transmission CHRYSLER CARAVAN 2002 Repair Manual

PLE:When testing the resistance of the battery pos-
itive cable, touch the voltmeter leads to the battery
positive cable terminal clamp and to the battery pos-
itive cable eyelet terminal at the starter solenoid
B(+) terminal stud. If you probe the battery positive
terminal post and the battery positive cable eyelet
terminal at the starter solenoid B(+) terminal stud,
you are reading the combined voltage drop in the
battery positive cable terminal clamp-to-terminal
post connection and the battery positive cable.
VOLTAGE DROP TEST
The following operation will require a voltmeter
accurate to 1/10 (0.10) volt. Before performing this
test, be certain that the following procedures are
accomplished:
²The battery is fully-charged and load tested.
Refer to Standard Procedures for the proper battery
charging and load test procedures.
²Fully engage the parking brake.
²If the vehicle is equipped with an automatic
transmission, place the gearshift selector lever in the
Park position. If the vehicle is equipped with a man-
ual transmission, place the gearshift selector lever in
the Neutral position and block the clutch pedal in the
fully depressed position.
²Verify that all lamps and accessories are turned
off.
²To prevent the engine from starting, remove the
Automatic Shut Down (ASD) relay. The ASD relay is
located in the Intelligent Power Module (IPM), in the
engine compartment. See the fuse and relay layout
label affixed to the underside of the IPM cover for
ASD relay identification and location.
(1) Connect the positive lead of the voltmeter to
the battery negative terminal post. Connect the neg-
ative lead of the voltmeter to the battery negative
cable terminal clamp (Fig. 13). Rotate and hold the
ignition switch in the Start position. Observe the
voltmeter. If voltage is detected, correct the poor con-
nection between the battery negative cable terminal
clamp and the battery negative terminal post.
(2) Connect the positive lead of the voltmeter to
the battery positive terminal post. Connect the nega-
tive lead of the voltmeter to the battery positive cable
terminal clamp (Fig. 14). Rotate and hold the ignition
switch in the Start position. Observe the voltmeter. If
voltage is detected, correct the poor connection
between the battery positive cable terminal clamp
and the battery positive terminal post.
(3) Connect the voltmeter to measure between the
battery positive cable terminal clamp and the starter
solenoid B(+) terminal stud (Fig. 15). Rotate and hold
the ignition switch in the Start position. Observe the
voltmeter. If the reading is above 0.2 volt, clean and
tighten the battery positive cable eyelet terminal con-nection at the starter solenoid B(+) terminal stud.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery positive cable.
(4) Connect the voltmeter to measure between the
battery negative cable terminal clamp and a good
clean ground on the engine block (Fig. 16). Rotate
and hold the ignition switch in the Start position.
Observe the voltmeter. If the reading is above 0.2
volt, clean and tighten the battery negative cable
eyelet terminal connection to the engine block.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery negative cable.
Fig. 13 TEST BATTERY NEGATIVE CONNECTION
RESISTANCE - TYPICAL
1 - VOLTMETER
2 - BATTERY
Fig. 14 TEST BATTERY POSITIVE CONNECTION
RESISTANCE - TYPICAL
1 - VOLTMETER
2 - BATTERY
RGBATTERY SYSTEM8Fa-17
BATTERY CABLES (Continued)
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(7) Remove the 2 upper clevies bolts.
(8) Remove axle from knuckle (Fig. 13).
(9) Remove the right front splash shield.
(10) Remove the accessory drive belt (Fig. 14),
refer to the cooling section.
(11) Disconnect the generator positive battery
cable.
(12) Unlock the electrical connector for the field
connector (Fig. 15).(13) Disconnect the field connector.
(14) Remove the axle from vehicle, oil will leak
from transmission.
(15) Remove the 3 mounting bolts for generator.
(16) Remove generator from vehicle (Fig. 16).
INSTALLATION
INSTALLATION - 2.4L
(1) Install the generator.
(2) Install the accessory drive belt, refer to the
Cooling System section for proper procedures.
(3) Connect B+ terminal to generator.
(4) Install nut holding B+ wire terminal to back of
generator.
Fig. 13 AXLE AND KNUCKLE
Fig. 14 ACCESSORY DRIVE BELT
Fig. 15 GENERATOR CONNECTORS
Fig. 16 GENERATOR REMOVEL/INSTALLATION
RGCHARGING8Fa-27
GENERATOR (Continued)
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(5) Connect the push-in field wire connector to
back of generator.
(6) Install the EVAP Purge solenoid to its bracket.
(7) Install the Air Box, refer to the Engine/Air
Cleaner for more information.
(8) Connect the Inlet Air Temperature sensor.
(9) Connect battery negative cable.
INSTALLATION - 2.5L
(1) Install generator.
(2) Install the 2 lower mounting Bolts (Fig. 8).
(3) Install the Air Cleaner Box (Fig. 7).
(4) Install the upper support bracket (Fig. 6).
(5) Install the wiring harness on upper generator
bracket (Fig. 6).
(6) Connect the field connection (Fig. 5).
(7) Connect the generator battery connection (Fig.
5).
(8) Raise vehicle and support.
(9) Install the generator drive belt (Fig. 4).
(10) Install the right front splash shield (Fig. 3).
(11) Lower vehicle.
(12) Install the engine cover (Fig. 2).
(13) Connect the negative battery cable (Fig. 1).
INSTALLATION - 3.3/3.8L
(1) Roll and place generator in position on vehicle
(Fig. 10).
(2) Install upper bolts to hold generator in place.
(3) Lubricate the o-ring. Install oil dip stick tube.
(4) Install the upper oil dip stick tube bolt.
(5) Place B+ terminal in position on generator.
(6) Install nut to hold B+ wire terminal to back of
generator.
(7) Connect the push-in field wire connector into
back of generator.
(8) Raise vehicle and support.
(9) Install the lower mounting bolt and tighten.
(10) Install the lower oil dip stick tube bolt and
tighten (Fig. 9).
(11) Install accessory drive belt, refer to the Cool-
ing System section for proper procedures.
(12) Install the right front lower splash shield.
(13) Lower vehicle.
(14) Install wiring harness to the oil dip stick tube
(15) Connect battery negative cable.
(16) Verify generator output rate.
INSTALLATION - 3.5L
(1) Install generator (Fig. 16) and the 3 mounting
bolts and tighten.
(2) Connect the generator positive battery cable
(Fig. 15).
(3) Connect the field connector and lock the con-
nector (Fig. 15).
(4) Install the axle shaft to the transmission.(5) Install axle to steering knuckle (Fig. 13).
(6) Install the 2 upper clevies bolts and tighten,
refer to the Suspension section.
(7) Install axle nut and tighten, refer to the Differ-
ential and Driveline section.
(8) Relocate the ABS sensor wiring to bracket (Fig.
12).
(9) Install the accessory drive belt (Fig. 14), refer
to the Cooling section.
(10) Install the right front splash shield.
(11) Install the right front tire, refer to the Wheels
and Tires section.
(12) Lower vehicle.
(13) Connect the negative battery cable.
GENERATOR DECOUPLER
PULLEY
DESCRIPTION
The Generator Decoupler is a one way clutch (Fig.
17). It is attached to the generator and replaces the
standard pulley. It is a non-serviceable item and is to
be replaced as an assembly. It is a dry operation (no
grease or lubricants). The operation of it is not tem-
perature sensitive and has a low sensitivity to elec-
trical load.
OPERATION
The generator decoupler is a one way clutch and
should be replaced as an assembly. It is designed to
help reduce belt tension fluctuation, reduce fatigue
loads, improve belt life, reduce hubloads on compo-
nents, and reduce noise.
Fig. 17 GENERATOR DECOUPLER 3.3/3.8L
8Fa - 28 CHARGINGRG
GENERATOR (Continued)
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STARTING
TABLE OF CONTENTS
page page
STARTING
DESCRIPTION.........................31
OPERATION...........................31
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - STARTING
SYSTEM TEST.......................31
DIAGNOSIS AND TESTING - CONTROL
CIRCUIT TEST........................34
DIAGNOSIS AND TESTING - FEED CIRCUIT
RESISTANCE TEST....................36
DIAGNOSIS AND TESTING - FEED CIRCUIT
TEST...............................36
SPECIFICATIONS
STARTER ...........................37Torques.............................37
STARTER MOTOR
REMOVAL
REMOVAL - 2.4L......................38
REMOVAL - 3.3/3.8L...................39
REMOVAL - 3.5L......................39
REMOVAL - 2.5L......................40
INSTALLATION
INSTALLATION - 2.4L..................41
INSTALLATION - 3.3/3.8L................41
INSTALLATION - 3.5L..................41
INSTALLATION - 2.5L..................41
STARTING
DESCRIPTION
The starting system has (Fig. 1):
²Ignition switch
²Starter relay
²Transmission Range Sensor or Park/Neutral
Switch
²Wiring harness
²Battery
²Starter motor with an integral solenoid
²Powertrain Control Module (PCM)
OPERATION
These components form two separate circuits. A
high amperage circuit that feeds the starter motor up
to 300+ amps, and a control circuit that operates on
less than 20 amps.
The PCM controls a double start over-ride safety
that does not allow the starter to be engaged if the
engine is already running.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - STARTING
SYSTEM TEST
For circuit descriptions and diagrams, refer to the
Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE PASSIVE RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
RGSTARTING8Fa-31
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INSPECTION
Before removing any unit from the starting system
for repair or diagnosis, perform the following inspec-
tions:
²Battery- Visually inspect the battery for indi-
cations of physical damage and loose or corroded
cable connections. Determine the state-of-charge and
cranking capacity of the battery. Charge or replace
the battery, if required. Refer to the Battery section
for more information.
²Ignition Switch- Visually inspect the ignition
switch for indications of physical damage and loose
or corroded wire harness connections.
²Transmission Range Sensor- Visually inspect
the transmission range sensor for indications of phys-
ical damage and loose or corroded wire harness con-
nections.
²Starter Relay- Visually inspect the starter
relay for indications of physical damage and loose or
corroded wire harness connections.
²Starter- Visually inspect the starter for indica-
tions of physical damage and loose or corroded wire
harness connections.
²Starter Solenoid- Visually inspect the starter
solenoid for indications of physical damage and loose
or corroded wire harness connections.
²Wiring- Visually inspect the wire harness for
damage. Repair or replace any faulty wiring, as
required. Check for loose or corroded wire harness
connections at main engine ground and remote jump
post.
²Power Distribution Center (PDC)- Visually
inspect the B+ connections at the PDC for physical
damage and loose or corroded harness connections.
Fig. 1 STARTING SYSTEM SCHEMATIC
1 - SOLENOID TERMINAL
2 - STARTER SOLENOID
3 - STARTER MOTOR
4 - STARTER RELAY CONNECTOR
5 - PCM
6 - GROUND CIRCUIT
7 - TRANSMISSION RANGE SENSOR/PARK/NEUTRAL SENSE
8 - IGNITION SWITCH
9 - IGNITION FEED
10 - BATTERY
11 - BATTERY RELAY FEED
12 - POSITIVE CABLE
13 - NEGATIVE CABLE
14 - CLUTCH INTERLOCK SWITCH (MTX ONLY)
8Fa - 32 STARTINGRG
STARTING (Continued)
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CONDITION POSSIBLE CAUSE CORRECTION
STARTER
ENGAGES,
SPINS OUT
BEFORE
ENGINE
STARTS.1. BROKEN TEETH ON
STARTER RING GEAR.1. REMOVE STARTER. INSPECT RING GEAR AND REPLACE
IF NECESSARY.
2. STARTER ASSEMBLY
FAULTY.2. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
STARTER DOES
NOT
DISENGAGE.1. STARTER
IMPROPERLY
INSTALLED.1. INSTALL STARTER. TIGHTEN STARTER MOUNTING
HARDWARE TO CORRECT TORQUE SPECIFICATIONS.
2. STARTER RELAY
FAULTY.2. REFER TO RELAY TEST, IN THIS SECTION. REPLACE
RELAY, IF NECESSARY.
3. IGNITION SWITCH
FAULTY.3. REFER TO IGNITION SWITCH TEST, IN THE STEERING
SECTION. REPLACE SWITCH, IF NECESSARY.
4. STARTER ASSEMBLY
FAULTY.4. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
5. FAULTY TEETH ON
RING GEAR.5. ROTATE FLYWHEEL 360É, AND INSPECT TEETH AND RING
GEAR REPLACED IF DAMAGED.
DIAGNOSIS AND TESTING - CONTROL
CIRCUIT TEST
The starter control circuit has:
²Starter motor with integral solenoid
²Starter relay
²Transmission range sensor, or Park/Neutral
Position switch with automatic transmissions
²Ignition switch
²Battery
²All related wiring and connections
²Powertrain Control Module (PCM)
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 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) Perform a visual inspection of the starter/
starter solenoid for corrosion, loose connections or
faulty wiring.
(4) Locate and remove the starter relay from the
Power Distribution Center (PDC). Refer to the PDC
label for relay identification and location.
(5) 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 crank or solenoid chatters,
check wiring and connectors from starter relay to
starter solenoid for loose or corroded connections.
Particularly 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. Inspect the ring gear
teeth.
STARTER RELAY
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK/NEUTRAL POSITION
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.
8Fa - 34 STARTINGRG
STARTING (Continued)
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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 75  5 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.CAV FUNCTION
30 B (+)
85 P/N POSITION SW.SENSE
86 IGNITION SWITCH OUTPUT
87 STARTER RELAY OUTPUT
87A NO CONNECT
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 and
the clutch pedal is depressed (manual trans). Check
for battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position and the
clutch pedal is depressed (manual trans), and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK, 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.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. It is grounded
through the transmission range sensor only when the
gearshift selector lever is in the Park or Neutral
positions. Check for continuity to ground at the cav-
ity for relay terminal 85. If not OK with an auto-
matic transmission, check for an open or short circuit
to the transmission range sensor and repair. It is
grounded by the PCM if the conditions are right to
start the car. For automatic trans. cars the PCM
must see Park Neutral switch and near zero engine
rpm. For manual trans. cars the PCM only needs to
see near zero engine rpm. To diagnose the Park Neu-
tral switch of the trans range sensor refer to the
transaxle section for more information. Check for
continuity to ground while the ignition switch is in
the start position. If not OK and the vehicle has an
automatic trans. verify Park Neutral switch opera-
Starter Relay Pinout
Starter Relay Pinout
RGSTARTING8Fa-35
STARTING (Continued)
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tion. If that checks OK check for continuity between
PCM and the terminal 85. Repair open circuit as
required. If OK, the PCM may be defective.
SAFETY SWITCHES
For diagnostics of the Transmission Range Sensor,
refer to the Transaxle section for more information.
If equipped with Clutch Interlock/Upstop Switch,
refer to Diagnosis and Testing in the Clutch section.
IGNITION SWITCH
After testing starter solenoid and relay, test igni-
tion switch and wiring. Refer to the Ignition Section
or Wiring Diagrams for more information. Check all
wiring for opens or shorts, and all connectors for
being loose or corroded.
BATTERY
For battery diagnosis and testing, refer to the Bat-
tery section for procedures.
ALL RELATED WIRING AND CONNECTORS
Refer to Wiring Diagrams for more information.
DIAGNOSIS AND TESTING - 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: Ignition and Fuel systems must be dis-
abled to prevent engine start while performing the
following tests.
(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) Gain access to battery terminals.
(3) 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. Rotate and hold the
ignition switch in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact 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
block near the battery cable attaching point.
Rotate and hold the ignition switch in the START
position. If voltage reads above 0.2 volt, correct
poor contact at ground cable attaching point. If
voltage reading is still above 0.2 volt after correct-
ing poor contacts, replace ground cable.
(4) Connect positive voltmeter lead to the starter
motor housing and the negative lead to the battery
negative terminal. Hold the ignition switch key in
the START position. If voltage reads above 0.2 volt,
correct poor starter to engine ground.
(a) Connect the positive voltmeter lead to the
battery positive terminal, and negative lead to bat-
tery cable terminal on starter solenoid. Rotate and
hold the ignition switch in the START position. If
voltage reads above 0.2 volt, correct poor contact at
battery cable to solenoid connection. If reading is
still above 0.2 volt after correcting poor contacts,
replace battery positive cable.
(b) If resistance tests do not detect feed circuit
failures, replace the starter motor.
DIAGNOSIS AND TESTING - FEED CIRCUIT
TEST
NOTE: The following results are based upon the
vehicle being at room temperature.
The following procedure will require a suitable
volt-ampere tester (Fig. 3).
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
(1) Check battery before performing this test. Bat-
tery must be fully charged.
(2) Connect a volt-ampere tester to the battery ter-
minals. Refer to the operating instructions provided
with the tester being used.
Fig. 3 Volt Ampere Tester
8Fa - 36 STARTINGRG
STARTING (Continued)
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(3) 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.
(4) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
and SET parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(5) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
3).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 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, the problem is the starter. Replace
the starter refer to starter removal.
(6) After the starting system problems have been
corrected, verify the battery state-of-charge and
charge battery if necessary. Disconnect all testing
equipment and connect ASD relay. Start the vehicle
several times to assure the problem has been cor-
rected.SPECIFICATIONS
STARTER
MANUFACTURER NIPPONDENSO
Engine Application 2.4L /3.3/3.8L
Power rating 1.2 Kw
Voltage 12 VOLTS
No. of Fields 4
No. of Poles 4
Brushes 4
Drive Conventional Gear Train
Free running Test
Voltage 11
Amperage Draw 73 Amp
Minimum Speed 3401 RPM
SolenoidClosing Voltage 7.5 Volts
Cranking Amperage Draw
test150 - 200 Amps.
Engine should be up to operating temperature.
Extremely heavy oil or tight engine will increase
starter amperage draw.
Torques
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Starter Mounting Bolts 47.4 35
Starter Solenoid Battery Nut 11.3 8.3 100
RGSTARTING8Fa-37
STARTING (Continued)
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INSTALLATION - 3.3/3.8L
(1) Install coil over studs on bracket.
(2) Install 2 bolts to ignition coil.
(3) Install 2 nuts to the ignition coil studs. Tighten
nuts and bolts.
(4) Connect the electrical connector to the ignition
coil.
(5) Install the ignition cables to the ignition coil.
(6) Reposition the Power steering reservoir. Slide
bracket over the mounting stud (Fig. 11).
(7) Install 2 bolts to the Power steering reservoir
to intake manifold.
(8) Tighten the lower nut to stud on ignition coil
bracket.
(9) Install the throttle and speed control cables to
clip.
(10) Connect the negative battery cable.
KNOCK SENSOR
DESCRIPTION
The knock sensor threads into the cylinder block.
The knock sensor is designed to detect engine vibra-
tion that is caused by detonation.
OPERATION
When the knock sensor detects a knock in one of
the cylinders, it sends an input signal to the PCM. In
response, the PCM retards ignition timing for all cyl-
inders by a scheduled amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increases, the
knock sensor output voltage also increases.
The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives as an input the knock sensor voltage signal.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maxi-
mum authority that long term memory has over tim-
ing retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (aslong as rpm is above the minimum rpm) except WOT.
The PCM, using short term memory, can respond
quickly to retard timing when engine knock is
detected. Short term memory is lost any time the
ignition key is turned off.
NOTE: Over or under tightening affects knock sen-
sor performance, possibly causing improper spark
control.
REMOVAL
REMOVAL - 2.4L
The knock sensor threads into the side of the cyl-
inder block in front of the starter (Fig. 12).
(1) Disconnect electrical connector from knock sen-
sor.
(2) Use a crow foot socket to remove the knock
sensors.
REMOVAL - 3.8L
The knock sensor threads into the side of the cyl-
inder block in the rear.
(1) Disconnect the negative battery cable.
(2) Raise vehicle and support.
(3) On All Wheel Drive vehicles remove the PTU
(Power Transfer Unit), refer to the Transmission sec-
tion for more information.
(4) Disconnect electrical connector from knock sen-
sor.
(5) Use a crow foot socket to remove the knock
sensor.
INSTALLATION
INSTALLATION - 2.4L
The knock sensor threads into the side of the cyl-
inder block in front of the starter (Fig. 12).
(1) Install knock sensor. Tighten knock sensor to
10 N´m (7 ft. lbs.) torque.Over or under tighten-
ing effects knock sensor performance, possibly
causing improper spark control.
(2) Attach electrical connector to knock sensor.
INSTALLATION - 3.8L
The knock sensor threads into the side of the cyl-
inder block in the rear.
(1) Install knock sensor. Tighten knock sensor to
10 N´m (7 ft. lbs.) torque.Over or under tighten-
ing effects knock sensor performance, possibly
causing improper spark control.
(2) Attach electrical connector to knock sensor.
8I - 8 IGNITION CONTROLRS
IGNITION COIL (Continued)
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