How To Test The Ignition Coils (1996-2001 3.0L V6 Toyota Camry)

TEST 3: Making Sure The Ignition Coil Is Getting Its Activation Signal

Besides 10 to 12 Volts, the ignition coil receives an activation signal. This activation signal comes from the igniter (ignition control module).

It's not uncommon for the igniter to fail, and when it does, it stops sending an activation signal to the COP ignition coil.

The cool thing is that you and I can easily check if the ignition coil is receiving this activation signal with a 12 Volt automotive test light.

These are the test steps:

1. 1

   Disconnect the ignition coil from its connector.

2. 2

   Connect the crocodile clip of the 12V test light to the battery positive (+) terminal.

3. 3

   Gently probe the terminal of the connector labeled with the number 2.
   
   Depending on the ignition coil you're testing, terminal 2 will correspond to a wire with an unique color. Since we're only talking about a 2-wire connector, it'll be the wire that IS NOT the BLK/RED (BLK/ORG) wire.

4. 4

   Have your helper crank the engine as you observe the 12V test light.

5. 5

   The 12V test light should flash ON and OFF the whole time the engine is cranking and/or running.

Let's take a look at what your test results mean:

CASE 1: The test light flashed ON and OFF. This is the correct and expected test result and confirms the ignition coil is receiving an activation signal.

You can conclude that the ignition coil is bad and needs to be replaced if you have confirmed:

• The ignition coil's spark plug wire and spark plug boot are not sparking (TEST 1).
• The ignition coil is getting power (TEST 2).
• The ignition coil is receiving its activation signal (this test section).

CASE 2: The test light DID NOT flash ON and OFF. This let's you know that the ignition coil is not getting an activation signal from the igniter (ignition control module).

Without an activation signal, the ignition coil is not gonna spark, therefore, you can conclude that the ignition coil itself is not bad.

The most likely cause of this missing activation signal is a malfunctioning igniter (ignition control module). Your next step is to test the igniter.

TEST 4: Checking For Spark On The Ignition Coil Tower

If you've reached this test section, your TEST 1 spark test result confirms that one or more spark plug wires didn't spark, but you did get spark from the spark plug boot directly under the ignition coil.

This usually points to a bad ignition coil because the coil must fire spark from both its spark plug wire and the spark plug boot.

The one thing that complicates this is a bad spark plug wire. Even if the ignition coil is firing spark from both ends, a bad spark plug wire can prevent the spark from reaching the spark plug it's connected to.

To confirm if the spark plug wire is good or bad, we're gonna insert the spark tester directly into the tower of the non-sparking spark plug wire and check it (the tower) for spark.

• If the spark tester sparks, the spark plug wire is bad, and the ignition coil is good.
• If there's no spark from the coil's non-sparking plug wire tower, the ignition coil is bad.

IMPORTANT: The ignition coil itself must remain bolted in place (on the valve cover) to perform this test.

These are the test steps:

1. 1

   Disconnect the spark plug wire from the tower its connected to (on the ignition coil).

2. 2

   Insert the spark tester in the coil tower.

3. 3

   With a jump start cable, connect the spark tester to the battery negative (-) post.

4. 4

   Have your helper crank the engine as you observe it from a safe distance.

5. 5

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

6. 6

   Repeat steps 1 thru 5 on any remaining spark plug wire.

Let's interpret your test result:

CASE 1: You got spark from the ignition coil. This is the correct and expected test result.

With this spark test result you can conclude that the spark plug wire is bad if you have confirmed:

• The ignition coil's spark plug wire did not spark (TEST 1).
• The ignition coil's spark plug boot (the one that sits directly under it) did spark (TEST 1).
• The ignition coil's spark plug wire tower did spark (this test section).

Replace all of the spark plug wires with a new set.

CASE 2: You DID NOT get spark from the ignition coil. With this spark test result you can conclude that the ignition coil is bad if you have confirmed:

• The ignition coil's spark plug wire did not spark (TEST 1).
• The ignition coil's spark plug boot (the one that sits directly under it) did spark (TEST 1).
• The ignition coil's spark plug wire tower DID NOT spark (this test section).

More 3.0L Toyota Camry Tutorials

You can find a complete list of 3.0L Toyota Camry tutorials and wiring diagrams in this index:

• 3.0L Toyota Camry Index of Articles.

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

• How To Test Engine Compression (1992-2006 3.0L V6 Toyota Camry).
• How To Test For A Blown Head Gasket (1992-2006 3.0L V6 Toyota Camry).
• How To Test The TPS (1997-2001 3.0L V6 Toyota Camry).
• How To Test The MAF Sensor (1997-2001 3.0L V6 Toyota Camry).