TEST 4: Ignition Coil Switching Signal Circuit

Making Sure The Ignition Coil Is Being Activated. How To Test The GM 2.2L Ignition Coil Pack

OK, if you read the Basic Theory section, at the beginning of the article, you know that the switching signal is the one that activates the ignition coil to start sparking away. Well, this part will have you testing this signal, using an LED Light. Do not use a 12 Volt test light for this test.

Although the photos in the image viewer show only the ignition coil pack that feeds spark to cylinders 1 and 4 removed, the following test steps also apply to the ignition coil pack that feeds cylinders 2 and 3.

These are the test steps:

  1. With the ignition coil pack still off (from TEST 3).
  2. Connect the the black lead of the LED light to the male spade terminal labeled with the letter B in the photo of the image viewer.
  3. Connect the red lead of the LED light to the positive battery terminal.
  4. When all is ready, have your assistant crank the car while you observe the LED Light.
  5. If all is well, the LED light should blink On and Off the whole time the engine is cranking.

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

CASE 1: If the LED Light blinked On and Off while the engine was cranking, then this result confirms that the ignition coil pack is bad. Replace the ignition coil pack.

Here's why: If the the ignition coil is receiving Power, which you verified in TEST 3, and is getting the switching signal from the ignition control module (ICM), then it has to spark. Since it isn't, you now know beyond a shadow of a doubt that it's bad.

CASE 2: If the LED Light DID NOT blink On and Off while the engine was cranking, then this test result confirms that the ignition control module (ICM) is bad. Replacing the Ignition Module will solve the No Spark Condition on these two ‘Paired Cylinders’ that aren't getting spark.

TEST 5: Ignition Module's Triggering Signal

Making Sure The Ignition Control Module Is Being Activated. How To Test The GM 2.2L Ignition Coil Pack

If in TEST 1 you got a No spark result on all of the spark plug wires, then there's a good possibility that the ignition control module (ICM) isn't getting the Triggering signals to activate the ignition coil packs or it's bad. In this test step, I'll show you how to test for these two IC Signal (Ignition Control Signals).

To accomplish this test, you'll need a multimeter that can read Hertz (Hz) Frequency and the test goes like this:

  1. Part 1
    1. Place the multimeter in Frequency Hz mode (don't have a digital multimeter that can read Hertz frequency? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing).
    2. Both ignition control module connectors MUST be connected to the ignition control module (ICM).
    3. Connect the RED test lead of the multimeter to the wire labeled with the letter B. This the Triggering signal (IC Signal) for the coil pack that feeds cylinders 1 and 4.
    4. Connect the BLACK test lead of the multimeter to engine ground.
    5. With the Key On and Engine NOT CRANKING, you should have 0 Hz.
    6. Have an assistant crank the engine while you observe the multimeter (or oscilloscope).
    7. The multimeter should register a Hertz reading that should fluctuate around 3 Hz, as the engine is cranking (the minimum and maximum Hertz reading attained will depend on the cranking RPMs. Engine temperature, oil viscosity and battery charge condition will have a direct effect on this).
  2. Part 2
    1. Disconnect the red multimeter test lead from the wire that you just tested.
    2. Now, connect the RED test lead of the multimeter to the wire labeled with the letter C. This the Triggering signal (IC Signal) for the coil pack that feeds cylinders 2 and 3.
    3. With the BLACK test lead of the multimeter still grounded.
    4. Turn the Key On, but don't crank the engine, as in the last test, you should have 0 Hz.
    5. Have your assistant crank the engine again, while you observe the multimeter (or oscilloscope).
    6. The multimeter should register a Hertz reading that should fluctuate around 3 Hz, as the engine is cranking.

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

CASE 1: If the multimeter registered the indicated Hertz (Hz) values on both circuits, this results indicates to you that the ignition control module is bad and needs to be replaced to solve your 'no spark no start' condition.

CASE 2: If the multimeter DID NOT register the indicated Hertz (Hz) values on both circuits, this result usually indicates that the crankshaft position sensor is bad Although it's beyond the scope of this article to test the crank sensor, you can find the test for it here: How To Test The Ignition Control Module (ICM) & Crank Sensor: Chevrolet Cavalier Pontiac Sunfire 2.2L 4 cylinder.

Chevrolet Vehicles:

  • Cavalier 2.2L
    • 1997, 1998, 1999, 2000, 2001, 2002
  • S10 Pickup 2.2L
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003

GMC Vehicle:

  • Sonoma 2.2L
    • 1997, 1998, 1999, 2000, 2001, 2002, 2003

Isuzu Vehicles:

  • Hombre 2.2L
    • 1997, 1998, 1999, 2000

Pontiac Vehicle:

  • Sunfire 2.2L
    • 1997, 1998, 1999, 2000, 2001, 2002