How To Test The Ignition Module And Crank Sensor (2.3L Ranger, Mustang, B2300)

This tutorial will help you to diagnose a bad ignition control module (ICM) and/or a bad crankshaft position sensor on your 2.3L Ford Mustang or Ranger (Mazda B2300) without removing them from your Ford.

Specifically, with this tutorial I'm gonna' help you diagnose two of the most common failures with this type of ignition control module (ICM) setup:

  1. No start due to a no-spark condition either because the:
    1. Crankshaft position sensor has failed.
    2. OR
    3. The ignition module has failed.
  2. Misfire due to a bad ignition module.

Since the ICM isn't cheap and replacing the crank sensor is labor intensive (you've got to remove the timing belt), testing the ICM and crank sensor, on your 2.3L Ford Ranger or Mustang (or B2300), becomes a must!

For your cross reference information, the ignition control module test that this article covers are:

  1. AutoZone part #:
    1. Duralast F138
  2. O'reilly part #:
    1. BWD CBE42
    2. Motorcraft DY959
    3. AC Delco F1929A
  3. Others:
    3. Airtex Part # 6H1091
    4. WELLS Part # F138

En Español Puedes encontrar este tutorial en Español aquí: Cómo Probar El Módulo De Encendido Y El Sensor del Cigüeñal (2.3L Ford) (en:

What Tools Do I Need To Test The Ignition Control Module Or The Crank Sensor?

I can tell you right off the bat that the one thing you don't need is a scan tool. You need a few basic things and they are:

  1. Multimeter
    1. A digital or analog multimeter will work.
    2. If you need to buy one or are looking to upgrade, check out my recommendations here: Buying A Digital Multimeter For Automotive Diagnostic Testing.
  2. Wire Piercing Probe
    1. This tool is a time saver of the first order. To see what this tool looks like, click here: Wire Piercing Probe.

You'll also need basic hand tools to remove the ignition module (if it tests bad that is), like a ratchet wrench, sockets, etc.

Ignition Module Circuit Descriptions

Ignition Module Circuit Descriptions. How To Test The Ignition Module And Crank Sensor (2.3L Ranger, Mustang, B2300)

The ignition control module has two connectors. Looking down at the ignition module (with the ignition module still bolted to the intake manifold), you'll notice that the ignition control module has a top connector and a bottom connector.

In the pin out charts below is a brief job description of what each wire does.

NOTE: Although I've included the color of the wires, in the charts below, there's a good chance that these colors won't match what's on your particular Ford Ranger or Mustang or Mazda B2300. This is no cause for concern because the wires' job description doesn't change.

Wiring Diagram: The following wiring diagram may be of help: 1992-1994 2.3L Ford Ranger Ignition System Wiring Diagram.

Top ICM Connector Pin outs
Pin Wire Color Description
1 Red w/ Light Green stripe * Ignition Power (Hot in Start/Run)
2 Gray * Cylinder Identification (CID)
3 Gray w/ Orange stripe * PIP (PCM Module Signal)
4 Dark Blue * PIP (Crank Sensor Signal)
5 Pink * SPOUT Signal
6 Dark Blue w/ Yellow stripe * Dual Plug Inhibit (DPI) Input

   * Your specific Ford vehicle may have different colors.

Bottom ICM Connector Pin out
Pin Wire Color Description
7 Orange w/ Red stripe * Ignition Ground
8 Tan w/ Light Blue stripe * Coil 3 (Spark Plugs #1 and #4 Left Side Engine)
9 Tan w/ Light Green stripe * Coil 4 (Spark Plugs #2 and #3 Left Side of Engine)
10 Tan w/ Orange stripe * Coil 2 (Spark Plugs #2 and #3 Right Side of Engine)
11 Tan w/ White stripe * Coil 1 (Spark Plugs #1 and #4 Right Side of Engine)
12 Tan w/ Yellow stripe * Ignition Diagnostic Monitor (IDM)

   * Your specific Ford vehicle may have different colors.

Where To Buy The Ignition Module And Save

How The Ignition Control Module Works

The ignition module is tasked with activating the two ignition coil packs that feed the 8 spark plugs that the 2.3L 4 cylinder engine is equipped with.

Now, I won't go into minute technical detail as to how everything works in this ignition system. Just the basics that you and I need to get to the bottom of the problem. In a nutshell, this is what happens when you turn On the Key and crank the engine:

  1. The crank sensor is fed with power and Ground.
    1. The crank sensor is a Hall-Effect type sensor.
    2. The crankshaft rotation induces the crank sensor to start creating two separate crank signals.
    3. One crank signal is called the CKP (crankshaft position) signal.
      1. The CKP signal is only sent to the ICM.
    4. The other crank signal is called the CDI (Cylinder Identification) signal.
      1. The CID (Cylinder Identification) signal is the one that helps the ignition control module synchronize the ignition coil packs so that they fire in the correct firing order.
      2. Both the ICM and the PCM receive the CID signal.
  2. The ignition module now starts to activate the coil packs.
  3. During engine cranking, only the Right side spark plugs (exhaust manifold side of the engine) are fired.
    1. Once the engine starts, the PCM now commands the ICM to fire both coil packs through the Dual Plug Inhibit (DPI) circuit (circuit 6 of the ICM Top Connector), .
  4. Each coil pack feeds spark to 4 spark plugs on either side of the engine.
    1. Spark Plugs on the intake manifold side of the engine are referred to as: Intake Side Spark Plugs or Right Side Spark Plugs.
    2. Spark Plugs on the exhaust manifold side of the engine are referred to as: Exhaust Side Spark Plugs or Left Side Spark Plugs.

If you're reading this tutorial, it's because you've got a problem and this stinks, but the really cool thing is that you can test the ignition control module and the crank sensor without having to replace them first, and I'll show you how.

Let's turn the page and get testing.

Ford Vehicles:

  • Mustang 2.3L
    • 1991, 1992, 1993
  • Ranger 2.3L
    • 1989, 1990, 1991, 1992, 1993,1994, 1995, 1996, 1997, 1998

Mazda Vehicles:

  • B2300 2.3L
    • 1994, 1995