air condition DODGE NEON 1999 Service Owner's Manual

must be replaced withonlythe recommended part
for adequate strength, performance and safety.
(1) To remove fan from motor shaft, bench support
the motor and motor shaft, while removing the fan
retaining clip, so that the shaft and motor will not be
damaged by excessive force.Surface burr removal
may be required to remove fan from motor
shaft (Fig. 25).Do not permit the fan blades to
touch the bench.
(2) To install fan on motor shaft, slide the fan over
shaft. Support motor and shaft as above while
installing fan retaining clip.
INSTALLATION FAN MODULE
(1) Install module to radiator. Torque shroud to
radiator fasteners to 7.5 N´m (65 in. lbs.).
(2) Connect fan motor lead.For wiring diagrams
of fan motor systems Refer to 8W Wiring Dia-
grams.
ELECTRIC FAN MOTORÐSERVICE
WARNING: Do not disassemble the fan motor from
the support bracket.
Electric fan motor is serviced as an assembly with
the fan module.
FAN SHROUD
Some fan shrouds are equipped with flapped doors
to prevent the shroud from restricting air flow at
high speeds.
All vehicles have fan shrouds to improve fan air
flow efficiency.
The shroud supports the electric fan motor and
fan. For removal and installation procedures, refer to
radiator removal in this Section.
ENGINE BLOCK HEATER
REMOVAL
(1) Drain coolant from radiator and cylinder block.
Refer to Cooling System Drain, Clean, Flush and
Refill of this section for procedure.
(2) Detach power cord plug from heater.
(3) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tionedupward.
(3) With heater seated, tighten center screw
securely to assure a positive seal.
(4) Fill cooling system with coolant to the proper
level, vent air, and inspect for leaks. Pressurize sys-
tem with Radiator Pressure Tool before looking for
leaks.
ACCESSORY DRIVE BELTS
AIR CONDITIONING COMPRESSOR AND
POWER STEERING PUMP
(1) Loosen the power steering pump locking bolts
A and B and pivot bolt C (Fig. 26) to remove and
install belt and/or adjust belt tension.
(2) Using a 1/2º breaker bar, adjust belt tension by
applying torque to the square D hole on the power
steering pivot bracket. Adjust tension to specification
given in Belt Tension Chart.
(3) Tighten in order, first tighten locking bolt A to
27 N´m (20 ft. lbs.) then, bolt B to 27 N´m (20 ft. lbs.)
Then pivot bolt C to 54 N´m (40 ft. lbs.).
GENERATOR BELT
(1) Loosen pivot bolt E then locking nut F and
adjusting bolt G (Fig. 27) to remove and install belt
and/or adjust belt tension.
(2) Tighten adjusting bolt G, adjust belt tension to
specification shown in Belt Tension Chart.
(3) Tighten pivot bolt E to 54 N´m (40 ft. lbs.).
Locking nut F to 54 N´m (40 ft. lbs.).
CLEANING AND INSPECTION
WATER PUMP
Replace water pump body assembly if it has any of
these defects:
(1) Cracks or damage on the body.
(2) Coolant leaks from the shaft seal, evident by
coolant traces on the pump body.
(3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or the
engine block.
Fig. 25 Servicing Radiator Fan
PLCOOLING 7 - 21
REMOVAL AND INSTALLATION (Continued)

Cooling System). Run engine with radiator cap
installed until upper radiator hose is hot. Stop
engine and drain water from system. If water is
dirty, fill, run and drain system again until water
runs clear.
RADIATOR FLUSHING
Drain cooling system and remove radiator hoses
from engine. Install suitable flushing gun in radiator
lower hose. Fill radiator with clean water and turn
on air in short blasts.
CAUTION: Internal radiator pressure must not
exceed 138 kPa (20 psi) as damage to radiator may
result. Continue this procedure until water runs
clear.
ENGINE FLUSHING
Drain radiator (see:Cooling System Draining)
and remove hoses from radiator. Remove engine ther-
mostat and reinstall thermostat housing. A gasket
may be needed to seal the housing to cylinder head
because the seal is part of thermostat. Install suit-
able flushing gun to thermostat housing hose. Turn
on water, and when engine is filled, turn on air, but
no higher than 138 kPa (20 psi) in short blasts. Allowengine to fill between blasts of air. Continue this pro-
cedure until water runs clean. Install thermostat and
fill cooling system. Refer to (Cooling System Refill-
ing) for procedure.
REVERSE FLUSHING
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system, using air
pressure in a direction opposite to that of the normal
flow of water. This is only necessary with dirty sys-
tems and evidence of partial plugging.
CHEMICAL CLEANING
One type of corrosion encountered with aluminum
cylinder heads is aluminum hydroxide deposits. Cor-
rosion products are carried to the radiator and depos-
ited when cooled off. They appear as dark grey when
wet and white when dry. This corrosion can be
removed with a two part cleaner (oxalic acid and
neutralizer) available in auto parts outlets. Follow
manufacturers directions for use.
ADJUSTMENTS
PROPER BELT TENSION
Satisfactory performance of the belt driven accesso-
ries depends on belt condition and proper belt ten-
sion. Refer to Accessory Drive Belt Inspection in this
section. There are two belt tensioning methods given
in order of preference:
²Belt tension gauge method.
²Torque equivalent method.
The belt tension gauge method usually requires the
vehicle to be raised on a hoist and the splash shield
removed.
TORQUE EQUIVALENT METHOD
Adjustable accessory brackets provided with a 13
mm (1/2 in.) square hole for a torque wrench can use
an equivalent torque value for belt adjustment.
Equivalent torque values for adjusting these acces-
sory drive belts are specified in the Belt Tension
Chart.
Fig. 29 Cooling System Pressure Cap
BELT TENSION CHART
ACCESSORY
DRIVE BELTGAUGE TORQUE
Power Steering
Pump and A/C
CompressorNew 135 lb. 121 N´m (90 ft.
lbs.)
Used 100 lb. 81 N´m 60 ft.
lbs.)
Generator New 135 lb. Gauge
adjustment
method only Used 100 lb.
PLCOOLING 7 - 23
CLEANING AND INSPECTION (Continued)

STARTING SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSE CORRECTION
STARTER FAILS TO
ENGAGE.1. Battery discharged or faulty.
2. Starting circuit wiring faulty.
3. Starter relay faulty.
4. Ignition switch faulty.
5. Park/Neutral position switch
(auto trans) faulty or mis-adjusted.
6. Clutch pedal position switch
(man trans) faulty.
7. Starter solenoid faulty.
8. Starter assembly faulty.1. Refer to Group 8A, Battery. Charge or replace
battery, if required.
2. Refer to Feed Circuit Resistance Test and
Feed Circuit Test in this section.
3. Refer to Relay Test, in this section. Replace
relay, if necessary.
4. Refer to Ignition Switch Test, in Group 8D
Ignition System or Group 8W, Wiring Diagrams.
Replace switch, if necessary.
5. Refer Park/Neutral Position Switch Test, in
Group 21, Transaxle. Replace switch, if
necessary.
6. Refer to Clutch Pedal Position Switch Test, in
Group 6, Clutch. Replace switch, if necessary.
7. Refer to Solenoid Test, in this section.
Replace starter assembly, if necessary.
8. If all other starting system components and
circuits check OK, replace starter assembly.
STARTER ENGAGES,
FAILS TO TURN
ENGINE.1. Battery discharged or faulty.
2. Starting circuit wiring faulty.
3. Starter assembly faulty.
4. Engine seized.1. Refer to Group 8A, Battery. Charge or replace
battery as necessary.
2. Refer to the Feed Circuit Resistance Test and
the Feed Circuit Test in this section. Repair as
necessary.
3. If all other starting system components and
circuits check OK, replace starter assembly.
4. Refer to Group 9 Engine, for diagnostic and
service procedures.
STARTER ENGAGES,
SPINS OUT BEFORE
ENGINE STARTS.1. Broken teeth on starter ring gear.
2. Starter assembly faulty.1. Remove starter. Inspect ring gear and replace
if necessary.
2. If all other starting system components and
circuits check OK, replace starter assembly.
STARTER DOES NOT
DISENGAGE.1. Starter improperly installed.
2. Starter relay faulty.
3. Ignition switch faulty.
4. Starter assembly faulty.1. Install starter. Tighten starter mounting
hardware to correct torque specifications.
2. Refer to Relay Test, in this section. Replace
relay, if necessary.
3. Refer to Ignition Switch Test, in Group 8D,
Ignition System. Replace switch, if necessary.
4. If all other starting system components and
circuits check OK, replace starter assembly.
PLSTARTING 8B - 5
DIAGNOSIS AND TESTING (Continued)

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.
PLCHARGING SYSTEM 8C - 3
DIAGNOSIS AND TESTING (Continued)

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 (Fig. 2) 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.
Test points on the generator may be reached by
either removing the air cleaner housing or below by
raising the vehicle on a hoist.
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 vehicle interior lamps on.
(5) Start engine. Bring engine speed up to 2400
rpm and hold.
(6) Testing (- ground) circuitry:
(a) Touch the negative lead of voltmeter directly
to battery positivePOST(Fig. 4).
(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. Refer to Group 8, Wiring
for connector location. A voltage drop test may be
Fig. 2 Generator Terminals
Fig. 3 Electrical Resistance Test
Fig. 4 Battery Voltage Test
PLCHARGING SYSTEM 8C - 7
DIAGNOSIS AND TESTING (Continued)

performed at each (- ground) connection in this cir-
cuit to locate the excessive resistance.
(7) Testing (+ positive) circuitry:
(a) Touch the positive lead of voltmeter directly
to battery negativePOST.
(b) Touch the negative lead of voltmeter to the
ground terminal stud on the generator case (not
the terminal mounting nut). Voltage should be no
higher than 0.3 volts. If voltage is higher than 0.3
volts, touch test lead to terminal mounting stud
nut and then to the wiring connector. If voltage is
now below 0.3 volts, look for dirty, loose or poor
connection at this point. A voltage drop test may be
performed at each (+ positive) connection in this
circuit to locate the excessive resistance. This test
can also be performed between the generator 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.
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.
BATTERY TEMPERATURE SENSOR
To perform a complete test of this sensor and its
circuitry, refer to the appropriate Powertrain Diag-
nostic Procedures manual. To test the sensor only,
refer to the following:
(1) The sensor is located under the battery and is
attached to the battery tray (Fig. 5). A two-wire pig-
8C - 8 CHARGING SYSTEMPL
DIAGNOSIS AND TESTING (Continued)

IGNITION SYSTEM
CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION......................... 1
DESCRIPTION AND OPERATION
AUTOMATIC SHUTDOWN RELAY............ 3
CAMSHAFT POSITION SENSOR............. 4
COMBINATION ENGINE COOLANT
TEMPERATURE SENSOR................. 5
CRANKSHAFT POSITION SENSOR........... 4
ELECTRONIC IGNITION COILS.............. 3
IGNITION INTERLOCK.................... 7
IGNITION SWITCH....................... 7
IGNITION SYSTEM....................... 1
INTAKE AIR TEMPERATURE SENSOR........ 6
KNOCK SENSOR......................... 6
LOCK KEY CYLINDER..................... 7
MANIFOLD ABSOLUTE PRESSURE SENSOR
(MAP)............................... 6
POWERTRAIN CONTROL MODULE.......... 2
SPARK PLUG CABLES.................... 2
SPARK PLUGS.......................... 2
THROTTLE POSITION SENSOR (TPS)........ 6
DIAGNOSIS AND TESTING
CAMSHAFT POSITION SENSOR AND
CRANKSHAFT POSITION SENSOR......... 9
CHECK COIL TEST....................... 8
ENGINE COOLANT TEMPERATURE SENSOR . . . 9
FAILURE TO START TESTÐ2.0/2.4L......... 8
IGNITION TIMING PROCEDURE............. 9
INTAKE AIR TEMPERATURE SENSOR........ 9
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR TEST......................... 9
SPARK PLUG CONDITION................ 10TESTING FOR SPARK AT COILÐ2.0/2.4L..... 7
THROTTLE POSITION SENSOR............. 9
REMOVAL AND INSTALLATION
AUTOMATIC SHUTDOWN RELAY........... 13
CAMSHAFT POSITION SENSORÐDOHC..... 14
CAMSHAFT POSITION SENSORÐSOHC..... 13
COMBINATION ENGINE COOLANT
TEMPERATURE SENSORÐDOHC........ 15
COMBINATION ENGINE COOLANT
TEMPERATURE SENSORÐSOHC......... 15
CRANKSHAFT POSITION SENSOR.......... 15
IGNITION COIL......................... 13
IGNITION INTERLOCK................... 18
IGNITION SWITCH...................... 16
LOCK CYLINDER HOUSING............... 18
LOCK KEY CYLINDER.................... 17
MAP/IAT SENSORÐDOHC................ 16
MAP/IAT SENSORÐSOHC................ 16
POWERTRAIN CONTROL MODULE (PCM) . . . 12
SPARK PLUG CABLE SERVICE............ 13
SPARK PLUG SERVICE.................. 12
SPARK PLUG TUBES.................... 13
THROTTLE POSITION SENSOR............ 16
SPECIFICATIONS
FIRING ORDERÐ2.0L................... 18
IGNITION COIL......................... 19
SPARK PLUG CABLE RESISTANCEÐDOHC . . 18
SPARK PLUG CABLE RESISTANCEÐSOHC . . . 18
SPARK PLUG.......................... 19
TORQUE SPECIFICATION................. 18
VECI LABEL........................... 18
GENERAL INFORMATION
INTRODUCTION
This section describes the electronic ignition sys-
tem for the 2.0L engines used in Neon vehicles.
The On-Board Diagnostics Section in Group 25
describes diagnostic trouble codes.
Group 0, Lubrication and Maintenance, contains
general maintenance information for ignition relateditems. The Owner's Manual also contains mainte-
nance information.DESCRIPTION AND OPERATION
IGNITION SYSTEM
Ignition system operation and diagnostics, are
identical for 2.0L Single Overhead Cam (SOHC) and
2.0L Duel Overhead Cam (DOHC) engines.
PLIGNITION SYSTEM 8D - 1

The major difference between the two engines is
component location which affects the ignition system
service procedures. There are various sensors that
are in different locations due to a different cylinder
head and intake manifold.
The 2.0L engines use a fixed ignition timing sys-
tem. The distributorless electronic ignition system is
referred to as the Direct Ignition System (DIS).
Basic ignition timing is not adjustable.The
Powertrain Control Module (PCM) determines spark
advance. The system's three main components are
the coil pack, crankshaft position sensor, and cam-
shaft position sensor.
POWERTRAIN CONTROL MODULE
The Powertrain Control Module (PCM) controls the
ignition system (Fig. 1). The PCM supplies battery
voltage to the ignition coil through the Auto Shut-
down (ASD) Relay. The PCM also controls the 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 maintains
spark advance at 9É BTDC. During engine operation
the following inputs determine the amount of spark
advance provided by the PCM.
²Intake air temperature
²Coolant temperature
²Engine RPM
²Intake manifold vacuum
²Knock sensor
The PCM also regulates the fuel injection system.
Refer to the Fuel Injection sections of Group 14.
SPARK PLUGS
The 2.0L engines uses resistor spark plugs. For
spark plug identification and specifications, Refer to
the Specifications section at the end of this group.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 0.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective. Refer to the
Spark Plug Condition section of this group. After
cleaning, file the center electrode flat with a small
point file or jewelers file. Adjust the gap between the
electrodes (Fig. 2) to the dimensions specified in the
chart at the end of this section.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion and damage.
Tighten spark plugs to 28 N´m (20 ft. lbs.) torque.
SPARK PLUG CABLES
Spark plug cables are sometimes referred to as sec-
ondary ignition wires. The wires transfer electrical
current from the coil pack to individual spark plugs
at each cylinder. The resistor type, nonmetallic spark
plug cables provide suppression of radio frequency
emissions from the ignition system.
Check the spark plug cable connections for good
contact at the coil and spark plugs. Terminals should
be fully seated. The nipples and spark plug covers
should be in good condition. Nipples should fit tightly
on the coil. Spark plug boot should completely cover
the spark plug hole in the cylinder head cover. Install
the boot until the terminal snaps over the spark
plug. A snap must be felt to ensure the spark plug
cable terminal engaged the spark plug.
Loose cable connections will corrode, increase resis-
tance and permit water to enter the coil towers.
These conditions can cause ignition malfunction.
Fig. 1 Powertrain Control Module
Fig. 2 Setting Spark Plug Electrode Gap
8D - 2 IGNITION SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

train Control Module (PCM) with an input signal
(voltage). The signal represents throttle blade posi-
tion. As the position of the throttle blade changes,
the resistance of the TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
powertrain control module) represents throttle blade
position. The TPS output voltage to the PCM varies
from approximately 0.38 volts to 1.2 volts at mini-
mum throttle opening (idle) to a maximum of 3.1
volts to 4.4 volts at wide open throttle.
Along with inputs from other sensors, the PCM
uses the TPS input to determine current engine oper-
ating conditions. The PCM also adjusts fuel injector
pulse width and ignition timing based on these
inputs.
IGNITION SWITCH
In the RUN position, the ignition switch connects
power from the Power Distribution Center (PDC) to a
30 amp fuse in the fuse block, back to a bus bar in
the PDC. The bus bar feeds circuits for the Power-
train Control Module (PCM), duty cycle purge sole-
noid, EGR solenoid, and ABS system. The bus bar in
the PDC feeds the coil side of the radiator fan relay,
A/C compressor clutch relay, and the fuel pump relay.
It also feeds the Airbag Control Module (ACM)
LOCK KEY CYLINDER
The lock cylinder is inserted in the end of the
housing opposite the ignition switch. The ignition key
rotates the cylinder to 5 different detents (Fig. 16):
²Accessory
²Off (lock)
²Unlock
²On/Run
²Start
IGNITION INTERLOCK
All vehicles equipped with automatic transaxles
have an interlock system. The system prevents shift-
ing the vehicle out of Park unless the ignition lock
cylinder is in the Off, Run or Start position. In addi-
tion, the operator cannot rotate the key to the lock
position unless the shifter is in the park position. On
vehicles equipped with floor shift refer to Group 21 -
Transaxle for Automatic Transmission Shifter/Igni-
tion Interlock.
DIAGNOSIS AND TESTING
TESTING FOR SPARK AT COILÐ2.0/2.4L
WARNING: THE DIRECT IGNITION SYSTEMS GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
The coil pack contains independent coils. Each coil
must be checked individually.
CAUTION: Spark plug wire damage may occur if
the spark plug is moved more than 1/4 inch away
from the engine ground.
CAUTION: Do not leave any one spark plug cable
disconnected any longer than 30 seconds or possi-
ble heat damage to catalytic converter will occur.
CAUTION: Test must be performed at idle and in
park only with the parking brake on.
NOTE: New isolated engine valve cover may not
provide adequate ground. Use engine block as
engine ground.
Fig. 15 MAP/IAT sensorÐDOHCFig. 16 Ignition Lock Cylinder Detents
PLIGNITION SYSTEM 8D - 7
DESCRIPTION AND OPERATION (Continued)

Connect the DVM between the center and sensor
ground terminal. Refer to Group 8W - Wiring Dia-
grams for correct pinout.
With the ignition switch in the ON position, check
the output voltage at the center terminal wire of the
connector. Check the output voltage at idle and at
Wide-Open-Throttle (WOT). At idle, TPS output volt-
age should be approximately 0.38 volts to 1.2 volts.
At wide open throttle, TPS output voltage should be
approximately 3.1 volts to 4.4 volts. The output volt-
age should gradually increase as the throttle plate
moves slowly from idle to WOT.
Check for spread terminals at the sensor and PCM
connections before replacing the TPS.
SPARK PLUG CONDITION
NORMAL OPERATING CONDITIONS
The few deposits present will be probably light tan
or slightly gray in color with most grades of commer-
cial gasoline (Fig. 21). There will not be evidence of
electrode burning. Gap growth will not average more
than approximately 0.025 mm (.001 in) per 1600 km
(1000 miles) of operation for non platinum spark
plugs. Non-platnium spark plugs that have normal
wear can usually be cleaned, have the electrodes filed
and regapped, and then reinstalled.
CAUTION: Never attempt to file the electrodes or
use a wire brush for cleaning platinum spark plugs.
This would damage the platinum pads which would
shorten spark plug life.Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
for unleaded fuel. During combustion, fuel with MMT
may coat the entire tip of the spark plug with a rust
colored deposit. The rust color deposits can be misdi-
agnosed as being caused by coolant in the combustion
chamber. Spark plug performance is not affected by
MMT deposits.
COLD FOULING (CARBON FOULING)
Cold fouling is sometimes referred to as carbon
fouling because the deposits that cause cold fouling
are basically carbon (Fig. 21). A dry, black deposit on
one or two plugs in a set may be caused by sticking
valves or misfire conditions. Cold (carbon) fouling of
the entire set may be caused by a clogged air cleaner.
Cold fouling is normal after short operating peri-
ods. The spark plugs do not reach a high enough
operating temperature during short operating peri-
ods.Replace carbon fouled plugs with new
spark plugs.
FUEL FOULING
A spark plug that is coated with excessive wet fuel
is called fuel fouled. This condition is normally
observed during hard start periods.Clean fuel
fouled spark plugs with compressed air and
reinstall them in the engine.
OIL FOULING
A spark plug that is coated with excessive wet oil
is oil fouled. In older engines, wet fouling can be
caused by worn rings or excessive cylinder wear.
Break-in fouling of new engines may occur before
normal oil control is achieved.Replace oil fouled
spark plugs with new ones.
OIL OR ASH ENCRUSTED
If one or more plugs are oil or ash encrusted, eval-
uate the engine for the cause of oil entering the com-
bustion chambers (Fig. 22). Sometimes fuel additives
can cause ash encrustation on an entire set of spark
plugs.Ash encrusted spark plugs can be cleaned
and reused.
HIGH SPEED MISS
When replacing spark plugs because of a high
speed miss condition;wide open throttle opera-
tion should be avoided for approximately 80 km
(50 miles) after installation of new plugs.This
will allow deposit shifting in the combustion chamber
to take place gradually and avoid plug destroying
splash fouling shortly after the plug change.
Fig. 21 Normal Operation and Cold (Carbon) Fouling
8D - 10 IGNITION SYSTEMPL
DIAGNOSIS AND TESTING (Continued)