How To Test The Coil Packs, Ignition Module And CKP Sensor (1989-1994 2.3L Ranger, Mustang, B2300)

TEST 13: Cylinders 1 And 4 Activation Signal (Intake Side)

The ignition coil pack fires spark to the intake side spark plugs of cylinders 1 and 4 when it receives an activation signal from the ignition control module.

In this test section, you'll use a 12-Volt automotive test light to confirm that the ICM is sending the intake side 1/4 activation signal to the ignition coil pack.

The instructions below will help you test this activation signal at the coil pack connector.

The result of this test will help you determine if the ignition coil pack that supplies spark to the intake side spark plugs (for cylinders 1 and 4) is defective or if the ignition control module is defective.

NOTE: To perform this test, you'll need to crank the engine in your 2.3L Ford Ranger (Ford Mustang, Mazda B2300). Be careful and take all necessary safety precautions!

OK, to start this test, this is what you need to do:

1. 1

   Connect the sharp end of your 12 Volt test light to the wire that connects to the terminal labeled with the number 1.
   
   If you pierce the wire with the test light, do it a few inches away from the coil pack connector.
   
   On all vehicles covered by this tutorial, this will be the tan with light blue stripe wire.
   
   NOTE: Remember, you're testing the coil pack that feeds spark to the intake side spark plugs.

2. 2

   Connect the 12 Volt test light's alligator clip directly on the battery positive (+) post.

3. 3

   When ready, have a helper crank and start the engine while you observe the 12 Volt test light.
   
   IMPORTANT: Both the coil pack and the ignition module must be connected to their connectors for this test.

4. 4

   The 12 Volt test light should flash ON and OFF as the engine cranks.
   
   NOTE: Whatever the test light does when you turn on the key and before you start the engine DOES NOT matter, the result you want to look for is when the engine is cranking.

OK, let's interpret your test results:

CASE 1: The 12 Volt test light flashed ON and OFF. This is the correct test result and confirms that the ignition control module (ICM) is working properly and sending the activation signal the ignition coil pack needs to fire spark to the intake side spark plugs for cylinders 1 and 4.

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

• Confirmed that the intake manifold side spark plug wires for cylinders 2 and 3 are sparking (TEST 1).
• Confirmed that the intake side spark plug wires for cylinders 1 and 4 ARE NOT sparking (TEST 1).
• Confirmed that the intake side ignition coil towers for cylinders 1 and 4 ARE NOT sparking (TEST 5).
• Confirmed that the intake side ignition coil pack is receiving the 1/4 activation signal (this test section).

CASE 2: The 12 Volts test light DID NOT flash ON and OFF. This tells you that the ignition control module (ICM) is NOT sending the activation signal the ignition coil pack needs to fire spark to the intake side spark plugs for cylinders 1 and 4.

This test result tells you that the ignition control module is defective, if you have:

• Confirmed that the intake manifold side spark plug wires for cylinders 2 and 3 are sparking (TEST 1).
• Confirmed that the intake manifold side spark plug wires for cylinders 1 and 4 ARE NOT sparking (TEST 1).
• Confirmed that the intake side ignition coil towers for cylinders 1 and 4 ARE NOT sparking (TEST 5).
• Confirmed that the intake side ignition coil pack IS NOT receiving the 1/4 activation signal (this test section).

TEST 14: Cylinders 2 And 3 Activation Signal (Intake Side)

The ignition coil pack fires spark to the intake side spark plugs of cylinders 2 and 3 when it receives an activation signal from the ignition control module.

In this test section, you'll use a 12-Volt automotive test light to confirm that the ICM is sending the intake side 2/3 activation signal to the ignition coil pack.

The instructions below will help you test this activation signal at the coil pack connector.

The result of this test will help you determine if the ignition coil pack that supplies spark to the intake side spark plugs (for cylinders 2 and 3) is defective or if the ignition control module is defective.

NOTE: To perform this test, you'll need to crank the engine in your 2.3L Ford Ranger (Ford Mustang, Mazda B2300). Be careful and take all necessary safety precautions!

OK, to start this test, this is what you need to do:

1. 1

   Connect the sharp end of your 12 Volt test light to the wire that connects to the terminal labeled with the number 3.
   
   If you pierce the wire with the test light, do it a few inches away from the coil pack connector.
   
   On all vehicles covered by this tutorial, this will be the tan with light green stripe wire.
   
   NOTE: Remember, you're testing the coil pack that feeds spark to the intake side spark plugs.

2. 2

   Connect the 12 Volt test light's alligator clip directly on the battery positive (+) post.

3. 3

   When ready, have a helper crank and start the engine while you observe the 12 Volt test light.
   
   IMPORTANT: Both the coil pack and the ignition module must be connected to their connectors for this test.

4. 4

   The 12 Volt test light should flash ON and OFF as the engine cranks.
   
   NOTE: Whatever the test light does when you turn on the key and before you start the engine DOES NOT matter, the result you want to look for is when the engine is cranking.

OK, let's interpret your test results:

CASE 1: The 12 Volt test light flashed ON and OFF. This is the correct test result and confirms that the ignition control module (ICM) is working properly and sending the activation signal the ignition coil pack needs to fire spark to the intake side spark plugs for cylinders 2 and 3.

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

• Confirmed that the intake manifold side spark plug wires for cylinders 1 and 4 are sparking (TEST 1).
• Confirmed that the intake side spark plug wires for cylinders 2 and 3 ARE NOT sparking (TEST 1).
• Confirmed that the intake side ignition coil towers for cylinders 2 and 3 ARE NOT sparking (TEST 5).
• Confirmed that the intake side ignition coil pack is receiving the 2/3 activation signal (this test section).

CASE 2: The 12 Volts test light DID NOT flash ON and OFF. This tells you that the ignition control module (ICM) is NOT sending the activation signal the ignition coil pack needs to fire spark to the intake side spark plugs for cylinders 2 and 3.

This test result tells you that the ignition control module is defective, if you have:

• Confirmed that the intake manifold side spark plug wires for cylinders 1 and 4 are sparking (TEST 1).
• Confirmed that the intake manifold side spark plug wires for cylinders 2 and 3 ARE NOT sparking (TEST 1).
• Confirmed that the intake side ignition coil towers for cylinders 2 and 3 ARE NOT sparking (TEST 5).
• Confirmed that the intake side ignition coil pack IS NOT receiving the 2/3 activation signal (this test section).

TEST 15: Checking For Spark Directly On The Ignition Coil Tower

If you've reached this point, TEST 1 has confirmed one of the following conditions:

• One spark plug wire (of the seven) IS NOT sparking.
• Two spark plug wires that DO NOT belong to 'paired' cylinders ARE NOT sparking.

In this test section, we'll check for spark directly at the ignition coil tower of the spark plug wire that does not spark.

If the tower sparks, you can conclude that the spark plug wire is defective and all spark plug wires need to be replaced.

If the tower DOES NOT spark, you can conclude that the ignition coil pack (which the tower is part of) is defective and needs to be replaced.

NOTE: To perform this test, you'll need to crank the engine. Be careful and take all necessary safety precautions!

Let's get started:

1. 1

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

2. 2

   Place your spark tester in the ignition coil tower (see the illustration above).

3. 3

   Ground the spark tester directly on the battery negative (-) post using a jump-start cable.

4. 4

   Have your helper crank the engine while you observer the spark tester.

5. 5

   The spark tester should spark.

6. 6

   Repeat steps 1 through 5 on any other ignition coil tower whose spark plug did not spark.
   
   IMPORTANT: Remember, this test section only applies to spark plug wires that DO NOT belong to 'paired' cylinders

OK, let's interpret your test results:

CASE 1: The spark tester sparked. This test result tells you the spark plug wire is bad.

Replace all of the spark plug wires if you have:

• Confirmed that the spark plug wire DID NOT spark in TEST 1.
• Confirmed that the tower that connects to the non-sparking spark plug wire sparks (this test section).

Replacing all of the spark plug wires should solve the issue.

CASE 2: The spark tester DID NOT spark. This test result eliminates the spark plug wire as bad, since the ignition coil tower does not spark.

You can conclude that the ignition coil pack is bad if you have:

• Confirmed that the spark plug wire DID NOT spark in TEST 1.
• Confirmed that the tower that connects to the non-sparking spark plug wire DOES NOT spark (this test section).