How To Test The Ignition Coil Pack (2000-2004 2.0L Ford Focus)

Testing the ignition coil pack on your 2.0L Ford Focus, to see if it's causing an engine no-start problem or a cylinder misfire, isn't difficult nor complicated.

In this tutorial, I'm gonna show you how to test the ignition coil pack with each test laid out in a simple, step-by-step way so you can quickly confirm if the coil pack is the issue.

And the best part is, you don't need any expensive diagnostic equipment, you only need three basic tools: a spark tester, a multimeter, and a 12 Volt test light.

NOTE: This tutorial applies to both the single overhead cam (SOHC) and double overhead cam (DOHC) 2.0L engines used in the Ford Focus between 2000 and 2004.

APPLIES TO: This tutorial applies to the following vehicles:

• 2.0L (SOHC) Ford Focus: 2000, 2001, 2002, 2003, 2004.
• 2.0L (DOHC) Ford Focus: 2000, 2001, 2002, 2003, 2004.

IGNITION COIL TESTS (2005-2010) FOCUS:

• How To Test The COP Ignition Coils (2005-2010 2.0L Ford Focus).

Symptoms Of A Bad Ignition Coil Pack

The ignition coil generates the spark that the spark plug wires deliver to the spark plugs to get your Focus's engine started and running.

When either the spark plug wires or the coil pack fails, you'll see one or more of the following driveability issues appear:

• Rough idle and stalling.
• Lack of power on acceleration.
• Bad gas mileage.
• The engine cranks but won't start.
• Misfire trouble codes —the check engine light illuminates with with one or more of the following codes:
  • P0300: Random Cylinder Misfire.
  • P0301: Cylinder #1 Misfire.
  • P0302: Cylinder #2 Misfire.
  • P0303: Cylinder #3 Misfire.
  • P0304: Cylinder #4 Misfire.
• Rotten egg smell from the exhaust from unburned fuel entering the catalytic converter and creating a sulfur smell.

What Tools Do I Need To Test The Ignition Coil?

To diagnose your Ford Focus's ignition coil pack (and spark plug wires), you're gonna need a few basic tools. Don't worry, they're not expensive. Here's what you'll need:

• A 12 Volt test light with an incandescent bulb to check the coil A and B activation signals. If you don't have one, this is the one I use and recommend: Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).
• A spark tester. This tool is a must have. If you don't have one and need to buy one, I recommend the HEI spark tester. It's accurate and the one I always use: OTC 6589 Electronic Ignition Spark Tester (Amazon affiliate link).
• Battery jump start cables to help you Ground the spark tester to the battery negative (-) terminal.
• A helper. Someone to help you crank the engine during the tests.

NOTE: To troubleshoot and diagnose a bad coil pack on your Ford Focus, a spark tester is a must-have tool. If you use the wrong tool or method, you'll end up chasing the wrong conclusion and wasting both time and money.

Where To Buy The Ignition Coil And Save

When you're ready to replace the ignition coil pack on your 2.0L Ford Focus, I recommend two solid brands: Standard Motor Products and Motorcraft (with Motorcraft being the factory original part):

TEST 1: Testing For Spark At The Spark Plug Wire

To start our coil pack diagnostic, we're gonna test all four spark plug wires for spark with a spark tester.

It doesn't matter which type of spark tester you use, as long as you use one. If you don't, you'll end up with misleading test results that'll have you chasing your tail instead of pinpointing the cause of the issue.

One more thing you need to know about the coil pack: it's actually made up of two separate ignition coils. Each one has two towers and fires spark to a pair of cylinders at the same time (waste-spark system).

• Ignition Coil A: Fires spark to cylinders 1 and 4.
• Ignition Coil B: Fires spark to cylinders 2 and 3.

So, when you're doing your spark tests and you see two wires not sparking, the first thing to check is whether they belong to a paired set —either 1 and 4, or 2 and 3.

NOTE: If your Ford Focus has the single overhead cam (SOHC) engine, I recommend you use spark plug wire pullers to disconnect the high-tension wires from their spark plugs. This will help you avoid having the wire's metal terminal stay stuck on the spark plug (a common issue). The terminal can be reattached, but it's a hassle (you're probably better off not having to deal with it). If you don't have one, this is the one that I recommend, and you can buy it here: Performance Tool W80519 Adjustable Spark Plug Boot And Wire Remover (Amazon affiliate link).

These are the test steps:

1. 1

   Remove the spark plug wire (high tension cable) from the spark plug.

2. 2

   Attach the a spark tester to high tension wire.

3. 3

   Connect the spark tester to the battery negative (-) terminal with a battery jump start cable.

4. 4

   Have your helper crank the vehicle as you stand at a safe distance from the engine.
   
   NOTE: Be careful, the engine may start.

5. 5

   As the engine cranks or runs, observe the spark tester.

6. 6

   You're gonna' get one of two results: Spark or NO spark.

7. 7

   Now repeat this test on the other spark plug wires.

IMPORTANT: To correctly interpret your spark test result, you need to keep in mind that the coil pack is made up of two ignition coils firing spark to paired cylinders (1 & 4, or 2 & 3). If you got no spark on two spark plug wires, check to see if they belong to paired or unpaired cylinders (e.g., 1 & 3, 2 & 4, or 1 & 2).

CASE 1: All four spark plug wires sparked. This is the correct test result and it tells you the coil pack and spark plug wires are OK.

If you're troubleshooting a cylinder misfire condition, you can rule out a bad coil pack (as the cause). For more misfire troubleshooting tips, go to: Other Things That Can Cause A Misfire.

CASE 2: You got NO spark from only one spark plug wire. This result could be due to a bad spark plug wire or a bad coil pack.

Your next step is to check for spark directly on the coil pack tower that feeds that spark plug wire with spark. Head over 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). You now need to check for spark directly at the coil towers those non-sparking wires connect to.

For this spark test, jump over to: TEST 4: Testing For Spark At The Ignition Coil Pack (Paired Cylinders).

CASE 4: You got NO spark from two spark plug wires that do not belong to paired cylinders. Your next step is to check each coil pack tower (the ones those non-sparking wires connect to) directly for spark.

We'll perform this spark check here: TEST 3: Testing For Spark At The Ignition Coil Pack (Non-Paired Cylinders).

CASE 5: None of the spark plug wires sparked. This lack of spark wil definitely keep the engine from starting.

This lack of spark is generally caused by a lack of power (to the coil pack) or the crankshaft position (CKP) sensor has failed.

Your next step is to check that the coil pack is getting power. Go to: TEST 5: Making Sure The Coil Pack Is Getting IGN 12 Volts.

TEST 2: Testing For Spark At The Ignition Coil Pack

Your spark checks in TEST 1 confirm that you've got one spark plug wire that isn't sparking while cranking the engine.

This could be either because the wire itself is bad or because the coil pack is bad.

The cool thing is we can easily figure out which one it is by doing a spark test on that non-sparking wire's tower (on the coil pack).

Depending on the spark test result, we'll know if the spark plug wire is bad or if the coil pack is toast.

All right, let's get going:

1. 1

   Remove the spark plug wire that did not fire off spark from the coil pack.

2. 2

   Place the spark tester directly on the coil pack tower of the spark plug wire you just removed (see the example in the photo above).

3. 3

   Connect the spark tester to the battery negative (-) terminal with a battery jump start cable.

4. 4

   Have your helper crank the engine.
   
   CAUTION: The engine may start, so be careful.

5. 5

   You're gonna' get one of two results: Spark or NO spark.

Alright, let's find out what your spark test result means:

CASE 1: You got spark at the coil pack tower. This result tells you the coil pack is good and the spark plug wire is bad; replace all wires as a set.

CASE 2: You got no spark at the tower. This result confirms the coil pack is bad, and the reason the spark plug wire didn't spark in TEST 1. Replace the coil pack to fix the misfire and clear the CEL.

Ready to replace the coil pack? Here are two coil packs I recommend from two brands I trust —Standard Motor Products and Motorcraft— both of which I've used for years:

• Standard Motor Products FD497T Ignition Coil (Amazon affiliate link).
• Motorcraft - IGN Coil DG536 (Amazon affiliate link).

TEST 3: Testing For Spark At The Ignition Coil Pack (Non-Paired Cylinders)

IMPORTANT: This test step only applies if in TEST 1 you got two non-sparking spark plug wires and they DO NOT belong to paired cylinders.

Your spark checks in TEST 1 confirmed you've got two spark plug wires (that don't connect to paired cylinders) not sparking.

Those two wires didn't spark for one of two reasons:

• The spark plug wires themselves are bad.
• The coil pack is toast.

We can find out which of the two is the issue by checking each tower for spark with our spark tester. Depending on the result, we'll know if the plug wires are bad, if the coil pack is bad, or if both are bad.

NOTE: Paired cylinders are 1 & 4 and 2 & 3. If both non-sparking wires belong to paired cylinders, this test doesn't apply. Go to: TEST 4: Testing For Spark At The Ignition Coil Pack (Paired Cylinders).

Alright, here are the test steps:

1. 1

   Remove the spark plug wire that did not spark from the coil pack.

2. 2

   Place the spark tester directly on the coil pack tower for that wire (see the example in the photo above).

3. 3

   Connect the spark tester to the battery negative (-) terminal using a battery jump start cable.

4. 4

   Have your helper crank the engine.
   
   CAUTION: The engine may start, so be careful.

5. 5

   You'll see one of two results: Spark or NO spark.

6. 6

   Remove the spark tester and reconnect the wire to its coil pack tower.

7. 7

   Repeat the same spark test on the other coil pack tower —the one that connects to the second non-sparking wire you identified in TEST 1.

Let's find out what your spark test result means:

CASE 1: You got spark at both towers. This confirms the coil pack is good and the spark plug wires (that didn't spark) are bad. Replace all four spark plug wires as a set.

CASE 2: You got no spark from one tower but spark from the other. This tells you that:

• The ignition coil pack is bad —since only one tower is sparking.
• The spark plug wire is bad —this is the wire that belongs to the tower that sparked.

Replace the coil pack and all four spark plug wires.

CASE 3: You got no spark from both towers. This means the ignition coil pack is bad and explains why those two spark plug wires didn't spark in TEST 1.

Need a coil pack? The following are from Standard Motor Products and Motorcraft, brands I've used for years and recommend:

• Standard Motor Products FD497T Ignition Coil (Amazon affiliate link).
• Motorcraft - IGN Coil DG536 (Amazon affiliate link).