How To Test The Ignition Control Module (1990-1995 3.0L V6 Ford Taurus, Mercury Sable)

The ignition control module (ICM) on the 1990-1995 3.0L Ford Taurus and Mercury Sable can be easily tested without removing it from its spot on the distributor.

In this tutorial, I'm going to show you a simple way to see if the ICM is toast and causing the engine not to start.

All of the test steps are outlined in a clear, step-by-step manner —and the best part is, you don't need any expensive diagnostic equipment to perform them.

With your test results, you'll quickly and easily know if the ICM is bad and needs to be replaced, or if something else is causing the problem.

APPLIES TO: This tutorial applies to the following vehicles:

• 3.0L V6 Ford Taurus: 1990, 1991, 1992, 1993, 1994, 1995.
• 3.0L V6 Mercury Sable: 1990, 1991, 1992, 1993, 1994, 1995.

IGN SYSTEM WIRING DIAGRAMS:

• Ignition System Wiring Diagram (1990 3.0L V6 Ford Taurus, Mercury Sable).
• Ignition System Wiring Diagram (1991 3.0L V6 Ford Taurus, Mercury Sable).
• Ignition System Wiring Diagram (1992-1995 3.0L V6 Ford Taurus, Mercury Sable).

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

As I mentioned earlier, you don't need any fancy or expensive diagnostic equipment to find out if the ignition control module is bad and causing the engine not to start. But you'll need a few important tools. These are:

1. Multimeter: We'll need to make sure the ICM is getting power, and a multimeter will help us do just that. If you don't have one or need to upgrade, this is the one I use and recommend: Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter (Amazon affiliate link).
2. LED light: This LED light will help us check the PIP signal while cranking the engine. It's inexpensive, and if you don't have one, you can buy it here: Oznium Flush Mount 12V LED Light (Amazon affiliate link).
3. 12-Volt automotive test light: This test light needs to be the incandescent type, which is also very inexpensive. It'll help us check the ignition coil control signal. If you already have one, awesome. If not, this is the one I recommend, and you can buy it here: Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).

TEST 1: Making Sure The ICM Is Getting Power

To get the ball rolling on our ignition control module (ICM) diagnostic, we're going to make sure the red with light green stripe (RED/LT GRN) wire of the module's 6-wire connector is delivering 10 to 12 Volts to it.

This battery voltage is available to the ICM with the key in either the RUN or START position. For our test, we'll check for voltage with the key in the RUN position and the engine OFF.

Once we've confirmed that the RED/LT GRN wire —which connects to the female terminal 3— is getting power, our next step will be to see if the ICM is producing an ignition coil activation signal in TEST 2.

Alright, here we go:

1. 1

   Disconnect the ICM from its 6-wire connector.

2. 2

   Place your multimeter Volts DC mode.

3. 3

   Connect the black multimeter test lead to the battery negative (-) post.

4. 4

   Turn the key to the ON position but don't start the engine.

5. 5

   With the red multimeter test lead, probe female terminal 3 of the connector.
   
   NOTE: Double-check that terminal 3 corresponds to the RED/LT GRN wire.

6. 6

   Your multimeter should read 10 to 12 Volts DC.

OK, let's see what your result means:

CASE 1: The ICM is getting battery power. This is exactly what we wanted to see.

Now that you've confirmed the ICM is getting power from the RED/LT GRN wire, our next step is to see if it's activating the ignition coil. For this test, head over to: TEST 2: Checking The Ignition Coil Activation Signal.

CASE 2: The ICM isn't getting battery power. Without these 10 to 12 Volts, the ignition module won't be able to activate the ignition coil.

Your next step is to find out why the RED/LT GRN wire isn't getting power and restore it to the circuit. Once terminal 3 starts delivering power to the ICM, the ignition module should begin activating the ignition coil and get the engine started.

TEST 2: Checking The Ignition Coil Activation Signal

As you already know, the ignition control module (ICM) is the component responsible for activating the ignition coil so it can start delivering spark to the distributor. In this test section, we're going to see if the ignition module is actually sending its ignition coil activation signal to the coil.

The wire that delivers this activation signal to the ignition coil will be one of the following, depending on the year of your vehicle:

• 1990: Dark green with yellow stripe (DK GRN/YEL).
• 1991–1995: Tan with yellow stripe (TAN/YEL).

We're going to check for this activation signal at the ignition coil's connector —it's the easiest place to access it.

To perform the test, we'll use a regular 12-Volt automotive test light with an incandescent bulb. If you don't have one and need to buy it, this is the one I recommend (and the one I personally use): Lisle 28400 Heavy Duty 12 Volt Test Light (Amazon affiliate link).

CAUTION: You'll be working around a cranking engine. Keep your hands, tools, loose clothing, and test leads clear of moving engine parts such as belts and pulleys. Secure any long hair and avoid leaning over the engine while performing the test. Always stay alert and aware of your surroundings when working near moving components.

Alright, let's get to work:

1. 1

   Disconnect the ignition coil from its electrical connector.

2. 2

   Connect the test light's crocodile clip to the battery positive (+) terminal.

3. 3

   With the metal point of the 12 Volt test light, back-probe terminal 1 of the connector.
   
   Make sure that terminal 1 connects either to the DK GRN/YEL (1990) or the TAN/YEL (1991-1995) wire.

4. 4

   Have your helper crank the engine while you observe the 12 Volt test light.

5. 5

   You'll see one of two things:
   
   1.) The 12 Volt test light flashes ON and OFF.
   
   2.) The 12 Volt test light DOES NOT flash ON and OFF.
   
   NOTE: Don't worry about what the test light does before cranking the engine. What matters is whether the test light flashes ON and OFF while the engine's being cranked.

Let's see what your result means:

CASE 1: The 12V test light DID NOT flash ON and OFF while cranking the engine. This result lets us know the ignition module isn't activating the ignition coil to start firing spark. Now that we've confirmed the ICM isn't triggering the ignition coil, our next step is to check the Profile Ignition Pickup (PIP) signal.

There are two ways to check this signal: one is with a multimeter, and the other is with an LED light.

• Multimeter test: It's the most accurate way of checking the PIP signal, but requires turning the engine over by hand using a 1/2-inch ratchet and socket on the crankshaft pulley.
• LED light test: Allows you to use the starter motor to crank the engine.

Both tests will let you know whether the PIP signal is present or not —so the choice is yours.

• TEST 3: Testing The PIP Signal With A Multimeter.
• TEST 4: Testing The PIP Signal With An LED Light.

CASE 2: The test light flashed ON and OFF. This confirms the ignition control module is actively trying to get the ignition coil to spark -meaning the ICM is not defective.

This test result also lets you know that the profile ignition pickup (PIP) sensor inside the distributor is OK. If the PIP sensor were bad, it wouldn't be generating its signal —and the ICM wouldn't be actively trying to trigger the ignition coil to spark.

If the engine isn't starting, it's not due to the ignition control module (or PIP sensor). Have you tested the ignition coil? Have you done any other ignition system tests? If not, the following tutorial will help you out: Ignition Coil And Basic Ignition System Tests (1990-1995 3.0L V6 Ford Taurus, Mercury Sable).

TEST 3: Testing The PIP Signal With A Multimeter

The profile ignition pickup (PIP) sensor is the component that tells both the ignition control module (ICM) and the powertrain control module (PCM) which cylinder is coming up on its compression stroke, effectively acting as a crankshaft position sensor.

The signal it produces is an ON/OFF voltage signal that works as follows:

• ON: PIP signal voltage is above 8 Volts DC.
• OFF: PIP signal voltage is below 2 Volts DC.

Although the PIP sensor is located inside the distributor, you and I can still check its signal output without removing either the ICM or the distributor from the engine.

For our PIP signal test, we're going to tap into the wire that connects to terminal 6 of the ignition module's 6-wire connector. Depending on the specific year of your Ford Taurus or Mercury Sable, the wire that connects to terminal 6 will be one of the following colors:

• 1990-1991: Dark blue (DK BLU).
• 1992-1995: Gray with orange Stripe (GRY/ORG).

In this section, we'll check the PIP signal using a multimeter, which is the most accurate way to do it short of using an oscilloscope.

On last and important thing —this test is done by turning the engine over by hand using a 1/2-inch ratchet and the appropriate socket on the crankshaft pulley, not by cranking the engine with the starter motor.

If you prefer to test the signal with the engine actually cranking (with the starter motor), head over to TEST 4, which covers testing the PIP signal with an LED light.

NOTE: The ignition module must remain connected to its 6-wire connector to check the PIP signal output.

All right, let's get going.

1. 1

   Raise the front right side of your vehicle and place it on jack stands.
   
   IMPORTANT: NEVER trust the jack alone to keep the vehicle raised. ALWAYS use jack stands.

2. 2

   Remove the front right tire and the water splash shield that is covering the crankshaft pulley.

3. 3

   Disconnect the ignition coil from its electrical connector.
   
   NOTE: This is an important safety precaution —do not continue to the next step without doing this first.

4. 4

   Disconnect the PCM from its 60-pin connector.
   
   This step is important, as we need to isolate the PIP signal from the PCM.

5. 5

   Set your multimeter to Volts DC mode.

6. 6

   Connect the black multimeter test lead to the battery negative (-) terminal.

7. 7

   Connect the red multimeter test lead to the PIP signal wire, using the appropriate tool.
   
   The PIP signal wire connects to terminal 6 and will be either a DK BLU wire (1990-1991) or a GRY/ORG wire (1992-1995).

8. 8

   Turn the ignition key to the ON position, but don't start or crank the engine.

9. 9

   Slowly rotate the crankshaft pulley by hand using a 1/2-inch ratchet and the appropriate socket.
   
   NOTE: Rotate the pulley at least two full revolutions to ensure all of the tone wheel slots pass by the Hall effect sensor.

10. 10

    Watch your multimeter for voltage changes. Voltage should toggle between ON and OFF voltage states as you turn the crankshaft pulley.
    
    ON: Voltage above 8 Volts DC.
    
    OFF: Voltage below 2 Volts DC.

OK, let's interpret your test results.

CASE 1: The multimeter toggled between ON and OFF voltage states (ON voltage above 8 Volts). With this test result, we can conclude that the PIP sensor is functioning correctly and producing the signal that both the ICM and PCM need to create and maintain spark.

You can conclude that the ignition module is bad and needs to be replaced —but only if you've checked and confirmed the following:

• None of the six spark plug wires are sparking, and the ignition coil does not spark.
• The ignition module is getting battery power –10-12 Volts (TEST 1).
• The ignition module isn't sending an ignition coil activation signal (TEST 2).
• In this test section, you've confirmed that the PIP sensor is creating and sending out a valid PIP signal.

CASE 2: The multimeter toggled between ON and OFF voltage states, but the ON voltage was less than 8 Volts. This test result generally indicates that the PIP sensor —although it's producing a signal— is failing.

If your vehicle is showing engine performance issues such as starting fine but then running rough after it's been running for a while, or if it won't restart after being shut off, this test result confirms that the PIP sensor is bad and needs to be replaced.

CASE 3: The multimeter DID NOT toggled between ON and OFF voltage states. Without a PIP signal, the ignition control module won't activate the ignition coil to start sparking —and without spark, the engine won't start.

But before we calling the PIP sensor bad, we need to check the PIP SIG and PIP OUT circuit inside the Ignition Control Module. For this test, head over to: TEST 5: Testing The PIP SIG And PIP OUT Circuit.

TEST 4: Testing The PIP Signal With An LED Light

One of my go-to methods for checking any ON/OFF signal is using an LED light, and the PIP signal confirmation test lends itself perfectly to this method since it lets you visually see the signal pulsing ON and OFF.

Before we begin, I want to point something out. If your Ford Taurus or Mercury Sable doesn't start at all, you can quickly confirm the presence of the PIP signal using an LED light. However, if your vehicle starts, runs, and then —after warming up— won't restart, you really need to perform the PIP signal test using a multimeter instead.

The main reason is that the LED light method will only help you diagnose a bad ignition module if the PIP sensor is producing a voltage peak of 8 Volts or more. The only way to confirm that voltage peak is with a multimeter. If the voltage peak is below 8 Volts, the PIP sensor is failing —but the LED light won't make you aware of that.

To test the PIP signal, we're going to tap into the PIP signal output wire at the ignition control module (ICM). This is the wire that connects to terminal 6 of the ICM connector. Depending on the year of your specific vehicle, it'll be one of the following:

• 1990–1991: Dark blue (DK BLU).
• 1992–1995: Gray with orange stripe (GRY/ORG).

If you need to ID terminal 6 of the ICM connector, see the pinout illustration of the ICM above for reference.

If you don't have an LED light to perform this test, this is the one I recommend and you can buy it here: Oznium Flush Mount 12V LED Light (Amazon affiliate link).

CAUTION: You'll be working around a cranking engine. Keep your hands, tools, loose clothing, and test leads clear of moving engine parts such as belts and pulleys. Secure any long hair and avoid leaning over the engine while performing the test. Always stay alert and aware of your surroundings when working near moving components.

NOTE: The ignition module must remain connected to its 6-wire connector to check the PIP signal output.

This is what you need to do:

1. 1

   Disconnect the ignition coil from its electrical connector.
   
   NOTE: This is an important safety precaution —do not continue to the next step without doing this first.

2. 2

   Disconnect the PCM from its 60-pin connector.
   
   NOTE: This step is important, as it isolates the PIP signal wire circuit.

3. 3

   Disconnect the ICM from its 6-wire connector.

4. 4

   Connect the red wire of the LED light to the battery positive (+) terminal.
   
   NOTE: You'll need to use a jumper wire to have the red lead of the LED reach the battery terminal.

5. 5

   Connect the black wire of the LED to the PIP signal wire, using the appropriate tool.
   
   The PIP signal wire connects to terminal 6 and will be either a DK BLU wire (1990-1991) or a GRY/ORG wire (1992-1995).
   
   NOTE: The ignition module needs to remain connected to its 6-wire connector.

6. 6

   When all is set up, crank the engine.

7. 7

   The LED light should flash ON and OFF as the engine cranks if the PIP signal is being generated and sent to the ICM.

OK, let's interpret your test results.

CASE 1: The LED light flashed ON and OFF. This confirms that the PIP sensor is functioning and producing a signal that the ICM can use to start activating the ignition coil.

If you've checked and confirmed the following, then you can conclude that the ignition module is toast and needs to be replaced:

• None of the six spark plug wires are sparking, and the ignition coil isn't sparking either.
• The ignition module is being supplied with battery voltage (confirmed in TEST 1).
• The ignition module isn't creating an ignition coil activation signal (confirmed in TEST 2).
• In this test section, you've confirmed that the PIP sensor is generating a valid PIP signal.

CASE 2: The LED light did not flash ON and OFF. This usually means that the PIP sensor is toast.

But to be sure, we need to perform one more test —to check for continuity between the PIP SIG pin and the PIP OUT pin on the ignition module itself (after removing it). For this test, head over to: TEST 5: Testing The PIP SIG And PIP OUT Circuit.

TEST 5: Testing The PIP SIG And PIP OUT Circuit

As the PIP signal is generated, it's first sent to the ignition control module (ICM). From there, the ICM sends it out to the PCM via terminal 6 of its 6-wire connector.

In this test section, we want to make sure that the PIP SIG IN and PIP OUT circuit inside the module has a resistance under 200 Ohms —which would confirm that the circuit within the ICM is OK.

Any resistance reading above 200 Ohms indicates a problem inside the ignition module —it won't allow the PIP signal to reach the PCM and confirming the ICM is deep-fried.

Specifically, we want to make sure the circuit isn't open. If it is, your multimeter will show infinite resistance or the letters OL. Again, the correct specification is 200 Ohms or less.

IMPORTANT: If you find that the circuit is within spec (200 Ohms or less) and you reinstall the same ignition control module, it's absolutely critical that you apply thermal paste between the module and its mounting surface. This is not dielectric grease —they are two different things. Failing to use thermal paste will cause the module to overheat and fry shortly after installation.

These are the test steps:

1. 1

   Disconnect the ignition module from its 6-wire connector.

2. 2

   Remove the ignition control module from the distributor.
   
   You'll need a 5.5mm or 7/16" socket to remove the two small bolts securing the module to the distributor.
   
   NOTE: You may need to slightly loosen the distributor and rotate it to access the bolts securing the module. If you do, make sure to create alignment marks on both the distributor and the engine before moving it. This will ensure that once you're done, you can reinstall and tighten the distributor back into its exact original position.

3. 3

   Set your multimeter to Ohms mode.

4. 4

   Check the resistance between the PIP SIG pin and the PIP OUT pin.
   
   NOTE: These "pins" are the male spade terminals on the ICM itself —see the pinout ID illustration of the ignition module above.

5. 5

   Your multimeter should register a resistance under 200 Ohms.

Let's see what your result means:

CASE 1: The resistance of the circuit is under 200 Ohms. This is exactly what we wanted to see —it confirms that the circuit is OK.

You can conclude that the PIP sensor is toast (and the reason the engine isn't starting) if you've confirmed the following:

• There's no spark coming from any of the six spark plug wires, and the ignition coil itself isn't sparking either.
• The ignition control module is getting power (TEST 1).
• The ignition module isn't activating the ignition coil to spark (TEST 2).
• The PIP signal ON/OFF pulse isn't present in the PIP signal wire (TEST 3 or TEST 4).
• In this test section, you've confirmed that the PIP SIG and PIP OUT circuit inside the ICM are OK.

CASE 2: The resistance is not within specification. This tells you that the ignition module has an internal problem with this circuit replace the —ignition control module.

NOTE: In some rare cases, even though the PIP SIG and PIP OUT circuit inside the ICM is fried, the PIP sensor in the distributor can also be bad. So, if after installing the new ignition control module and you still don't get spark, then the PIP sensor itself is also bad and needs to be replaced.

We can confirm this by performing a multimeter voltage test on the PIP signal as described in TEST 3. However, this is only possible once a new ICM has been installed —one with the PIP SIG and PIP OUT circuit reading under 200 Ohms, since only then will the PIP signal be able to exit the ignition module and be properly measured as it's sent out through the PIP OUT wire.

More 3.0L V6 Ford Taurus Diagnostic Tutorials

You can find a complete list of diagnostics tutorials for the 3.0L V6 Taurus and Mercury Sable in this index:

• 3.0L V6 Ford Taurus Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test The MAF Sensor (1991-1995 3.0L V6 Ford Taurus, Mercury Sable).
• How To Test The Fuel Pump (1990-1999 3.0L V6 Ford Taurus, Mercury Sable).
• How To Test The TPS With A Multimeter (1991-1995 3.0L V6 Ford Taurus, Mercury Sable).
• How To Test For A Blown Head Gasket (1990-2007 3.0L V6 Ford Taurus, Mercury Sable).