How To Test The Ignition Coil (1989-1992 1.6L Toyota Corolla)

TEST 3: Checking The Distributor Cap For Spark

The spark tests in TEST 1 showed that some spark plugs aren't sparking. This usually happens for one of two reasons:

1. Bad spark plug wire: The spark plug wire is old or damaged and can no longer transmit spark to its spark plug.
2. Bad distributor cap: The metal terminal inside the distributor cap tower is covered in carbon tracks or corrosion, and no longer able to transmit spark to the spark plug wire.

To figure out which one's the problem, we'll run a quick spark test on the distributor cap tower(s) connected to the non-sparking spark plug wire(s). If more than one wire isn't sparking, we'll test them one at a time.

Here's what we're looking for:

• If the distributor cap tower sparks: The spark plug wire is bad.
• If there's no spark: The distributor cap tower itself is bad.

Alright, let's get started:

1. 1

   Make sure all spark plug wires are connected to their spark plugs (if any were disconnected).

2. 2

   Unplug the spark plug wire that didn't spark from its tower on the distributor cap.
   
   NOTE: If more than one wire isn't sparking, we'll test them one at a time. For now, disconnect only one from its distributor cap tower. In Step 8, we'll move on to the next.

3. 3

   Insert the spark tester into the distributor cap tower.

4. 4

   Ground the spark tester to the battery's negative (-) terminal using a battery jump-start cable.
   
   NOTE: The jump-start cable also helps keep the spark tester in place inside the distributor tower.

5. 5

   Have someone crank the engine.
   
   CAUTION: The engine might start during this test. Stay alert and take all safety precautions.

6. 6

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

7. 7

   Take out the spark tester and reconnect the spark plug wire.

8. 8

   Repeat the test for any other distributor cap towers connected to non-sparking spark plug wires from TEST 1.

Let's break down what your test result means:

CASE 1: The spark tester sparked while in the distributor cap tower. That's the result we're looking for.

This means the distributor cap tower is working fine, and the spark plug wire that didn't spark is bad. Replace all spark plug wires as a set.

CASE 2: The spark tester DID NOT spark while in the distributor cap tower. That points to a bad distributor cap.

Replace both the distributor cap and rotor, then recheck the non-sparking spark plug wires by running TEST 1 again.

TEST 4: Making Sure The Ignition Coil Is Getting Power

At this point, you've confirmed that:

• The spark plug wires aren't sparking (TEST 1).
• The ignition coil isn't sparking (TEST 2).

Now, we need to check if the ignition coil is getting 10-12 Volts DC when you turn the key to the ON position.

To do that, we're gonna test for voltage right at the ignition coil's (+) terminal (see the image above).

Alright, let's get to it:

1. 1

   Turn the key to the ON position, but don't crank the engine.

2. 2

   Take off the distributor cap if it's not already removed.

3. 3

   Set your multimeter to Volts DC mode.

4. 4

   Connect the black multimeter test lead to the battery's negative (-) terminal.

5. 5

   Use the red multimeter test lead to probe the ignition coil terminal marked (+).

6. 6

   Your multimeter should show 10 to 12 Volts DC.

Let's break down what your test result means:

CASE 1: The multimeter showed 10 to 12 Volts DC. That's the result we're looking for.

Next, we need to check if the ignition coil is getting its activation signal. Head over to: TEST 5: Making Sure The Ignition Coil Is Getting Its Activation Signal.

CASE 2: The multimeter DID NOT show 10 to 12 Volts DC. That usually means the ignition switch is faulty and isn't sending power to the ignition coil.

Fixing this is outside the scope of this guide, but you'll need to troubleshoot the issue. Once the ignition coil gets power again, it should start sparking.

TEST 5: Making Sure The Ignition Coil Is Getting Its Activation Signal

So far, your tests have confirmed:

• The spark plug wires aren't sparking (TEST 1).
• The ignition coil isn't sparking (TEST 2).
• The ignition coil is receiving 10 to 12 Volts (TEST 4).

For our final test, we're gonna check if the igniter is sending an activation signal to the coil.

To do this, we'll use a 12-volt automotive test light to probe the ignition coil's (-) terminal while we crank the engine.

If you don't have a 12-volt test light, here's the one I recommend: Lisle 28400 Heavy Duty 12 Volt Test Light (at: amazon.com).

IMPORTANT: The igniter must remain connected to its electrical connector for this test to function.

Alright, let's get to it:

1. 1

   Clip the 12V test light's crocodile clip to the battery's positive (+) terminal.

2. 2

   Touch the test light's metal probe to the ignition coil terminal labeled (-).
   
   NOTE: Keep the probe in contact with the terminal during the next step.

3. 3

   Have a helper crank the engine while you watch the 12V test light.

4. 4

   The 12V test light should flash ON and OFF continuously while the engine cranks and runs.

Let's break down your test result:

CASE 1: The 12V test light flashed ON and OFF. That's the correct result, which means the igniter is working and sending the activation signal to the ignition coil.

If you've confirmed all of the following:

• None of the four spark plug wires are sparking (TEST 1).
• The ignition coil's tower isn't sparking (TEST 2).
• The ignition coil is getting 10-12 Volts (TEST 4).
• The ignition coil is receiving the activation signal (this test).

Then the ignition coil is bad and needs to be replaced.

CASE 2: The 12V test light DID NOT flash ON and OFF. That means the ignition coil isn't sparking because it's not getting an activation signal from the igniter.

The igniter is responsible for generating and sending this signal. Your next step is to test the igniter.

More 1.6L Toyota Corolla Tutorials

You can find a complete list of 1.6L Toyota Corolla tutorials and wiring diagrams in this index:

• 1.6L Toyota Corolla Index of Articles.

Here's a sample of the tutorials you'll find there:

• How To Test The Fuel Pump (1989-1993 1.6L Toyota Corolla).
• How To Test The Throttle Position Sensor (1989-1997 1.6L Toyota Corolla).
• How To Test Engine Compression (1989-1997 1.6L Toyota Corolla).
• How To Test A Blown Head Gasket (1989-1997 1.6L Toyota Corolla).