1999 DODGE NEON Service Repair Manual

at about 20mVac (at about 700 rpm) and increases to
approximately 600 mVac (5000 rpm). If the output falls
outside of this range a DTC will be set.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
To perform a complete test of the MAP sensor and
its circuitry, refer to the DRB scan tool and appropri-
ate Powertrain Diagnostics Procedures manual. To
test the MAP sensor only, refer to the following:
CAUTION: When testing the MAP sensor, be sure
that the harness wires are not damaged by the test
meter probes.
(1) Test the MAP sensor output voltage at the
MAP sensor connector between terminals 1 and 4
(Fig. 82). With the ignition switch ON and the engine
not running, output voltage should be 4 to 5 volts.
The voltage should drop to 1.5 to 2.1 volts with a hot,
neutral idle speed condition. If OK, go to next step. If
not OK, go to step 3.
(2) Test PCM terminal 36 for the same voltage
described in the previous step to verify wire harness
condition. Repair as required.
(3) Test the MAP sensor ground circuit at sensor
connector terminal 1 and PCM terminal 43. If OK, go
to next step. If not OK, repair as required.
(4) Test MAP sensor supply voltage between sen-
sor connector terminals 3 and 1 with the key ON.
The voltage should be approximately 5 volts (6.5V).
Five volts (6.5V) should also be at terminal 61 of the
PCM. If OK, replace MAP sensor. If not OK, repair or
replace the wire harness as required.
THROTTLE POSITION SENSOR
To perform a complete test of the this sensor and
its circuitry, refer to the DRB scan tool and appropri-
ate Powertrain Diagnostics Procedures manual. To
test the throttle position sensor only, refer to the fol-
lowing:
The Throttle Position Sensor (TPS) can be tested
with a digital voltmeter (DVM). The center terminal
of the sensor is the output terminal. One of the other
terminals is a 5 volt supply and the remaining ter-
minal is ground.
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.
THROTTLE BODY MINIMUM AIR FLOW
(1) Turn ignition key to Off.
(2) Disconnect the PCV valve hose from the intake
manifold nipple (Fig. 83). Cap the PCV vacuum nip-
ple.
(3) Disconnect purge hose from the nipple on the
throttle body (Fig. 84).
(4) Use a piece of hose to attach Air Metering Ori-
fice 6457 (0.125 in. orifice) to the purge nipple on the
throttle body (Fig. 85).
(5) Ensure that all accessories are off.
Fig. 82 MAP Sensor Connector
Fig. 83 PCV Vacuum Nipple
14 - 48 FUEL SYSTEMPL
DIAGNOSIS AND TESTING (Continued)

(6) Connect the DRB scan tool to the data link
connector inside the passenger compartment.
(7) Run engine in Park or Neutral until the cooling
fan has cycled on and off at least once (180ÉF).
(8) Using the DRB scan tool, access Minimum Air-
flow Idle Speed.
(9) The following will then occur:
²Idle air control motor will fully close
²Idle spark advance will become fixed
²PCM will go open loop enriched
²DRB scan tool displays engine RPM
(10) If idle RPM is within the range shown in the
Idle Specification chart, throttle body minimum air-
flow is set correctly.
IDLE SPECIFICATION Ð2.0L ENGINEOdometer Reading Idle RPM
Below 1000 Miles.................550±1300 RPM
Above 1000 Miles.................600±1300 Miles
(11) If idle RPM is above specifications, use the
DRB scan tool to check idle air control motor opera-
tion. If idle air control motor is OK, replace throttle
body. If idle air flow is below specification, shut off
the engine and clean the throttle body as follows:
WARNING: CLEAN THROTTLE BODY IN A WELL
VENTILATED AREA. WEAR RUBBER OR BUTYL
GLOVES, DO NOT LET MOPAR PARTS CLEANER
COME IN CONTACT WITH EYES OR SKIN. AVOID
INGESTING THE CLEANER. WASH THOROUGHLY
AFTER USING CLEANER.
(a) Remove the throttle body from engine.
(b) While holding the throttle open, spray the
entire throttle body bore and the manifold side of
the throttle plate with Mopar Parts Cleaner.Only
use Mopar Parts Cleaner to clean the throttle
body.
(c) Using a soft scuff pad, clean the top and bot-
tom of throttle body bore and the edges and mani-
fold side of the throttle blade.The edges of the
throttle blade and portions of the throttle
bore that are closest to the throttle blade
when closed, must be free of deposits.
(d) Use compressed air to dry the throttle body.
(e) Inspect throttle body for foreign material.
(f) Install throttle body on manifold.
(g) Repeat steps 1 through 14. If the minimum
air flow is still not within specifications, the prob-
lem is not caused by the throttle body.
(12) Shut off engine.
(13) Remove Air Metering Orifice 6457. Install
purge hose.
(14) Remove cap from PCV valve. Connect hose to
PCV valve.
(15) Remove DRB scan tool.
VEHICLE SPEED SENSOR
To perform a complete test of the sensor and its
circuitry, refer to the DRB scan tool and appropriate
Powertrain Diagnostics Procedures Manual.
Fig. 84 Purge Hose
Fig. 85 Orifice 6457 Attached to Purge Nipple
PLFUEL SYSTEM 14 - 49
DIAGNOSIS AND TESTING (Continued)

REMOVAL AND INSTALLATION
THROTTLE BODYÐMANUAL TRANSMISSION
Remove throttle body cables using the following
procedures.
REMOVAL
(1) Remove throttle cable cover.
(2) Remove throttle cable from the throttle body
cam (Fig. 86) and (Fig. 87).
(3) Compress the retaining tabs on the cable and
slide cable out of bracket (Fig. 87).
(4) If equipped with speed control, remove speed
control cable from throttle lever by sliding clasp out
hole used for throttle cable.
(5) Remove 2 screws holding cable mounting
bracket and support bracket.
(6) Remove TPS connector.
(7) Remove Idle Air Control motor connector.
(8) Remove the EVAP purge hose.(9) Remove throttle body mounting bolts. Remove
throttle body.
(10) The rubber O-ring gasket on the intake man-
ifold is reusable. Wipe the O-ring clean before install-
ing throttle body (Fig. 92).
INSTALLATION
(1) Connect the electrical connetion to the throttle
body.
(2) Install gasket.
(3) Install throttle body on intake manifold.
Tighten mounting bolts 11.8 N´m (105 in. lbs.).
(4) Attach cable mounting bracket and support
bracket with 2 screws.
(5) Connect the EVAP purge hose to the throttle
body.
(6) Install cable housing(s) retainer tabs into
bracket.
(7) If equipped with speed control, rotate the throt-
tle lever forward to the wide open position and
install speed control cable clasp (Fig. 87).
(8) Rotate throttle lever to wide open position and
install throttle cable clasp (Fig. 87).
(9) Install throttle cable cover. Tighten bolt to 4.5
N´m (40 ins. lbs.).
THROTTLE BODYÐAUTOMATIC TRANSMISSION
REMOVAL
(1) Remove throttle cable cover.
(2) Remove throttle body cables using the following
procedures.
(3) Remove throttle cable from throttle body cam
(Fig. 88) and (Fig. 89).
(4) Compress the retaining tabs on the cable and
slide cable out of bracket (Fig. 89).
(5) Hold throttle lever in the wide open position.
Using finger pressure only, remove kickdown cable by
Fig. 86 Throttle Cable Attachment to Throttle Body
Fig. 87 Disconnecting Throttle Cable
Fig. 88 Throttle Body Cables Attachment to Throttle
Body
14 - 50 FUEL SYSTEMPL

PUSHING connector off the lever nail head (Fig. 88)
and (Fig. 90). DO NOT try to pull connector off per-
pendicular to the lever.
(6) Compress the retaining tabs on the cable and
slide cable out of bracket (Fig. 89).
(7) if equipped with speed control, hold throttle
lever in the wide open position. Using finger pressure
only, remove speed control cable by PUSHING con-
nector off the lever nail head (Fig. 88) and (Fig. 91).
DO NOT try to pull connector off perpendicular to
the lever.
(8) Compress the retaining tabs on the cable and
slide cable out of bracket (Fig. 89).
(9) Remove 2 screws holding cable mounting
bracket and support bracket.
(10) Remove TPS connector.
(11) Remove Idle Air Control motor connector.
(12) Remove EVAP purge hose.
(13) Remove throttle body mounting bolts. Remove
throttle body.(14) The rubber O-ring gasket on the intake man-
ifold is reusable. Wipe the O-ring clean before install-
ing throttle body (Fig. 92).
INSTALLATION
(1) Connect electrical connection to throttle body.
(2) Install throttle body on intake manifold.
Tighten mounting bolts 11.8 N.m (105 in. lbs.).
(3) Attach cable mounting bracket and support
bracket with 2 screws.
(4) Connect the EVAP purge hose.
(5) Install cable housing(s) retainer tabs into
bracket.
(6) Install throttle body cables using the following
procedures.
(7) From the engine compartment, rotate the
throttle lever forward to the wide open position and
install throttle cable clasp (Fig. 89).
(8) If equipped with speed control, rotate throttle
lever forward to the wide open position and slide
speed control cable connector onto nail head.
Fig. 89 Disconnecting Throttle Cable
Fig. 90 Transmission Kickdown Cable Connector
Fig. 91 Speed Control Cable Connector
Fig. 92 Re-Usable Throttle Body Gasket
PLFUEL SYSTEM 14 - 51
REMOVAL AND INSTALLATION (Continued)

(9) Rotate throttle lever forward to the wide open
position and slide kickdown cable connector onto nail
head.
(10) Install throttle cable cover. Tighten bolt to 5.6
N´m (50 ins. lbs.).
THROTTLE POSITION SENSOR (TPS)
The throttle position sensor attaches to the side of
the throttle body (Fig. 93).
REMOVAL
(1) Disconnect EVAP purge hose from throttle
body.
(2) Disconnect electrical connector from idle air
control motor and throttle position sensor.
(3) Remove throttle body. Refer to Throttle Body in
this section.
(4) Remove throttle position sensor mounting
screws.
(5) Remove throttle position sensor.
INSTALLATION
(1) The throttle shaft end of the throttle body
slides into a socket in the TPS (Fig. 94). The socket
has two tabs inside it. The throttle shaft rests
against the tabs. When indexed correctly, the TPS
can rotate clockwise a few degrees to line up the
mounting screw holes with the screw holes in the
throttle body. The TPS has slight tension when
rotated into position. If it is difficult to rotate the
TPS into position, install the sensor with the throttle
shaft on the other side of the tabs in the socket.
Tighten mounting screws to 2 N´m (17 in. lbs.)
torque.
(2) After installing the TPS, the throttle plate
should be closed. If the throttle plate is open, install
the sensor on the other side of the tabs in the socket.
(3) Install throttle body. Refer to Throttle Body in
this section.(4) Attach electrical connectors to idle air control
motor and throttle position sensor.
(5) Install EVAP purge hose to throttle body nip-
ple.
IDLE AIR CONTROL MOTOR
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable. Never use lubricants on O-rings or
seals, damage may result. If assembly of component
is difficult, use water to aid assembly. Use care when
removing hoses to prevent damage to hose or hose
nipple.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove throttle body. Refer to Throttle Body in
this section.
(3) Remove electrical connector from idle air con-
trol motor and throttle position sensor.
(4) Remove the EVAP purge hose from the throttle
body.
(5) Remove idle air control motor mounting screws
(Fig. 95).
(6) Remove motor from throttle body. Ensure the
O-ring is removed with the motor.
INSTALLATION
(1) The new idle air control motor has a new
O-ring installed on it. If pintle measures more than 1
inch (25 mm) it must be retracted. Use the DRB Idle
Air Control Motor Open/Close Test to retract the
pintle (battery must be connected.)
(2) Carefully place idle air control motor into
throttle body.
(3) Install mounting screws. Tighten screws to 2
N´m (17 in. lbs.) torque.
(4) Connect electrical connector to idle air control
motor and throttle position sensor.
Fig. 93 Throttle Position Sensor and Idle Air Control
Motor
Fig. 94 Throttle Position Sensor Installation
14 - 52 FUEL SYSTEMPL
REMOVAL AND INSTALLATION (Continued)

(5) Install throttle body. Refer to Throttle Body in
this section.
(6) Connect the EVAP purge hose to the throttle
body nipple.
(7) Connect negative cable to battery.
MAP/IAT SENSORÐSOHC
The MAP/IAT sensor attaches to the intake mani-
fold plenum (Fig. 96).
REMOVAL
(1) Disconnect the electrical connector from the
MAP/IAT sensor.
(2) Remove sensor mounting screws.
(3) Remove sensor.
INSTALLATION
(1) Insert sensor into intake manifold while mak-
ing sure not to damage O-ring seal.
(2) Tighten mounting screws to 2 N´m (20 in. lbs)
torque for plastic manifold and 3 N´m (30 in. lbs.) for
aluminum manifold.
(3) Attach electrical connector to sensor.
MAP/IAT SENSORÐDOHC
The MAP/IAT sensor attaches to the intake mani-
fold plenum (Fig. 98).
REMOVAL
(1) Remove air inlet duct wing nut and duct from
intake manifold (Fig. 97).
(2) Disconnect the electrical connector from the
MAP/IAT sensor.
(3) Remove sensor mounting screws.
(4) Remove sensor.
INSTALLATION
(1) Insert sensor into intake manifold while mak-
ing sure not to damage O-ring seals.(2) Tighten mounting screws to 2 N´m (20 in. lbs)
torque foe a plastic manifold and 3 N´m (30 in. lbs)
for a aluminum manifold.
(3) Attach electrical connector to sensor.
(4) Install air inlet duct wing nut and duct from
intake manifold, insure that the duct does not inter-
fer with ignition cables.
DUTY CYCLE EVAP PURGE SOLENOID VALVE
The solenoid attaches to a bracket near the front
engine mount (Fig. 99). The solenoid will not operate
unless it is installed correctly.
REMOVAL
(1) Disconnect electrical connector from solenoid.
(2) Disconnect vacuum tubes from solenoid.
Fig. 95 Servicing Idle Air Control MotorFig. 96 MAP/IAT SensorÐSOHC
Fig. 97 Air Inlet DuctÐDOHC
PLFUEL SYSTEM 14 - 53
REMOVAL AND INSTALLATION (Continued)

(3) Remove solenoid from bracket.
INSTALLATION
The top of the solenoid has TOP printed on it. The
solenoid will not operate unless it is installed cor-
rectly.
(1) Install solenoid on bracket.
(2) Connect vacuum tube to solenoid.
(3) Connect electrical connector to solenoid.
POWERTRAIN CONTROL MODULE (PCM)
The PCM attaches to the inner fender panel next
to the washer fluid bottle on the passenger side (Fig.
100).
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect positive cable from battery.
(3) Remove washer bottle neck.
(4) Squeeze tabs on PDC while pulling PDC up to
remove it from bracket. Lay PDC aside to gain access
to PCM bracket screws.
(5) Remove screws attaching PCM to body.
(6) Lift PCM up and disconnect the 2 40-way con-
nector.
(7) Remove PCM.
INSTALLATION
(1) Attach the 2 40-way connector to PCM.
(2) Install PCM. Tighten mounting screws to 9
N´m (80 in. lbs.) torque.
(3) Install PDC by pushing down into brackets.
(4) Install washer bottle neck.
(5) Connect positive cable to battery.
(6) Connect negative cable to battery.
CRANKSHAFT POSITION SENSOR
For removal/installation procedures refer to group
8D - Ignition System, Service Procedures.
CAMSHAFT POSITION SENSOR
For removal/installation procedures refer to group
8D - Ignition System, Service Procedures.
UPSTREAM HEATED OXYGEN SENSOR
REMOVAL
(1) Raise and support vehicle.
(2) Unplug sensor connector.
(3) Remove sensor using an oxygen sensor crow
foot wrench such as Snap-On tool YA8875 or equiva-
lent (Fig. 101).
(4) A
fter removing the sensor, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E tap.
If reusing the original sensor, coat the sensor threads
Fig. 98 MAP/IAT SensorÐDOHC
Fig. 99 Duty Cycle EVAP Purge Solenoid Valve
Fig. 100 Powertrain Control Module
14 - 54 FUEL SYSTEMPL
REMOVAL AND INSTALLATION (Continued)

with an anti-seize compound such as Loctitet771-64 or
equivalent.
INSTALLATION
New sensors have compound on the threads and do
not require an additional coating.
(1) Install sensor using an oxygen sensor crow foot
wrench such as Snap-On tool YA8875 or equivalent
(Fig. 101). Tighten the sensor to 28 N´m (20 ft. lbs.)
torque.
(2) Plug sensor connector.
(3) Lower vehicle.
DOWNSTREAM HEATED OXYGEN SENSOR
The downstream heated oxygen sensor threads into
the exhaust outlet pipe behind the catalytic convertor
(Fig. 102).
REMOVAL
(1) Raise vehicle.
(2) Disconnect electrical connector from sensor.
(3) Disconnect sensor electrical harness from clips
along body.
(4) Remove sensor using an oxygen sensor crow
foot wrench such as Snap-On tool YA8875 or equiva-
lent (Fig. 103).
(5) After removing the sensor, the exhaust mani-
fold threads must be cleaned with an 18 mm X 1.5 +
6E tap. If reusing the original sensor, coat the sensor
threads with an anti-seize compound such as Loctitet
771-64 or equivalent.
INSTALLATION
New sensors have compound on the threads and do
not require an additional coating.
(1) Install sensor using an oxygen sensor crow foot
wrench such as Snap-On tool YA8875 or equivalent
(Fig. 103). Tighten the sensor to 28 N´m (20 ft. lbs.)
torque.(2) Connect sensor electrical harness from clips
along body.
(3) Connect electrical connector from sensor.
(4) Lower vehicle.
AIR CLEANER ELEMENT
Neon vehicles do not use a heated air inlet system.
The PCM adjusts fuel injector pulse width and igni-
tion timing to compensate for different ambient tem-
peratures.
The air cleaner attaches to a bracket on the rear of
the cylinder head. An ambient air duct supplies
underhood air for the engine.
REMOVAL
(1) Remove air intake tube (Fig. 104) from air
cleaner and intake manifold (Fig. 105).
(2) Unfasten clasps on top of air cleaner housing.
Rotate front of housing forward then lift front away
from air cleaner housing (Fig. 106).
Fig. 101 Upstream Heated Oxygen Sensor Removal/
Installation
Fig. 102 Downstream Heated Oxygen Sensor
Fig. 103 Downstream Heated Oxygen Sensor
Removal/Installation
PLFUEL SYSTEM 14 - 55
REMOVAL AND INSTALLATION (Continued)