TEST 1: Testing The Power Circuit

Making Sure The ICM Is Getting 12 Volts. How To Test The Ignition Module And Crankshaft Position Sensor (GM 3.1L, 3.4L)

We'll begin by checking that the ignition control module is receiving 12 Volts. You can use a digital or analog multimeter or even a test light for this test. I do recommend using a wire-piercing probe to accomplish all of the tests in this article. (to see what this tool looks like, go here: Wire Piercing Tool). Whatever method you use, the key here is to be careful. Remember to use common sense and take all safety precautions.

Remember, although the photos in this article show the ignition module and coil pack assembly off of the car, these tests are ON CAR TESTS. DO NOT Remove the ignition module and coil pack Assembly from the vehicle to test it.

OK, these are the test steps:

  1. Put the multimeter in VOLTS DC mode.
  2. You can either disconnect the connector or not to test for this voltage. You'll probe the A circuit of Connector 1 of the ignition control module.
  3. With the red multimeter test lead and a suitable tool, probe the PINK (or PINK with BLACK stripe) wire of Connector 1.
  4. With the black multimeter test lead probe the battery negative (-) terminal.
  5. Turn Key On with the engine Off.
  6. You should see 12 Volts on the multimeter. Do you have 12 Volts?

Let's take a look at what your test results mean:

CASE 1: If your multimeter showed 12 Volts. Then everything is OK on the Power Circuit. You can go to Test 2 in the next page.

CASE 2: If your multimeter DID NOT show 12 Volts. Then you have found the cause of the no start condition of your car or truck (if you're driving an Isuzu). Why? Well, because without this voltage, the ignition module will not work. So then, this result tells you that the ignition module is not at fault.

The most common cause of this missing voltage will be a blown fuse. Check and repair or replace as necessary. The vehicle should start now.

TEST 2: Testing The Ground Circuit

Making Sure The ICM Is Getting Ground. How To Test The Ignition Module And Crankshaft Position Sensor (GM 3.1L, 3.4L)

In the previous test step (in the previous page), you verified that the ignition control module is indeed receiving 12 Volts. Now, I'm gonna' show you how to test its Ground circuit. Again, as in the last test step, I recommend that you use a wire piercing probe to accomplish this one.

Although the following test steps are explained using a multimeter, you can use a test light instead. OK, the ignition control module receives GROUND on the B circuit of Connector 1 (see the photo above).

Let's get started:

  1. Put the multimeter in VOLTS DC mode.
  2. With the black multimeter test lead and a wire piercing probe, probe the ignition module connector's BLACK with WHITE stripe wire.
  3. With the red multimeter test lead probe the battery positive (+) terminal.
  4. You should see 12 Volts on the multimeter. Do you have 12 Volts?

Let's take a look at what your test results mean:

CASE 1: Your multimeter registered 12 Volts. Then the Ground Circuit is OK. You can continue to Test 3. Test 3 will verify if the module is receiving the crankshaft position signal.

CASE 2: If your multimeter DID NOT register 12 Volts. Then there is an ‘open’ in this circuit. Just to be sure of this result, repeat the test after having checked all of your connections. Without a good Ground, the ignition module will not work. With this result, you have now eliminated the ignition module as the cause of the no start problem.

Repair the cause of the ‘open’ and retest. If the Ground Circuit is now working, the car or truck (Isuzu Rodeo or Trooper) should start.

Buick Vehicles:

  • Century 3.1L
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Regal 3.1L
    • 1994, 1995, 1996
  • Rendezvous 3.4L
    • 2002, 2003, 2004, 2005
  • Skylark 3.1L
    • 1994, 1995, 1996, 1997, 1998

Chevrolet Vehicles:

  • Beretta 3.1L
    • 1994, 1995, 1996
  • Corsica 3.1L
    • 1994, 1995, 1996
  • Impala 3.4L
    • 2000, 2001, 2002, 2003, 2004, 2005
  • Lumina 3.1L
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001

Chevrolet Vehicles:

  • Malibu 3.1L
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003
  • Monte Carlo 3.1L, 3.4L
    • 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Venture 3.4L
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

Oldsmobile Vehicles:

  • Achieva 3.1L
    • 1994, 1995, 1996, 1997, 1998
  • Alero 3.4L
    • 1999, 2000, 2001, 2002, 2003, 2004
  • Cutlass (Ciera & Supreme) 3.1L, 3.4L
    • 1993, 1994, 1995, 1996, 1997

Oldsmobile Vehicles:

  • Silhouette 3.1L, 3.4L
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004

Pontiac Vehicles:

  • Aztek 3.4L
    • 2001, 2002, 2003, 2004, 2005
  • Grand Am 3.1L, 3.4L
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

Pontiac Vehicles:

  • Grand Prix 3.1L
    • 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
  • Montana 3.4L
    • 1999, 2000, 2001, 2002, 2003, 2004, 2005
  • Trans Sport 3.4L
    • 1996, 1997, 1998

Isuzu Vehicles:

  • Rodeo 3.2L
    • 1993, 1994, 1995
  • Trooper 3.2L
    • 1992, 1993, 1994, 1995