2000 DODGE NEON engine

CLEANING AND INSPECTION
VALVE BODY
Allow all parts to soak a few minutes in a suitable
clean solvent. Wash thoroughly and blow dry with
compressed air. Be sure all passages are clean and
free from obstructions.
Inspect manual and throttle valve operating levers
and shafts for being bent, worn or loose. If a lever is
loose on its shaft, it should be replaced. Do not
attempt to straighten bent levers.
Inspect all mating surfaces for burrs, nicks and
scratches. Minor blemishes may be removed with cro-
cus cloth, using only a very light pressure. Using a
straightedge, inspect all mating surfaces for warpage
or distortion. Slight distortion may be corrected,
using a surface plate. Be sure all metering holes in
steel plate are open. Using a penlight, inspect bores
in valve body for scores, scratches, pits, and irregu-
larities.
Inspect all valve springs for distortion and col-
lapsed coils. Inspect all valves and plugs for burrs,
nicks, and scores. Small nicks and scores may be
removed with crocus cloth, providing extreme care is
taken not to round off sharp edges. The sharpness of
these edges is vitally important. It prevents foreign
matter from lodging between valve and valve body.
This reduces the possibility of sticking. Inspect all
valves and plugs for freedom of operation in valve
body bores.
When bores, valves, and plugs are clean and dry,
the valves and plugs should fall freely in the bores.
The valve body bores do not change their dimensions
with use. Therefore, a valve body that was function-
ing properly when vehicle was new, will operate cor-
rectly if it is properly and thoroughly cleaned. There
is no need to replace a valve body unless it is dam-
aged in handling.
ADJUSTMENTS
GEARSHIFT CABLE
Normal operation of the Park/Neutral Position
Switch provides a quick check to confirm proper link-
age adjustment. The engine starter should only oper-
ate when the transaxle shift lever is in the PARK (P)
or NEUTRAL (N) positions.
If the engine starts in any other gear position, or
the vehicle rolls when the shifter is in gated PARK
(P), a gearshift cable adjustment is necessary.
ADJUSTMENT
(1) Loosen set screw and remove knob from shifter
handle (Fig. 214).(2) Remove the center console assembly as shown
in (Fig. 215).
(3)Adjust gearshift cable as follows:
(a) Place gearshift lever in the PARK (P) posi-
tion.
(b) Loosen shift cable adjustment screw (Fig.
216).
(c) Move transaxle manual lever to the PARK.
Verify transaxle is in PARK by attempting to roll
vehicle in either direction.
Fig. 214 Gearshift Knob Removal/Installation
1 ± SHIFTER KNOB
2 ± SET SCREW
Fig. 215 Center Console Removal/Installation
1 ± CONSOLE
2 ± SCREW (4)
3 ± SCREW (2)
PLTRANSAXLE 21 - 135

(d) Tighten shift cable adjustment screw to 8
N´m (70 in. lbs.) torque.
(4) Verify proper cable adjustment. Engine should
start with the shifter lever in PARK (P) and NEU-
TRAL (N) positions ONLY.
(5) Install center console assembly (Fig. 215).
(6) Install gearshift knob and tighten set screw to
2 N´m (15 in. lbs.) torque (Fig. 214).
THROTTLE VALVE CABLE ADJUSTMENT
PROCEDURE
The transmission throttle valve is operated by a
cam on the valve body throttle lever. The throttle
lever is actuated by a cable connected to the engine
throttle body lever.
The throttle valve is located within the transaxle
valve body and is responsible for transaxle shift
speed, shift quality, and part-throttle downshift sen-
sitivity. Proper cable adjustment is essential for
proper transaxle operation.
NOTE: The air cleaner/throttle body assembly must
be installed into position before making this adjust-
ment.
(1) Verify cable is routed properly with no kinked
or binding conditions.(2) Release adjustment locking clip on cable at
throttle body.It is not necessary to remove clip.
(3) Grab cable conduit near adjustment body, push
in towards throttle body, then release grip (Fig. 217).
This allows cable to self adjust.
(4) Press locking clip to secure cable position (Fig.
218).
(5) Road test vehicle to verify proper transaxle
operation.
Fig. 216 Gearshift Cable Adjustment Screw
1 ± GEARSHIFT CABLE ADJUSTMENT SCREW
Fig. 217 Throttle Valve Cable Adjustment
1 ± TAB UNLOCKED
Fig. 218 Cable Locking Clip
1 ± TAB LOCKED
2 ± THROTTLE VALVE CABLE
21 - 136 TRANSAXLEPL
ADJUSTMENTS (Continued)

TIRES AND WHEELS
TABLE OF CONTENTS
page page
TIRES................................... 1WHEELS................................ 10
TIRES
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
TIRE...................................1
RADIAL-PLY TIRES........................2
SPARE TIRE±TEMPORARY..................3
REPLACEMENT TIRES.....................3
DIAGNOSIS AND TESTING
TREAD WEAR INDICATORS.................3
TIRE WEAR PATTERNS.....................4
TIRE NOISE OR VIBRATION.................4
VEHICLE LEAD DIAGNOSIS AND
CORRECTION..........................4
SERVICE PROCEDURES
PRESSURE GAUGES......................6TIRE INFLATION PRESSURES...............6
TIRE PRESSURE FOR HIGH SPEED
OPERATION............................6
TIRE AND WHEEL ROTATION................6
REPAIRING TIRE LEAKS....................7
TIRE AND WHEEL MATCH MOUNTING.........7
CLEANING AND INSPECTION
CLEANING TIRES.........................9
SPECIFICATIONS
TIRE SPECIFICATIONS.....................9
DESCRIPTION AND OPERATION
TIRE
Tires are designed and engineered for each specific
vehicle (Fig. 1). They provide the best overall perfor-
mance for normal operation. The ride and handling
characteristics match the vehicle's requirements.
With proper care they will give excellent reliability,
traction, skid resistance, and tread life.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain, in most
cases, much greater mileage than severe use or care-
less drivers. A few of the driving habits which will
shorten the life of any tire are:²Rapid acceleration
²Severe application of brakes
²High-speed driving
²Taking turns at excessive speeds
²Striking curbs and other obstacles
²Operating vehicle with over or under inflated
tire pressures
Radial ply tires are more prone to irregular tread
wear. It is important to follow the tire rotation inter-
val shown in the section on Tire Rotation. This will
help to achieve a greater tread-life potential.
PLTIRES AND WHEELS 22 - 1

TIRE WEAR PATTERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.
Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 4).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 4).
TIRE NOISE OR VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.To find out if tires are causing the noise or vibra-
tion, drive the vehicle over a smooth road at varying
speeds. Note the noise level during acceleration and
deceleration. The engine, differential and exhaust
noises will change as speed varies, while the tire
noise will usually remain constant.
VEHICLE LEAD DIAGNOSIS AND CORRECTION
Use the following chart to diagnose a vehicle that
has a complaint of a drift or lead condition. The use
of this chart will help to determine if the lead condi-
tion is the result of a bad tire or is caused by the
wheel alignment.
Fig. 4 Tire Wear Patterns
22 - 4 TIRES AND WHEELSPL
DIAGNOSIS AND TESTING (Continued)

EMISSION CONTROL SYSTEMS
TABLE OF CONTENTS
page page
ON-BOARD DIAGNOSTICS................... 1 EVAPORATIVE EMISSION CONTROLS......... 25
ON-BOARD DIAGNOSTICS
TABLE OF CONTENTS
page page
DESCRIPTION AND OPERATION
SYSTEM DESCRIPTION....................1
TASK MANAGER..........................2
MALFUNCTION INDICATOR LAMP (MIL)........5
DRB III STATE DISPLAY TEST MODE..........5
DRB III CIRCUIT ACTUATION TEST MODE......5
DIAGNOSTIC TROUBLE CODES..............5
DIAGNOSTIC TROUBLE CODE
DESCRIPTIONS.........................6MONITORED SYSTEMS....................15
TRIP DEFINITION........................19
MONITORED COMPONENT.................19
NON-MONITORED CIRCUITS...............23
HIGH AND LOW LIMITS....................24
LOAD VALUE............................24
DESCRIPTION AND OPERATION
SYSTEM DESCRIPTION
DESCRIPTION
OBD II requires that vehicles falling under OBD II
guidelines utilize the following system monitors:
²Comprehensive Component Monitor (inputs/out-
puts for powertrain management that affect emis-
sions, but do not have a specific major monitor)
²Fuel Control Monitor (fuel compensation
required to maintain stoichiometric ratio rich/lean)
²Misfire Monitor (change in crankshaft speed)
²Oxygen Sensor Heater Monitor (response and
performance of oxygen sensors)
²Catalyst Monitor (Performance and efficiency of
catalyst)
²Evaporative Emissions Monitor (performance of
and leaks from EVAP system)
²Exhaust Gas Recirculation Monitor (flow perfor-
mance of EGR system)
The software was rewritten to enable the PCM to
carry out the responsibilities to meet these required
guidelines. The PCM now contains a Task Manager.
OPERATION
The Powertrain Control Module (PCM) monitors
many different circuits in the fuel injection, ignition,
emission and engine systems. If the PCM senses a
problem with a monitored circuit often enough to
indicate an actual problem, it stores a Diagnostic
Trouble Code (DTC) in the PCM's memory. If the
code applies to a non-emissions related component or
system, and the problem is repaired or ceases to
exist, the PCM cancels the code after 40 warmup
cycles. Diagnostic trouble codes that affect vehicle
emissions illuminate the Malfunction Indicator Lamp
(MIL). Refer to Malfunction Indicator Lamp in this
section.
Certain criteria must be met before the PCM
stores a DTC in memory. The criteria may be a spe-
cific range of engine RPM, engine temperature,
and/or input voltage to the PCM.
The PCM might not store a DTC for a monitored
circuit even though a malfunction has occurred. This
may happen because one of the DTC criteria for the
circuit has not been met.For example, assume the
diagnostic trouble code criteria requires the PCM to
monitor the circuit only when the engine operates
between 750 and 2000 RPM. Suppose the sensor's
output circuit shorts to ground when engine operates
above 2400 RPM (resulting in 0 volt input to the
PLEMISSION CONTROL SYSTEMS 25 - 1

PCM). Because the condition happens at an engine
speed above the maximum threshold (2000 rpm), the
PCM will not store a DTC.
There are several operating conditions for which
the PCM monitors and sets DTC's. Refer to Moni-
tored Systems, Components, and Non-Monitored Cir-
cuits in this section.
NOTE: Various diagnostic procedures may actually
cause a diagnostic monitor to set a DTC. For
instance, pulling a spark plug wire to perform a
spark test may set the misfire code. When a repair
is completed and verified, use the DRB III scan tool
to erase all DTC's and extinguish the MIL.
Technicians can display stored DTC's by using the
DRB III scan tool. Refer to Diagnostic Trouble Codes
in this section. For DTC information, refer to charts
in this section.
TASK MANAGER
DESCRIPTION
The PCM is responsible for efficiently coordinating
the operation of all the emissions-related compo-
nents. The PCM is also responsible for determining if
the diagnostic systems are operating properly. The
software designed to carry out these responsibilities
is call the 'Task Manager'.
OPERATION
The Task Manager determines which tests happen
when and which functions occur when. Many of the
diagnostic steps required by OBD II must be per-
formed under specific operating conditions. The Task
Manager software organizes and prioritizes the diag-
nostic procedures. The job of the Task Manager is to
determine if conditions are appropriate for tests to berun, monitor the parameters for a trip for each test,
and record the results of the test. Following are the
responsibilities of the Task Manager software:
²Test Sequence
²MIL Illumination
²Diagnostic Trouble Codes (DTCs)
²Trip Indicator
²Freeze Frame Data Storage
²Similar Conditions Window
Test Sequence
In many instances, emissions systems must fail
diagnostic tests more than once before the PCM illu-
minates the MIL. These tests are know as 'two trip
monitors.' Other tests that turn the MIL lamp on
after a single failure are known as 'one trip moni-
tors.' A trip is defined as 'start the vehicle and oper-
ate it to meet the criteria necessary to run the given
monitor.'
Many of the diagnostic tests must be performed
under certain operating conditions. However, there
are times when tests cannot be run because another
test is in progress (conflict), another test has failed
(pending) or the Task Manager has set a fault that
may cause a failure of the test (suspend).
²Pending
Under some situations the Task Manager will not
run a monitor if the MIL is illuminated and a fault is
stored from another monitor. In these situations, the
Task Manager postpones monitorspendingresolu-
tion of the original fault. The Task Manager does not
run the test until the problem is remedied.
For example, when the MIL is illuminated for an
Oxygen Sensor fault, the Task Manager does not run
the Catalyst Monitor until the Oxygen Sensor fault is
remedied. Since the Catalyst Monitor is based on sig-
nals from the Oxygen Sensor, running the test would
produce inaccurate results.
²Conflict
There are situations when the Task Manager does
not run a test if another monitor is in progress. In
these situations, the effects of another monitor run-
ning could result in an erroneous failure. If thiscon-
flictis present, the monitor is not run until the
conflicting condition passes. Most likely the monitor
will run later after the conflicting monitor has
passed.
For example, if the Fuel System Monitor is in
progress, the Task Manager does not run the EGR
Monitor. Since both tests monitor changes in air/fuel
ratio and adaptive fuel compensation, the monitors
will conflict with each other.
²Suspend
Occasionally the Task Manager may not allow a two
trip fault to mature. The Task Manager willsus-
pendthe maturing of a fault if a condition exists
Fig. 1 Data Link (Diagnostic) Connector
1 ± DIAGNOSTIC CONNECTOR
25 - 2 EMISSION CONTROL SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

that may induce an erroneous failure. This prevents
illuminating the MIL for the wrong fault and allows
more precis diagnosis.
For example, if the PCM is storing a one trip fault
for the Oxygen Sensor and the EGR monitor, the
Task Manager may still run the EGR Monitor but
will suspend the results until the Oxygen Sensor
Monitor either passes or fails. At that point the Task
Manager can determine if the EGR system is actu-
ally failing or if an Oxygen Sensor is failing.
MIL Illumination
The PCM Task Manager carries out the illumina-
tion of the MIL. The Task Manager triggers MIL illu-
mination upon test failure, depending on monitor
failure criteria.
The Task Manager Screen shows both a Requested
MIL state and an Actual MIL state. When the MIL is
illuminated upon completion of a test for a third trip,
the Requested MIL state changes to OFF. However,
the MIL remains illuminated until the next key
cycle. (On some vehicles, the MIL will actually turn
OFF during the third key cycle) During the key cycle
for the third good trip, the Requested MIL state is
OFF, while the Actual MILL state is ON. After the
next key cycle, the MIL is not illuminated and both
MIL states read OFF.
Diagnostic Trouble Codes (DTCs)
With OBD II, different DTC faults have different
priorities according to regulations. As a result, the
priorities determine MIL illumination and DTC era-
sure. DTCs are entered according to individual prior-
ity. DTCs with a higher priority overwrite lower
priority DTCs.
Priorities
²Priority 0 ÐNon-emissions related trouble codes
²Priority 1 Ð One trip failure of a two trip fault
for non-fuel system and non-misfire.
²Priority 2 Ð One trip failure of a two trip fault
for fuel system (rich/lean) or misfire.
²Priority3ÐTwotrip failure for a non-fuel sys-
tem and non-misfire or matured one trip comprehen-
sive component fault.
²Priority4ÐTwotrip failure or matured fault
for fuel system (rich/lean) and misfire or one trip cat-
alyst damaging misfire.
Non-emissions related failures have no priority.
One trip failures of two trip faults have low priority.
Two trip failures or matured faults have higher pri-
ority. One and two trip failures of fuel system and
misfire monitor take precedence over non-fuel system
and non-misfire failures.DTC Self Erasure
With one trip components or systems, the MIL is
illuminated upon test failure and DTCs are stored.
Two trip monitors are components requiring failure
in two consecutive trips for MIL illumination. Upon
failure of the first test, the Task Manager enters a
maturing code. If the component fails the test for a
second time the code matures and a DTC is set.
After three good trips the MIL is extinguished and
the Task Manager automatically switches the trip
counter to a warm-up cycle counter. DTCs are auto-
matically erased following 40 warm-up cycles if the
component does not fail again.
For misfire and fuel system monitors, the compo-
nent must pass the test under a Similar Conditions
Window in order to record a good trip. A Similar Con-
ditions Window is when engine RPM is within6375
RPM and load is within610% of when the fault
occurred.
NOTE: It is important to understand that a compo-
nent does not have to fail under a similar window of
operation to mature. It must pass the test under a
Similar Conditions Window when it failed to record
a Good Trip for DTC erasure for misfire and fuel
system monitors.
DTCs can be erased anytime with a DRB III. Eras-
ing the DTC with the DRB III erases all OBD II
information. The DRB III automatically displays a
warning that erasing the DTC will also erase all
OBD II monitor data. This includes all counter infor-
mation for warm-up cycles, trips and Freeze Frame.
Trip Indicator
TheTripis essential for running monitors and
extinguishing the MIL. In OBD II terms, a trip is a
set of vehicle operating conditions that must be met
for a specific monitor to run. All trips begin with a
key cycle.
Good Trip
The Good Trip counters are as follows:
²Global Good Trip
²Fuel System Good Trip
²Misfire Good Trip
²Alternate Good Trip (appears as a Global Good
Trip on DRB III)
²Comprehensive Components
²Major Monitor
²Warm-Up Cycles
Global Good Trip
To increment a Global Good Trip, the Oxygen sen-
sor and Catalyst efficiency monitors must have run
and passed.
Fuel System Good Trip
To count a good trip (three required) and turn off
the MIL, the following conditions must occur:
PLEMISSION CONTROL SYSTEMS 25 - 3
DESCRIPTION AND OPERATION (Continued)

²Engine in closed loop
²Operating in Similar Conditions Window
²Short Term multiplied by Long Term less than
threshold
²Less than threshold for a predetermined time
If all of the previous criteria are met, the PCM will
count a good trip (three required) and turn off the
MIL.
Misfire Good Trip
If the following conditions are met the PCM will
count one good trip (three required) in order to turn
off the MIL:
²Operating in Similar Condition Window
²1000 engine revolutions with no misfire
Alternate Good Trip
Alternate Good Trips are used in place of Global
Good Trips for Comprehensive Components and
Major Monitors. If the Task Manager cannot run a
Global Good Trip because a component fault is stop-
ping the monitor from running, it will attempt to
count an Alternate Good Trip.
The Task Manager counts an Alternate Good Trip
for Comprehensive components when the following
conditions are met:
²Two minutes of engine run time
²No other faults occur
The Task Manager counts an Alternate Good Trip
for a Major Monitor when the monitor runs and
passes. Only the Major Monitor that failed needs to
pass to count an Alternate Good Trip.
Warm-Up Cycles
Once the MIL has been extinguished by the Good
Trip Counter, the PCM automatically switches to a
Warm-Up Cycle Counter that can be viewed on the
DRB III. Warm-Up Cycles are used to erase DTCs
and Freeze Frames. Forty Warm-Up cycles must
occur in order for the PCM to self-erase a DTC and
Freeze Frame. A Warm-Up Cycle is defined as fol-
lows:
²Engine coolant temperature must start below
and rise above 160É F
²Engine coolant temperature must rise by 40É F
²No further faults occur
Freeze Frame Data Storage
Once a failure occurs, the Task Manager records
several engine operating conditions and stores it in a
Freeze Frame. The Freeze Frame is considered one
frame of information taken by an on-board data
recorder. When a fault occurs, the PCM stores the
input data from various sensors so that technicians
can determine under what vehicle operating condi-
tions the failure occurred.
The data stored in Freeze Frame is usually
recorded when a system fails the first time for twotrip faults. Freeze Frame data will only be overwrit-
ten by a different fault with a higher priority.
CAUTION: Erasing DTCs, either with the DRB III or
by disconnecting the battery, also clears all Freeze
Frame data.
Similar Conditions Window
The Similar Conditions Window displays informa-
tion about engine operation during a monitor. Abso-
lute MAP (engine load) and Engine RPM are stored
in this window when a failure occurs. There are two
different Similar conditions Windows: Fuel System
and Misfire.
FUEL SYSTEM
²Fuel System Similar Conditions WindowÐ
An indicator that 'Absolute MAP When Fuel Sys Fail'
and 'RPM When Fuel Sys Failed' are all in the same
range when the failure occurred. Indicated by switch-
ing from 'NO' to 'YES'.
²Absolute MAP When Fuel Sys FailÐ The
stored MAP reading at the time of failure. Informs
the user at what engine load the failure occurred.
²Absolute MAPÐ A live reading of engine load
to aid the user in accessing the Similar Conditions
Window.
²RPM When Fuel Sys FailÐ The stored RPM
reading at the time of failure. Informs the user at
what engine RPM the failure occurred.
²Engine RPMÐ A live reading of engine RPM
to aid the user in accessing the Similar Conditions
Window.
²Adaptive Memory FactorÐ The PCM uti-
lizes both Short Term Compensation and Long Term
Adaptive to calculate the Adaptive Memory Factor
for total fuel correction.
²Upstream O2S VoltsÐ A live reading of the
Oxygen Sensor to indicate its performance. For
example, stuck lean, stuck rich, etc.
²SCW Time in Window (Similar Conditions
Window Time in Window)Ð A timer used by the
PCM that indicates that, after all Similar Conditions
have been met, if there has been enough good engine
running time in the SCW without failure detected.
This timer is used to increment a Good Trip.
²Fuel System Good Trip CounterÐATrip
Counter used to turn OFF the MIL for Fuel System
DTCs. To increment a Fuel System Good Trip, the
engine must be in the Similar Conditions Window,
Adaptive Memory Factor must be less than cali-
brated threshold and the Adaptive Memory Factor
must stay below that threshold for a calibrated
amount of time.
²Test Done This TripÐ Indicates that the
monitor has already been run and completed during
the current trip.
25 - 4 EMISSION CONTROL SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)