TEST 6: Verifying The Ignition Coil's Switching Signal
In this test you're gonna' verify that the ignition control module (ICM) is activating the ignition coil by verifying that the switching signal is present.
You're going to use a test light. This test is performed with the engine being cranked, so be careful and take all necessary safety precautions.
NOTE: This test is performed with the ignition coil connector connected to the ignition coil.
Here are the test steps:
Insert the metal probe end of the test light to the rear of the connector to back-probe the terminal on the right side of the ignition coil connector (look at the photo above).
The ‘right side’ in automotive speak always refers to anything on the passenger side.
Connect alligator clip end of the test light to the battery (+) positive terminal. It is IMPORTANT that it be connected at the battery positive terminal.
Have an assistant crank the engine.
The 12 Volt test light should blink on and off as the engine is being cranked.
When you probe the ignition coil's switching signal wire, the 12 Volt test light will come on with the key in the ON position and before you crank the engine, this is normal.
The 12 Volt test light result that you want to watch out for is while the engine is cranking. Whatever it does before you crank the engine doesn't matter.
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 lets you know that the ignition coil's activation signal is present.
You can conclude that the ignition coil is bad, and needs to be replaced, if you have:
- Confirmed that none of the spark plug wires are sparking (TEST 1).
- Confirmed that the ignition coil tower is not sparking (TEST 3 and TEST 4).
- Confirmed that the ignition coil and ICM are getting power (TEST 5).
- Confirmed that the ignition coil is getting its Switching Signal.
This also means that the ignition control module (ICM) and pick up coil (PIP sensor) are good. Replacing the ignition coil will solve your 'no spark no start' condition.
CASE 2: The 12 Volt test light DID NOT flash ON and OFF. Re-check all of your connections and retry the test again.
If the test light still does not flash on and off, this usually indicates one of two things: either the ignition control module is bad or the PIP sensor is bad.
Don't worry, in the next test step, we'll find out for sure. go to: TEST 7: Testing The Profile Ignition Pickup (PIP) Signal.
TEST 7: Testing The Profile Ignition Pickup (PIP) Signal
Here we'll check that the Profile Ignition Pickup (PIP) Sensor Signal is being received by the ignition control module (ICM).
The PIP Signal is critical for the ignition module to start sparking the ignition coil (and a bunch of other stuff the fuel injection computer needs to do, like start activating the fuel injectors).
This will be achieved by using an LED test tool. You can see an example of this tool here: The LED Light Test Tool And How To Make One. Do not use a test light in lieu of an LED Light.
Here are the test steps:
With a suitable tool, pierce the number 6 circuit wire of the ignition control module connector with key in the OFF position.
Connect the black wire of the LED to the tool that is piercing the wire.
Connect the red wire of the LED to the battery positive (+) terminal.
Have an assistant crank the engine while you observe the LED.
The LED should blink ON and OFF the whole time the engine is cranking.
Let's analyze your test result:
CASE 1: The LED light flashed on and off the whole time the engine was being cranked. Then the PIP (Profile Ignition Pickup) sensor is creating and sending its signal.
This result indicates that the ignition control module is bad and the cause of the no-spark no-start condition. Replace the ignition control module (ICM).
CASE 2: The LED Light DID NOT flash on and off the whole time the engine was being cranked. Then the PIP (Profile Ignition Pickup) sensor is bad and is the cause of the no-spark no-start condition.
Replacing the PIP sensor (in the distributor) will get the ignition coil sparking again.
CASE 3: After connecting the LED light and cranking the engine, the engine started. In about 9 times out of 10, this tells you that the PIP sensor is bad and needs to be replaced. For more info on this see the next section: Engine Started When Doing The PIP LED Light Test.
Engine Started When Doing The PIP LED Light Test
Over the years that this tutorial has been on the Internet I have received a lot of feedback on it and have been overwhelmed by the positive response.
One of the things folks have mentioned is that when the LED light has been connected and the engine cranked, the engine started and ran. It ran as long as the LED light was connected.
In about 99% of the cases, the thing that solved this ‘no start but starts with the LED light connected’ issue was replacing the PIP sensor.
So, if you're currently having this same experience, when doing this LED light test on the PIP sensor signal, you need to replace the PIP sensor to get your Ford vehicle back on the road.
Also, what most folks in the DIY'er category (and NOT professional techs) found was that buying a new distributor was the fastest and cheapest way of replacing the PIP sensor. In my own personal experience, I have found out that this is true since you need a press and some special adapters to dis-assemble the distributor to replace it. If you don't have them you can't remove and replace the PIP sensor.
On a last note, I want to thank all of the folks that have emailed me with their diagnostic and repair experiences on this particular tutorial. Thank you for sharing your test results with me and letting me share them with the DIY community that reads this blog. God bless and thank you for the beers!
Where To Buy The Ignition Module And Save
You can buy the ignition control module, the ignition coil, or the spark plug wires at any auto parts store, but I think you'll save some bucks buying what you need on the Internet. Take a look at the following links and compare:
NOTE: Before you order your ignition control module you need to check its color. Your vehicle will either have a grey or black ignition control module. You'll need to buy the same color module since they're not interchangeable.
Not sure if the above parts fit your particular Ford vehicle? Don't worry, once you get to the site they will make sure all parts fit. If they don't I'll find you the right ones.
If this info really saved the day, buy me a beer!