TEST 5: Making Sure The Coil Pack Is Getting 12 Volts
For this test section, our focus will be on verifying that the ignition coil pack is getting the necessary 10 to 12 Volts it needs to function.
The wire responsible for supplying these 10 to 12 Volts to the coil pack is the dark green with orange stripe (DK GRN/ORG) wire of the ignition coil pack's connector.
To confirm the presence of this voltage in the DK GRN/ORG wire, we'll use a multimeter set to Volts DC mode.
Here are the steps:
- 1
Disconnect the ignition coil pack from its connector.
- 2
Connect the black multimeter test lead to the battery negative (-) terminal.
- 3
Place your multimeter in Volts DC mode.
- 4
Gently probe the terminal labeled with the number 2 (see illustration above) with the red multimeter test lead (using an appropriate tool).
CAUTION: Be careful that the multimeter probe doesn't damage the female terminal, or you'll have to get a new connector. - 5
Have your helper crank the engine.
NOTE: This voltage must be checked with the engine cranking. - 6
You should see 10 to 12 Volts on your multimeter.
Let's take a look at what your test results mean:
CASE 1: The multimeter registered 10 to 12 Volts DC. This is the correct and expected test result.
The next step is to see if the ignition coil is getting its activation signals, go to: TEST 8: Making Sure The Ignition Coil Pack Is Getting Its Activation Signals.
CASE 2: The multimeter DID NOT register 10 to 12 Volts DC. Re-check all of your connections and retest. If still no voltage is present, this result exonerates the ignition coil pack since without it the ignition coil pack will not function.
Repairing the cause of this missing voltage will solve the 'no-spark no-start' issue of your vehicle.
The most common cause of this missing voltage is a bad crankshaft position sensor. You can find a step-by-step test of the crankshaft position sensor here: How To Test The CKP Sensor (1995-2000 2.0L Dodge Stratus, Plymouth Breeze).
TEST 6: Checking The Activation Signal For Cylinders 1 And 4
The individual ignition coil (within the coil pack) that supplies spark for cylinders #1 and #4 only does so when it gets an activation signal from the fuel injection computer.
The activation signal is basically the fuel injection computer toggling the ignition coil's Ground ON and OFF. This action triggers the individual ignition coil to spark.
The wire that delivers the activation signal for cylinders 1 and 4 is the dark blue with dark green stripe (DK BLU/DK GRN) wire of the ignition coil pack's electrical connector.
The DK BLU/DK GRN wire connects to the female terminal labeled with the number 1 in the illustration of the connectors above.
Checking for this ON/OFF activation signal isn't difficult at all, it can be done with a simple 12 Volt automotive LED light.
If you don't have an LED light, you can find out more about it and where to buy one here: The LED Light Test Tool And How To Make One (at: easyautodiagnostics.com).
NOTE: In some vehicles, the cylinder #1 and #4 signal wire is a dark blue with tan stripe (DK BLU/TAN) wire.
These are the test steps:
- 1
Disconnect the ignition coil pack from its connector.
- 2
With an appropriate tool, connect the black lead of the LED light to the DK BLU/DK GRN wire that connects to the terminal labeled with the number 1 in the illustration above.
The DK BLU/DK GRN wire is the one that feeds the activation signal to the ignition coil (within the coil pack) that feeds spark to cylinders 1 and 4 simultaneously.
NOTE: You can also insert the end of the black LED wire into the female terminal of the wire. Just be careful that the wire doesn't damage the female terminal, or you'll have to get a new connector. - 3
Connect the red lead of the LED light to the battery positive (+) terminal with a long jumper cable.
NOTE: You can also insert the end of the red LED wire into middle female terminal of the connector (which will have 10 to 12 Volts with the engine cranking). Just be careful that the wire doesn't damage the female terminal, or you'll have to get a new connector. - 4
Have your helper crank the engine while you observe the LED light.
- 5
If the activation signal is present, the LED light will flash ON and OFF the whole time the engine was cranking.
Let's take a look at what your test results mean:
CASE 1: The LED light flashed ON and OFF the whole time the engine was cranking. This is the correct test result and it confirms that the fuel injection computer (PCM) is providing the activation signal and the circuit is OK.
You can conclude the ignition coil pack is bad and needs to be replaced only if you have:
- Confirmed that the spark plug wires for cylinder #1 and cylinder #4 are not sparking (TEST 1).
- Confirmed that the ignition coil pack towers for cylinder #1 and cylinder #4 are not sparking (TEST 3).
- Confirmed that the ignition coil's activation signal is present in this test section.
CASE 2: The LED light DID NOT flash ON and OFF the whole time the engine was cranking. Without an activation signal, the ignition coil pack will not fire off spark to cylinders #1 and #4.
The most likely cause of this missing signal is:
- An open-circuit problem in the wire between the connector and the fuel injection computer.
- The fuel injection computer is fried (altho this is rare).
With this result you can conclude that the ignition coil pack itself is not the source of the misfire condition or no-spark condition.
TEST 7: Checking The Activation Signal For Cylinders 2 And 3
The individual ignition coil (within the coil pack) that supplies spark for cylinders #2 and #3 only does so when it gets an activation signal from the fuel injection computer.
The activation signal is basically the fuel injection computer toggling the ignition coil's Ground ON and OFF. This action triggers the individual ignition coil to spark.
The wire that delivers the activation signal for cylinders 2 and 3 is the black with grey stripe (BLK/GRY) wire of the ignition coil pack's electrical connector.
The BLK/GRY wire connects to the female terminal labeled with the number 3 in the illustration of the connectors above.
Checking for this ON/OFF activation signal isn't difficult at all, it can be done with a simple 12 Volt automotive LED light.
If you don't have an LED light, you can find out more about it and where to buy one here: The LED Light Test Tool And How To Make One (at: easyautodiagnostics.com).
These are the test steps:
- 1
Disconnect the ignition coil pack from its connector.
- 2
With an appropriate tool, connect the black lead of the LED light to the BLK/GRY wire that connects to the terminal labeled with the number 3 in the illustration above.
The BLK/GRY wire is the wire that feeds the activation signal to the ignition coil (within the coil pack) that feeds spark to cylinders 2 and 3 simultaneously.
NOTE: You can also insert the end of the black LED wire into the female terminal of the wire. Just be careful that the wire doesn't damage the female terminal, or you'll have to get a new connector. - 3
Connect the red lead of the LED light to the battery positive (+) terminal with a long jumper cable.
NOTE: You can also insert the end of the red LED wire into middle female terminal of the connector (which will have 10 to 12 Volts with the engine cranking). Just be careful that the wire doesn't damage the female terminal, or you'll have to get a new connector. - 4
Have your helper crank the engine while you observe the LED light.
- 5
If the activation signal is present, the LED light will flash ON and OFF the whole time the engine was cranking.
Let's take a look at what your test results mean:
CASE 1: The LED light flashed ON and OFF the whole time the engine was cranking. This is the correct test result and it confirms that the fuel injection computer (PCM) is providing the activation signal and the circuit is OK.
You can conclude the ignition coil pack is bad and needs to be replaced only if you have:
- Confirmed that the spark plug wires for cylinders #2 and #3 are not sparking (TEST 1).
- Confirmed that the ignition coil pack towers for cylinder #2 and cylinder #3 are not sparking (TEST 3).
- Confirmed that the ignition coil pack's activation signal is present in this test section.
CASE 2: The LED light DID NOT flash ON and OFF the whole time the engine was cranking. Without an activation signal, the ignition coil pack will not fire off spark to cylinders #2 and #3.
The most likely cause of this missing signal is:
- An open-circuit problem in the wire between the connector and the fuel injection computer.
- The fuel injection computer is fried (altho this is rare).
With this result you can conclude that the ignition coil pack itself is not the source of the misfire condition or no-spark condition.
