How To Test The Ignition Coil Pack (2001-2003 4.2L V6 Ford E150, E250)

TEST 8: Checking The IC Activation Signals

Your tests have confirmed that:

• All six spark plug wires do not spark (TEST 1).
• The RED/LT GRN wire is supplying 10 to 12 Volts (TEST 4).

For the final test, we'll check that the activation signals for ignition coil 1, 2, and 3 are being supplied to the ignition coil pack with a 12 Volt automotive test light (non-powered test light).

Here's the ignition coil's connector pinout:

• Terminal 1: DK BLU/LT GRN wire - activation signal cylinders 1 and 5.
• Terminal 2: PNK/WHT wire - activation signal cylinders 2 and 6.
• Terminal 3: RED/LT BLU - activation signal cylinders 3 and 4.

IMPORTANT: Be careful not to damage the female terminal or the connector with your 12V test light's probing tip. If the terminal or the connector get damaged, you'll need to replace the connector.

CAUTION: This test has to be performed with the engine cranking. Be careful and take all necessary safety precautions.

Alright, let's start:

1. 1

   Disconnect the ignition coil (IC) from its 4-wire electrical connector.

2. 2

   Connect the 12V test light's alligator clip to the battery positive (+) post.

3. 3

   With the test light's probing tip, gently probe terminal number 2.

4. 4

   Have your helper crank the engine.

5. 5

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

6. 6

   Repeat steps 2 thru 5 on female terminals 3 and 4.

Let's find out what your test result means:

CASE 1: The 12V test light flashed ON and OFF the whole time the engine was cranking on each terminal. With this test result you can conclude that the PCM is providing the activation signals for all three ignition coils (within the coil pack).

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

• Confirmed that all six spark plug wires are not sparking (TEST 1).
• Confirmed that the ignition coil is getting power (TEST 4).
• Confirmed that the ignition coil pack is receiving all three IC activation signals (this test section).

CASE 2: The 12V test light did not flash on and off at any of the terminals while the engine was cranking. This test result usually means that the crankshaft position (CKP) sensor.

Your next step is to test the CKP sensor:

• How To Test The CKP Sensor With A Multimeter (1997-2003 4.2L V6 Ford E150, E250).

Other Things That Can Cause A Misfire

One of the things that can be quite frustrating is the fact that quite a few other problems can cause an engine cylinder misfire (other than a bad ignition coil pack).

So, if your diagnostic tests confirm that the ignition coil pack is indeed working correctly (creating and delivering spark to all six cylinders), this section might help with a few other testing suggestions that should help you pinpoint the source of the misfire problem.

1. Check For Carbon Tracks:
   • Carbon tracks tend to develop on the spark plug's porcelain insulator and the inside of the spark plug boot. The main cause of a carbon track is oil leaking from the valve covers.
   • Inspect the inside of the spark plug wire boots and the ceramic insulator of the spark plug for carbon tracks. Replace the components as affected with carbon tracks.
   • The the orange arrows in the photo above point to what carbon tracks look like.
   • Here's a case study about carbon tracks: Carbon Tracks Are A Common Cause Of Ignition Misfires (at: easyautodiagnostics.com).
2. Check For Damaged Spark Plug Wires:
   • The most common issue is a broken or damaged spark plug boot. The boot covers the spark plug wire's metal terminal. If it's damaged, the metal terminal becomes exposed, causing the spark to jump to the exhaust manifold instead of the spark plug.
   • Another frequent problem I've encountered is a spark plug wire with a missing or detached metal terminal. This usually happened during a previous ignition system repair or diagnostic and the issue went unnoticed.
   • Replace any spark plug wire that has a damaged boot or is missing its metal terminal.
3. Look for Burned or Cut Spark Plug Wires:
   • If the spark plug wires aren't routed correctly, they can touch the exhaust manifold or a sharp edge on the engine. This contact causes the wire to get burned or cut. When this happens, the spark can jump from the damaged part of the wire to the Ground, causing a misfire because the spark never reaches the spark plug.
   • Replace any spark plug wire that shows signs of burning or cutting.
4. Check For Low Cylinder Compression:
   • One of the most overlooked diagnostic tests to find the root cause of misfire is the compression test.
   • You'll need an engine compression tester of course.
   • The engine between cylinders should not vary more 15%.
   • How To Test Engine Compression (1997-2003 4.2L V6 Ford E150, E250).
5. Check For A Bad Or Clogged Fuel Injector:
   • There are several methods to test them which are beyond the scope of this article, but the fastest way to test them is by checking the resistance (Ohms) value of each one and comparing them to each other.
   • Any resistance that's not within the average of the others indicates the fuel injector is fried.
   • You can buy a specific fuel injector tester online that activates by a predetermined pulse width and measuring the fuel pressure drop on a fuel pressure gauge.
   • How To Test The Fuel Injectors (2001-2003 4.2L V6 Ford E150, E250).

More 4.2L Ford E150 And E250 Test Tutorials

If this tutorial was helpful, be sure and take a look at all of the 4.2L V6 E150 and E250 diagnostic tutorials and wiring diagrams in this index:

• 4.2L Ford E150 And E250 Index of Articles.

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

• How To Test The Throttle Position Sensor (1997-2000 4.2L V6 Ford E150, E250).
• How To Test Engine Compression (1997-2003 4.2L V6 Ford E150, E250).
• How To Test The Fuel Pump (1997-2000 4.2L V6 Ford E150, E250).
• How To Test The CKP Sensor With A Multimeter (1997-2003 4.2L V6 Ford E150, E250).