2002 JEEP LIBERTY Low power

WARNING: THE EXHAUST MANIFOLD, EXHAUST
PIPES AND CATALYTIC CONVERTER BECOME
VERY HOT DURING ENGINE OPERATION. ALLOW
ENGINE TO COOL BEFORE REMOVING OXYGEN
SENSOR.
(1) Raise and support vehicle.
(2) Disconnect wire connector from O2S sensor.
CAUTION: When disconnecting sensor electrical
connector, do not pull directly on wire going into
sensor.
(3) Remove O2S sensor with an oxygen sensor
removal and installation tool.
(4) Clean threads in exhaust pipe using appropri-
ate tap.
INSTALLATION
Threads of new oxygen sensors are factory coated
with anti-seize compound to aid in removal.DO
NOT add any additional anti-seize compound to
threads of a new oxygen sensor.
(1) Install O2S sensor. Tighten to 30 N´m (22 ft.
lbs.) torque.
(2) Connect O2S sensor wire connector.
(3) Lower vehicle.
THROTTLE BODY
DESCRIPTION
The throttle body is located on the intake manifold.
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.
REMOVAL
2.4L
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 Powertrain Control Module (PCM).
(1) Remove air cleaner tube at throttle body.
(2) Disconnect throttle body electrical connectors
at IAC motor and TPS.
(3) Remove all control cables from throttle body
(lever) arm. Refer to the Accelerator Pedal and Throt-
tle Cable section for removal/installation procedures.
(4) Disconnect necessary vacuum lines at throttle
body.
(5) Remove 3 throttle body mounting bolts (Fig.
23).
(6) Remove throttle body from intake manifold.
(7) Check condition of old throttle body-to-intake
manifold o-ring.
3.7L
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 Powertrain Control Module (PCM).
(1) Remove air cleaner tube at throttle body.
(2) Disconnect throttle body electrical connectors
at IAC motor and TPS.
Fig. 23 THROTTLE BODY MOUNTING BOLTS - 2.4L
1 - THROTTLE BODY
2 - IGNITION COIL
3 - MOUNTING BOLTS (3)
KJFUEL INJECTION 14 - 43
OXYGEN SENSOR (Continued)

THROTTLE POSITION SENSOR
DESCRIPTION
The 3±wire Throttle Position Sensor (TPS) is
mounted on the throttle body and is connected to the
throttle blade shaft.
OPERATION
The 3±wire TPS provides the Powertrain Control
Module (PCM) with an input signal (voltage) that
represents the throttle blade position of the throttle
body. The sensor is connected to the throttle blade
shaft. As the position of the throttle blade changes,
the output voltage of the TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The
PCM receives an input signal voltage from the TPS.
This will vary in an approximate range of from .26
volts at minimum throttle opening (idle), to 4.49 volts
at wide open throttle. Along with inputs from other
sensors, the PCM uses the TPS input to determine
current engine operating conditions. In response to
engine operating conditions, the PCM will adjust fuel
injector pulse width and ignition timing.
The PCM needs to identify the actions and position
of the throttle blade at all times. This information is
needed to assist in performing the following calcula-
tions:
²Ignition timing advance
²Fuel injection pulse-width
²Idle (learned value or minimum TPS)
²Off-idle (0.06 volt)
²Wide Open Throttle (WOT) open loop (2.608
volts above learned idle voltage)
²Deceleration fuel lean out
²Fuel cutoff during cranking at WOT (2.608 volts
above learned idle voltage)
²A/C WOT cutoff (certain automatic transmis-
sions only)
REMOVAL
2.4L
The Throttle Position Sensor (TPS) is mounted to
the throttle body (Fig. 31).
(1) Disconnect TPS electrical connector.
(2) Remove 2 TPS mounting screws.
(3) Remove TPS.
Fig. 31 TPS/IAC MOTOR - 2.4L
1 - THROTTLE POSITION SENSOR (TPS)
2 - MOUNTING SCREWS
3 - IDLE AIR CONTROL MOTOR (IAC)
4 - MOUNTING SCREWS
KJFUEL INJECTION 14 - 47

STEERING
TABLE OF CONTENTS
page page
STEERING
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER
STEERING SYSTEM....................1DIAGNOSIS AND TESTING - POWER
STEERING FLOW AND PRESSURE........3
COLUMN...............................5
GEAR.................................13
LINKAGE..............................16
PUMP.................................17
STEERING
DESCRIPTION
Power steering systems consist of:
²Steering column & Intermediate Shaft
²Rack and pinion steering gear
²Belt driven hydraulic steering pump
²Pump pressure, supply and return hoses
²Oil Cooler
OPERATION
The steering column intermediate shaft attaches
the steering column to the gear pinion. The rotation
of the pinion moves the gear rack from side-to-side.
This lateral action of the rack pushes and pulls the
tie rods to change the direction of the front wheels.
Power assist is provided by an engine mounted
hydraulic pump. The pump supplies hydraulic fluid
to the steering gear. All vehicles are equipped with
an oil cooler.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER STEERING SYSTEM
STEERING NOISE
There is some noise in all power steering systems. One of the most common is a hissing sound evident at a
standstill/parking, or when the steering is at the end of it's travel. Hiss is a high frequency noise similar to that
of a water tap being closed slowly. The noise is present in all valves that have a high velocity fluid passing through
an orifice. There is no relationship between this noise and steering performance.
CONDITION POSSIBLE CAUSES CORRECTION
OBJECTIONAL HISS OR
WHISTLE1. Steering intermediate shaft to dash panel
seal.1. Check and repair seal at dash
panel.
2. Noisy valve in power steering gear. 2. Replace steering gear.
1. Gear mounting bolts loose. 1. Tighten bolts to specification.
2. Loose or damaged suspension
components.2. Inspect and repair suspension.
3. Internal gear noise. 3. Replace steering gear.
4. Loose or damaged intermediate shaft or
column.4. Inspect and repair or replace.
MOAN Pressure hose in contact with other
components.Reposition hose.
CHIRP OR SQUEAL 1. Loose belt. 1. Adjust or replace.
KJSTEERING 19 - 1

LOOSE STEERING AND VEHICLE LEAD
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE PLAY IN STEERING
WHEEL1. Worn or loose suspension or
steering components.1. Inspect and repair as necessary.
2. Worn or loose wheel bearings. 2. Inspect and replace bearings.
3. Steering gear mounting. 3. Tighten / replace gear mounting
bolts/ isolators to specification.
4. Gear out of adjustment. 4. Replace gear.
5. Worn or loose steering
intermediate shaft.5. Inspect and replace as
necessary.
VEHICLE PULLS, DRIFTS OR
LEADS TO ONE SIDE.1. Tire Pressure. 1. Adjust tire pressure.
2. Radial tire lead. 2. Rotate tires.
3. Brakes dragging. 3. Repair as necessary.
4. Wheel alignment. 4. Align front end.
DIAGNOSIS AND TESTING - POWER STEERING
FLOW AND PRESSURE
The following procedure is used to test the opera-
tion of the power steering system on the vehicle. This
test will provide the gallons per minute (GPM) or
flow rate of the power steering pump along with the
maximum relief pressure. Perform test any time a
power steering system problem is present. This test
will determine if the power steering pump or power
steering gear is not functioning properly. The follow-
ing pressure and flow test is performed using Power
Steering Analyzer Tool kit 6815 and (Fig. 1) Adapter
Kit 6893.
FLOW AND PRESSURE TEST
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect pressure gauge hose from the Power
Steering Analyzer to Tube 6844.
(3) Connect Adapter 6826 to Power Steering Ana-
lyzer test valve end.
(4) Disconnect the high pressure hose from the
power steering pump.
(5) Connect the tube to the pump hose fitting.
(6) Connect the power steering hose from the
steering gear to the adapter.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circu-
late power steering fluid through flow/pressure test
gauge and to get air out of the fluid. Then shut off
engine.
(9) Check fluid level, add fluid as necessary. Start
engine again and let idle.
(10) Check for air bubbles, Evacuate if necessary
(11) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure reading should be in
the range of 345-552 kPa (50-80 psi).
(12) Increase the engine speed to 1500 RPM and
read the flow meter. If the flow rate (GPM) is below
specification, (refer to pump specification chart for
GPM) the pump should be replaced.
CAUTION: The following test procedure involves
testing maximum pump pressure output and flow
control valve operation. Do not leave valve closed
for more than three seconds as the pump could be
damaged.
Fig. 1 Analyzer With Tube and Adapter
1 - TUBE
2 - ADAPTER FITTINGS
3 - ANALYZER
4 - GAUGE HOSE
KJSTEERING 19 - 3
STEERING (Continued)

GEAR
TABLE OF CONTENTS
page page
GEAR
DESCRIPTION.........................13
OPERATION...........................13
REMOVAL
REMOVAL - 4WD......................13
REMOVAL - 2WD......................14
INSTALLATION
INSTALLATION - 4WD..................14INSTALLATION - 2WD..................14
SPECIFICATIONS
TORQUE CHART......................15
SPECIAL TOOLS
OUTER TIE ROD END REMOVAL TOOL....15
GEAR
DESCRIPTION
A rack and pinion steering gear (Fig. 1) is made up
of two main components, the pinon shaft and the
rack. The gear cannot be adjusted or internally ser-
viced. If a malfunction or a fluid leak occurs, the gear
must be replaced as an assembly.
OPERATION
The steering column intermediate shaft is attached
to the gear pinion. The rotation of the pinion moves
the gear rack from side-to-side. This lateral action of
the rack pushes and pulls the tie rods, which are
connected to the steering knuckles to change the
direction of the front wheels.
REMOVAL
REMOVAL - 4WD
(1) Siphon the power steering fluid from the power
steering reservoir.
(2) Lock the steering wheel to prevent spinning of
the clockspring.
(3) Raise and support the vehicle.
(4) Remove the skid plate from under the front
end to gain access to the gear (Refer to 13 - FRAME
& BUMPERS/FRAME/FRONT SKID PLATE -
REMOVAL).
(5) Remove the front tire and wheel assemblies.
NOTE: Mark the alignment adjusting cams for eas-
ier installation.
(6) Remove the lower control arms. (Refer to 2 -
SUSPENSION/FRONT/LOWER CONTROL ARM -
REMOVAL).
(7) Remove the front axle. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/FRONT AXLE - REMOV-
AL).
(8) Remove the tie rod end nuts.
(9) Separate tie rod ends from the knuckles with
Puller C-3894-A.
(10) Remove the intermediate shaft lower coupler
bolt and slide the coupler off the gear (Fig. 2).
(11) Remove power steering pressure hose bracket
(Fig. 3).
(12) Remove the power steering lines from the
gear (Fig. 2).
(13) Remove the mounting bolts from the gear to
the front cradle (Fig. 3).
(14) Remove the steering gear from the vehicle.
Fig. 1 Rack & Pinion Steering Gear
1 - TIE ROD - INNER
2 - TIE ROD - INNER
3 - TIE ROD END - OUTER LH
4 - BOOTS
5 - TIE ROD END - OUTER RH
KJGEAR 19 - 13

REMOVAL - 2WD
(1) Siphon the power steering fluid from the power
steering reservoir.
(2) Lock the steering wheel to prevent spinning of
the clockspring.
(3) Raise and support the vehicle.
(4) Remove the skid plate from under the front
end to gain access to the gear(Refer to 13 - FRAME
& BUMPERS/FRAME/FRONT SKID PLATE -
REMOVAL).
(5) Remove the tire and wheel assembly.
NOTE: Mark the alignment adjusting cams and tie
rod end jam nuts on the steering gear for easier
installation.
(6) Remove the tie rod end nuts.
(7) Separate tie rod ends from the knuckles with
Puller C-3894-A.
(8) Remove the lower intermediate shaft coupler
bolt and slide the coupler off the gear (Fig. 2).(9) Remove power steering pressure hose bracket
(Fig. 3).
(10) Remove the power steering lines from the
gear (Fig. 2).
(11) Remove the mounting bolts from the gear to
the front cradle (Fig. 3).
(12) Remove the steering gear from the vehicle.
INSTALLATION
INSTALLATION - 4WD
(1) Transfer the tie rod ends to the new steering
gear (if needed).
(2) Install the steering gear to the vehicle.
(3) Install the gear mounting bolts to the front cra-
dle. (Fig. 3). Tighten the gear mounting bolts to 162
N´m (120 ft.lbs.)
(4) Install the power steering lines to the gear
(Fig. 2).
(5) Install the power steering pressure hose
bracket (Fig. 3).
(6) Install the lower coupler bolt and slide the cou-
pler on to the gear (Fig. 2).
(7) Install the tie rod end to the knuckle and
tighten the nuts.
(8) Install the front axle. (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/FRONT AXLE - INSTALLA-
TION).
(9) Install the lower control arms. (Refer to 2 -
SUSPENSION/FRONT/LOWER CONTROL ARM -
INSTALLATION).
(10) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(11) Install the skid plate (Refer to 13 - FRAME &
BUMPERS/FRAME/FRONT SKID PLATE - INSTAL-
LATION).
(12) Lower the vehicle.
(13) Unlock the steering wheel.
(14) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
(15) Reset the toe and center the steering wheel
(Refer to 2 - SUSPENSION/WHEEL ALIGNMENT -
STANDARD PROCEDURE).
INSTALLATION - 2WD
(1) Transfer the outer tie rod ends to the new
steering gear (if needed).
(2) Install the steering gear to the vehicle.
(3) Install the gear mounting bolts to the front cra-
dle. (Fig. 3). Tighten the gear mounting bolts to 162
N´m (120 ft.lbs.)
(4) Install the power steering lines to the gear
(Fig. 2).
Fig. 2 COUPLER BOLT
Fig. 3 RACK & PINION
19 - 14 GEARKJ
GEAR (Continued)

(5) Install the power steering pressure hose
bracket (Fig. 3).
(6) Install the lower coupler bolt and slide the cou-
pler on to the gear (Fig. 2).
(7) Install the tie rod end to the knuckle and
tighten the nuts.
(8) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(9) Install the skid plate(Refer to 13 - FRAME &
BUMPERS/FRAME/FRONT SKID PLATE - INSTAL-
LATION).(10) Lower the vehicle.
(11) Unlock the steering wheel.
(12) Fill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
(13) Reset the toe and center the steering wheel
(Refer to 2 - SUSPENSION/WHEEL ALIGNMENT -
STANDARD PROCEDURE).
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Rack and Pinion Steering
Gear
Gear to Frame Bolts162 120 Ð
Rack and Pinion Steering
Gear
Intermediate Shaft Bolt49 36 Ð
Tie Rod End
Knuckle Nut108 80 Ð
Tie Rod End
Jam Nut75 55 Ð
Power Steering Line
Pressure Line35 25 Ð
Power Steering Line
Return Line35 25 Ð
SPECIAL TOOLS
OUTER TIE ROD END REMOVAL TOOL
Puller C-3894-A
KJGEAR 19 - 15
GEAR (Continued)

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION.........................17
OPERATION...........................17
STANDARD PROCEDURE - POWER
STEERING PUMP - INITIAL OPERATION....18
REMOVAL
REMOVAL - 3.7L......................18
REMOVAL - 2.4L......................18
INSTALLATION
INSTALLATION - 3.7L..................19
INSTALLATION - 2.4L..................19
SPECIFICATIONS
TORQUE CHART......................19
SPECIAL TOOLS
POWER STEERING PUMP..............20
FLUID COOLER
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................20
HOSES
REMOVAL
REMOVAL - PRESSURE HOSE...........21
REMOVAL - RETURN HOSE (GEAR TO THE
COOLER)...........................21REMOVAL - RETURN HOSE (RESERVOIR
TO THE COOLER).....................21
INSTALLATION
INSTALLATION - PRESSURE HOSE.......21
INSTALLATION - RETURN HOSE (GEAR TO
THE COOLER)........................22
INSTALLATION - RETURN HOSE
(RESERVOIR TO THE COOLER)..........22
POWER STEERING PRESSURE SWITCH
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................22
PULLEY
REMOVAL.............................23
INSTALLATION.........................23
RESERVOIR
REMOVAL
REMOVAL - 3.7L......................24
REMOVAL - 2.4L......................24
INSTALLATION
INSTALLATION - 3.7L..................24
INSTALLATION - 2.4L..................24
PUMP
DESCRIPTION
Hydraulic pressure for the power steering system
is provided by a belt driven power steering pump
(Fig. 1). The pump shaft has a pressed-on high
strength plastic drive pulley that is belt driven by
the crankshaft pulley. The integral reservoir used on
the 3.7L only is attached to the pump body with
spring clips (Fig. 1). The 2.4L uses a remote fluid res-
ervoir (Fig. 2). The power steering pump is connected
to the steering gear by the pressure and return
hoses.
OPERATION
The power steering pump is a constant flow rate
and displacement, vane-type pump. The pump inter-
nal parts operate submerged in fluid. The flow con-
trol orifice is part of the high pressure line fitting.
The pressure relief valve inside the flow control valve
limits the pump pressure.Fig. 1 POWER STEERING PUMP ASSEMBLY
1 - RESERVOIR
2 - CAP
3 - PULLEY
4 - PUMP BODY
5 - RESERVOIR RETAINING CLIPS
KJPUMP 19 - 17