COIL PACK

How The Coil Pack Works

The PCM (Powertrain Control Module=Fuel Injection Computer) is the one
that controls the whole show in this type of ignition system since the ‘Ignition
Control Module’ function is handled by the PCM itself. So, in a nutshell, here's
what happens when you turn the key to crank and start the car:
1. 1
The Auto Shut Down (ASD) Relay provides the ignition
coil pack with 12 Volts (only when the engine is
cranking or running).
2. 2
The crankshaft position (CKP) sensor starts to create its
CKP signal, as the engine cranks.
3. 3
The CKP signal, upon being received by the PCM along
with other necessary sensor information, starts to do its
little song and dance and decides which ignition coil
(within the coil pack assembly) to fire. It does this by
sending the coil pack three different Switching signals
(thru' separate circuits).
• The term Switching signal describes the PCM's
action of switching the Primary Current (12
Volts), flowing thru' each ignition coil within the
coil pack, ON and OFF by interrupting their
Ground path. It's this signal that makes the
ignition coils fire spark.
4. 4
The coil pack is made up of three separate and
individual ignition coils, therefore each one gets its own
switching signal from the PCM. Each ignition coil within
the coil pack has two towers that feed spark to two
cylinders at the same time. These two cylinders (that get
spark at the same time) are called ‘Paired Cylinders’
• One ignition coil within the coil pack fires spark to
cylinders 3 and 6. So, cylinders 3 and 6 are
‘Paired Cylinders’.
COIL PACK
• One ignition coil fires cylinders 1 and 4. So,
cylinders 1 and 4 are ‘Paired Cylinders'.
• The other ignition coil fires cylinders 2 and 5. So,
cylinders 2 and 5 are ‘Paired Cylinders’.
1. 5
As each individual ignition coil, within the ignition coil
pack, get their Switching signal, they then fire spark to
two different cylinders at the exact same time (in what's
known as the Waste Spark method).
To test the Chrysler ignition coil (for these specific 3.3L, 3.8L Chrysler engines
this article covers) the only thing that you have to worry about is knowing
that two cylinders get spark at the exact same time (#3 and #6, #1 and #4, #2
and #5) from separate ignition coils within the coil pack assembly.

You can use a multimeter or a test light to test the power (12 Volt) Circuit of
the Chrysler coil pack.
The coil pack can be connected or not to its connector. The following test
steps assume that you'll test the power circuit with a multimeter and with
the connector connected to the ignition coil pack.
1. 1
The 4 wires in the ignition coil pack's connector are
usually sheathed in black electrical tape that has
probably turned plastic hard, remove enough of this
electrical tape to expose the three wires for testing.
2. 2
With the ignition coil connected to its connector.
3. 3
Put the multimeter in VOLTS DC mode (don't have a
digital multimeter? Need to buy one? Click here to

1.
2. 4
Probe the circuit labeled with the number 3 (see photo
in image viewer) with the red multimeter test lead
(using an appropriate tool to pierce the wire).
3. 5
COIL PACK
With the black multimeter test lead probe the battery
negative (-) terminal.
1.
Have your helper turn the key to the ON position and
then crank the engine. Continuous voltage is only
provided when the engine is being cranked.
2. 7
You should see 10-12 Volts on your multimeter, or if
you're using a test light, the test light should light up.

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

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 coil pack. Repairing
the cause of this missing voltage will solve the 'no-spark no-start' condition
of your Chrysler (or Dodge or Plymouth) mini-van. The most common
reasons for no power are:
• The Crankshaft Position (CKP) sensor is bad. If the CKP sensor is bad,
the PCM will not power up the Auto Shut Down (ASD) Relay, which in
turn will not power up the ignition coil pack or any other ignition
system or fuel system component.

OK, this is the final test (and the one you signed up for). In this test step,
we're gonna' verify that the crank sensor is actually creating a crankshaft
position signal.
The one thing you need to keep in mind, to get an accurate test result, is to
manually turn the engine using a socket and ratchet wrench (on the
crankshaft pulley).
In case you're wondering: ‘Why turn the engine over by hand?’ This is to
ensure that you get a very accurate test result.
COIL PACK
These are the steps:
1. 1
Disable the ignition system by disconnecting the
distributor from its electrical connectors. This is
important!
2. 2
Place your multimeter in Volts DC mode.

IMPORTANT: The crank sensor must be connected to

its engine wiring harness connector for this test!
3. 3
Connect the red multimeter test lead to the BLU
wire with an appropriate tool. The BLU wire connects to
the connector terminal identified with the number 2 in
the illustration.

You should use a back-probe or a wire-piercing tool to

attach to your multimeter to check for this crankshaft
position signal (Wire Piercing Probe).
4. 4
Connect the multimeter's black lead directly on the
battery negative (-) terminal or a good Ground point
on the engine.
5. 5
Turn the key to the On Position but don't crank the
engine. This will power up the crank sensor.
6. 6
With an appropriate tool, turn the crankshaft pulley
by hand. Do not crank the engine with the key from
inside of the vehicle.
7. 7
If the crank sensor is functioning correctly, your
multimeter will register an On/Off voltage signal as you
crank the engine by hand. ‘On’ will register 5 Volts on
the multimeter and ‘Off’ will register 0.1 Volts.
Let's find out what your test results mean:
COIL PACK
CASE 1: The multimeter registered the On/Off voltage values the whole
time you hand cranked the engine. This test result confirms the crankshaft
position sensor is working and is not the cause of your Galant's ‘no-spark
no-start’ condition.
CASE 2: The multimeter DID NOT register the On/Off voltage values. This
test result confirms the crankshaft position sensor is bad and needs to be
replaced.
To explain this a bit further: You have:
• Checked/confirmed that the crankshaft position sensor is being fed
power on the RED wire (TEST 1).
• Checked/confirmed that the crankshaft position sensor is being fed
Ground on the BLK wire (TEST 2).
• In this test step, you confirmed that the sensor is not creating the
On/Off voltage signal (On= 5 Volts, Off= 0.1 Volts).
Taking these 3 specific test results into account, you can conclude the
crankshaft position sensor on your 2.4L Mitsubishi Galant is bad.
Where To Buy The Crank Sensor And Save
The following links will help you comparison shop for the crankshaft
position sensor.

Not sure if the above crankshaft position sensor fits your particular Galant?
Don't worry, once you get to the site, they'll make sure it fits. If it doesn't fit,
they'll find you the right one.