2000 DODGE NEON ignition switch

The sensor return circuit connects to internal ground
circuits within the Powertrain Control Module
(PCM).
SPEED CONTROLÐPCM INPUT
OPERATION
The speed control system provides five separate
voltages (inputs) to the Powertrain Control Module
(PCM). The voltages correspond to the ON, OFF,
SET, RESUME, CANCEL, and COAST.
The speed control ON voltage informs the PCM
that the speed control system has been activated.
The speed control SET voltage informs the PCM that
a fixed vehicle speed has been selected. The speed
control RESUME voltage indicates the previous fixed
speed is requested. The speed control CANCEL volt-
age tells the PCM to deactivate but retain set speed
in memory (same as depressing the brake pedal). The
speed control OFF voltage tells the PCM that the
speed control system has deactivated.
Inputs Required for Operation
The inputs required by the PCM to operate the
Speed Control System include:
²Speed Control switches
²Brake switch
²Park/Neutral switch
²Vehicle speed signal
²Engine speed
²CCD bussed message from TCM
SCI RECEIVEÐPCM INPUT
OPERATION
SCI Receive is the serial data communication
receive circuit for the DRB scan tool. The PowertrainControl Module (PCM) receives data from the DRB
through the SCI Receive circuit.
PARK/NEUTRAL POSITION SWITCHÐPCM
INPUT
DESCRIPTION
The park/neutral position switch is located on the
automatic transaxle housing (Fig. 19).
OPERATION
Manual transaxles do not use park/neutral
switches. The switch provides an input to the PCM to
indicate whether the automatic transaxle is in Park/
Neutral, or a drive gear selection. This input is used
to determine idle speed (varying with gear selection)
and ignition timing advance. The park/neutral input
is also used to cancel vehicle speed control. The park/
neutral switch is sometimes referred to as the neu-
tral safety switch.
The PCM delivers 8.5 volts to the center terminal
of the Park/Neutral switch. When the gear shift lever
is moved to either the Park or the Neutral position,
the PCM receives a ground signal from the Park/
Neutral switch. With the shift lever positioned in
Drive or Reverse, the Park/Neutral switch contacts
open, causing the signal to the PCM to go high.
THROTTLE POSITION SENSORÐPCM INPUT
DESCRIPTION
The throttle position sensor mounts to the side of
the throttle body (Fig. 20).
The Throttle Position Sensor (TPS) connects to the
throttle blade shaft. The TPS is a variable resistor
that provides the PCM with an input signal (voltage).
The signal represents throttle blade position. As the
Fig. 18 Power Steering Pressure Switch
1 ± POWER STEERING PRESSURE SWITCH
Fig. 19 Park/Neutral Switch
1 ± PARK/NEUTRAL SWITCH
2 ± TRANSAXLE HOUSING
14 - 36 FUEL SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

position of the throttle blade changes, the resistance
of the TPS changes.
OPERATION
The PCM supplies approximately 5 volts DC 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 0.35 to 1.03 volts at minimum
throttle opening (idle) to a maximum of 3.1 to 4.0
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.
When the TPS indicates a voltage that is too high,
too low or not believable, the PCM sets a DTC. When
the DTC is set, the MIL is illuminated and the PCM
moves into limp-in mode. Limp-in for the TPS is
divided into three categories:
²Idle
²Part-throttle
²Wide open throttle (WOT)
VEHICLE SPEED SIGNAL (VSS)ÐPCM INPUT
DESCRIPTION
The PCM requires the VSS to be able to control
the following programs:
²Speed Control
²IAC motor (during deceleration)
²Injection pulse width (during deceleration)
²OBD II diagnostics
²PCM mileage EEPROM
²Road speed shutdown
²Speedometer/Odometer (bused message)NOTE: Road Speed Shutdown is the PCM shutting
off fuel injectors above a preset vehicle speed.
The vehicle speed sensor is located in the transmis-
sion extension housing (Fig. 21) and (Fig. 22).
OPERATION
The vehicle speed sensor on 3 speed automatic and
manual transaxle vehicles is a Hall-effect sensor.
This sensor is mechanically driven by a pinion gear
that is in mesh with the right axle drive shaft. The
hall-effect sensor switches a 5 volt signal sent from
the PCM from a ground to an open circuit.
Fig. 20 Throttle Position Sensor and Idle Air Control
Motor
Fig. 21 Vehicle Speed SensorÐAutomatic
Transmission
1 ± TRANSAXLE EXTENSION HOUSING
2 ± VEHICLE SPEED SENSOR
Fig. 22 Vehicle Speed SensorÐManual
Transmission
1 ± TRANSAXLE
2 ± SPEED SENSOR
3 ± SPEED SENSOR RETAINING BOLT
PLFUEL SYSTEM 14 - 37
DESCRIPTION AND OPERATION (Continued)

Like all Hall-effect sensors, the electronics of the
sensor needs a power source. This power source is
provided by the PCM. It is the same 8 volt power
supply that is used by the CKP and CMP sensors.
The vehicle speed sensor generates 8 pulses per
sensor revolution. This signal, in conjunction with a
closed throttle signal from the throttle position sen-
sor, indicates a closed throttle deceleration to the
PCM. Under deceleration conditions, the PCM
adjusts the Idle Air Control (IAC) motor to maintain
a desired MAP value.
When the vehicle is stopped at idle, a closed throt-
tle signal is received by the PCM (but a speed sensor
signal is not received). Under idle conditions, the
PCM adjusts the IAC motor to maintain a desired
engine speed.
AIR CONDITIONING CLUTCH RELAYÐPCM
OUTPUT
DESCRIPTION
The air conditioning clutch relay is located in the
PDC. The inside top of the PDC cover has a label
showing relay and fuse location.
OPERATION
The PCM controls the air conditioning clutch relay
ground circuit. The A/C clutch relay coil side contains
a 10 amp fuse between the buss bar in the Power
Distribution Center (PDC) and the relay. The power
side of this relay is fused with a 40 amp fuse. When
the PCM receives an air conditioning input, it
grounds the A/C compressor clutch relay and the
radiator fan relay.
When the PCM senses low idle speeds or wide open
throttle through the throttle position sensor, it
removes the ground for the A/C compressor clutch
relay. When the relay de-energizes, the contacts open
preventing air conditioning clutch engagement. Also,
if the PCM senses a part throttle launch condition, it
disables the A/C compressor clutch for several sec-
onds.
AUTOMATIC SHUTDOWN RELAYÐPCM
OUTPUT
DESCRIPTION
The ASD relay is located in the PDC. The inside
top of the PDC cover has a label showing relay and
fuse location.
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
generator field and PCM sense circuit.A buss bar in the power distribution center (PDC)
supplies voltage to the solenoid side and contact side
of the relay. The ASD relay power circuit contains a
fuse between the buss bar in the PDC and 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 infor-
mation.
The PCM controls the 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 unless the 02
Heater Monitor test is being run. When the ignition
switch is in the On or Crank position, the PCM mon-
itors the crankshaft position sensor and camshaft
position sensor signals to determine engine speed
and ignition timing (coil dwell). If the PCM does not
receive the crankshaft position sensor and camshaft
position sensor signals when the ignition switch is in
the Run position, it will de-energize the ASD relay.
CHARGING SYSTEM INDICATOR LAMPÐPCM
OUTPUT
OPERATION
The PCM turns the instrument panel Charging
System Lamp on. Refer to the Charging system sec-
tion information.
FUEL PUMP RELAYÐPCM OUTPUT
DESCRIPTION
The fuel pump relay is located in the PDC. The
inside top of the PDC cover has a label showing relay
and fuse location.
OPERATION
The fuel pump relay supplies battery voltage to the
fuel pump. A buss bar in the Power Distribution Cen-
ter (PDC) supplies voltage to the solenoid side and
contact side of the relay. The fuel pump relay power
circuit contains a fuse between the buss bar in the
PDC and the relay. The fuse also protects the power
circuit for the Automatic Shutdown (ASD) relay. The
fuse is located in the PDC. Refer to the Wiring Dia-
grams for circuit information.
The PCM controls the fuel pump relay by switch-
ing 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
ignition switch is in the On position, the PCM ener-
gizes the fuel pump. If the crankshaft position sensor
does not detect engine rotation, the PCM de-ener-
gizes the relay after approximately one second.
14 - 38 FUEL SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

PROPORTIONAL PURGE SOLENOIDÐPCM
OUTPUT
DESCRIPTION
OPERATION
All vehicles use a proportional purge solenoid. The
solenoid regulates the rate of vapor flow from the
EVAP canister to the throttle body. The PCM oper-
ates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged.
The proportional purge solenoid operates at a fre-
quency of 200 hz and is controlled by an engine con-
troller circuit that senses the current being applied
to the proportional purge solenoid (Fig. 23) and then
adjusts that current to achieve the desired purge
flow. The proportional purge solenoid controls the
purge rate of fuel vapors from the vapor canister and
fuel tank to the engine intake manifold.
GENERATOR FIELDÐPCM OUTPUT
OPERATION
Refer to the Battery section for information and
refer to the Charging section for information. The
PCM regulates the charging system voltage within a
range of 12.9 to 15.0 volts. The charging system is
turned ON and OFF with the Ignition Switch. When
the Ignition Switch is turned to the ON position, bat-
tery voltage is applied to the generator rotor through
one of the two field terminals to produce a magnetic
field. The amount of DC current produced by the
generator is controlled by the Electronic Voltage Reg-
ulator (EVR) in the PCM. This circuitry is connectedin series with the second rotor field terminal and
ground.
The voltage determined by the PCM as the final
goal for the charging system is called ªtarget charg-
ing voltage.º The PCM monitors battery voltage. If
the sensed voltage is 0.5 volts or lower than the tar-
get voltage, the PCM grounds the field winding until
sensed battery voltage is 0.5 volts above target volt-
age.
IDLE AIR CONTROL MOTORÐPCM OUTPUT
DESCRIPTION
The Idle Air Control (IAC) motor is mounted on the
throttle body. The PCM operates the idle air control
motor (Fig. 24).
OPERATION
The PCM adjusts engine idle speed through the
idle air control motor to compensate for engine load,
coolant temperature or barometric pressure changes.
The throttle body has an air bypass passage that
provides air for the engine during closed throttle idle.
The idle air control motor pintle protrudes into the
air bypass passage and regulates air flow through it.
The PCM adjusts engine idle speed by moving the
IAC motor pintle in and out of the bypass passage.
The adjustments are based on inputs the PCM
receives. The inputs are from the throttle position
sensor, crankshaft position sensor, coolant tempera-
ture sensor, MAP sensor, vehicle speed sensor and
various switch operations (brake, park/neutral, air
conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
²Deceleration air flow control
²A/C compressor load control (also opens the pas-
sage slightly before the compressor is engaged so
that the engine rpm does not dip down when the
compressor engages)
Target Idle
Target idle is determined by the following inputs:
²Gear position
²ECT Sensor
²Battery voltage
²Ambient/Battery Temperature Sensor
²VSS
²TPS
²MAP Sensor
Fig. 23 Proportional Purge Solenoid
PLFUEL SYSTEM 14 - 39
DESCRIPTION AND OPERATION (Continued)

DATA LINK CONNECTOR
DESCRIPTION
The data link connector is located inside the vehi-
cle, under the instrument panel, left of the steering
column (Fig. 25).
OPERATION
The data link connector (diagnostic connector)
links the DRB scan tool with the powertrain control
module (PCM). Refer to On-Board Diagnostics in the
General Diagnosis section of this group.
FUEL INJECTORSÐPCM OUTPUT
DESCRIPTION
OPERATION
The 2.0L engine uses electrically operated top feed
fuel injectors (Fig. 26). The Automatic Shutdown
(ASD) relay supplies battery voltage to the fuel injec-
tors. The PCM controls the ground path for each
injector in sequence. By switching the ground paths
on and off, the PCM fine-tunes injector pulse width.
Injector pulse width refers to the amount of time an
injector operates.
The PCM determines injector synchronization from
the camshaft position sensor and crankshaft position
sensor inputs. The PCM grounds the ASD and fuel
pump relays after receiving the camshaft position
sensor and crankshaft position sensor inputs.
The PCM energizes the injectors in a sequential
order during all engine operating conditions except
start-up. For the first injector pulse width during
start-up, all injectors are energized at the same time.
Once the PCM determines crankshaft position, it
begins energizing the injectors in sequence.
IGNITION COILÐPCM OUTPUT
DESCRIPTION
The coil assembly consists of 2 coils molded
together. The coil assembly is mounted over the valve
cover (Fig. 27).
OPERATION
High tension leads route to each cylinder from the
coil. The coil fires two spark plugs every power
Fig. 24 Idle Air Control MotorÐTypical
Fig. 25 Data Link Connector
1 ± DATA LINK CONNECTOR
Fig. 26 Fuel Injector
1 ± FUEL INJECTOR
2 ± NOZZLE
3 ± TOP (FUEL ENTRY)
14 - 40 FUEL SYSTEMPL
DESCRIPTION AND OPERATION (Continued)

STEERING COLUMN
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
STEERING COLUMN......................29
STEERING COLUMN LOWER COUPLING......29
DIAGNOSIS AND TESTING
STEERING COLUMN......................30
STEERING COLUMN LOWER COUPLING......30
REMOVAL AND INSTALLATION
SERVICE WARNINGS AND CAUTIONS........31STEERING COLUMN......................31
STEERING COLUMN LOWER COUPLING......38
SPECIFICATIONS
STEERING COLUMN FASTENER TORQUE
SPECIFICATIONS.......................41
DESCRIPTION AND OPERATION
STEERING COLUMN
This vehicle is equipped with both tilt and non-tilt
steering columns. Both steering columns have been
designed to be serviced only as complete assemblies
if an internal component is found to be defective (Fig.
1). The shaft, bearings and upper coupling are all
serviced with the column.
The replaceable components on the steering col-
umn assembly are:
²the key cylinder
²the ignition switch
²the multi-function switch
²the clockspring²the trim shrouds
²the steering wheel
²the driver airbag module
These components can be serviced without removal
of the steering column from the vehicle. Refer to the
appropriate group and section of this service manual
for servicing these components separately.
STEERING COLUMN LOWER COUPLING
This vehicle uses a corrugated design lower cou-
pling to connect the steering column to the steering
gear (Fig. 2).
This coupling has a hollow corrugated tube that
allows the coupling to bend rather than collapse
when a vehicle is involved in a collision.
Fig. 1 Steering Column
1 ± UPPER MOUNTING NUTS
2 ± STEERING COLUMN
3 ± LOWER MOUNTING NUTS
Fig. 2 Steering Column Lower Coupling
1 ± FLEX JOINT
2 ± SEAL COLLAR SEALING SURFACE
3 ± TO STEERING COLUMN
4 ± CORRUGATED TUBE SECTION
5 ± TO STEERING GEAR
PLSTEERING 19 - 29

(20) Lower the steering column away from the
instrument panel.
(21) Disconnect the wiring harness electrical con-
nector from the clockspring (Fig. 13).
(22) Disconnect the wiring harness electrical con-
nectors from the multi-function switch, windshield
wiper switch, and ignition switch (Fig. 14).(23) If the vehicle is equipped with a Sentry Key
Immobilizer Module (SKIM), disconnect its electrical
connector (Fig. 15).
(24) Remove the steering column from the vehicle.
(25) If the steering column is being replaced, per-
form the following:
(a) Remove the ignition key cylinder from the
steering column. To do this, insert the key and
turn the ignition key cylinder to the ON position.
Next, depress the retaining tab and remove the
Ignition key cylinder by pulling the key and cylin-
der straight out of the column together (Fig. 16).
Fig. 11 Interlock Cable
1 ± IGNITION SWITCH
2 ± CLIP
3 ± INTERLOCK CABLE
4 ± BTSI SOLENOID
Fig. 12 Steering Column Mounting Nuts
1 ± UPPER MOUNTING NUTS
2 ± STEERING COLUMN
3 ± LOWER MOUNTING NUTS
Fig. 13 Clockspring Electrical Connector
1 ± STEERING COLUMN
2 ± CLOCKSPRING
3 ± CLOCKSPRING ELECTRICAL CONNECTOR
4 ± IGNITION SWITCH ELECTRICAL CONNECTOR
Fig. 14 Electrical Connectors
1 ± MULTI-FUNCTION SWITCH ELECTRICAL CONNECTOR
2 ± WINDSHIELD WIPER SWITCH ELECTRICAL CONNECTOR
3 ± IGNITION SWITCH ELECTRICAL CONNECTOR
19 - 34 STEERINGPL
REMOVAL AND INSTALLATION (Continued)

(b) Disengage the latch hooks on the back of the
clockspring by lifting the clockspring slightly to
clear the column housing with the top latch hook.
Next, lower the clockspring slightly to do the same
for the lower latch hook (Fig. 17). Remove the
clockspring from the column.
(c) Remove the two screws securing the multi-
function/windshield wiper switch to the steering
column (Fig. 18). Pull the switch straight away
from the column to remove it.
(d) If the column is equipped with a SKIM,
remove the module from the column by removing
the two mounting screws and sliding the SKIM off
the non-halo trim ring (Fig. 19).
(e) Remove the non-halo trim ring from the col-
umn by unclipping it from the ignition cylinder
housing (Fig. 19).
(f) Remove the ignition switch from the steering
column by first removing the mounting screw (Fig.
20). Once the screw is removed, pull the switch
straight out away from the column ignition cylin-
der housing.
INSTALLATION
(1) If the steering column is being replaced, per-
form the following on the column before installing it
on the vehicle:
(a) Ensure the ignition switch is positioned in
the ON position.
(b) Install the ignition switch on the steering
column by pushing the tapered end onto the shaft
and steering column ignition cylinder housing.
Install the screw securing the switch to the column
(Fig. 20).(c) Install the non-halo trim ring on the column
until its tabs snap into place on the ignition cylin-
der housing (Fig. 19).
(d) If the column is equipped with a Sentry Key
Immobilizer Module (SKIM), install the module on
the column by sliding the module onto the non halo
trim ring and installing the two mounting screws
(Fig. 19). Tighten the mounting screws to a torque
of 3 N´m (25 in. lbs.).
(e) Position the multi-function/windshield wiper
switch in onto the top of the column and install the
two screws securing the switch in place (Fig. 18).
(f) Place the clockspring onto the end of the col-
umn engaging the clockspring latch hooks into the
column (Fig. 17).
Fig. 15 SKIM Electrical Connector
1 ± STEERING COLUMN
2 ± SKIM ELECTRICAL CONNECTOR
3 ± SKIM
Fig. 16 Ignition Key Cylinder Retaining Tab
1 ± IGNITION KEY
2 ± RETAINING TAB
3 ± STEERING COLUMN
Fig. 17 Clockspring Latch Hooks
1 ± CLOCKSPRING
2 ± LATCH HOOKS
3 ± STEERING COLUMN
PLSTEERING 19 - 35
REMOVAL AND INSTALLATION (Continued)