
The downstream heated oxygen sensor threads into
the outlet pipe at the rear of the catalytic convertor
(Fig. 19).
OPERATION
Separate controlled ground circuits are run
through the PCM for the upstream O2 sensors.
As vehicles accumulate mileage, the catalytic con-
vertor deteriorates. The deterioration results in a
less efficient catalyst. To monitor catalytic convertor
deterioration, the fuel injection system uses two
heated oxygen sensors. One sensor upstream of the
catalytic convertor, one downstream of the convertor.
The PCM compares the reading from the sensors to
calculate the catalytic convertor oxygen storage
capacity and converter efficiency. Also, the PCM uses
the upstream heated oxygen sensor input when
adjusting injector pulse width.
When the catalytic converter efficiency drops below
emission standards, the PCM stores a diagnostic
trouble code and illuminates the malfunction indica-
tor lamp (MIL).
The O2S produce voltages from 0 to 1 volt, depend-
ing upon the oxygen content of the exhaust gas in
the exhaust manifold. When a large amount of oxy-
gen is present (caused by a lean air/fuel mixture), the
sensors produces a low voltage. When there is a
lesser amount present (rich air/fuel mixture) it pro-
duces a higher voltage. By monitoring the oxygen
content and converting it to electrical voltage, the
sensors act as a rich-lean switch.The oxygen sensors are equipped with a heating
element that keeps the sensors at proper operating
temperature during all operating modes. Maintaining
correct sensor temperature at all times allows the
system to enter into closed loop operation sooner.
Also, it allows the system to remain in closed loop
operation during periods of extended idle.
In Closed Loop operation the PCM monitors the
O2S input (along with other inputs) and adjusts the
injector pulse width accordingly. During Open Loop
operation the PCM ignores the O2 sensor input. The
PCM adjusts injector pulse width based on prepro-
grammed (fixed) values and inputs from other sen-
sors.
The Automatic Shutdown (ASD) relay supplies bat-
tery voltage to both the upstream and downstream
heated oxygen sensors. The oxygen sensors are
equipped with a heating element. The heating ele-
ments reduce the time required for the sensors to
reach operating temperature.
UPSTREAM OXYGEN SENSOR
The input from the upstream heated oxygen sensor
tells the PCM the oxygen content of the exhaust gas.
Based on this input, the PCM fine tunes the air-fuel
ratio by adjusting injector pulse width.
The sensor input switches from 0 to 1 volt, depend-
ing upon the oxygen content of the exhaust gas in
the exhaust manifold. When a large amount of oxy-
gen is present (caused by a lean air-fuel mixture), the
sensor produces voltage as low as 0.1 volt. When
there is a lesser amount of oxygen present (rich air-
fuel mixture) the sensor produces a voltage as high
as 1.0 volt. By monitoring the oxygen content and
converting it to electrical voltage, the sensor acts as
a rich-lean switch.
The heating element in the sensor provides heat to
the sensor ceramic element. Heating the sensor
allows the system to enter into closed loop operation
sooner. Also, it allows the system to remain in closed
loop operation during periods of extended idle.
In Closed Loop, the PCM adjusts injector pulse
width based on the upstream heated oxygen sensor
input along with other inputs. In Open Loop, the
PCM adjusts injector pulse width based on prepro-
grammed (fixed) values and inputs from other sen-
sors.
DOWNSTREAM OXYGEN SENSOR
The downstream heated oxygen sensor input is
used to detect catalytic convertor deterioration. As
the convertor deteriorates, the input from the down-
stream sensor begins to match the upstream sensor
input except for a slight time delay. By comparing
the downstream heated oxygen sensor input to the
Fig. 19 O2 SENSOR DOWNSTREAM 1/2 - 2.4/3.3/
3.8L
1 - 1/2 02S
2 - 1/1 02S
RSFUEL INJECTION14-31
O2 SENSOR (Continued)

SERVICE WARNINGS AND CAUTIONS
WARNING: POWER STEERING FLUID, ENGINE
PARTS AND EXHAUST SYSTEM MAY BE
EXTREMELY HOT IF ENGINE HAS BEEN RUNNING.
DO NOT START ENGINE WITH ANY LOOSE OR DIS-
CONNECTED HOSES. DO NOT ALLOW HOSES TO
TOUCH HOT EXHAUST MANIFOLD OR CATALYST.
WARNING: FLUID LEVEL SHOULD BE CHECKED
WITH THE ENGINE OFF TO PREVENT PERSONAL
INJURY FROM MOVING PARTS.
CAUTION: When the system is open, cap all open
ends of the hoses, power steering pump fittings or
power steering gear ports to prevent entry of for-
eign material into the components.
STANDARD PROCEDURE - POWER STEERING
PUMP INITIAL OPERATION
CAUTION: The fluid level should be checked with
engine off to prevent injury from moving compo-
nents. Use only MoparTPower Steering Fluid (MS-
5931) or approved equivalent. Do not overfill.
Read the fluid level through the side of the power
steering fluid reservoir. The fluid level should indi-
cateªFILL RANGEºwhen the fluid is at a temper-
ature of approximately 21ÉC to 27ÉC (70ÉF to 80ÉF).
(1) Wipe the filler cap and area clean, then remove
the cap.
(2) Fill the fluid reservoir to the proper level and
let the fluid settle for at least two (2) minutes.
(3) Start the engine and let run for a few seconds,
then turn the engine off.
(4) Add fluid if necessary. Repeat the above steps
until the fluid level remains constant after running
the engine.
(5) Raise the front wheels off the ground.
(6) Start the engine.
(7) Slowly turn the steering wheel right and left,
lightly contacting the wheel stops.
(8) Add fluid if necessary.
(9) Lower the vehicle, then turn the steering wheel
slowly from lock-to-lock.
(10) Stop the engine. Check the fluid level and
refill as required.
(11) If the fluid is extremely foamy, allow the vehi-
cle to stabilize a few minutes, then repeat the above
procedure.
REMOVAL - PUMP (2.4L ENGINE)
(1) Remove the (-) negative battery cable from the
battery and isolate cable.
(2) Remove the cap from the power steering fluid
reservoir.
(3) Using a siphon pump, remove as much power
steering fluid as possible from the power steering
fluid reservoir.
(4) Raise the vehicle on jack stands or centered on
a frame contact type hoist. See Hoisting in Lubrica-
tion and Maintenance.
(5) Disconnect the oxygen sensor wiring harness
from the vehicle wiring harness at the rear engine
mount bracket.
NOTE: The exhaust system needs to be removed
from the engine to allow for an area to remove the
power steering pump from the vehicle.
(6) Remove the four bolts and flag nuts securing
the catalytic converter from the exhaust manifold
(Fig. 3).
(7) Disconnect all the exhaust system isolators/
hangers from the brackets on the exhaust system (2
at the mufflers and 1 at the resonator) (Fig. 4).
(8) Remove the exhaust system by moving it as far
rearward, then lowering the front below the cross-
member and out of the vehicle.
(9) Remove the power steering fluid supply hose
from the fitting on the power steering pump. Drain
off excess power steering fluid from hose.
Fig. 3 Catalytic Converter to Exhaust Manifold
1 - CATALYTIC CONVERTER
2 - BOLT
3 - GASKET
4 - FLAG NUT
RSPUMP19-25
PUMP (Continued)

(transmission fluid) this indicates that the Transmis-
sion differential carrier seal should be replaced. If
the fluid leaking is light brown (gear lube) this indi-
cates that the Power Transfer Unit input seal should
be replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
If fluid is leaking from weep hole B (Fig. 5) the
type of fluid leaking will determine which seal is
leaking. If the fluid leaking is red in color (transmis-
sion fluid) this indicates that the input shaft end seal
should be replaced. If the fluid leaking is light brown
(gear lube) this indicates that the half shaft innerseal and P.T.U. input shaft cover seal should be
replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
Before condemning any seal or gasket be sure that
the rear rocker arm cover on the engine is not the
cause of the oil leak. Oil leaking from the rocker arm
cover is easily mistaken for a leaking Power Transfer
Unit.
STANDARD PROCEDURE - FLUID LEVEL
INSPECTION
(1) Raise vehicle on hoist.
(2) Remove PTU inspection plug (Fig. 6).
(3) Fluid level should be within 3/16º from bottom
of inspection hole. Add Moparž Gear and Axle Lubri-
cant 80W-90 as necessary with suitable suction gun
(Fig. 7).
(4) Install inspection plug and torque to 20 N´m
(180 in. lbs.) torque.
(5) Lower vehicle.
STANDARD PROCEDURE - PTU FLUID CHANGE
NOTE: PTU Fluid should be changed upon servic-
ing the unit, or at the unit's regular scheduled inter-
val. (Refer to LUBRICATION & MAINTENANCE/
MAINTENANCE SCHEDULES - DESCRIPTION)
(1) Raise vehicle on hoist.
(2) Remove PTU inspection plug (Fig. 8).
Fig. 3 Seal Location
1 - INPUT SHAFT
2 - OUTPUT SHAFT
3 - REAR COVER
4 - P.T.U. CASE
5 - INPUT SHAFT SEAL
Fig. 4 Seal Location
1 - P.T.U. INPUT SHAFT COVER SEAL
2 - HALF SHAFT INNER SEAL
3 - INSIDE VIEW OF P.T.U. END COVER
Fig. 5 Weep Hole Locations
1 - ENGINE OIL PAN
2 - WEEP HOLE ªAº
3 - TRANSAXLE CASE
4 - P.T.U.
5 - WEEP HOLE ªBº
21 - 4 POWER TRANSFER UNITRS
POWER TRANSFER UNIT (Continued)

STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 236).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over±run-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock±up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
Fig. 235 Torque Converter Fluid Operation
1 - APPLY PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD3 - RELEASE PRESSURE
4 - THE PISTON MOVES SLIGHTLY REARWARD
Fig. 236 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
21 - 124 AUTOMATIC - 31THRS
TORQUE CONVERTER (Continued)

TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the front
cover's friction material, a total converter engage-
ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.
The engagement and disengagement of the TCC
are automatic and controlled by the Powertrain Con-
trol Module (PCM). The engagement cannot be acti-
vated in the lower gears because it eliminates the
torque multiplication effect of the torque converter
necessary for acceleration. Inputs that determine
clutch engagement are: coolant temperature, vehicle
speed and throttle position. The torque converter
clutch is engaged by the clutch solenoid on the valve
body. The clutch will engage at approximately 56
km/h (35 mph) with light throttle, after the shift to
third gear.
REMOVAL
(1) Remove transmission and torque converter
from vehicle. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 31TH - REMOVAL)
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.(1) Lubricate converter hub and oil pump seal lip
with transmission fluid.
(2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 237). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 31TH - INSTALLATION)
(9) Fill the transmission with the recommended
fluid.
Fig. 237 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
RSAUTOMATIC - 31TH21 - 125
TORQUE CONVERTER (Continued)

STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 338).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over±run-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock±up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the front
cover's friction material, a total converter engage-ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.
Fig. 337 Torque Converter Fluid Operation
1 - APPLY PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD3 - RELEASE PRESSURE
4 - THE PISTON MOVES SLIGHTLY REARWARD
Fig. 338 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
RSAUTOMATIC - 41TE21 - 285
TORQUE CONVERTER (Continued)

The engagement and disengagement of the TCC
are automatic and controlled by the Powertrain Con-
trol Module (PCM). The engagement cannot be acti-
vated in the lower gears because it eliminates the
torque multiplication effect of the torque converter
necessary for acceleration. Inputs that determine
clutch engagement are: coolant temperature, vehicle
speed and throttle position. The torque converter
clutch is engaged by the clutch solenoid on the valve
body. The clutch will engage at approximately 56
km/h (35 mph) with light throttle, after the shift to
third gear.
REMOVAL
NOTE: If torque conveter assembly is being
replaced, it is necessary to restart the TCC Break-In
Strategy. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Remove transmission and torque converter
from vehicle. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 41TE - REMOVAL)
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
NOTE: If torque conveter is being replaced, it is
necessary to restart the TCC Break-In Strategy.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/TRANSMISSION CONTROL MODULE -
STANDARD PROCEDURE)
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.
(1) Lubricate converter hub and oil pump seal lip
with transmission fluid.
(2) Place torque converter in position on transmis-
sion.CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 339). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE - INSTALLATION)
(9) Fill the transmission with the recommended
fluid. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 41TE/FLUID - STANDARD PROCE-
DURE)
(10) If torque conveter was replaced, it is neces-
sary to reset the TCC Break-In Strategy. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/TRANSMISSION CONTROL MODULE -
STANDARD PROCEDURE)
Fig. 339 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
21 - 286 AUTOMATIC - 41TERS
TORQUE CONVERTER (Continued)

TIRES/WHEELS
TABLE OF CONTENTS
page page
TIRES/WHEELS
DIAGNOSIS AND TESTING..................1
TIRE AND WHEEL VIBRATION..............1
STANDARD PROCEDURE...................4
TIRE AND WHEEL BALANCE...............4
TIRE AND WHEEL MATCH MOUNTING.......6
TIRE AND WHEEL ROTATION..............6
REMOVAL...............................7
INSTALLATION............................7
TIRES
DESCRIPTION............................8
DIAGNOSIS AND TESTING..................9
TIRE NOISE............................9
TIRE/VEHICLE LEAD.....................9
TIRE WEAR PATTERNS..................11
TREAD WEAR INDICATORS...............11
STANDARD PROCEDURE..................11
TIRE INFLATION PRESSURES.............11
TIRE PRESSURE FOR HIGH SPEED
OPERATION...........................12TIRE LEAK REPAIRING..................12
CLEANING..............................13
WHEELS
DESCRIPTION...........................13
DIAGNOSIS AND TESTING.................13
WHEEL INSPECTION....................13
CLEANING..............................14
SPECIFICATIONS........................14
WHEEL COVER
DESCRIPTION...........................14
REMOVAL..............................14
INSTALLATION...........................14
WHEEL MOUNTING STUDS - FRONT
REMOVAL..............................15
INSTALLATION...........................16
WHEEL MOUNTING STUDS - REAR
REMOVAL..............................16
INSTALLATION...........................17
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND WHEEL
VIBRATION
Tire and wheel imbalance, runout and force varia-
tion can cause vehicles to exhibit steering wheel
vibration.
VISUAL INSPECTION
Visual inspection of the vehicle is recommended
prior to road testing or performing any other proce-
dure. Raise vehicle on a suitable hoist. Refer to
Hoisting in Lubrication and Maintenance.
Inspect for the following:
²Verify correct (OEM) wheel and tire, as well as
correct wheel weights. Aluminum wheels require
unique wheel weights. They are designed to fit the
contour of the wheel (Fig. 1).
²Inspect tires and wheels for damage, mud pack-
ing and unusual wear; correct as necessary.
²Check and adjust tire air pressure to the pres-
sure listed on the label attached to the rear face of
the driver's door.
ROAD TEST
Road test vehicle on a smooth road for a least five
miles to warm tires (remove any flat spots). Lightlyplace hands on steering wheel at the 10:00 and 2:00
positions while slowly sweeping up and down from 90
to 110 km/h (55 to 70 mph) where legal speed limits
allow.
Observe the steering wheel for:
²Visual Nibble (oscillation: clockwise/counter-
clockwise, usually due to tire imbalance)
Fig. 1 Aluminum Wheel Weight
1 - TIRE
2 - WHEEL
3 - WHEEL WEIGHT
RSTIRES/WHEELS22-1