How To Test The Ignition Coil (1993-1995 1.6L Toyota Corolla)

If the ignition coil fails, in your Corolla, the engine is not gonna start due to a lack of spark. The good news is that testing the ignition coil isn't that hard.

In this tutorial, I'm gonna show you my ignition coil testing method step-by-step. With your test results, you'll quickly find out if the ignition coil is good or if it's bad and needs to be replaced.

NOTE: This test is done with the ignition coil still in the car. The images show the distributor removed only to clearly demonstrate the test connections. You don’t need to take it out of the engine for any of these steps.

APPLIES TO: This tutorial applies to the following vehicles:

• 1.6L (4A-FE) Toyota Corolla: 1993, 1994, 1995.
• 1.6L Geo Prizm: 1993, 1994, 1995.

Ignition Coil Test Tutorials:

• How To Test The Ignition Coil (1989-1992 1.6L Toyota Corolla).
• How To Test The Ignition Coil (1996-1997 1.6L Toyota Corolla).

Ignition Coil Basics

Your Toyota Corolla's ignition coil plays a key role in getting your engine started and running. Its job? Turning 12 Volts into the high-voltage spark needed to ignite the air-fuel mix in the engine's cylinders.

Here's how it works:

1. Pickup coil signals: When you turn the key and crank the engine, the pickup coil inside the distributor sends two signals —RPM (NE) and crankshaft position (G)— to the fuel injection computer.
2. Igniter activation: Once the computer gets these signals, it sends an activation signal to the igniter (ignition control module).
3. Ignition coil activation: The igniter then activates the ignition coil inside the distributor.
4. Ignition coil spark: The coil boosts 12V battery power into high voltage.
5. Spark distribution: This high voltage travels through the distributor cap and rotor to the spark plugs.
6. Cylinder ignition: At the spark plug, the high voltage jumps the spark plug gap, turns into a spark and ignites the air-fuel mix.
7. Engine starts: With all four cylinders getting spark and igniting their air/fuel mixture, the engine starts and runs.

To diagnose the ignition coil properly, you've gotta remember one key thing —it needs both an activation signal from the igniter and battery power to work right.

If either one is missing, the coil won't create the spark needed to start and keep the engine running.

What Tools Do I Need To Test The Ignition System?

You'll need three tools to test the ignition system on your 1993-1995 1.6L Toyota Corolla:

• Spark tester: This tool gives you an accurate spark test result. There are plenty to choose from, but I recommend the OTC HEI spark tester. You can check it out and buy it here: OTC 6589 Electronic Ignition Spark Tester (at: amazon.com).
• Multimeter: A multimeter helps confirm if the ignition coil's getting power (TEST 4). If you don't have one, here's the one I recommend: Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter with NCV Feature, Mastech MS8268 Upgraded, MS88 (at: amazon.com).
• 12V automotive test light: This test light checks whether the ignition coil is getting its activation signal in TEST 5. If you need one, this is the one I use and recommend: Lisle 28400 Heavy Duty 12 Volt Test Light (at: amazon.com).

Where To Buy The Ignition Coil And Save

I'm recommending the Standard Motor Products UF204 Ignition Coil as the one you should purchase, since it's a well-known after-market brand. Once you get to amazon. Com thru the links below, you can also choose other brands too!

NOTE: Not sure if this ignition coil fits your Corolla? No worries! When you click the link and head to the site, they'll ask for your car's details to make sure it matches. If it doesn't, they'll help you find the right one.

TEST 1: Checking The Spark Plug Wires For Spark

The first thing we're gonna do, to get our diagnostic started, is check for spark at each spark plug wire. This will tell us if the engine's no-start issue comes from a lack of spark.

For the best results, use a proper spark tester. I recommend the OTC 6589 Electronic Ignition Spark Tester —I use it myself, and it works right out of the box. You can check it out and grab one here: OTC 6589 Electronic Ignition Spark Tester (at: amazon.com).

Let's get started:

1. 1

   Pull the spark plug wire off the #1 cylinder's spark plug.

2. 2

   Plug the spark tester into the spark plug wire.

3. 3

   Use a battery jump-start cable to Ground the spark tester directly to the battery's negative (-) terminal.

4. 4

   Have someone crank the engine while you watch the spark tester.

5. 5

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

6. 6

   Remove the spark tester from the spark plug wire and reconnect the wire to its spark plug.

7. 7

   Repeat steps 1 through 6 for the other spark plug wires.

Now, let's break down what your test result means:

CASE 1: All four spark plug wires sparked. That's exactly what you wanna see —it means the ignition system isn't the reason your engine won't start.

You can also rule out these parts as the cause:

• The igniter (ignition control module).
• The ignition coil.
• The pickup coil (inside the distributor).
• The distributor cap and rotor.
• The spark plug wires.

If the engine won't start, the problem isn't the ignition coil or in the ignition system.

CASE 2: Some, but not all, spark plug wires sparked. This usually means the wires that didn't spark are bad, or the distributor cap has failed.

To dig deeper, head over to: TEST 3: Checking The Distributor Cap For Spark.

CASE 3: None of the spark plug wires sparked. That means the engine won't start because there's no spark at all.

For our next step we need to check if the ignition coil itself is sparking. Head over to: TEST 2: Checking The Ignition Coil For Spark.

TEST 2: Checking The Ignition Coil For Spark

In most cars, the ignition coil sits outside the distributor, and a high-tension wire connects it to the distributor to send the spark.

In the Toyota Corolla, the ignition coil is inside the distributor. In this setup, it sends the spark straight to the distributor cap.

From there, the cap directs the spark to the distributor rotor, which then passes it to the metal terminals inside the cap.

Next, the spark moves through the distributor cap towers, into the spark plug wires, and finally reaches all four spark plugs.

In this section, we're gonna remove the distributor cap and use a spark tester to check for spark right at the ignition coil.

• If the ignition coil sparks: The issue is probably a bad distributor cap or rotor, keeping the engine from starting.
• If there's no spark: We'll move on to TEST 4 to keep troubleshooting.

Alright, let's get to it:

1. 1

   Remove the distributor cap from the distributor.
   
   NOTE: The distributor must be connected to both its electrical connectors.

2. 2

   Place the spark tester on the ignition coil's metal terminal.
   
   NOTE: The spark tester might slip off while cranking the engine, so it's a good idea to wrap them together with black electrical tape. This keeps them connected and ensures solid metal-to-metal contact.

3. 3

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

4. 4

   Have someone crank the engine while you watch the spark tester.

5. 5

   You'll get one of two results: Spark or no spark.

Now, let's break down what your test result means:

CASE 1: The spark tester sparked. That's exactly what we wanna see.

If you've:

• Confirmed that none of the four spark plugs are sparking (TEST 1).
• Confirmed in this test that the ignition coil is sparking.

Then the no-spark issue (at the spark plug wires) is caused by a bad distributor cap or rotor, and they need to be replaced.

If the spark plug wires are as old as the distributor cap and rotor, it's time to replace them too.

CASE 2: The spark tester DID NOT spark. No spark usually means one of these problems:

1. The ignition coil is bad.
2. The ignition coil isn't getting power.
3. The ignition coil isn't receiving its activation signal from the igniter.

Next, check if the ignition coil is getting voltage. Go to: TEST 4: Making Sure The Ignition Coil Is Getting Power.