check engine CHRYSLER VOYAGER 1996 Workshop Manual

²Transmission range sensor, or Park/Neutral
Position switch with automatic transmissions
²Clutch Pedal Position Switch with manual
transmissions
²Ignition switch
²Battery
²All related wiring and connections
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
²To disable ignition and fuel systems, disconnect
the Automatic Shutdown Relay (ASD). The ASD relay
is located in the in the Power Distribution Center
(PDC). Refer to the PDC cover for the proper relay
location.
STARTER SOLENOID
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK POSITION WITH THE
PARKING BRAKE APPLIED
(1) Verify battery condition. Battery must be in
good condition with a full charge before performing
any starter tests. Refer to Battery Tests.
(2) Perform Starter Solenoid test BEFORE per-
forming the starter relay test.
(3) Raise the vehicle.
(4) Perform a visual inspection of the starter/
starter solenoid for corrosion, loose connections or
faulty wiring.
(5) Lower the vehicle.
(6) Locate and remove the starter relay from the
Power Distribution Center (PDC). Refer to the PDC
label for relay identification and location.
(7) Connect a remote starter switch or a jumper
wire between the remote battery positive post and
terminal 87 of the starter relay connector.
(a) If engine cranks, starter/starter solenoid is
good. Go to the Starter Relay Test.
(b) If engine does not or solenoid chatters, check
wiring and connectors from starter relay to starter
solenoid for loose or corroded connections. Particu-
larly at starter terminals.
(c) Repeat test. If engine still fails to crank prop-
erly, trouble is within starter or starter mounted
solenoid, and replace starter.
STARTER RELAY
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK POSITION/NEUTRAL
WITH THE PARKING BRAKE APPLIED
RELAY TEST
The starter relay is located in the Power Distribu-
tion Center (PDC) in the engine compartment. Refer
to the PDC label for relay identification and location.
Remove the starter relay from the PDC as
described in this group to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 7565 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery B+ lead to terminals 86 and
a ground lead to terminal 85 to energize the relay.
The relay should click. Also test for continuity
between terminals 30 and 87, and no continuity
between terminals 87A and 30. If OK, refer to Relay
Circuit Test procedure. If not OK, replace the faulty
relay.
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the starter solenoid field coils. There should be
continuity between the cavity for relay terminal 87
and the starter solenoid terminal at all times. If OK,
go to Step 4. If not OK, repair the open circuit to the
starter solenoid as required.
(4) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is energized when
the ignition switch is held in the Start position. On
Starter Relay
8B - 2 STARTERNS
DIAGNOSIS AND TESTING (Continued)

vehicles with a manual transmission, the clutch
pedal must be fully depressed for this test. Check for
battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position, and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK with an
automatic transmission, check for an open or short
circuit to the ignition switch and repair, if required.
If the circuit to the ignition switch is OK, see the
Ignition Switch Test procedure in this group. If not
OK with a manual transmission, check the circuit
between the relay and the clutch pedal position
switch for an open or a short. If the circuit is OK, see
the Clutch Pedal Position Switch Test procedure in
this group.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. On vehicles with an
automatic transmission, it is grounded through the
park/neutral position switch only when the gearshift
selector lever is in the Park or Neutral positions. On
vehicles with a manual transmission, it is grounded
at all times. Check for continuity to ground at the
cavity for relay terminal 85. If not OK with an auto-
matic transmission, check for an open or short circuit
to the park/neutral position switch and repair, if
required. If the circuit is OK, see the Park/Neutral
Position Switch Test procedure in this group. If not
OK with a manual transmission, repair the circuit to
ground as required.
SAFETY SWITCHES
For diagnostics,
²Clutch Pedal Position Switch, refer to Group 6,
Clutch.
²Park/Neutral Position Switch, refer to Group 21,
Transaxle
IGNITION SWITCH
After testing starter solenoid and relay, test igni-
tion switch and wiring. Refer to Group 8D, Ignition
Systems or Group 8W, Wiring Diagrams. Check all
wiring for opens or shorts, and all connectors for
being loose or corroded.
BATTERY
Refer to Group 8A, Battery for proper procedures.
ALL RELATED WIRING AND CONNECTORS
Refer to Group 8W, Wiring Diagrams,
FEED CIRCUIT RESISTANCE TEST
Before proceeding with this operation, review Diag-
nostic Preparation and Starter Feed Circuit Tests.
The following operation will require a voltmeter,
accurate to 1/10 of a volt.
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
(1) To disable the ignition and fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(2) With all wiring harnesses and components
properly connected, perform the following:
(a) Connect the negative lead of the voltmeter to
the battery negative post, and positive lead to the
battery negative cable clamp (Fig. 2). Rotate and
hold the ignition switch in the START position.
Observe the voltmeter. If voltage is detected, cor-
rect poor contact between cable clamp and post.
(b) Connect positive lead of the voltmeter to the
battery positive post, and negative lead to the bat-
tery positive cable clamp. Rotate and hold the igni-
tion switch key in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between the cable clamp and post.
(c) Connect negative lead of voltmeter to battery
negative terminal, and positive lead to engine
Fig. 2 Test Battery Connection Resistance
NSSTARTER 8B - 3
DIAGNOSIS AND TESTING (Continued)

CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
(1) Connect a volt-ampere tester to the battery ter-
minals (Fig. 7). Refer to the operating instructions
provided with the tester being used.
(2) To disable the ignition and fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location. The 2.5L Diesel Engine, to disable the
engine from starting, disconnect wire connector from
the Fuel Solenoid.
(3) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
position or with the clutch pedal depressed and SET
parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(4) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
6).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 amps or the Diesel engine
above 450 amps, check for engine seizing or faulty
starter.
²If voltage reads 12.4 volts or greater and amper-
age reads 0 to 10 amps, check for corroded cables
and/or bad connections.
²Voltage below 9.6 volts and amperage draw
above 300 amps or Diesel engine above 500 amps,
the problem is the starter. Replace the starter refer
to starter removal.
(5) After the starting system problems have been
corrected, verify the battery state-of-charge and
charge battery if necessary. Disconnect all testingequipment and connect ASD relay or the Fuel Sole-
noid. Start the vehicle several times to assure the
problem has been corrected.
REMOVAL AND INSTALLATION
STARTERÐ2.4L ENGINE
REMOVAL
(1) Release hood latch and open hood.
(2) Disconnect battery negative cable (Fig. 8).
(3) Hoist and support vehicle on safety stands.
(4) Disconnect solenoid wire connector from termi-
nal.
(5) Remove nut holding B+ wire to terminal.
(6) Disconnect solenoid and B+ wires from starter
terminals.
(7) Remove bolts holding starter to transaxle bell-
housing (Fig. 9).
(8) Remove starter.
Fig. 7 Volt-Ampere Tester Connections
Fig. 8 Battery Negative Cable
Fig. 9 Starter±2.4L Engine
NSSTARTER 8B - 5
DIAGNOSIS AND TESTING (Continued)

GENERATOR
The generator is belt-driven by the engine. It is
serviced only as a complete assembly. If the genera-
tor fails for any reason, the entire assembly must be
replaced.
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The Y type stator winding connections deliver the
induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicle electrical system
through the generator, battery, and ground terminals.
Noise emitting from the generator may be caused
by:
²Worn, loose or defective bearings
²Loose or defective drive pulley
²Incorrect, worn, damaged or misadjusted drive
belt
²Loose mounting bolts
²Misaligned drive pulley
²Defective stator or diode
BATTERY TEMPERATURE SENSOR
The temperature sensor, in the PCM, is used to
determine the battery temperature. This temperature
data, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
System voltage will be higher at colder temperatures
and is gradually reduced at warmer temperatures.
ELECTRONIC VOLTAGE REGULATOR
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-
ing circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
Operation:The amount of DC current produced
by the generator is controlled by EVR circuitry con-
tained within the PCM. This circuitry is connected in
series with the generators second rotor field terminal
and its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage and bat-
tery temperature (refer to Battery Temperature Sen-
sor for more information). It then compensates and
regulates generator current output accordingly. Also
refer to Charging System Operation for additional
information.
DIAGNOSIS AND TESTING
CHARGING SYSTEM
When the ignition switch is turned to the ON posi-
tion, battery potential will register on the voltmeter.
During engine cranking a lower voltage will appear
on the meter. With the engine running, a voltage
reading higher than the first reading (ignition in ON)
should register.
The following are possible symptoms of a charging
system fault:
²The voltmeter does not operate properly
²An undercharged or overcharged battery condi-
tion occurs.
Remember that an undercharged battery is often
caused by:
²Accessories being left on with the engine not
running
²A faulty or improperly adjusted switch that
allows a lamp to stay on. See Ignition-Off Draw Test
in Group 8A, Battery for more information.
The following procedures may be used to correct a
problem diagnosed as a charging system fault.
INSPECTION
(1) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.
(2) Inspect all fuses in the fuseblock module and
Power Distribution Center (PDC) for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.
(3) Inspect the electrolyte level in the battery.
Replace battery if electrolyte level is low.
(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. Refer to the Gen-
erator Removal/Installation section of this group for
torque specifications.
(5) Inspect generator drive belt condition and ten-
sion. Tighten or replace belt as required. Refer to
Belt Tension Specifications in Group 7, Cooling Sys-
tem.
(6) Inspect automatic belt tensioner (if equipped).
Refer to Group 7, Cooling System for information.
(7) Inspect connections at generator field, battery
output, and ground terminals. Also check ground con-
nection at engine. They should all be clean and tight.
Repair as required.
8C - 2 CHARGING SYSTEMNS
DESCRIPTION AND OPERATION (Continued)

CHARGING SYSTEM RESISTANCE TESTS
These tests will show the amount of voltage drop
across the generator output wire from the generator
output (B+) terminal to the battery positive post.
They will also show the amount of voltage drop from
the ground (-) terminal on the generator or case
ground (Fig. 1) to the battery negative post.
A voltmeter with a 0±18 volt DC scale should be
used for these tests. By repositioning the voltmeter
test leads, the point of high resistance (voltage drop)
can easily be found.
PREPARATION
(1) Before starting test, make sure battery is in
good condition and is fully-charged. See Group 8A,
Battery for more information.
(2) Check condition of battery cables at battery.
Clean if necessary.
(3) Start the engine and allow it to reach normal
operating temperature.
(4) Shut engine off.
(5) Connect an engine tachometer.
(6) Fully engage the parking brake.
TEST
(1) Start engine.
(2) Place heater blower in high position.
(3) Turn on headlamps and place in high-beam
position.
(4) Turn rear window defogger on.
(5) Bring engine speed up to 2400 rpm and hold.
(6) Testing (+ positive) circuitry:
(a) Touch the negative lead of voltmeter directly
to battery positivePOST(Fig. 2).
(b) Touch the positive lead of voltmeter to the
B+ output terminal stud on the generator (not the
terminal mounting nut). Voltage should be no
higher than 0.6 volts. If voltage is higher than 0.6
volts, touch test lead to terminal mounting stud
nut and then to the wiring connector. If voltage is
now below 0.6 volts, look for dirty, loose or poor
connection at this point. Also check condition of the
generator output wire-to-battery bullet connector.
Refer to Group 8, Wiring for connector location. A
voltage drop test may be performed at each (-
ground) connection in this circuit to locate the
excessive resistance.
(7) Testing (- ground) circuitry:
(a) Touch the positive lead of voltmeter directly
to battery negativePOST.
(b) Touch the negative lead of voltmeter to the
generator case. Voltage should be no higher than
0.3 volts. If voltage is higher than 0.3 volts, touch
test lead to generator case and then to the engine
block. If voltage is now below 0.3 volts, look for
dirty, loose or poor connection at this point. A volt-
age drop test may be performed at each connectionin this circuit to locate the excessive resistance.
This test can also be performed between the gener-
ator case and the engine. If test voltage is higher
than 0.3 volts, check for corrosion at generator
mounting points or loose generator mounting.
CURRENT OUTPUT TEST
The current output test will determine if the
charging system can deliver its minimum test cur-
rent (amperage) output. Refer to the Specifications
section at the end of this group for minimum test
current (amperage) requirements.
The first part of this test will determine the com-
bined amperage output of both the generator and the
Electronic Voltage Regulator (EVR) circuitry.
PREPARATION
(1) Determine if any Diagnostic Trouble Codes
(DTC) exist. To determine a DTC, refer to On-Board
Diagnostics in this group. For repair, refer to the
appropriate Powertrain Diagnostic Procedures man-
ual.
(2) Before starting test, make sure battery is in
good condition and is fully-charged. See Group 8A,
Battery for more information.
(3) Check condition of battery cables at battery.
Clean if necessary.
(4) Perform the Voltage Drop Test. This will
ensure clean and tight generator/battery electrical
connections.
(5) Be sure the generator drive belt is properly
tensioned. Refer to Group 7, Cooling System for
information.
(6) A volt/amp tester equipped with both a battery
load control (carbon pile rheostat) and an inductive-
type pickup clamp (ammeter probe) will be used for
this test. Refer to operating instructions supplied
with tester. When using a tester equipped with an
inductive-type clamp, removal of wiring at the gener-
ator will not be necessary.
(7) Start the engine and allow it to reach operating
temperature.
(8) Shut engine off.
(9) Turn off all electrical accessories and all vehicle
lighting.
(10) Connect the volt/amp tester leads to the bat-
tery. Be sure the carbon pile rheostat control is in the
OPEN or OFF position before connecting leads. See
Load Test in Group 8A, Battery for more information.
Also refer to the operating instructions supplied with
test equipment.
(11) Connect the inductive clamp (ammeter probe).
Refer to the operating instructions supplied with test
equipment.
(12) If volt/amp tester is not equipped with an
engine tachometer, connect a separate tachometer to
the engine.
8C - 4 CHARGING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)

TEST
(1) Perform the previous test Preparation.
(2) Fully engage the parking brake.
(3) Start engine.
(4) Bring engine speed to 2500 rpm.
(5) With engine speed held at 2500 rpm, slowly
adjust the rheostat control (load) on the tester to
obtain the highest amperage reading. Do not allow
voltage to drop below 12 volts. Record the reading.
This load test must be performed within 15 sec-
onds to prevent damage to test equipment.On
certain brands of test equipment, this load will be
applied automatically. Refer to the operating manual
supplied with test equipment.
(6) The ammeter reading must meet the Minimum
Test Amps specifications as displayed in the Genera-tor Ratings chart. This can be found in the Specifica-
tions section at the end of this group. A label stating
a part reference number is attached to the generator
case. On some engines this label may be located on
the bottom of the case. Compare this reference num-
ber to the Generator Ratings chart.
(7) Rotate the load control to the OFF position.
(8) Continue holding engine speed at 2500. If EVR
circuitry is OK, amperage should drop below 15±20
amps. With all electrical accessories and vehicle
lighting off, this could take several minutes of engine
operation. If amperage did not drop, refer to the
appropriate Powertrain Diagnostic Procedures man-
ual for testing.
(9) Remove volt/amp tester.
If minimum amperage could not be met, refer to
the appropriate Powertrain Diagnostic Procedures
manual for testing.
ON-BOARD DIAGNOSTIC SYSTEM TEST
GENERAL INFORMATION
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the charging sys-
tem, making sure they are operational. A Diagnostic
Trouble Code (DTC) is assigned to each input and
output circuit monitored by the OBD system. Some
circuits are checked continuously and some are
checked only under certain conditions.
If the OBD system senses that a monitored circuit
is bad, it will put a DTC into electronic memory. The
DTC will stay in electronic memory as long as the
circuit continues to be bad. The PCM is programmed
to clear the memory after 50 engine starts if the
problem does not occur again.
DIAGNOSTIC TROUBLE CODES
Refer to Group 25, On Board Diagnostic for more
information. A DTC description can be read using the
DRB scan tool. Refer to the appropriate Powertrain
Diagnostic Procedures manual for information.
A DTC does not identify which component in a cir-
cuit is bad. Thus, a DTC should be treated as a
symptom, not as the cause for the problem. In some
cases, because of the design of the diagnostic test
procedure, a DTC can be the reason for another DTC
to be set. Therefore, it is important that the test pro-
cedures be followed in sequence, to understand what
caused a DTC to be set.
ERASING DIAGNOSTIC TROUBLE CODES
The DRB Scan Tool must be used to erase a DTC.
Fig. 1 Generator Terminals
Fig. 2 Battery Voltage TestÐTypical
NSCHARGING SYSTEM 8C - 7
DIAGNOSIS AND TESTING (Continued)

IGNITION SYSTEM
CONTENTS
page page
GENERAL INFORMATION................... 1
2.4L ENGINE............................ 16
3.0L ENGINE............................ 233.3/3.8L ENGINE........................ 28
IGNITION SWITCH AND LOCK CYLINDER..... 35
GENERAL INFORMATION
INDEX
page page
GENERAL INFORMATION
AUTOMATIC SHUTDOWN (ASD) RELAY....... 4
CAMSHAFT POSITION SENSOR............. 5
CRANKSHAFT POSITION SENSOR........... 5
ENGINE COOLANT TEMPERATURE (ECT)
SENSOR.............................. 6
IGNITION COIL.......................... 4
IGNITION SYSTEM....................... 2
INTRODUCTION......................... 1
KNOCK SENSOR......................... 7
LOCK KEY CYLINDER..................... 7
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR.............................. 6
POWERTRAIN CONTROL MODULE........... 1
SPARK PLUG CABLE...................... 3
SPARK PLUGSÐ2.4/3.0L................... 2
SPARK PLUGSÐ3.3/3.8L................... 2
THROTTLE POSITION SENSOR (TPS)........ 7DIAGNOSIS AND TESTING
CAMSHAFT POSITION SENSOR AND
CRANKSHAFT POSITION SENSOR......... 11
CHECK COIL TESTÐ2.4L.................. 9
CHECK COIL TESTÐ3.3/3.8L................ 9
ENGINE COOLANT TEMPERATURE SENSOR . . 11
FAILURE TO START TEST................. 10
IGNITION TIMING PROCEDURE............ 11
INTAKE AIR TEMPERATURE SENSOR........ 11
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR TEST........................ 11
SPARK PLUG CONDITION................. 11
TESTING FOR SPARK AT COILÐ2.4/3.3/3.8L
ENGINES............................. 8
TESTING FOR SPARK AT COILÐ3.0L......... 8
THROTTLE POSITION SENSOR............ 13
SERVICE PROCEDURES
IGNITION TIMING PROCEDURE............ 15
POWERTRAIN CONTROL MODULE.......... 13
SPARK PLUG GAP ADJUSTMENT........... 13
GENERAL INFORMATION
INTRODUCTION
This group describes the ignition systems for the
2.4, 3.0, and 3.3/3.8L engines.
On Board Diagnostics is described in Group 25 -
Emission Control Systems.
Group 0 - Lubrication and Maintenance, contains
general maintenance information for ignition related
items. The Owner's Manual also contains mainte-
nance information.
POWERTRAIN CONTROL MODULE
The ignition system is regulated by the Powertrain
Control Module (PCM) (Fig. 1). The PCM supplies
battery voltage to the ignition coil through the Auto
Shutdown (ASD) Relay. The PCM also controls
ground circuit for the ignition coil. By switching the
ground path for the coil on and off, the PCM adjusts
ignition timing to meet changing engine operating
conditions.
During the crank-start period the PCM advances
ignition timing a set amount. During engine opera-
tion, the amount of spark advance provided by the
PCM is determined by the following input factors:
NSIGNITION SYSTEM 8D - 1

²available manifold vacuum
²barometric pressure
²engine coolant temperature
²engine RPM
²intake air temperature (2.4L only)
²throttle position
The PCM also regulates the fuel injection system.
Refer to the Fuel Injection sections of Group 14.
IGNITION SYSTEM
NOTE: The 2.4, 3.0 and 3.3/3.8L engines use a fixed
ignition timing system. Basic ignition timing is not
adjustable. All spark advance is determined by the
Powertrain Control Module (PCM).
The distributorless ignition system used on 2.4 and
3.3/3.8L engines is refered to as the Direct Ignition
System (DIS). The system's three main components
are the coil pack, crankshaft position sensor, and
camshaft position sensor. The crankshaft position
sensor and camshaft position sensor are hall effect
devices.
The 3.0L engine uses a distributor, crankshaft sen-
sor and ignition coil. The system's main components
are the distributor, distributor pickup, camshaft sig-
nal, crankshaft signal and ignition coil.
SPARK PLUGSÐ2.4/3.0L
All engines use resistor spark plugs. They have
resistance values ranging from 6,000 to 20,000 ohms
when checked with at least a 1000 volt spark plug
tester.Do not use an ohm meter to check the resis-
tance of the spark plugs. This will give an inac-
curate reading.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. An iso-
lated plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
Group O - Lubrication and Maintenance.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective, carbon or oil
fouled. Refer to the Spark Plug Condition section of
this group. After cleaning, file the center electrode
flat with a small flat point file or jewelers file. Adjust
the gap between the electrodes (Fig. 2) to the dimen-
sions specified in the chart at the end of this section.
Special care should be used when installing spark
plugs in the 2.4L cylinder head spark plug wells. Be
sure the plugs do not drop into the wells, damage to
the electrodes can occur.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap. Overtightening can
also damage the cylinder head. Tighten spark plugs
to 28 N´m (20 ft. lbs.) torque.SPARK PLUGSÐ3.3/3.8L
The 3.3/3.8L engines utilize platinum spark plugs.
Refer to the maintenance schedule in Group 0 of this
service manual.
Fig. 1 Powertrain Control Module
Fig. 2 Setting Spark Plug Electrode Gap
8D - 2 IGNITION SYSTEMNS
GENERAL INFORMATION (Continued)

All engines use resistor spark plugs. They have
resistance values ranging from 6,000 to 20,000 ohms
when checked with at least a 1000 volt spark plug
tester.
Do not use an ohm meter to check the resis-
tance of the spark plugs. This will give an inac-
curate reading.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. An iso-
lated plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
Group O - Lubrication and Maintenance.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective, carbon or oil
fouled. Refer to the Spark Plug Condition section of
this group.
The spark plugs are double platinum and have a
recommended service life of 100,000 miles for normal
driving conditions per schedule A in this manual. The
spark plugs have a recommended service life of
75,000 miles for serve driving conditions per schedule
B in this manual. A thin platinum pad is welded to
both electrode ends as show in (Fig. 3). Extreme care
must be used to prevent spark plug cross threading,
mis-gaping and ceramic insulator damage during
plug removal and installation.
CAUTION: Never attempt to file the electrodes or
use a wire brush for cleaning platinum plugs. This
would damage the platinum pads which would
shorten spark plug life.
Apply a very small amount of anti-seize compound
to the threads when reinstalling the vehicle's original
spark plugs that have been determined good.Do not
apply anti-seize compound to new spark plugs.
NOTE: Anti-seize compound is electrically conduc-
tive and can cause engine misfires if not applied
correctly. It is extremely important that the anti-
seize compound doesn't make contact with the
spark plug electrodes or ceramic insulator.
Never force a gap gauge between the platinum
electrodes or adjust the gap on platinum spark plugs
without reading the 3.3/3.8L Spark Plug Gap Mea-
surement procedures in this section.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap. Overtightening can
also damage the cylinder head. Tighten spark plugs
to 28 N´m (20 ft. lbs.) torque.
Due to the engine packaging environment for the
3.3/3.8L engines, extreme care should be used wheninstalling the spark plugs to avoid cross threading
problems.
3.3/3.8L SPARK PLUG GAP MEASUREMENT
CAUTION: The Platinum pads can be damaged dur-
ing the measurement of checking the gap if extreme
care is not used.
²USE ONLY A TAPER GAP GAUGE (Fig. 2)
²Never force the gap gauge through the platinum
pads. Only apply enough force until resistance is felt.
²Never use a wire brush or spark plug cleaner
machine to clean platinum spark plugs
²Use an OSHA approved air nozzle when drying
gas fouled spark plugs.
If gap adjustment is required of platinum plug,
bend only the ground electrode. DO NOT TOUCH
the platinum pads. Use only a proper gapping tool
and check with a taper gap gauge.
CAUTION: Cleaning of the platinum plug may dam-
age the platinum tip.
SPARK PLUG CABLE
Spark Plug cables are sometimes referred to as
secondary ignition wires. The wires transfer electri-
cal current from the ignition coil pack, distributor
(3.0L), to individual spark plugs at each cylinder. The
resistive spark plug cables are of nonmetallic con-
struction. The cables provide suppression of radio fre-
quency emissions from the ignition system.
Check the spark plug cable connections for good
contact at the coil, distributor cap towers (3.0L), and
spark plugs. Terminals should be fully seated. The
insulators should be in good condition and should fit
tightly on the coil, distributor (3.0L) and spark plugs.
Spark plug cables with insulators that are cracked or
torn must be replaced.
Fig. 3 Platinum Pads
NSIGNITION SYSTEM 8D - 3
GENERAL INFORMATION (Continued)

Clean Spark Plug cables with a cloth moistened
with a non-flammable solvent. Wipe the cables dry.
Check for brittle or cracked insulation.
SPARK PLUG CABLESÐ3.3/3.8L
The spark plug cables and spark plug boots are
made from high temperature silicone materials. The
spark plug boots utilize metal heat shields for ther-
mal protection from the exhaust manifold. The heat
shields slide over the spark plug boots. The notches
on the heat shields ensure the spark plug boot and
shield twist together during spark plug boot removal.
They also identify proper heat shield installation on
the boot for service.Refer to 3.3/3.8L Spark Plug
Cable removal and installation.All spark plug
cable leads are properly identified with cylinder num-
bers. The inside of the spark plug boot is coated with
a special high temperature silicone grease for greater
sealing and to minimize boot bonding to the spark
plug insulator. The convoluted tubing on the rear
plug cables are made of a high temperature plastic
material. Under normal driving conditions, the spark
plug cables have a recommended service life of a
100,000 miles. The spark plugs have a recommended
service life of 75,000 miles for severe driving condi-
tions per schedule B in this manual.
The spark plug heat shield can be reused if an
ignition cable is replaced due to failure. Never reuse
heat shield's that have heat shield anti-twist, side or
spark plug attachment tabs bent or missing. Ensure
that the heat shield is properly attached to the spark
plug to avoid RFI problems. The bottom of the spark
plug heat shield must make contact with the spark
plug hex.
The front ignition cables must not make contact
with the oil dip stick tube and #5 cable must not
touch the coil mounting bolt to avoid abrasion/dielec-
tric failures.
IGNITION COIL
WARNING: THE DIRECT IGNITION SYSTEM GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
The ignition coil assembly consists of 3 indepen-
dent coils molded together (Fig. 4). The coil assembly
is mounted on the intake manifold. Spark plug cables
route to each cylinder from the coil. The coil fires two
spark plugs every power stroke. One plug is the cyl-
inder under compression, the other cylinder fires on
the exhaust stroke. The Powertrain Control Module
(PCM) determines which of the coils to charge and
fire at the correct time.
Coil 1 fires cylinders 1 and 4, coil 2 fires cylinders
2 and 5, coil 3 fires cylinders 3 and 6.The Auto Shutdown (ASD) relay provides battery
voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
the PCM breaks the contact, the energy in the coil
primary transfers to the secondary causing the
spark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Auto Shut-
down (ASD) RelayÐPCM Output, in this section for
relay operation.
AUTOMATIC SHUTDOWN (ASD) RELAY
The Powertrain Control Module (PCM) operates
the Auto Shutdown (ASD) relay by switching the
ground path on and off.
The ASD relay supplies battery voltage to the fuel
injectors, electronic ignition coil and the heating ele-
ments in the oxygen sensors.
The PCM controls the relay by switching the
ground path for the solenoid side of the relay on and
off. The PCM turns the ground path off when the
ignition switch is in the Off position unless the 02
Heater Monitor test is being run. Refer to Group 25,
On-Board Diagnostics. When the ignition switch is in
the On or Crank position, the PCM monitors the
crankshaft position sensor and camshaft position sen-
sor signals to determine engine speed and ignition
timing (coil dwell). If the PCM does not receive the
crankshaft position sensor and camshaft position sen-
sor signals when the ignition switch is in the Run
position, it will de-energize the ASD relay.
The ASD relay is located in the Power Distribution
Center (PDC). The PDC is located on the driver's
side inner fender well (Fig. 5). A label on the under-
side of the PDC cover identifies the relays and fuses
in the PDC.
Fig. 4 Ignition Coil Pack
8D - 4 IGNITION SYSTEMNS
GENERAL INFORMATION (Continued)