volt CHRYSLER VOYAGER 2004 Manual PDF

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(4) Reconnect the instrument panel switch bank
and test the heated seat system for proper operation.
If the system is still inoperative proceed with check-
ing remaining components.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel center bezel.
Refer toInstrument Panel Center Bezelin the
Body section for the procedure.
(3) Remove the three screws (Fig. 4) that secure
the heated seat switch to the back of the instrument
panel center bezel.
(4) Remove the heated seat switch from the back
of the instrument panel center bezel.
INSTALLATION
(1) Position the heated seat switch onto the back
of the instrument panel center bezel.
(2) Install and tighten the three screws that secure
the heated seat switch to the back of the instrument
panel center bezel (Fig. 4). Tighten the screws to 1.5
N´m (13 in. lbs.).
(3) Install the center bezel onto the instrument
panel. Refer toInstrument Panel Center Bezelin
the Body section for the procedure.
(4) Reconnect the battery negative cable.
HEATED SEAT ELEMENTS
DESCRIPTION
The heated seat system includes two seat heating
elements in each front seat, one for the seat cushion
and the other for the seat back. The two elements for
each seat that are connected in series with the
Heated Seat Module (HSM). The temperature sensor
is a Negative Temperature Coefficient (NTC) ther-
mistor. One temperature sensor is used for each seat,
and it is located on the seat cushion heating element
for all models.
The seat heating elements are sewn into the seat
cushion cover trim and seat back cover trim units.
The heated seat elements and the temperature sen-
sor cannot be adjusted or repaired and, if faulty or
damaged, the seat element assembly must be
replaced. Refer to the procedure in this section.
OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the resistance of the elements to the
current flow is released in the form of heat. The tem-
perature sensor is a NTC thermistor. When the tem-
perature of the seat cushion cover rises, the
resistance of the sensor decreases. The heated seat
module supplies a five-volt signal to one side of each
sensor, and monitors the voltage drop through the
sensor on a return circuit. The heated seat module
uses this temperature sensor input to monitor the
temperature of the seat, and regulates the current
flow to the seat heating elements accordingly.
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENTS
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, at the heated seat module. For circuit descrip-
tions and diagrams, refer to section 8W, Wiring Dia-
grams.
In order to access and test the heated seat ele-
ments it will be necessary to remove the appropriate
Fig. 4 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
8G - 10 HEATED SEAT SYSTEMRS
DRIVER HEATED SEAT SWITCH (Continued)

Page 507 of 2585

(3) Connect the negative battery cable.
(4) Verify heated seat system operation.
(5) Install the appropriate seat cushion or seat
back trim cover. Make certain the seat wire harness
is correctly routed through the seat and seat back.
The excess wire between the cushion and back ele-
ments should be securely tucked between the rear of
the cushion foam and the rear carpet flap of the trim
cover.
HEATED SEAT SENSOR
DESCRIPTION
Two heated seat sensors are used per vehicle, one
in each front seat cushion heating element. The
heated seat temperature sensor is a Negative Tem-
perature Coefficient (NTC) thermistor.
The heated seat sensors cannot be repaired or
adjusted and if found to be faulty, the complete
heated seat cushion element must be replaced.
OPERATION
The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
heated seat module supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The heated
seat module uses this temperature sensor input to
monitor the temperature of the seat, and regulates
the current flow to the seat heating elements accord-
ingly.
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the green 4-way heated seat mod-
ule wire harness connector.
(2) Using an ohmmeter, check the resistance
between cavities 2 and 3. The sensor resistance
should be between 50 kilohms at 15É C (60É F) and 2
kilohms at 30É C (85É F). If not OK, replace the
faulty seat element and sensor assembly.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 6). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switchassembly that also includes the hazard, rear window
wiper and washer switches. The heated seat switches
each provide a resistor multiplexed signal to its
respective Heated Seat Module (HSM) through sepa-
rate hard wired circuits. Each switch has an Off,
Low, and High position so that both the driver and
the front seat passenger can select a preferred seat
heating mode. Each switch has two Light-Emitting
Diodes (LED) which light to indicate that the heater
for the seat is turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the high position LED indi-
cator illuminates. When the switch rocker is moved
to its neutral position (middle), Off is selected and
both LED indicators are extinguished.
Each switch provides separate resistor multiplexed
hard wire inputs to its respective Heated Seat Mod-
ule (HSM) to indicate the selected switch position.
The heated seat module responds to the heated seat
switch status messages by controlling the output to
the seat heater elements of the selected seat. The
Fig. 6 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
8G - 12 HEATED SEAT SYSTEMRS
HEATED SEAT ELEMENTS (Continued)

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Low heat position set point is about 36É C (97É F),
and the High heat position set point is about 41É C
(105É F).
DIAGNOSIS AND TESTING - PASSENGER
HEATED SEAT SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: REFER TO THE RESTRAINTS SECTION
OF THIS MANUAL BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
CHECKING SWITCH SIGNAL AND WIRING AT THE
MODULE
(1) Disconnect and isolate the battery negative
cable.
(2) Access and disconnect the gray 4-way connector
from the heated seat module. Visually inspect wiring
terminals for damage that would prevent positive
connection. If not OK, repair or replace the necessary
components.
(3) Reconnect the negative battery cable and Turn
heated seat ON in the LO position. Using an Ohm-
meter, check the resistance between cavities 2 and 3
of the gray connector noted above. Resistance should
be about 3.5 kiloohms (3500 ohms). If not OK, check
resistance directly at switch, as noted below. If OK,
proceed. If NOT OK replace the switch or faulty wir-
ing.
(4) Turn heated seat ON in the HI position. Using
an Ohmmeter, check the resistance between cavities
2 and 3 of the gray connector noted above. Resistance
should be about 1.4 kiloohms (1400 ohms). If not OK,
check resistance directly at switch, as noted below. If
OK, proceed. If NOT OK replace the switch or faulty
wiring.
(5) With the system ON in the HI position, Check
for battery voltage and ground at cavities 4 and 1. If
OK, proceed with testing remaining components. If
NOT OK, repair open or wiring short.
CHECKING SWITCH ONLY
(1) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL). Check for continuity between the
ground circuit cavity (#10) of the instrument panel
switch bank electrical connector and a good ground.There should be continuity. If OK, go to Step 2. If not
OK, repair the open ground circuit to ground as
required.
(2) Reconnect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (run) cir-
cuit cavity of the instrument panel switch bank con-
nector (#4). If OK, turn the ignition switch to the Off
position, and go to Step 3. If not OK, repair the open
fused ignition switch output (run) circuit as required.
(3) Test the heated seat switch as shown in the
Heated Seat Switch Test chart and the connector pin-
out below (Fig. 7). If OK, go to Step 4. If not OK,
replace the faulty switch bank assembly.
PASSENGER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin3&4OPEN
Low Pin3&43570
High Pin3&41430
All resistance values are  1%.
(4) Reconnect the instrument panel switch bank
and test the heated seat system for proper operation.
If the system is still inoperative proceed with check-
ing remaining components.
Fig. 7 Instrument Panel Switch Bank Connector
RSHEATED SEAT SYSTEM8G-13
PASSENGER HEATED SEAT SWITCH (Continued)

Page 511 of 2585

HORN SYSTEM TEST
CONDITION POSSIBLE CAUSE CORRECTION
HORN SOUNDS CONTINUOUSLY.
NOTE: IMMEDIATELY UNPLUG HORN
RELAY IN THE IPM.(1) HORN RELAY
INOPERATIVE.(1) REPLACE RELAY.
(2) HORN CONTROL
CIRCUIT TO RELAY
SHORTED TO GROUND.(2) CHECK TERMINAL 85 IN IPM
FOR CONTINUITY TO GROUND. IF
CONTINUITY TO GROUND
INDICATES:
(A) STEERING WHEEL HORN
SWITCH/LEAD SHORTED TO
GROUND.
(B) WIRING HARNESS SHORTED
TO GROUND. FIND THE SHORT
AND REPAIR AS NECESSARY.
(3) PINCHED HORN
SWITCH WIRE UNDER
DRIVER AIRBAG MODULE.(3) REPLACE DRIVER AIRBAG TRIM
COVER.
(4) HORN SWITCH
INOPERATIVE.(4) REPLACE DRIVER AIRBAG TRIM
COVER.
(5) CLOCKSPRING
INOPERATIVE.(5) REPLACE CLOCKSPRING.
(6) FRONT CONTROL
MODULE INOPERATIVE.(6) REFER TO ELECTRONIC
CONTROL MODULES/FRONT
CONTROL MODULE.
HORN SOUND INTERMITTENTLY AS
THE STEERING WHEEL IS TURNED.(1) HORN RELAY
CONTROL CIRCUIT X3 IS
SHORTED TO GROUND
INSIDE STEERING
COLUMN OR WHEEL.(1) REMOVE DRIVER AIRBAG
AND/OR WHEEL. CHECK FOR
RUBBING OR LOOSE WIRE/
CONNECTOR, REPAIR AS
NECESSARY.
(2) PINCHED HORN
SWITCH WIRE UNDER
DRIVER AIRBAG MODULE.(2) REPLACE DRIVER AIRBAG TRIM
COVER.
(3) HORN SWITCH
INOPERATIVE.(3) REPLACE DRIVER AIRBAG TRIM
COVER.
(4) CLOCKSPRING
INOPERATIVE.(4) REPLACE CLOCKSPRING.
HORN DOES NOT SOUND (1) CHECK FUSE 8 IN
INTELLIGENT POWER
MODULE.(1) REPLACE FUSE IF BLOWN
REPAIR AS NECESSARY.
(2) NO VOLTAGE AT HORN
RELAY TERMINALS 30 &
86, AND FUSE IS OK.(2) NO VOLTAGE, REPAIR THE
CIRCUIT AS NECESSARY.
(3) OPEN CIRCUIT FROM
TERMINAL 85 OF THE
HORN RELAY TO HORN
SWITCH, X3 CIRCUIT.(3) REPAIR CIRCUIT AS
NECESSARY.
8H - 2 HORNRS
HORN SYSTEM (Continued)

Page 512 of 2585

CONDITION POSSIBLE CAUSE CORRECTION
(4) HORN INOPERATIVE
OR DAMAGED.(4) CHECK VOLTAGE AT HORN
WHEN HORN SWITCH IS
PRESSED. IF NO VOLTAGE,
REPLACE HORN.
(5) HORN SWITCH
INOPERATIVE.(5) REPLACE DRIVER AIRBAG TRIM
COVER.
(6) CLOCKSPRING
INOPERATIVE.(6) REPLACE CLOCKSPRING.
(7) FRONT CONTROL
MODULE INOPERATIVE.(7) REFER TO ELECTRONIC
CONTROL MODULES/FRONT
CONTROL MODULE.
FUSE BLOWS WHEN HORN SOUNDS (1) SHORT CIRCUIT IN
HORN OR HORN WIRING.(1) REMOVE HORN RELAY, CHECK
FOR SHORTED HORN OR HORN
WIRING. DISCONNECT HORN WIRE
HARNESS TO ISOLATE SHORT
AND REPAIR AS NECESSARY.
(2) CLOCKSPRING
INOPERATIVE.(2) REPLACE CLOCKSPRING.
FUSE BLOWS WITHOUT BLOWING
HORN(1) SHORT CIRCUIT. (1) REMOVE RELAY, INSTALL NEW
FUSE, IF FUSE DOES NOT BLOW
REPLACE HORN RELAY. IF FUSE
BLOWS WITH RELAY REMOVED,
CHECK FOR SHORT TO GROUND
WITH OHMMETER ON CIRCUIT
BETWEEN TERMINALS 30 & 86
AND THE FUSE TERMINAL. REPAIR
AS NECESSARY.
(2) CLOCKSPRING
INOPERATIVE.(2) REPLACE CLOCKSPRING.
HORN
DIAGNOSIS AND TESTING - HORN
HORN
(1) Disconnect wire connector at horn.
(2) Using a voltmeter, connect one lead to ground
terminal and the other lead to the positive wire ter-
minal (Fig. 1).
(3) Depress the horn switch, battery voltage
should be present.
(4) If no voltage, refer toHORNS WILL NOT
SOUND. If voltage is OK, go to step Step 5.
(5) Using ohmmeter, test ground wire for continu-
ity to ground.
(6) If no ground repair as necessary.
(7) If wires test OK and horn does not sound,
replace horn.
HORNS SOUND CONTINUOUSLY
CAUTION: Continuous sounding of horns may
cause relay to fail.
The horn switch (membrane) sometimes can be the
cause without the switch being depressed.
(1) Remove the horn relay from the intelligent
power module.
(2) Using a continuity tester, test continuity from
the X3 cavity of the horn relay to ground. Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
(a) If continuity is detected, proceed to step Step
3.
(b) If NO continuity, replace the horn relay.
(3) Remove the airbag trim cover from the steering
wheel and disengage horn connector.
RSHORN8H-3
HORN SYSTEM (Continued)

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(4) Install horn relay into Integrated Power Mod-
ule (IPM).
(a) If horn does not sound, replace airbag trim
cover.
(b) If horn sounds, repair grounded X3 circuit
from IPM to clockspring in the steering column.
HORNS WILL NOT SOUND
Check horn fuse#8intheIPM. If fuse is blown,
check for a shorted switch in the airbag module. and
refer to FUSE BLOWN section. If fuse is OK, refer to
FUSE OK section.
FUSE BLOWN
(1) Verify condition of battery terminals and volt-
age, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
- DIAGNOSIS AND TESTING). If battery connec-
tions and battery charge is OK proceed to Step 2.
(2) Using a voltmeter, test for battery voltage at
both sides of horn fuse 7. If voltage is OK, on both
sides of fuse, proceed to Fuse OK. If voltage is OK,
on one side of fuse, the fuse is blown, proceed to Step
3.
(3) Using a suitable ammeter in place of the fuse,
test amperage draw of the horn circuit. If amperage
draw is greater than 20 amps without the horn
switch depressed, a grounded circuit exists between
the fuse and the horn relay. Proceed to Step 4. If
amperage draw is greater than 20 amps with the
horn switch depressed, a grounded circuit exists
between the horn relay and the horn. Proceed to step
Step 5.
(4) Remove the horn relay from the IPM. If the
amperage draw drops to 0 amps, the horn switch or
circuit is shorted. If the amperage draw does not
drop to 0 amps, repair short at the IPM.
(5) Disengage a wire connector from one of the
horns. If amperage drops and the connected horn
sounds, replace the faulty horn. If amperage does not
drop with both horns disconnected and the horn
switch depressed, proceed to Step 6.
(6) Using a continuity tester, with the horns dis-
connected test continuity of the X2 cavity of the horn
relay to ground. If continuity is detected, the circuit
is grounded between the Junction Block and the
horns. Locate and repair pinched harness.
FUSE OK
(1) Remove the horn relay from the intelligent
power module.
(2) Using a continuity tester, Depress horn switch
and test continuity from the X3 cavity of the horn
relay to ground.
(a) If continuity is detected, proceed to Step 3.
(b) If NO continuity, proceed to Step 4.(3) Using a suitable jumper wire, jump across the
fuse F62 cavity and the X2 cavity of the horn relay in
the Junction Block.
(a) If the horn sounds, replace the horn relay.
(b) If the horn does not sound, proceed to Step 4.
(4) Remove airbag trim cover from steering wheel.
Refer to ELECTRICAL, RESTRAINTS.
(5) Test continuity across horn switch connectors
with horn switch depressed.
(a) If continuity is detected, repair open circuit
between the relay and the horn switch.
(b) If NO continuity, replace airbag trim cover.
(6) Install horn relay into intelligent power mod-
ule.
(7) Disengage wire connectors from horns.
(8) Using a voltmeter, with the horn switch
depressed test voltage across horn connector termi-
nals of the wire harness (Fig. 1).
(a) If voltage is detected, replace horns.
(b) If NO voltage, proceed to step Step 9.
(9) With the horn switch depressed, test for volt-
age between the X2 circuit and ground.
(a) If voltage OK, repair system ground at right
cowl area.
(b) If NO voltage, repair open X2 circuit between
the relay and the horns.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Hoist and support the front of the vehicle on
safety stands.
(3) From behind the front fascia and forward of
the left front wheel, disconnect the wire connectors
from horn.
(4) Remove the mounting bracket attaching nut
from the bottom of radiator closure panel. Do not
remove the horn from mounting bracket.
(5) Separate the horn(s) from vehicle.
Fig. 1 Horn Connector
8H - 4 HORNRS
HORN (Continued)

Page 518 of 2585

FIRING ORDERAUTO SHUT DOWN RELAY
DESCRIPTION
The relay is located in the Power Distribution Cen-
ter (PDC). For the location of the relay within the
PDC, refer to the PDC cover for location. Check elec-
trical terminals for corrosion and repair as necessary
OPERATION
The engine switched battery (NGC vehicles)
informs the PCM when the ASD relay energizes. A 12
volt signal at this input indicates to the PCM that
the ASD has been activated. This input is also used
to power certain drivers on NGC vehicles.
When energized, the ASD relay on NGC vehicles
provides power to operate the injectors, ignition coil,
generator field, O2 sensor heaters (both upstream
and downstream), evaporative purge solenoid, EGR
solenoid (if equipped) wastegate solenoid (if
equipped), and NVLD solenoid (if equipped).
The ASD relay also provides a sense circuit to the
PCM for diagnostic purposes. If the PCM does not
receive 12 volts from this input after grounding the
control side of the ASD relay, it sets a Diagnostic
Trouble Code (DTC). The PCM energizes the ASD
any time there is an engine speed that exceeds a pre-
determined value (typically about 50 rpm). The ASD
relay can also be energized after the engine has been
turned off to perform an O2 sensor heater test, if
vehicle is equipped with OBD II diagnostics.
As mentioned earlier, the PCM energizes the ASD
relay during an O2 sensor heater test. On NGC vehi-
cles it checks the O2 heater upon vehicle start. The
PCM still operates internally to perform several
checks, including monitoring the O2 sensor heaters.
FIRING ORDER 2.4L
Firing Order 1-2-3-4-5-6 3.3/3.8L
1 - Electrical Connector
RSIGNITION CONTROL8I-3
IGNITION CONTROL (Continued)

Page 519 of 2585

CAMSHAFT POSITION
SENSOR
DESCRIPTION
The camshaft position sensor for the 3.3/3.8L is
mounted in the front of the timing case cover (Fig. 6)
and the camshaft position sensor for the 2.4L is
mounted on the end of the cylinder head (Fig. 3).
OPERATION
The camshaft position sensor provides cylinder
identification to the Powertrain Control Module
(PCM) (Fig. 1). The sensor generates pulses as
groups of notches on the camshaft sprocket pass
underneath it (Fig. 2). The PCM keeps track of
crankshaft rotation and identifies each cylinder by
the pulses generated by the notches on the camshaft
sprocket. Four crankshaft pulses follow each group of
camshaft pulses.
When the PCM receives 2 cam pulses followed by
the long flat spot on the camshaft sprocket, it knows
that the crankshaft timing marks for cylinder 1 are
next (on driveplate). When the PCM receives one
camshaft pulse after the long flat spot on the
sprocket, cylinder number 2 crankshaft timing marks
are next. After 3 camshaft pulses, the PCM knows
cylinder 4 crankshaft timing marks follow. One cam-
shaft pulse after the 3 pulses indicates cylinder 5.
The 2 camshaft pulses after cylinder 5 signals cylin-
der 6 (Fig. 2). The PCM can synchronize on cylinders
1or4.When metal aligns with the sensor, voltage goes
low (less than 0.3 volts). When a notch aligns with
the sensor, voltage switches high (5.0 volts). As a
group of notches pass under the sensor, the voltage
switches from low (metal) to high (notch) then back
to low. The number of notches determine the amount
of pulses. If available, an oscilloscope can display the
square wave patterns of each timing event.
Top Dead Center (TDC) does not occur when
notches on the camshaft sprocket pass below the sen-
sor. TDC occurs after the camshaft pulse (or pulses)
and after the 4 crankshaft pulses associated with the
particular cylinder. The arrows and cylinder call outs
on (Fig. 2) represent which cylinder the flat spot and
notches identify, they do not indicate TDC position.
Fig. 1 Camshaft Position Sensor
1 - ELECTRICAL CONNECTOR
2 - O-RING
3 - PAPER SPACERFig. 2 Camshaft Sprocket
1 - CAMSHAFT SPROCKET
2 - CYL #6
3 - CYL #5
4 - CYL #4
5 - CYL #3
6 - CYL #2
7 - CYL #1
8I - 4 IGNITION CONTROLRS

Page 522 of 2585

OPERATION
The coil fires two spark plugs every power stroke.
One plug is the cylinder under compression, the
other cylinder fires on the exhaust stroke. The Pow-
ertrain Control Module (PCM) determines which of
the coils to charge and fire at the correct time.
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 magnetic energy in
the coil 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 cam-
shaft position sensor inputs. Refer to Auto Shutdown
(ASD) RelayÐPCM Output, in this section for relay
operation.
REMOVAL
REMOVAL - 2.4L
The electronic ignition coil pack attaches directly
to the valve cover.
(1) Diconnect the negative battery cable.
(2) Disconnect electrical connector from coil pack.
(3) Remove coil pack mounting bolts.
(4) Remove coil pack and heat shield (Fig. 9).
REMOVAL - 3.3/3.8L
(1) Disconnect the negative battery cable.(2) Remove the throttle and speed control cables
from clip.
(3) Remove 2 bolts from the Power steering reser-
voir to intake manifold.
(4) Loosen the lower nut for the power steering
reservoir from stud on ignition coil bracket.
(5) Reposition the Power steering reservoir (Fig.
11).
(6) Remove the ignition cables from the ignition
coil.
(7) Disconnect the electrical connector from the
ignition coil.
(8) Remove 2 nuts from the ignition coil studs.
INSTALLATION
INSTALLATION - 2.4L
(1) Install ignition coil and heat shield to valve
cover and tighten bolts.
(2) Connect the electrical connector to the ignition
coil.
(3) Transfer spark plug cables to new coil pack.
The coil pack towers are numbered with the cylinder
identification. Be sure the ignition cables are fully
seated onto the towers.
(4) Connect the negative battery cable.
INSTALLATION - 3.3/3.8L
(1) Install coil over studs on bracket.
(2) Install 2 nuts to the ignition coil studs. Tighten
nuts and bolts.
Fig. 10 IGNITION COIL - 3.3/3.8L
1 -Ignition Coil
Fig. 11 IGNITION COIL BRACKET 3.3/3.8L
RSIGNITION CONTROL8I-7
IGNITION COIL (Continued)

Page 523 of 2585

(3) Connect the electrical connector to the ignition
coil.
(4) Install the ignition cables to the ignition coil.
(5) Reposition the Power steering reservoir. Slide
bracket over the mounting stud (Fig. 11).
(6) Install 2 bolts to the Power steering reservoir
to intake manifold.
(7) Tighten the lower nut to stud on ignition coil
bracket.
(8) Install the throttle and speed control cables to
clip.
(9) 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 (as
long 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.
8I - 8 IGNITION CONTROLRS
IGNITION COIL (Continued)

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