How To Test Ignition Coils (1995-1998 1.5L Toyota Tercel)

TEST 2: Checking For Spark Directly On The Ignition Coil's Tower

If you've reached this point, an ignition coil's spark plug wire IS NOT sparking, but its spark plug boot is (TEST 1).

NOTE: If the ignition coil's spark plug and spark plug boot sparked, this test does not apply to you.

The lack of spark from the spark plug wire means that either the spark plug wire or the ignition coil is bad.

To find out, we'll place the spark tester directly on the ignition coil's tower and test for spark (see photo above).

If the spark tester sparks, you can conclude that the spark plug wire is bad.

If the spark tester DOES NOT spark, you can conclude that the ignition coil is bad.

Let's get testing:

1. 1

   Disconnect the spark plug wire that did not spark (in TEST 1) from its ignition coil.

2. 2

   Place the spark tester in the ignition coil's tower, as shown in the photo above.

3. 3

   Ground the HEI spark tester with a battery jump start cable directly on the battery negative (-) terminal.
   
   The battery jump-start cable will also hold the spark tester in place.

4. 4

   Have a helper crank the engine while you observe the spark tester.

5. 5

    The spark tester should spark.

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

CASE 1: The spark tester sparked. This test result confirms that the spark plug wire (that connects to the ignition coil's tower) is bad.

Replace the spark plug wire if you have:

• Confirmed that the ignition coil's spark plug wire DOES NOT spark (TEST 1).
• Confirmed that the ignition coil's spark plug boot does spark (TEST 1).
• Confirmed that the ignition coil's spark plug wire tower sparked (this test section).

CASE 2: The spark tester DID NOT spark. This test result confirms that the ignition coil is bad.

Replace the ignition coil if you have:

• Confirmed that the ignition coil's spark plug wire DOES NOT spark (TEST 1).
• Confirmed that the ignition coil's spark plug boot does spark (TEST 1).
• Confirmed that the ignition coil's spark plug wire tower DID NOT spark (this test section).

TEST 3: Making Sure The Ignition Coil Is Getting Power

Although it's rare for just one ignition coil to lose power (and cause it to stop creating and delivering spark), it does happen.

So in this test section, we're going to do a simple multimeter Volts test on the ignition coil connector to ensure that it's receiving 10 to 12 Volts DC.

In the photo above, the female terminal labeled with the number 1 is the one that delivers power to the ignition coil. It's important to note that:

• On the 1995 Toyota Tercel, a black with orange stripe (BLK/ORG) wire connects to terminal 1.
• On the 1996-1998 Toyota Tercel, a black with white stripe (BLK/WHT) wire connects to terminal 1.

If power is present, we'll move on to our last test, which is making sure that the ignition coil receives an activation signal from the igniter.

Let's get testing:

1. 1

   Disconnect the ignition coil from its electrical connector.

2. 2

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

3. 3

   Place your multimeter in Volts DC mode.

4. 4

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

5. 5

   With the red multimeter test lead and an appropriate terminal probe, probe the female terminal labeled with the number 1 (see the photo above).
   
   CAUTION: To avoid damaging the female terminal, do not insert the multimeter's probe into the terminal. I recommend using a back probe or a wire piercing probe on the wire.

6. 6

   Your multimeter should register 10 to 12 Volts DC.

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

CASE 1: Your multimeter reported 10 to 12 Volts DC. This is the correct and expected test result and tells you that the ignition coil is receiving power.

Your next step is to ensure that the ignition coil is receiving an activation signal. Go to: TEST 4: Checking For The Ignition Coil's Activation Signal.

CASE 2: Your multimeter report 0 Volts DC. This tells you that the ignition coil is not receiving power. Without power, it won't create and deliver spark to its two cylinders.

The most likely cause of these missing 10 to 12 Volts is an open-circuit problem in the BLK/WHT (or BLK/ORG) wire of the ignition coil's connector.

Your next step is to find and repair the cause of this missing voltage.