2000 DODGE NEON Service Repair Manual

Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
OPERATION
The amount of DC current produced by the gener-
ator is controlled by EVR circuitry contained within
the PCM. This circuitry is connected in series with
the generators second rotor field terminal and its
ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage (B+) and
battery temperature (refer to Battery Temperature
Sensor for more information). It then determines a
target charging voltage. If sensed battery voltage is
0.5 volts or lower than the target voltage, the PCM
grounds the field winding until sensed battery volage
is 0.5 volts above target voltage. A circuit in the PCM
cycles the ground side of the generator field up to
100 times per second (100Hz), but has the capability
to ground the field control wire 100% of the time (full
field) to achieve the target voltage. If the charging
rate cannot be monitored (limp-in), a duty cycle of
25% is used by the PCM in order to have some gen-
erator output. Also refer to Charging System Opera-
tion for additional information.
REMOVAL AND INSTALLATION
GENERATOR
REMOVAL
(1) Disconnect battery negative cable (Fig. 1).
(2) Loosen the jam nut and adjustment bolt.
(3) Raise vehicle and support.(4) Remove accessary drive splash shield (Fig. 2).
(5) Loosen the lower mounting bolt.
(6) Remove the generator drive belt.
(7) Disconnect the generator field circuit wiring
connector. Push theREDlocking tab to release.
(8) Remove the B+ terminal nut and wire.
(9) Remove the upper and lower mounting bolt
(Fig. 3) and move generator off of pivot bracket.
(10) Remove pivot bracket.
(11) Remove Generator (Fig. 4) through wheel
well.
INSTALLATION
(1) Install generator (Fig. 4) through wheel well.
Fig. 1 Battery Cable
Fig. 2 Splash Shield and Belt
Fig. 3 Lower Mounting Bolt
8C - 2 CHARGING SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

(2) Install lower pivot bracket and tighten bolts to
54 N´m (40 ft. lbs.).(3) Loose install the upper and lower mounting
bolts (Fig. 3).
(4) Connect the generator field circuit wiring con-
nector. Push theREDlocking tab to lock.
(5) Install the B+ terminal nut and wire.
(6) Install the generator drive belt.
(7) Lower vehicle.
(8) Tension belt.
(9) Tighten adjustment bolt.
(10) Tighten the jam nut
(11) Raise vehicle and support.
(12) Tighten lower mounting bolt and tighten bolts
to 54 N´m (40 ft. lbs.)..
(13) Install splash shield (Fig. 2).
(14) Lower vehicle.
(15) Connect battery cable (Fig. 1).
SPECIFICATIONS
GENERATOR RATINGS
TYPE PART NUMBER RATED SAE AMPS ENGINES MINIMUM TEST AMPS
Mitsubishi 4794222AA 85 AMPS 2.0L 75 AMPS
TORQUE
DESCRIPTION TORQUE
Battery Terminal Nut......... 9N´m(75in.lbs.)
Battery Hold Down Clamp Bolt . . 9 N´m (75 in. lbs.)
Generator Mounting Bolt..... 54N´m(40ft.lbs.)
Generator Pivot Bolt......... 54N´m(40ft.lbs.)
Pivot Bracket Bolts.......... 54N´m(40ft.lbs.)
Fig. 4 Generator
PLCHARGING SYSTEM 8C - 3
REMOVAL AND INSTALLATION (Continued)

IGNITION SYSTEM
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
IGNITION SYSTEM........................1
SPARK PLUGS...........................1
SPARK PLUG CABLES.....................1
ELECTRONIC IGNITION COILS...............2
AUTOMATIC SHUTDOWN RELAY.............2
CRANKSHAFT POSITION SENSORÐPCM
INPUT................................3
CAMSHAFT POSITION SENSORÐPCM
INPUT................................4
KNOCK SENSOR..........................5
IGNITION SWITCH........................5
LOCK KEY CYLINDER......................5
IGNITION INTERLOCK.....................6
REMOVAL AND INSTALLATION
SPARK PLUG SERVICE....................6SPARK PLUG CABLE SERVICE..............6
IGNITION COIL...........................6
AUTOMATIC SHUTDOWN RELAY.............6
CAMSHAFT POSITION SENSOR..............6
CRANKSHAFT POSITION SENSOR............8
KNOCK SENSOR..........................8
IGNITION SWITCH........................8
LOCK KEY CYLINDER......................9
IGNITION INTERLOCK....................10
SPECIFICATIONS
VECI LABEL............................10
FIRING ORDERÐ2.0L....................10
TORQUE SPECIFICATION..................11
SPARK PLUG CABLE RESISTANCEÐSOHC....11
SPARK PLUG...........................11
IGNITION COIL..........................11
DESCRIPTION AND OPERATION
IGNITION SYSTEM
DESCRIPTION
The system's three main components are the coil
pack, crankshaft position sensor, and camshaft posi-
tion sensor.
OPERATION
Basic ignition timing is not adjustable.The
Powertrain Control Module (PCM) determines spark
advance. The 2.0L engines use a fixed ignition timing
system. The distributorless electronic ignition system
is referred to as the Direct Ignition System (DIS).
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.
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. Aftercleaning, file the center electrode flat with a small
point file or jewelers file. Adjust the gap between the
electrodes (Fig. 1) to the dimensions specified in the
chart at the end of this section by bending the
ground electrode (just above the attachment weld)
with the appropriate tool.
Never apply any force between the electrode or
damage to the center electrode assembly will result.
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.
PLIGNITION SYSTEM 8D - 1

Loose cable connections will corrode, increase resis-
tance and permit water to enter the coil towers.
These conditions can cause ignition malfunction.
Plastic clips in various locations protect the cables
from damage. When the cables are replaced the clips
must be used to prevent damage to the cables, and
should be rotated about 30É below the horizontal.
ELECTRONIC IGNITION COILS
DESCRIPTION
The coil pack consists of 2 coils molded together.
The coil pack is mounted on the valve cover (Fig. 2).
OPERATION
WARNING: THE DIRECT IGNITION SYSTEM GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
High tension leads route to each cylinder from the
coil. The coil fires two spark plugs every power
stroke. One plug is the cylinder under compression,
the other cylinder fires on the exhaust stroke. Coil
number one fires cylinders 1 and 4. Coil number two
fires cylinders 2 and 3. The 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 energy in the coil
primary transfers to the secondary causing thespark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Auto Shut-
down (ASD) RelayÐPCM Output, in this section for
relay operation.
AUTOMATIC SHUTDOWN RELAY
DESCRIPTION
The ASD relay is located in the PDC (Fig. 3). The
inside top of the PDC cover has label showing relay
and fuse identification.
Fig. 1 Checking Spark Plug Electrode Gap
1 ± TAPER GAUGE
Fig. 2 Ignition Coil Pack
1 ± IGNITION COILS
2 ± SPARK PLUG CABLE
3 ± SPARK PLUG INSULATOR
Fig. 3 Power Distribution Center (PDC)
8D - 2 IGNITION SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

OPERATION
The Automatic Shutdown (ASD) relay supplies bat-
tery voltage to the fuel injectors, electronic ignition
coil and the heating elements in the oxygen sensors.
A buss bar in the Power Distribution Center (PDC)
supplies voltage to the solenoid side and contact side
of the relay. The fuse also protects the power circuit
for the fuel pump relay and pump. The fuse is
located in the PDC. Refer to the Wiring Diagrams for
circuit information.
The PCM controls the ASD relay by switching the
ground path for the solenoid side of the relay on and
off. The PCM turns the ground path off when the
ignition switch is in the Off position. When the igni-
tion switch is in On or Start, the PCM monitors the
crankshaft and camshaft position sensor signals to
determine engine speed and ignition timing (coil
dwell). If the PCM does not receive crankshaft and
camshaft position sensor signals when the ignition
switch is in the Run position, it will de-energize the
ASD relay.
CRANKSHAFT POSITION SENSORÐPCM
INPUT
DESCRIPTION
The crankshaft position sensor mounts to the
engine block behind the generator, just above the oil
filter (Fig. 4).
The PCM uses the Crankshaft Position sensor to
calculate the following:
²Engine RPM²TDC number 1 and 4
²Ignition coil synchronization
²Injector synchronization
²Camshaft-to-crankshaft misalignment (Timing
belt skipped 1 tooth or more diagnostic trouble code).
OPERATION
The Crankshaft Position (CKP) sensor is a Hall-ef-
fect sensor. The second crankshaft counterweight has
two sets of four timing reference notches including a
60 degree signature notch (Fig. 5).
Fig. 5 Timing Reference Notches
1 ± MACHINED NOTCHES
2 ± CRANKSHAFT POSITION SENSOR
Fig. 4 Crankshaft Position Sensor
1 ± CRANKSHAFT POSITION SENSOR
2 ± OIL FILTER
3 ± GENERATOR
PLIGNITION SYSTEM 8D - 3
DESCRIPTION AND OPERATION (Continued)

The PCM sends approximately 8 volts to the Hall-
effect sensor. This voltage is required to operate the
Hall-effect chip and the electronics inside the sensor.
A ground for the sensor is provided through the sen-
sor return circuit. The input to the PCM occurs on a
5 volt output reference circuit.
The notches generate pulses from high to low in
the crankshaft position sensor output voltage. When
a metal portion of the counterweight aligns with the
crankshaft position sensor, the sensor output voltage
goes low (less than 0.5 volts). When a notch aligns
with the sensor, voltage goes high (5.0 volts). As a
group of notches pass under the sensor, the output
voltage switches from low (metal) to high (notch)
then back to low.
If available, an oscilloscope can display the square
wave patterns of each voltage pulses. From the width
of the output voltage pulses, the PCM calculates
engine speed. The width of the pulses represent the
amount of time the output voltage stays high before
switching back to low. The period of time the sensor
output voltage stays high before switching back to
low is referred to as pulse width. The faster the
engine is operating, the smaller the pulse width on
the oscilloscope.
By counting the pulses and referencing the pulse
from the 60 degree signature notch, the PCM calcu-
lates crankshaft angle (position). In each group of
timing reference notches, the first notch represents
69 degrees before top dead center (BTDC). The sec-
ond notch represents 49 degrees BTDC. The third
notch represents 29 degrees. The last notch in each
set represents 9 degrees before top dead center
(TDC).
The timing reference notches are machined at 20É
increments. From the voltage pulse width the PCM
tells the difference between the timing reference
notches and the 60 degree signature notch. The 60
degree signature notch produces a longer pulse width
than the smaller timing reference notches. If the
camshaft position sensor input switches from high to
low when the 60 degree signature notch passes under
the crankshaft position sensor, the PCM knows cylin-
der number one is the next cylinder at TDC.CAMSHAFT POSITION SENSORÐPCM INPUT
DESCRIPTION
The camshaft position sensor attaches to the rear
of the cylinder head. The PCM determines fuel injec-
tion synchronization and cylinder identification from
inputs provided by the camshaft position sensor (Fig.
6) and crankshaft position sensor. From the two
inputs, the PCM determines crankshaft position.
OPERATION
The PCM sends approximately 8 volts to the hall
affect sensor. This voltage is required to operate the
hall effect chip and the electronics inside the sensor.
A ground for the sensor is provided through the sen-
sor return circuit. The input to the PCM occurs on a
5 volt output reference circuit.
A target magnet attaches to the rear of the cam-
shaft and indexes to the correct position. The target
magnet has four different poles arranged in an asym-
metrical pattern (Fig. 7). As the target magnet
rotates, the camshaft position sensor senses the
change in polarity (Fig. 8). The sensor output switch
switches from high (5.0 volts) to low (0.5 volts) as the
target magnet rotates. When the north pole of the
target magnet passes under the sensor, the output
switches high. The sensor output switches low when
the south pole of the target magnet passes under-
neath.
The sensor also acts as a thrust plate to control
camshaft endplay.
Fig. 6 Camshaft Position SensorÐSOHC
8D - 4 IGNITION SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

KNOCK SENSOR
DESCRIPTION
The knock sensor threads into the cylinder block.
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.
NOTE: Over or under tightening affects knock sen-
sor performance, possibly causing improper spark
control.
IGNITION SWITCH
In the RUN position, the ignition switch connects
power from the Power Distribution Center (PDC) to a
fuse in the fuse block, back to a bus bar in the PDC.
The bus bar feeds circuits for the Powertrain Control
Module (PCM), Proportional purge solenoid, EGR
solenoid, and ABS system. The bus bar in the PDC
feeds the coil side of the radiator fan relay, A/C com-
pressor clutch relay, and the fuel pump relay. It also
feeds the Airbag Control Module (ACM)
LOCK KEY CYLINDER
DESCRIPTION
The lock cylinder is inserted in the end of the
housing opposite the ignition switch.
OPERATION
The ignition key rotates the cylinder to 5 different
detents (Fig. 9) :
²Accessory
²Off (lock)
²Unlock
²On/Run
²Start
Fig. 7 Target MagnetÐTypical
1 ± CAM MAGNET/TARGET
2 ± CAMSHAFT POSITION SENSOR
Fig. 8 Target Magnet Polarity
1 ± TARGET MAGNET
Fig. 9 Ignition Lock Cylinder Detents
PLIGNITION SYSTEM 8D - 5
DESCRIPTION AND OPERATION (Continued)