ECU DODGE NEON 1999 Service Owner's Guide

(6) If turning the switch ON produced no distinct
current draw on the ammeter the problem should be
isolated in the following manner:
(a) Confirm the ignition switch is ON.
(b) Ensure that the heated rear glass feed wire
is connected to the terminal or pigtail and that the
ground wire is in fact grounded.
(c) Ensure that the maxi-fuse and control circuit
fuse are OK and all electrical connections are
secure.
(7) When the above steps have been completed and
the system is still inoperative, one or more of the fol-
lowing is defective:
(a) Control switch/timer relay module.
(b) All rear window grid lines would have to be
broken or one of the feed wires are not connected
for the system to be inoperative.
(8) If turning the switch ON produces severe volt-
meter deflection, the circuit should be closely checked
for a shorting condition.
(9) If the system operation has been verified but
indicator lamp does not light, replace the switch.
(10) For detailed wiring information, refer to group
8W, Wiring Diagrams.
GRID LINES
The horizontal grid lines and vertical bus bar lines
printed and fired on inside surface of rear window
glass (Fig. 2) comprise an electrical parallel circuit.
The electrically conductive lines are composed of a
silver-ceramic material which when fired on glass
becomes bonded to the glass and is highly resistant
to abrasion. It is possible, however, that a break may
occur in an individual grid line resulting in no cur-
rent flow through the line. To detect breaks in grid
lines the following procedure is required:
(1) Turn ignition ON and turn control switch to
ON. The indicator light should come on.(2) Using a DC voltmeter with 0-15 volt range,
contact terminal B with negative lead of voltmeter.
With positive lead of voltmeter, contact terminal A
(Fig. 2). The voltmeter should read 10-14 volts. A
lower voltage reading indicates a poor connection in
the feed or the ground circuit.
(3) With negative lead of voltmeter, contact a good
body ground point. The voltage reading should not
change.
(4) Connect negative lead of voltmeter to terminal
B and touch each grid line at Mid-Point with Positive
lead. A reading of:
²Approximately 6 volts indicates the line is OK
²0 volts indicates a break in line between Mid-
Point C and terminal A
²10-14 volts indicates a break between Mid-Point
C and terminal B
Move the lead toward the break and voltage will
change as soon as break is crossed. Refer to (Fig. 2)
and (Fig. 3).
REAR WINDOW DEFOGGER SWITCH
The rear window defogger switch may be tested in-
vehicle or bench tested. In vehicle testing is accom-
plished in the following manner:
(1) Remove the switch from the instrument panel
but leave the switch connected, refer to Group 8E,
Fig. 2 Rear Glass Grid Line Test
Fig. 3 Systems Electrical Circuit
8N - 2 ELECTRICALLY HEATED SYSTEMSPL
DIAGNOSIS AND TESTING (Continued)

IMMOBILIZER SYSTEM
CONTENTS
page page
DESCRIPTION AND OPERATION
IMMOBILIZER RECEIVER................ 1
IMMOBILIZER SYSTEM.................. 1
IMMOBILIZER TRANSMITTER............. 2
POWER-UP MODE...................... 2
DIAGNOSIS AND TESTING
IMMOBILIZER DIAGNOSIS............... 2SERVICE PROCEDURES
VEHICLE IMMOBILIZER SYSTEM.......... 3
REMOVAL AND INSTALLATION
IMMOBILIZER RECEIVER................ 3
DESCRIPTION AND OPERATION
IMMOBILIZER SYSTEM
The Immobilizer system includes the following
unique items:
²An immobilizer module receiver that controls
system operation and also controls the RKE and Illu-
minated entry systems, if equipped.
²An encoded Crankshaft Position Sensor for the
ignition system. The Immobilizer module decodes the
signal from the crankshaft so the PCM can recognize
it as a valid Crankshaft Position Sensor signal, and
allow the engine to run.
²A wiring harness that interconnects the crank-
shaft sensor, the immobilizer receiver, and the PCM.
²Two key fob transmitters.
The Immobilizer System prevents unauthorized
operation of the vehicle by disabling the engine and
starter. The system will NOT allow the vehicle to
start unless the UNLOCK button on the RKE trans-
mitter is pressed. The system will be activated after
turning the ignition switch to the OFF position and
using one of the following methods.
(1) Press the LOCK button on the RKE transmit-
ter.
(2) LOCK the doors by pressing a power lock but-
ton switch.
(3) LOCK the driver or passenger door using the
key.
²The Security light will flash, for about 16 sec-
onds, indicating that the engine and starter will be
disabled.
²The Security light remaining on, indicates the
system is not operational.
²The Immobilizer will activate automatically
within 10 minutes of the ignition switch being in the
OFF position, whether the vehicle has been locked or
unlocked.²An attempt to start the vehicle without pressing
the UNLOCK button on the RKE transmitter will
result in a warning chime and the Security light
flashing.
NOTE: The ignition switch must be in the OFF posi-
tion in order for the system to be activated, whether
the doors are closed or not.
IMMOBILIZER RECEIVER
The immobilizer receiver is programmed to
respond to the Lock and Unlock radio signals issued
by the immobilizer transmitters. The receiver will
only respond to the radio signals of transmitters (up
to four) whose vehicle access codes have been stored
in the receiver's electronic memory. The receiver is
programmed at the assembly plant with the vehicle
access codes of the two transmitters that are shipped
with the vehicle.
The immobilizer receiver also has a central pro-
cessing unit, which contains the immobilizer system
logic. The programming in the immobilizer receiver
allows the system to learn and retain transmitter
vehicle access codes, as well as to communicate with
the Powertrain Control Module (PCM) and/or the
DRB scan tool on the Chrysler Collision Detection
(CCD) data bus network.
The CCD data bus network allows the sharing of
sensor information. This helps to reduce wiring har-
ness complexity, reduce internal controller hardware,
and reduce component sensor current loads. At the
same time, the CCD data bus network provides
increased reliability and enhanced diagnostic capabil-
ities.
Each immobilizer transmitter has a different vehi-
cle access code, which must be programmed into the
memory of the immobilizer receiver in the vehicle in
order to operate the immobilizer system. A DRB scan
tool must be used to program new or additional
PLIMMOBILIZER SYSTEM 8Q - 1

transmitter vehicle access codes into the memory of
the immobilizer receiver. Refer to the Vehicle Theft
Security System menu item on the DRB scan tool for
the procedures.
The immobilizer receiver recognizes the Lock and
Unlock signals received from the programmed immo-
bilizer transmitters. If the code sent by the key fob
transmitter is recognized as valid by the Immobilizer
module, it will decode the Crankshaft Position Sensor
signal, enable the starter circuit, and allow the
engine to run.
The immobilizer receiver is mounted to the dash
panel with a hook and loop fastener patch. It is
located behind the instrument cluster and above the
heater-A/C housing. The receiver is connected to the
dash panel cross-body wiring harness. (Fig. 1)
For diagnosis of the vehicle immobilizer receiver or
the CCD data bus, a DRB scan tool is required. Refer
to the Vehicle Theft Security System menu item of
the DRB scan tool for the procedures. The immobi-
lizer receiver contains no servicable parts. If faulty,
the unit must be replaced.
IMMOBILIZER TRANSMITTER
The vehicle immobilizer system includes two trans-
mitters that are supplied with the vehicle when it isshipped from the factory. Each of the two transmit-
ters is equipped with two buttons labeled with Inter-
national Standards Organization (ISO) symbols for
Lock, and Unlock. Two spare batteries (enough for
one transmitter) are also shipped with the transmit-
ters. The transmitters are equipped with a key ring
and are designed to serve as a key fob. The operating
range of the radio frequency transmitter signal is up
to 7 meters (23 feet) from the immobilizer receiver.
Each transmitter has a different vehicle access
code, which must be programmed into the memory of
the immobilizer receiver in the vehicle in order to
operate the immobilizer system. The two transmit-
ters shipped with the vehicle have their vehicle
access codes programmed into the receiver at the fac-
tory. A DRB scan tool must be used to program new
or additional transmitter vehicle access codes into
the memory of the immobilizer receiver. Refer to the
Vehicle Theft Security System menu item on the
DRB scan tool for the procedures.
Each transmitter operates on two Duracell DL2016
(or equivalent) batteries. Typical battery life is from
one to two years.
POWER-UP MODE
When the vehicle immobilizer system senses that
the vehicle battery has been disconnected and recon-
nected, it enters its power-up mode. If the immobi-
lizer system was armed prior to the battery
disconnect, the system remains armed when the bat-
tery is reconnected.
If the immobilizer system was disarmed prior to
the battery disconnect, the system will remain dis-
armed if the battery is reconnected within five min-
utes. The system will passively arm itself when the
battery is reconnected more than five minutes after a
battery disconnect or failure. After any passive arm-
ing, the system will have to be actively disarmed
using one of the transmitters.
The power-up mode logic also applies if the battery
goes dead, and battery jump-starting is attempted.
The engine no-run feature will prevent the engine
from operating until the vehicle immobilizer system
has been actively disarmed.
DIAGNOSIS AND TESTING
IMMOBILIZER DIAGNOSIS
Refer to the 1998 PL Powertrain Diagnostic Man-
ual for complete diagnostic procedures of the immo-
bilizer system.
Fig. 1 Immobilizer Module Location
8Q - 2 IMMOBILIZER SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

SERVICE PROCEDURES
VEHICLE IMMOBILIZER SYSTEM
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, 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.
NOTE: The following tests may not prove conclu-
sive in the diagnosis of this system. The most reli-
able, efficient, and accurate means to diagnose the
Vehicle Immobilizer System involves the use of a
DRB scan tool. Refer to the Vehicle Theft Security
System menu item on the DRB scan tool for the
procedures.
The vehicle immobilizer system and the Chrysler
Collision Detection (CCD) data bus network should
be diagnosed using the DRB scan tool. The DRB will
allow confirmation that the CCD data bus is func-
tional, that the immobilizer receiver is placing the
proper messages on the CCD data bus, and that the
Powertrain Control Module (PCM) is receiving the
CCD data bus messages. Refer to the Vehicle Theft
Security System menu item on the DRB scan tool for
the procedures. Refer to 8W-39 - Vehicle Theft Secu-
rity System in Group 8W - Wiring Diagrams for com-
plete circuit descriptions and diagrams.
(1) With the ignition switch in the Off position,
depress the Lock or Unlock button of the immobilizer
transmitter. Listen for the immobilizer receiver to
issue an audible chirp (Unlock) or chirps (Lock). If
OK, go to Step 2. If not OK, replace the transmitter
batteries with known good units and repeat Step 1. If
still not OK, go to Step 2.
(2) Check the fuse in the Power Distribution Cen-
ter (PDC). If OK, go to Step 3. If not OK, repair the
shorted circuit or component as required and replace
the faulty fuse.
(3) Disconnect and isolate the battery negative
cable. Unplug the wire harness connector at the
immobilizer receiver. Check for continuity between
the ground circuit cavity of the immobilizer receiver
wire harness connector and a good ground. There
should be continuity. If OK, go to Step 4. If not OK,
repair the open circuit to ground as required.
(4) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
immobilizer receiver wire harness connector. If OK,
refer to the Vehicle Theft Security System menu itemon the DRB scan tool for further diagnosis. If not
OK, repair the open circuit to the PDC fuse as
required.REMOVAL AND INSTALLATION
IMMOBILIZER RECEIVER
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, 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 Top Cover and
Cluster Bezel and Right Trim panel. Remove the
receiver from the dash panel above the heater-A/C
housing (Fig. 2).
(3) Unplug the immobilizer receiver from the wire
harness connector.
(4) Reverse the removal procedures to install.
(5) Refer to the Vehicle Theft Security System
menu item on the DRB scan tool for the procedures
to program transmitter vehicle access codes into the
memory of the new immobilizer receiver.
Fig. 2 Immobilizer Receiver Remove/Install
PLIMMOBILIZER SYSTEM 8Q - 3

(7) It is necessary that the window be free to slide
up and down in the glass channels. If the window is
not free to move up and down, the window lift motor
will not be able to move the glass.
(8) To determine if the glass is free, disconnect the
regulator from the glass lift plate. Remove the two
attaching nuts, and slide the window up and down by
hand. This check can not be made on a four door
vehicle.
REMOVAL AND INSTALLATION
WINDOW SWITCH
REMOVAL
(1) Using a flat tool, insert tool in the slot on the
bottom of the switch bezel (Fig. 4).
(2) Pry the bezel from the door trim panel.
(3) Disconnect wire connector from switch.
(4) Remove switch by releasing the tabs from
bezel.
INSTALLATION
For installation, reverse above procedures.
2 DOOR WINDOW MOTOR
WARNING: DO NOT HAVE ANY HANDS OR FIN-
GERS IN SECTOR GEAR AREA WHERE THEY CAN
BE PINCHED BY SMALL MOVEMENTS OF REGULA-
TOR LINKAGE.
REMOVAL
(1) Move the window to the full-up position, if pos-
sible.
(2) Remove door trim panel and window regulator,
refer to Group 23 Body for removal procedures.
WARNING: FAILURE TO CLAMP THE SECTOR
GEAR TO THE MOUNTING PLATE WHEN REMOV-
ING THE MOTOR CAN RESULT IN INJURY.
(3) Secure the sector gear and mounting plate with
a C clamp or similar clamping tool. This will prevent
a sudden and forceful movement of the regulator
when the motor is removed.
(4) Remove three mounting screws that hold motor
gearbox to regulator (Fig. 5).
(5) Remove motor from regulator.
Fig. 2 Driver Side Window Switch Continuity Test
Fig. 3 Passenger Side Window Switch Continuity
Test
Fig. 4 Switch Removal
8S - 2 POWER WINDOWSPL
DIAGNOSIS AND TESTING (Continued)

TESTING FOR A SHORT TO GROUND
(1) Remove the fuse and disconnect all items
involved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.
(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch
the voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that gen-
eral area of the wiring harness.
TESTING FOR A SHORT TO GROUND ON
FUSES POWERING SEVERAL LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the suspected fused circuits.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.
(4) Start connecting the items in the fuse circuit
one at a time. When the fuse blows the circuit with
the short to ground has been isolated.
TESTING FOR A VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to
the side of the circuit closest to the battery (Fig. 8).
(2) Connect the other lead of the voltmeter to the
other side of the switch or component.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The steps
are listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem.
(6) Verify proper operation. For this step check for
proper operation of all items on the repaired circuit.
Refer to the wiring diagrams.
SERVICE PROCEDURES
WIRING REPAIR
When replacing or repairing a wire, it is important
that the correct gage be used as shown in the wiring
diagrams. The wires must also be held securely in
place to prevent damage to the insulation.
(1) Disconnect battery negative cable
(2) Remove 1 inch of insulation from each end of
the wire.
(3) Place a piece of heat shrink tubing over one
side of the wire. Make sure the tubing will be long
enough to cover and seal the entire repair area.
(4) Spread the strands of the wire apart on each
part of the exposed wire (example 1). (Fig. 9)
(5) Push the two ends of wire together until the
strands of wire are close to the insulation (example
2) (Fig. 9)
(6) Twist the wires together (example 3) (Fig. 9)
(7) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(8) Center the heat shrink tubing over the joint,
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing.
(9) Secure the wire to the existing ones to prevent
chafing or damage to the insulation
(10) Connect battery and test all affected systems.
TERMINAL/CONNECTOR REPAIR-MOLEX
CONNECTORS
(1) Disconnect battery.
Fig. 8 Testing for Voltage Drop
8W - 01 - 10 8W - 01 GENERAL INFORMATIONPL
DIAGNOSIS AND TESTING (Continued)

assure gasket rails are flat. Flatten rails with a ham-
mer on a heavy steel plate if required. Gasket sur-
faces must be free of oil and dirt. Make sure old
gasket material is removed from blind attaching
holes.
FORM-IN-PLACE GASKET APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier then using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 inch.) diameter or less of seal-
ant to one gasket surface. Be certain the material
surrounds each mounting hole. Excess material can
easily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
The MopartSilicone Rubber Adhesive Sealant gas-
ket material or equivalent should be applied in a con-
tinuous bead approximately 3 mm (0.120 inch) in
diameter. All mounting holes must be circled. For
corner sealing, a 3.17 or 6.35 mm (1/8 or 1/4 inch.)
drop is placed in the center of the gasket contact
area. Uncured sealant may be removed with a shop
towel. Components should be torqued in place while
the sealant is still wet to the touch (within 10 min-
utes). The usage of a locating dowel is recommended
during assembly to prevent smearing material off the
location.
CRANKSHAFT SPROCKET BOLT ACCESS PLUG
An Access plug is located in the right inner fender
shield. Remove the plug and insert the proper size
socket, extension and ratchet, when crankshaft rota-
tion is necessary.
ENGINE CORE PLUGS
REMOVAL
Using a blunt tool such as a drift or a screwdriver
and a hammer, strike the bottom edge of the cup
plug (Fig. 1). With the cup plug rotated, grasp firmly
with pliers or other suitable tool and remove plug
(Fig. 1).
CAUTION: Do not drive cup plug into the casting
as restricted cooling can result and cause serious
engine problems.
INSTALLATION
Thoroughly remove all rust and clean inside of cup
plug hole in cylinder block or head. Be sure to
remove old sealer. Lightly coat inside of cup plug hole
with sealer. Make certain the new plug is cleaned of
all oil or grease. Using proper drive plug, drive plug
into hole so that the sharp edge of the plug is atleast 0.5 mm (0.020 inch.) inside the lead in chamfer
(Fig. 1).
It is in not necessary to wait for curing of the seal-
ant. The cooling system can be refilled and the vehi-
cle placed in service immediately.
ENGINE PERFORMANCE
If a loss of performance is noticed, timing belt or
chain may have skipped one or two teeth. Camshaft
and crankshaft timing should be checked. Refer to
Group 9, Engine Timing belt or chain installation.
It is important that the vehicle is operating to its
optimum performance level to maintain fuel economy
and lowest vehicle emissions. If vehicle is not operat-
ing to these standards, refer to Engine Diagnosis out-
lined is this section. The following procedures can
assist in achieving the proper engine diagnosis.
(1) Test cranking amperage draw. Refer to Group
8B, Starting.
(2) Check intake manifold for vacuum leaks.
(3) Perform cylinder compression pressure test.
Refer to Engine Diagnosis, outlined in this section.
(4) Clean or replace spark plugs as necessary and
adjust gap as specified in Group 8D, Ignition System.
Tighten to specifications.
(5) Test resistance of spark plug cables. Refer to
Group 8D, Ignition System.
(6) Test ignition coils primary and secondary resis-
tance. Replace parts as necessary. Refer to Group 8D,
Ignition System.
(7) Check fuel pump pressure at idle and different
RPM ranges. Refer to Group 14, Fuel System for
Specifications.
(8) The air filter elements should be replaced as
specified in Group 0, Lubrication and Maintenance.
(9) Inspect crankcase ventilation system as out-
lined in Group 25, Emission Control Systems.
(10) Road test vehicle as a final test.
Fig. 1 Core Hole Plug Removal
9 - 2 ENGINEPL
GENERAL INFORMATION (Continued)

ENGINE DIAGNOSIS
INDEX
page page
DIAGNOSIS AND TESTING
CYLINDER COMBUSTION PRESSURE
LEAKAGE TEST........................ 8
CYLINDER COMPRESSION PRESSURE TEST . . 7
ENGINE DIAGNOSISÐMECHANICAL......... 11
ENGINE DIAGNOSISÐPERFORMANCE...... 10GENERAL INFORMATION.................. 7
INSPECTION (ENGINE OIL LEAKS IN
GENERAL)............................ 8
INTAKE MANIFOLD LEAKAGE DIAGNOSIS..... 7
LASH ADJUSTER (TAPPET) NOISE DIAGNOSIS.. 8
DIAGNOSIS AND TESTING
GENERAL INFORMATION
Engine diagnosis is helpful in determining the
causes of malfunctions.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
Refer to the Service DiagnosisÐMechanical Chart
and the Service DiagnosisÐPerformance Chart, for
possible causes and corrections of malfunctions. Refer
to Group 14, Fuel System, for the fuel system diag-
nosis.
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water (Spray Bottle) at
the suspected leak area.
(3) If a change in RPM'S, the area of the suspected
leak has been found.
(4) Repair as required.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect coil wire from distributor and
secure to good ground to prevent a spark from start-
ing a fire (Conventional Ignition System). For Direct
Ignition System DIS disconnect the coil connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine until
maximum pressure is reached on gage. Record this
pressure as #1 cylinder pressure.
(7) Repeat the previous step for all remaining cyl-
inders.
(8) Compression should not be less than (689kPa)
100 psi and not vary more than 25 percent from cyl-
inder to cylinder.
(9) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(10) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
PLENGINE 9 - 7

EXHAUST SYSTEM AND INTAKE MANIFOLD
CONTENTS
page page
GENERAL INFORMATION
CATALYTIC CONVERTER................... 4
EXHAUST BALL JOINT COUPLING.......... 1
EXHAUST FLEX-JOINT COUPLING (LEV)...... 2
EXHAUST GAS RECIRCULATION (EGR)
SYSTEM.............................. 3
EXHAUST SYSTEMS...................... 1
HEAT SHIELDS.......................... 3
DESCRIPTION AND OPERATION
EXHAUST MANIFOLD..................... 3
INTAKE MANIFOLD DOHC................. 3
INTAKE MANIFOLD SOHC................. 3
DIAGNOSIS AND TESTING
EXHAUST SYSTEM DIAGNOSIS CHART...... 4REMOVAL AND INSTALLATION
EXHAUST MANIFOLD.................... 11
EXHAUST PIPE AND MUFFLER............. 4
INTAKE MANIFOLDÐDOHC ENGINE......... 9
INTAKE MANIFOLDÐSOHC ENGINE......... 6
CLEANING AND INSPECTION
EXHAUST MANIFOLD.................... 12
INTAKE MANIFOLD DOHC................ 12
INTAKE MANIFOLD SOHC................ 12
SPECIFICATIONS
TORQUE CHART........................ 12
GENERAL INFORMATION
EXHAUST SYSTEMS
The exhaust system has an underfloor catalytic
converter, tail pipe, and muffler (Fig. 1).
EXHAUST BALL JOINT COUPLING
An exhaust ball joint coupling (Fig. 2) is used to
secure the exhaust pipe to the engine exhaust mani-
fold. This flexible joint moves back and forth as the
engine moves, preventing breakage that could occur
from the back-and-forth motion of a transverse
mounted engine.
Fig. 1 Exhaust System
PLEXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 1

The exhaust ball joint consists of two bolts, two
springs, and a ball joint seal ring, which is a sepa-
rate part from the exhaust pipe.
EXHAUST FLEX-JOINT COUPLING (LEV)
An exhaust flex-joint coupling is used on Low
Emission Vehicles (LEV) (Fig. 3). This coupling is
used to secure the catalytic converter to the exhaust
manifold. This coupling actually moves back and
forth as the engine moves, preventing breakage that
could occur from the back and forth motion of a
transverse mounted engine.
The exhaust flex-joint is welded to the catalytic
converter.
CATALYTIC CONVERTER
There is no regularly scheduled maintenance on
any Chrysler catalytic converter (Fig. 4). If damaged,
the converter must be replaced.
CAUTION: Due to exterior physical similarities of
some catalytic converters with pipe assemblies,
extreme care should be taken with replacement
parts.
The combustion reaction caused by the catalyst
releases additional heat in the exhaust system. Caus-
ing temperature increases in the area of the reactor
under severe operating conditions. Such conditions
can exist when the engine misfires or otherwise does
not operate at peak efficiency.Do notremove spark
plug wires from plugs or by any other means short
out cylinders if exhaust system is equipped with a
catalytic converter. Failure of the catalytic converter
can occur due to temperature increases caused by
unburned fuel passing through the converter.
The use of the catalysts also involves some non-au-
tomotive problems. Unleaded gasoline must be used
to avoid poisoning the catalyst core. Do not allow
engine to operate above 1200 RPM in neutral for
extended periods over 5 minutes. This condition may
result in excessive exhaust system/floor pan temper-
atures because of no air movement under the vehicle.
Fig. 2 Ball Joint Connection
Fig. 3 Flex-Joint (LEV)
Fig. 4 Exhaust System ComponentsÐTypical
11 - 2 EXHAUST SYSTEM AND INTAKE MANIFOLDPL
GENERAL INFORMATION (Continued)