Voyager: 1996, 1997.
Symptoms Of A Bad Ignition Coil
Typically , the ignition coil pack fails in one of two ways. It stops creating spark for a single cylinder or it stops creating spark for two or more cylinders.
In both cases, you may see one or more of the following symptoms:
- Cylinder misfire: This can cause the engine to run rough, hesitate, or even stall.
- Check engine light on: The check engine light will illuminate when an ignition coil pack fails.
- Misfire trouble codes: You'll see one or more of the following cylinder misfire trouble codes:
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
- Rough idle: The engine may vibrate or shake excessively at idle.
- Reduced power: The engine may not produce as much power as it normally does.
- Bad gas mileage: The minivan may get worse gas mileage than usual.
- Engine doesn't start: This is the worst case scenario and happens when the ignition coil pack stops creating and supplying spark to two or more cylinders.
What Tools Do I Need?
To troubleshoot the ignition coil pack, you'll need a few basic tools. Here's the list:
- A spark tester.
- You can use any spark tester your used to using, the one that I use and always recommend (for its ease of use and accuracy) is the HEI spark tester (by OTC).
- You can see an example of the HEI spark tester and where to buy it here: The HEI Spark Tester (The Best Spark Tester On the Market) (at: easyautodiagnostics.com).
- A multimeter.
- An LED light.
- You can see an example of this tool here and where to buy it: The LED Light Test Tool And How To Make One (at: easyautodiagnostics.com).
- Battery jump start cables.
- Someone to help you crank the car.
Waste Spark Ignition System Basics
In this tutorial, you're gonna see the terms "paired cylinders" and "non-paired cylinders" quite a bit and it's important to understand what these mean to successfully diagnose the ignition coil pack as good or bad.
The first thing to know is that the ignition system on your 2.4L minivan is a "waste-spark" ignition system. This means that the ignition coil pack is made up of two individual ignition coils within it and one ignition coil is responsible for firing two spark plugs simultaneously.
In the case of your 2.4L minivan:
- Cylinders #1 and #4 get spark at the same time from one ignition coil within the ignition coil pack.
- Cylinders #2 and #3 get spark at the same time from one ignition coil within the ignition coil pack.
The cylinders (#1 and #4, #2 and #3) that get spark at the exact same time are called "paired cylinders".
Here are some more specifics: The two spark plugs that get spark at the same time are connected to cylinders that are opposite in their firing order. So when one cylinder is on its compression stroke, the other is on its exhaust stroke.
The term "waste-spark" comes from the idea that one of the sparks is "wasted" on the cylinder that's on its exhaust stroke, where no combustion is happening. The system is designed this way for simplicity and cost-effectiveness. While it may sound like the extra spark is "wasted," it actually doesn't harm the system and is an efficient way to make sure all cylinders get their necessary spark.
So, when you're dealing with "paired cylinders", you're essentially looking at two cylinders that get spark at the same time —one doing useful work (compression stroke) and the other not so much (exhaust stroke). In your minivan, the "paired cylinders" are:
- Cylinder #1 and cylinder #4.
- Cylinder #2 and cylinder #3.
On the other hand "non-paired cylinders", are any two cylinders that DO NOT get spark at the same time.
TEST 1: Checking All Four Spark Plug Wires For Spark
To get our ignition coil pack diagnostic started, we're gonna test all four spark plug wires for spark with a spark tester.
It's important to use a spark tester because only a spark tester will give you an accurate test result. Any other method of checking for spark that does not involve a spark tester will have you chasing ghosts and you'll end up replacing parts that won't solve the problem.
You might already have an idea which cylinder is the one misfiring or maybe not. Either way, I suggest that you test all four cylinders for spark. Remember, the successful outcome of your ignition coil pack diagnostic lies in the usage of a spark tester.
Let's get started:
Remove the spark plug wire (high tension cable) from the cylinder #1 spark plug.
Attach the spark tester to the spark plug wire.
Ground the spark tester with a battery jump start cable.
Connect the spark tester to a clean metal surface on the engine or directly on the battery negative (-) terminal.
Have your helper crank the vehicle while you keep you eye on the spark tester.
NOTE: The vehicle may or may not start, either way be careful.
You're gonna' get one of two results: spark or no spark.
Now repeat this test on the other cylinders.
Let's take a look at what your test results mean:
CASE 1: You got spark from all four spark plug wires. This is the correct test result and it indicates that the ignition coil pack and spark plug wires are OK.
The cause of your misfire condition is not due to a bad ignition coil pack. Go to: Other Possible Misfire Causes to see further tips and suggestions.
CASE 2: You got NO spark from only one spark plug wire. The next step is to check for spark directly on the ignition coil pack tower that feeds spark that spark plug wire (that did not spark). Go to: TEST 2: Testing For Spark At The Ignition Coil Pack.
CASE 3: You got NO spark from two spark plug wires that connect to paired cylinders (1 and 4 or 2 and 3). The next step is check for spark directly on the ignition coil pack towers that feed those spark plug wires with spark, go to: TEST 3: Testing For Spark At The Ignition Coil Pack (Paired Cylinders).
CASE 4: You got NO spark from two spark plug wires that DO NOT connect to paired cylinders. The next step is check for spark directly on the ignition coil pack towers that feed those spark plug wires with spark, go to: TEST 4: Testing For Spark At The Ignition Coil Pack (Non-Paired Cylinders).
CASE 5: You got NO spark from none of the spark plug wires. This usually indicates that the ignition coil pack is not getting power or that the crankshaft position sensor is bad.
Your next step is to make sure that the ignition coil pack is getting 10 to 12 Volts. For this test go to: TEST 5: Making Sure The Coil Pack Is Getting 12 Volts.