In this tutorial, I'll help you pinpoint the cause of an engine no-start problem to the ignition control module or the ignition coil or the Profile Ignition Pickup (PIP) sensor in four easy test steps.
NOTE: This tests in this tutorial will only help you in a 'cranks but does not start due to a lack of spark' problem.
So before you start testing, it's important that you have checked and verified that there is NO SPARK at the ignition coil. Why? Well, because if the ignition coil sparks, that would be a clear indication that it and the ignition module and the crankshaft position (PIP) sensor are working.
This tutorial applies to both the gray colored ignition control module and the black colored ignition control module.
The gray colored ignition control module is called the Push Start Module and the black colored ignition control module is called the Computer Controlled Dwell Module. These ignition control modules are not interchangeable.
If you need the tests for the Ford fender mounted ignition control module (ICM), go here: Ford Fender Mounted Ignition Control Module (ICM) Tests.
To test Ford Coil-On-Plug Ignition Coils (4.6L and 5.4L V8 engines), go here: Ford Coil-On-Plug (COP) Ignition Coil Tests.
Contents of this tutorial:
- How Does The Ignition Control Module Work?
- What Tools Do I Need For The Ignition Module Test?
- Where To Buy The Ignition Module And Save.
- TEST INFO: Circuit Descriptions.
- TEST 1: Checking For Power (12 V).
- TEST 2: Testing The Ground Circuit.
- TEST 3: Ignition Coil Switching Signal.
- TEST 4: Testing The PIP Signal.
You can find this tutorial in Spanish here: Cómo Probar El Módulo De Encendido De Ford (Montado En El Distribuidor) (at: autotecnico-online.com).
How Does The Ignition Control Module Work?
Here's a little background information to help you diagnose this no-spark condition. In a nutshell, when the system is working properly, at CRANK-UP and at all engine speeds, the ignition control module controls the ignition coil.
How? This is primarily done thru' the Profile Ignition Pickup sensor signal which is received by the ignition control module (and also the ECM).
The ignition control module (ICM) upon receiving this signal, starts switching the ignition coil's Ground ON and OFF. As you may already know, it's this action that makes the ignition coil spark away.
The Profile Ignition Pickup sensor signal (more commonly called the PIP signal) is critical for the ignition control module to start sparking the ignition coil at START UP and at all engine speeds.
The Profile Ignition Pickup sensor is a Hall Effect type crankshaft position sensor and produces a digital (ON/OFF) signal that can be seen with an LED or an oscilloscope.
On an oscilloscope, it produces a digital square waveform. This sensor is located in the distributor.
What Tools Do I Need For The Ignition Module Test?
There are several ways to test this ignition control module. An oscilloscope is the best way to check all of the input and output signals but it's not the only way. I'll show you just how.
Anyway, if you have access to an oscilloscope, I have included photos of what the waveforms should look like. Whether you use a multimeter or an oscilloscope, you'll be able to successfully diagnose this no-start condition! So, here's the basic list:
- An LED light.
- You can see what this tool looks like here: The LED Light Test Tool And How To Make One.
- Automotive 12 Volt test light.
- Multimeter.
- A cheapie one will do, whether its digital or an analog multimeter.
- If you need to buy one or are looking to upgrade, check out my recommendations here: Buying A Digital Multimeter For Automotive Diagnostic Testing.
- Repair manual.
- This is not an absolute must but you may need it for whatever other information this article does not cover or provide.
- Helper.
- To help you crank the engine while you observe the LED light (or test light or multimeter).
By the way, you don't need an automotive scan tool for any of these tests.
We'll first check for the basics like battery voltage and engine Ground to the ignition control module.
Then we'll test the ignition coil switching signal that the signal generates in action and from the results you get you'll be able to pinpoint the problem to the ignition control module (ICM) or the ignition coil or the Profile Ignition Pickup (PIP) sensor or completely eliminate these as the cause of the no-start condition.
IMPORTANT: All of the tests are on-car tests, do not remove the ignition control module assembly from the vehicle (all of the figures show the module assembly off of the vehicle but this is just for illustration purposes only). Also, the battery must be in a fully charged condition for all tests in this article. And lastly, this fast test only tests for a no-spark no-start condition.
Where To Buy The Ignition Module And Save
If you find, after testing the testing the ignition module your test results indicate a bad one then take a look at the links below. I think they'll save you some bucks (especially on the original Motorcraft ignition module):
NOTE: If you're not sure if the above ICM fit your particular Ford don't worry. Once you get to the site, they'll make sure it's the right one, if not, they'll find you the right one.
If your test results indicate that the PIP sensor is bad (which is located inside the distributor), the best option for replacing it is buying the entire distributor.
Why? Because specialized tools are needed to disassemble the distributor to replace the PIP sensor. I recommend buying the distributor from a known automotive brand -AVOID BUYING A CHINESE KNOCK-OFF DISTRIBUTOR!
Known good automotive brands are: Cardone, Autoline, WAI Global, Spectra Premium.
