OPERATION
The Transmission Control Module (TCM) supplies
the road speed and distance traveled inputs to the
PCM. From these inputs and the throttle position
sensor input, the PCM determines when a decelera-
tion condition occurs.
FUEL INJECTOR
DESCRIPTION
The injectors are positioned in the intake manifold
or cylinder head with the nozzle ends directly above
the intake valve port (Fig. 9).
OPERATION
The fuel injectors are 12 volt electrical solenoids
(Fig. 10). The injector contains a pintle that closes off
an orifice at the nozzle end. When electric current is
supplied to the injector, the armature and needle
move a short distance against a spring, allowing fuel
to flow out the orifice. Because the fuel is under high
pressure, a fine spray is developed in the shape of a
hollow cone or two streams. The spraying action
atomizes the fuel, adding it to the air entering the
combustion chamber. Fuel injectors are not inter-
changeable between engines.
The PCM provides battery voltage to each injector
through the ASD relay. Injector operation is con-
trolled by a ground path provided for each injector by
the PCM. Injector on-time (pulse-width) is variable,
and is determined by the PCM processing all the
data previously discussed to obtain the optimum
injector pulse width for each operating condition. Thepulse width is controlled by the duration of the
ground path provided.
REMOVAL
REMOVAL - 2.4L
The fuel rail must be removed first (Fig. 11). Refer
to Fuel Rail Removal in this section.
(1) Disconnect injector wiring connector from injec-
tor.
(2) Position fuel rail assembly so that the fuel
injectors are easily accessible (Fig. 12).
(3) Rotate injector and pull injector out of fuel rail.
The clip will stay on the injector.
(4) Check injector O-ring for damage. If O-ring is
damaged, it must be replaced. If injector is reused, a
protective cap must be installed on the injector tip to
Fig. 9 Fuel Injector Location - Typical
1 - FUEL RAIL
2 - INTAKE MANIFOLD
3 - FUEL INJECTORS
Fig. 10 FUEL INJECTOR - TYPICAL
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
Fig. 11 FUEL RAIL AND INJECTORS 2.4L
1 - Fuel Injectors
2 - Fuel Rail
RSFUEL INJECTION14-25
ENGINE SPEED SENSOR (Continued)
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²Manifold pressure
²Injector pulse-width
²Spark-advance programs
²Shift-point strategies (F4AC1 transmissions
only, via the PCI bus)
²Idle speed
²Decel fuel shutoff
The PCM recognizes a decrease in manifold pres-
sure by monitoring a decrease in voltage from the
reading stored in the barometric pressure memory
cell. The MAP sensor is a linear sensor; as pressure
changes, voltage changes proportionately. The range
of voltage output from the sensor is usually between
4.6 volts at sea level to as low as 0.3 volts at 26 in. of
Hg. Barometric pressure is the pressure exerted by
the atmosphere upon an object. At sea level on a
standard day, no storm, barometric pressure is 29.92
in Hg. For every 100 feet of altitude barometric pres-
sure drops .10 in. Hg. If a storm goes through it can
either add, high pressure, or decrease, low pressure,
from what should be present for that altitude. You
should make a habit of knowing what the average
pressure and corresponding barometric pressure is
for your area.
REMOVAL
REMOVAL - 2.4L
(1) Disconnect the negative battery cable.
(2) Disconnect electrical connector and vacuum
hose from MAP sensor (Fig. 18).
(3) Remove two screws holding sensor to the
intake manifold.
REMOVAL - 3.3/3.8L
(1) Disconnect the negative battery cable.
(2) Remove vacuum hose and mounting screws
from manifold absolute pressure (MAP) sensor (Fig.
19).
(3) Disconnect electrical connector from sensor.
Remove sensor.
INSTALLATION
INSTALLATION - 2.4L
(1) Install sensor.
(2) Install two screws and tighten.
(3) Connect the electrical connector and vacuum
hose to the MAP sensor (Fig. 18).
(4) Connect the negative battery cable.
INSTALLATION - 3.3/3.8L
(1) Install sensor (Fig. 19).(2) Install screws and tighten toPLASTIC MAN-
IFOLD 1.7 N´m (15 in. lbs.) ALUMINUM MANI-
FOLD 3.3 N´m (30 in. lbs.).
(3) Connect the electrical connector to the sensor.
Install vacuum hose.
(4) Connect the negative battery cable.
O2 SENSOR
DESCRIPTION
The upstream oxygen sensor threads into the out-
let flange of the exhaust manifold (Fig. 20) or (Fig.
21).
Fig. 20 O2 SENSOR UPSTREAM 1/1 - 2.4L
Fig. 21 O2 SENSOR UPSTREAM 1/1 - 3.3/3.8L
14 - 30 FUEL INJECTIONRS
MAP SENSOR (Continued)
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INSTALLATION - UPSTREAM 1/1 - 3.3/3.8L
The engines uses two heated oxygen sensors.
(1) 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 Loctite
771- 64 or equivalent. New sensors have compound
on the threads and do not require an additional coat-
ing.
(2) Install sensor and tighten to 27 N´m (20 ft.
lbs.).
(3) Connect the electrical connector for the O2 sen-
sor and install onto bracket.
(4) Connect the electrical connector for the speed
control servo.
(5) Install the speed control servo and bracket
refer to the Speed Control Servo for more informa-
tion.
(6) Connect the speed control vacuum harness to
servo.
(7) Install the battery tray, refer to the Battery
section for more information.
(8) Install battery, refer to the Battery section for
more information.
INSTALLATION DOWNSTREAM 2/1 -
2.4/3.3/3.8L
The O2S is located on the side of the catalytic con-
verter.
Threads of new oxygen sensors are factory coated
with anti-seize compound to aid in removal.DONOT add any additional anti-seize compound to
the threads of a new oxygen sensor.
(1) Install sensor and tighten to 27 N´m (20 ft.
lbs.).
(2) Connect the electrical connector.
(3) Lower vehicle.
(4) Install the negative battery cable.
THROTTLE BODY
DESCRIPTION
The throttle body is located on the intake manifold
(Fig. 26) or (Fig. 27). Fuel does not enter the intake
manifold through the throttle body. Fuel is sprayed
into the manifold by the fuel injectors.
OPERATION
Filtered air from the air cleaner enters the intake
manifold through the throttle body. The throttle body
contains an air control passage controlled by an Idle
Air Control (IAC) motor. The air control passage is
used to supply air for idle conditions. A throttle valve
(plate) is used to supply air for above idle conditions.
Certain sensors are attached to the throttle body.
The accelerator pedal cable, speed control cable and
transmission control cable (when equipped) are con-
nected to the throttle body linkage arm.
A (factory adjusted) set screw is used to mechani-
cally limit the position of the throttle body throttle
plate.Never attempt to adjust the engine idle
speed using this screw.All idle speed functions are
controlled by the PCM.
Fig. 25 DOWNSTREAM 2/1 O2 SENSOR
Fig. 26 IAC MOTOR 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
RSFUEL INJECTION14-33
O2 SENSOR (Continued)
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(3) Carefully install the ignition switch. The
switch will snap over the retaining tabs (Fig. 16) .
Install mounting screw (Fig. 12).
(4) Install upper and lower shrouds.
(5) Install key cylinder (cylinder retaining tab will
depress only in the RUN position).
(6) Connect negative cable to battery.(7) Check for proper operation of ignition switch
and key-in warning switch.
LOCK CYLINDER HOUSING
DESCRIPTION - IGNITION INTERLOCK
All vehicles equipped with automatic transaxles
have an interlock system. The system prevents shift-
ing the vehicle out of Park unless the ignition lock
cylinder is in the Unlock, Run or Start position. In
addition, the operator cannot rotate the key to the
lock position unless the shifter is in the park posi-
tion. On vehicles equipped with floor shift refer to
the - Transaxle for Automatic Transmission Shifter/
Ignition Interlock.
REMOVAL
(1) Disconnect negative (ground) cable from the
battery and isolate cable from battery terminal.
(2) Remove the screws attaching the lower steer-
ing column cover to the instrument panel (Fig. 17),
then remove the cover from the lower instrument
panel.
Fig. 15 Ignition Switch Connectors
1 - KEY IN SWITCH
2 - PRNDL SWITCH
3 - IGNITION SWITCH
Fig. 16 Ignition Switch Installation
1 - IGNITION SWITCH
2 - ACTUATOR SHAFT
3 - RETAINING TABS
Fig. 17 Lower Steering Column Cover Attachment
1 - PARK BRAKE RELEASE HANDLE
2 - STEERING COLUMN COVER
3 - STEERING COLUMN
4 - ATTACHING CLIP
5 - ATTACHING SCREWS
6 - HOOD RELEASE LEVER
7 - ATTACHING SCREWS
RSCOLUMN19-17
IGNITION SWITCH (Continued)
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(10) On both sides of vehicle, remove nut attaching
outer tie rod end to steering knuckle (Fig. 4).
Remove nut by holding tie rod end stud with a
socket while loosening and removing nut with
wrench.
(11) Remove bolts fastening leak detection pump to
cradle crossmember reinforcement. (Refer to 25 -EMISSIONS CONTROL/EVAPORATIVE EMIS-
SIONS/LEAK DETECTION PUMP - REMOVAL)
(12) Remove both outer tie rods from steering
knuckles, using Puller, Special Tool C-3894±A (Fig.
5).
(13) Remove the lower control arm rear bushing
retainer bolts located on each side of each lower con-
trol arm rear bushing.
NOTE: The bolts fastening the cradle crossmember
reinforcement are of two different thread sizes. Note
the location of the various sizes.
(14) Remove the bolts attaching the cradle cross-
member reinforcement to the front suspension cradle
crossmember (Fig. 6). Remove the 2 bolts fastening
the reinforcement and rear of cradle crossmember to
the body of the vehicle. Remove lower rear bushings,
then the reinforcement.
(15) If the vehicle is equipped with All-Wheel-
Drive, remove the power transfer unit (Refer to 21 -
TRANSMISSION/TRANSAXLE/POWER TRANSFER
UNIT - REMOVAL).
(16) Remove tube nuts and power steering pres-
sure and return hoses from the power steering gear
(Fig. 7).
Fig. 3 Power Steering Cooler
1 - CRADLE CROSSMEMBER REINFORCEMENT
2 - POWER STEERING COOLER
Fig. 4 Removing/Installing Tie Rod End Attaching
Nut
1 - TIE ROD END
2 - STEERING KNUCKLE
3 - WRENCH
4 - SOCKET
5 - TIE ROD END STUD
Fig. 5 Tie Rod Removal With Tool C-3894-A
1 - OUTER TIE ROD
2 - SPECIAL TOOL C-3894-A
3 - STEERING KNUCKLE
19 - 28 GEARRS
GEAR (Continued)
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(17) Remove the 3 bolts and nuts mounting the
steering gear to the front suspension cradle (Fig. 8).
NOTE: The next step must be done to allow the
removal of the steering gear from the front suspen-
sion cradle. The steering gear can not be removed
from the vehicle with the intermediate coupler
attached to the steering gear.
(18) Lower steering gear from suspension cradle
enough to allow access to the intermediate coupler
roll pin (Fig. 9). Install Remover/Installer Special
Tool 6831A through the center of the roll pin, secur-
ing with the knurled nut (Fig. 9). Hold threaded rod
stationary while turning nut, this will pull the roll
pin out of the intermediate coupler.
(19) Separate the coupler from the shaft of the
steering gear.(20) Remove the power steering gear from the
vehicle.
REMOVAL - RHD GEAR
(1) Remove cap from power steering fluid reser-
voir.
(2) Using a siphon pump, remove as much fluid as
possible from the power steering fluid reservoir.
CAUTION: Locking the steering column in the
straight-ahead position will prevent the clockspring
from being accidentally over-extended when the
steering column is disconnected from the interme-
diate steering coupler.
(3) Position the steering wheel in the STRAIGHT-
AHEAD position. Lock the steering wheel in place
using a steering wheel holding tool.
(4) With the ignition key in the locked position
turn the steering wheel to the left until the steering
wheel is in the locked position.
(5) With the vehicle on the ground, disconnect the
steering column shaft coupler from the steering gear
intermediate coupler (Fig. 2).
(6) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(7) Remove front wheel and tire assemblies.
(8) If power steering cooler equipped, remove a
hose at power steering cooler and allow fluid to
drain.
(9) Remove 2 bolts attaching power steering cooler
to cradle crossmember reinforcement (Fig. 3).
(10) On both sides of vehicle, remove nut attaching
outer tie rod end to steering knuckle (Fig. 4).
Remove nut by holding tie rod end stud with a
socket while loosening and removing nut with
wrench.
(11) Remove both tie rod ends from steering
knuckles using Puller, Special Tool C-3894±A (Fig. 5).
(12) Remove the lower control arm rear bushing
retainer bolts located on each side of each lower con-
trol arm rear bushing.
NOTE: The bolts fastening the cradle crossmember
reinforcement are of two different thread sizes. Note
the location of the various sizes.
(13) Remove the bolts attaching the cradle cross-
member reinforcement to the front suspension cradle
crossmember (Fig. 6). Remove the 2 bolts fastening
the reinforcement and rear of cradle crossmember to
the body of the vehicle. Remove the reinforcement.
(14) If the vehicle is equipped with All-Wheel-
Drive, remove the power transfer unit (Refer to 21 -
TRANSMISSION/TRANSAXLE/POWER TRANSFER
UNIT - REMOVAL).
Fig. 6 Cradle Crossmember Reinforcement
Attachment
1 - STEERING GEAR
2 - RIGHT LOWER CONTROL ARM
3 - LEFT LOWER CONTROL ARM
4 - CRADLE CROSSMEMBER REINFORCEMENT
5 - REAR CRADLE CROSSMEMBER ISOLATOR BUSHING
6 - STABILIZER BAR
7 - CRADLE CROSSMEMBER
RSGEAR19-29
GEAR (Continued)
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TRANSMISSION/TRANSAXLE
TABLE OF CONTENTS
page page
POWER TRANSFER UNIT..................1
31TH AUTOMATIC TRANSAXLE.............2141TE AUTOMATIC TRANSAXLE............161
T850 MANUAL TRANSAXLE...............308
POWER TRANSFER UNIT
TABLE OF CONTENTS
page page
POWER TRANSFER UNIT
DESCRIPTION..........................1
OPERATION............................3
DIAGNOSIS AND TESTING
SEAL IDENTIFICATION..................3
FLUID LEAK DIAGNOSIS................4
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
INSPECTION..........................5
STANDARD PROCEDURE - PTU FLUID
CHANGE.............................5
REMOVAL.............................6
INSTALLATION..........................7
ADJUSTMENTS
OUTPUT FLANGE SHIM SELECTION.......7
SPECIFICATIONS
TORQUE.............................8
SPECIAL TOOLS
SDP POWER TRANSFER UNIT............8
DIFFERENTIAL CARRIER SEAL
REMOVAL.............................9
INSTALLATION..........................9
END COVER BALL BEARING
REMOVAL.............................9INSTALLATION.........................10
END COVER SEAL
REMOVAL.............................11
INSTALLATION.........................11
HALF SHAFT INNER SEAL
REMOVAL.............................12
INSTALLATION.........................13
INPUT SHAFT COVER SEAL
REMOVAL.............................13
INSTALLATION.........................14
INPUT SHAFT END SEAL
REMOVAL.............................16
INSTALLATION.........................16
INPUT SHAFT SEAL
REMOVAL.............................17
INSTALLATION.........................18
OUTER HALF SHAFT SEAL
REMOVAL.............................19
INSTALLATION.........................19
REAR COVER O-RING
REMOVAL.............................19
INSTALLATION.........................20
POWER TRANSFER UNIT
DESCRIPTION
The Power Transfer Unit (P.T.U.) is attached to a
modified automatic transaxle case where the right
half shaft extension housing would normally be
located.
The Power Transfer Unit is sealed from the trans-
axle and has its own oil sump. The Unit uses MopartSAE 80W-90 Gear and Axle Lubricant (MS-9020) and
holds 1.15 liters (1.22 quarts).
Service of the Power Transfer Unit is limited to:
²Fluid Change
²Seals
²Gaskets
²One ball bearing
²Output flange
If the ring gear and pinion, any tapered roller
bearings, case, covers, or pinion carrier fail the entire
unit must be replaced.
RSTRANSMISSION/TRANSAXLE21-1
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END COVER SEAL
REMOVAL
The Power Transfer Unit must be removed from
the vehicle to perform this operation. (Refer to 21 -
TRANSMISSION/TRANSAXLE/POWER TRANSFER
UNIT - REMOVAL)
(1) Remove P.T.U. end cover bolts (Fig. 22).
(2) Gently tap on end cover ears with a hammer to
separate end cover from the case (Fig. 23).
(3) Clean and inspect sealer surfaces.
INSTALLATION
(1) Reinstall cover and tighten bolts to 28 N´m
(250 in. lbs.) in the sequence shown in (Fig. 24).
Retighten first bolt after all others are tight.
CAUTION: When end cover is installed be careful
not to damage the P.T.U. Input Shaft Cover Seal.
(2) Reinstall P.T.U. into vehicle.
(3) Check and fill fluids as required.
Fig. 22 P.T.U. End Cover Bolts
1 - POWER TRANSFER UNIT
2 - FILL PLUG
3 - END COVER
4 - OUTPUT SHAFT
Fig. 23 End Cover Removal
1 - END COVER EARS
2 - HAMMER
3 - POWER TRANSFER UNIT
Fig. 24 Bolt Tightening Sequence
RSPOWER TRANSFER UNIT21-11
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