2000 DODGE NEON pressure

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)

SPECIFICATIONS
VECI LABEL
Always use the information found on the Vehicle
Emission Control Information (VECI) label. The
VECI label is located in the engine compartment.
TORQUE
DESCRIPTION TORQUE
Air Cleaner Lid Screws...... 3.9N´m(35in.lbs.)
Crankshaft Position Sensor Mounting Bolts . . 8 N´m
(70 in. lbs.)
Engine Coolant Temperature Sensor...... 18N´m
(165 in. lbs.)
IAC Motor-To-Throttle Body Bolts....... 4.5N´m
(40 in. lbs.)
MAP Sensor............... 4.5N´m(40in.lbs.)
Oxygen Sensor............. 28N´m(20ft.lbs.)
Powertrain Control Module (PCM) Mounting
Screws.................. 4N´m(35in.lbs.)
Throttle Body Mounting Bolts........... 23N´m
(200 in. lbs.)
Throttle Position Sensor Mounting Screws . . 2 N´m
(20 in. lbs.)
Vehicle Speed Sensor Mounting Bolt..... 2.2N´m
(20 in. lbs.)
SPECIAL TOOLS
FUEL
Extractor C±4334
Pressure Gauge Assembly C±4799±B
Fuel Pressure Test Adapter 6539
Spanner Wrench 6856
Metering Orifice
Fuel Line Adapter 1/4
O2S (Oxygen Sensor) Remover/InstallerÐC-4907
PLFUEL SYSTEM 14 - 49

STEERING
TABLE OF CONTENTS
page page
POWER STEERING......................... 1
POWER STEERING PUMP.................. 16STEERING GEAR.......................... 21
STEERING COLUMN....................... 29
POWER STEERING
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
POWER STEERING SYSTEM................1
POWER STEERING FLUID HOSES............2
POWER STEERING FLUID COOLER...........2
POWER STEERING FLUID PRESSURE
SWITCH...............................3
DIAGNOSIS AND TESTING
STEERING SYSTEM DIAGNOSIS CHARTS......4
POWER STEERING SYSTEM FLOW AND
PRESSURE TEST........................9
SERVICE PROCEDURES
POWER STEERING SYSTEM FLUID LEVEL
CHECK...............................11REMOVAL AND INSTALLATION
SERVICE WARNINGS AND CAUTIONS........11
POWER STEERING FLUID PRESSURE HOSE . . . 11
POWER STEERING FLUID RETURN HOSE.....12
POWER STEERING FLUID COOLER..........13
POWER STEERING FLUID PRESSURE
SWITCH..............................14
SPECIFICATIONS
POWER STEERING FASTENER TORQUE
SPECIFICATIONS.......................15
SPECIAL TOOLS
POWER STEERING.......................15
DESCRIPTION AND OPERATION
POWER STEERING SYSTEM
Turning of the steering wheel is converted into lin-
ear travel through the meshing of the helical pinion
teeth with the rack teeth within the steering gear.
Power assist steering is provided by an open-cen-
ter, rotary-type control valve. It is used to direct
power steering fluid from the power steering pump to
either side of the integral steering rack piston. Road
feel is controlled by the diameter of a torsion bar
which initially steers the vehicle. As steering effort
increases as in a turn, the torsion bar twists, causing
relative rotary motion between the rotary valve body
and valve spool. This movement directs fluid behind
the integral rack piston, which in turn builds up
hydraulic pressure and assists in the turning effort.
This vehicle comes with power steering as stan-
dard equipment and it is the only steering systemavailable. The power steering system consists of
these major components:
²POWER STEERING PUMP
²POWER STEERING GEAR
²POWER STEERING FLUID RESERVOIR
(mounted on the pump)
²POWER STEERING FLUID PRESSURE HOSE
²POWER STEERING FLUID RETURN HOSE
²POWER STEERING FLUID COOLER (on some
models)
For information on the first two components, refer
to their respective sections within this service man-
ual group. Information on the third component can
be found in POWER STEERING PUMP. Information
on all other components can be found in this section
of this service manual group.
PLSTEERING 19 - 1

POWER STEERING FLUID HOSES
The power steering fluid hoses connect the compo-
nents of the power steering system. They transfer
fluid from one component to the next.
The power steering fluid pressure hose is a high
pressure hose that connects the power steering pump
to the gear. At both ends of the flexible hose portion
are steel fittings that are pressure crimped to the
flexible hose. A standard tube nut fitting with an
O-ring is used at each end to connect it to either the
power steering pump or the gear.
The power steering fluid return hose is a special
rubber hose that connects the power steering gear or
the power steering fluid cooler on some models, back
to the fluid reservoir mounted on the power steering
pump. The power steering gear has a steel fitting
attached to its outlet port that the return hose is
pushed onto. On vehicles equipped with a power
steering fluid cooler, the return hose attaches to the
cooler outlet tube instead of the steering gear steel
fitting. The hose is secured to either component using
a standard adjustable clamp. The other end of the
power steering fluid return hose attaches to the
power steering fluid reservoir on the power steering
pump using a standard adjustable clamp.
POWER STEERING FLUID COOLER
Some models of this vehicle are equipped with a
cooler for the power steering system fluid (Fig. 1).
The purpose of the cooler is to keep the temperature
of the power steering system fluid from rising to a
level that would affect the performance of the power
steering system.
The power steering fluid cooler is located at the
front of the front suspension crossmember. It is
mounted to the crossmember top surface using 2 fas-
teners.The cooler is placed in series with the power steer-
ing fluid return hose, between the steering gear fluid
outlet port and the fluid return hose leading to the
power steering fluid reservoir. The power steering
gear has a steel fitting attached to its outlet port
that a short hose leading to the cooler is pushed onto.
This hose is secured to both the steering gear outlet
fitting and the cooler using standard adjustable
clamps. The cooler is secured to the power steering
fluid return hose using a standard adjustable clamp.
The cooler used on this vehicle is referred to as a
fluid-to-air type cooler. This means that the air flow
across the tubes of the cooler is used to extract the
heat from the cooler which it has absorbed from the
power steering fluid flowing through it. Utilizing a
small air dam mounted to its base to redirect air
across its coils, the cooler lowers the temperature of
the power steering fluid prior to it entering the
power steering fluid reservoir where it is resupplied
to the power steering pump.
Fig. 1 Power Steering Fluid Cooler
1 ± POWER STEERING FLUID COOLER
2 ± TRANSAXLE
3 ± CLAMP
4 ± AIR DAM
5 ± CROSSMEMBER
19 - 2 STEERINGPL
DESCRIPTION AND OPERATION (Continued)

POWER STEERING FLUID PRESSURE SWITCH
A power steering pressure switch is used to
improve the vehicle's idle quality. The pressure
switch improves vehicle idle quality by causing a
readjustment of the engine idle speed as necessary
when increased fluid pressure is sensed in the power
steering system.
The pressure switch functions by signaling the
powertrain control module that an increase in pres-
sure of the power steering system is putting addi-
tional load on the engine. This type of condition
exists when the front tires of the vehicle are turned
while the vehicle is stationary and the engine is at
idle speed. When the powertrain control module
receives the signal from the power steering pressure
switch, it directs the engine to increase its idle speed.
This increase in engine idle speed compensates for
the additional load, thus maintaining the required
engine idle speed and idle quality.The power steering pressure switch is mounted
directly to the power steering gear (Fig. 2).
Fig. 2 Switch Location
1 ± WIRING HARNESS CONNECTOR
2 ± POWER STEERING GEAR
3 ± POWER STEERING FLUID PRESSURE SWITCH
4 ± REAR OF FRONT SUSPENSION CROSSMEMBER
PLSTEERING 19 - 3
DESCRIPTION AND OPERATION (Continued)

DIAGNOSIS AND TESTING
STEERING SYSTEM DIAGNOSIS CHARTS
POWER STEERING NOISE
CONDITION POSSIBLE CAUSES CORRECTION
OBJECTIONABLE HISS OR
WHISTLE*1. Damaged or mispositioned
steering column shaft/coupling dash
panel seal.1. Reposition or replace steering
column shaft/coupling dash panel
seal.
2. Noisy valve in power steering
gear.2. Replace power steering gear.
RATTLE OR CLUNK 1. Power steering gear loose on
front suspension crossmember.1. Inspect power steering gear
mounting bolts. Replace as
necessary. Tighten to the specified
torque.
2. Front suspension crossmember
mounting fasteners loose at frame.2. Tighten the front suspension
crossmember mounting fasteners to
the specified torque.
3. Loose tie rod (outer or inner). 3. Check tie rod pivot points for
wear. Replace worn/loose parts as
required.
4. Loose lower control arm mounting
bolts at front suspension
crossmember.4. Tighten control arm mounting
bolts to the specified torques.
5. Loose strut assembly mounting
fasteners at strut tower.5. Tighten strut assembly fasteners
to the specified torques.
6. Power steering fluid pressure
hose touching the body of the
vehicle.6. Adjust hose to proper position by
loosening, repositioning, and
tightening fitting to specified torque.
Do not bend tubing.
7. Internal power steering gear
noise.7. Replace power steering gear.
8. Damaged front suspension
crossmember.8. Replace front suspension
crossmember.
CHIRP OR SQUEAL (POWER
STEERING PUMP)1. Loose power steering pump drive
belt.1. Check and replace automatic belt
tensioner as necessary. Replace belt
if worn or glazed.
19 - 4 STEERINGPL

CONDITION POSSIBLE CAUSES CORRECTION
WHINE OR GROWL (POWER
STEERING PUMP)**1. Low fluid level. 1. Fill power steering fluid reservoir
to proper level and check for leaks.
2. Power steering hose touching
vehicle body or frame.2. Adjust hose to proper position by
loosening, repositioning, and
tightening fitting to specified torque.
Do not bend tubing. Replace hose if
damaged.
3. Extreme wear of power steering
pump internal components.3. Replace power steering pump and
flush system as necessary.
SUCKING AIR SOUND 1. Loose clamp on power steering
fluid return hose.1. Tighten or replace hose clamp.
2. Missing O-Ring on power steering
hose connection.2. Inspect connection and replace
O-Ring as required.
3. Low power steering fluid level. 3. Fill power steering fluid reservoir
to proper level and check for leaks.
4. Air leak between power steering
fluid reservoir and power steering
pump.4. Replace power steering pump
(with reservoir).
SQUEAK OR RUBBING SOUND 1. Steering column shroud rubbing. 1. Realign shrouds as necessary.
2. Steering column shaft rubbing. 2. Move or realign item rubbing
shaft.
3. Steering column shaft dry-rubbing
seal at dash panel.3. Lubricate contact surface.
4. Steering gear internally noisy. 4. Replace steering gear.
SCRUBBING OR KNOCKING
NOISE.1. Incorrect tire or wheel size. 1. Replace incorrect size tire or
wheel with size used as original
equipment.
2. Interference between steering
gear and other vehicle components.2. Check for bent or misaligned
components and correct as
necessary.
3. Steering gear internal stops worn
excessively.3. Replace steering gear.
NOTE: * There is some noise in all power steering
systems. One of the most common is a hissing
sound evident when turning the steering wheel
when at a standstill or when parking and the steer-
ing wheel is at the end of its travel. Hiss is a very
high frequency noise similar to that experienced
while slowly closing a water tap. The noise is
present in every valve and results when high veloc-
ity fluid passes valve orifice edges. There is no
relationship between this noise and the perfor-
mance of the steering system.NOTE: ** Power steering pump growl results from
the development of high pressure fluid flow. Nor-
mally this noise level should not be high enough to
be objectionable.
PLSTEERING 19 - 5
DIAGNOSIS AND TESTING (Continued)

STEERING WHEEL FEEL
CONDITION POSSIBLE CAUSES CORRECTION
STEERING WHEEL/
COLUMN CLICKING,
CLUNKING OR RATTLING.1. Steering column preload is not set
properly.1. Loosen steering column coupling pinch
bolt to reset steering column preload.
Replace pinch bolt and torque to
specifications.
2. Loose steering coupling pinch
bolt.2. Replace pinch bolt and torque to
specifications.
3. Steering column bearings. 3. Replace steering column.
STEERING WHEEL HAS
FORE AND AFT
LOOSENESS.1. Steering wheel retaining nut not
properly tightened and torqued.1. Tighten the steering wheel retaining nut
to its specified torque.
2. Steering column preload is not set
properly.2. Loosen steering column coupling pinch
bolt to reset steering column preload.
Replace pinch bolt and torque to
specifications.
3. Steering column lower bearing
spring retainer slipped on steering
column shaft.3. Replace steering column.
STEERING WHEEL OR
DASH VIBRATES DURING
LOW SPEED OR
STANDSTILL STEERING
MANEUVERS.1. Air in the fluid of the power
steering system.1. Bleed air from system following the
power steering pump initial operation
service procedure.*
2. Tires not properly inflated. 2. Inflate tires to the specified pressure.
3. Excessive engine vibration. 3. Ensure that the engine is running
properly.
4. Loose tie rod end jam nut. 4. Tighten the inner to outer tie rod jam nut
to the specified torque.
5. Overcharged air conditioning
system.5. Check air conditioning pump head
pressure and correct as necessary.
STEERING CATCHES,
STICKS IN CERTAIN
POSITIONS OR IS
DIFFICULT TO TURN.1. Low power steering fluid level. 1. Fill power steering fluid reservoir to
specified level and check for leaks.
2. Tires not inflated to specified
pressure.2. Inflate tires to the specified pressure.
3. Lack of lubrication in front
suspension control arm ball joints.3. Lubricate ball joints if ball joints are not a
lubricated for life type ball joint. If ball joint
is a lubricated for life ball joint, replace ball
joint or control arm.
4. Lack of lubrication in steering gear
outer tie rod ends.4. Lubricate tie rod ends if they are not a
lubricated for life type. If tie rod end is a
lubricated for life type, replace tie rod end.
5. Loose power steering pump drive
belt.5. Check and replace automatic belt
tensioner as necessary. If drive belt is worn
or glazed, replace belt.
19 - 6 STEERINGPL
DIAGNOSIS AND TESTING (Continued)