2002 JEEP LIBERTY The

A ªtap downº feature is used to decelerate without
disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.
OVERSHOOT/UNDERSHOOT
If the vehicle operator repeatedly presses and
releases the SET button with their foot off of the
accelerator (referred to as a ªlift foot setº), the vehicle
may accelerate and exceed the desired set speed by
up to 5 mph (8 km/h). It may also decelerate to less
than the desired set speed, before finally achieving
the desired set speed.
The Speed Control System has an adaptive strat-
egy that compensates for vehicle-to-vehicle variations
in speed control cable lengths. When the speed con-
trol is set with the vehicle operators foot off of the
accelerator pedal, the speed control thinks there is
excessive speed control cable slack and adapts
accordingly. If the ªlift foot setsº are continually used,
a speed control overshoot/undershoot condition will
develop.
To ªunlearnº the overshoot/undershoot condition,
the vehicle operator has to press and release the set
button while maintaining the desired set speed using
the accelerator pedal (not decelerating or accelerat-
ing), and then turning the cruise control switch to
the OFF position (or press the CANCEL button if
equipped) after waiting 10 seconds. This procedure
must be performed approximately 10±15 times to
completely unlearn the overshoot/undershoot condi-
tion.
DIAGNOSIS AND TESTING - ROAD TEST
Perform a vehicle road test to verify reports of
speed control system malfunction. The road testshould include attention to the speedometer. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8J,
Instrument Cluster for speedometer diagnosis.
If a road test verifies a system problem and the
speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures service manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose, damaged or corroded electrical connec-
tions at the servo. Corrosion should be removed from
electrical terminals and a light coating of Mopar
MultiPurpose Grease, or equivalent, applied.
²Leaking vacuum reservoir.
²Loose or leaking vacuum hoses or connections.
²Defective one-way vacuum check valve.
²Secure attachment of both ends of the speed con-
trol servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Failed speed control servo. Do the servo vacuum
test.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals or seals. If
these components are damaged, intermittent or
complete system failure may occur.
SPECIFICATIONS
TORQUE - SPEED CONTROL
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Servo Mounting Bracket-to-Servo Nuts 9 - 75
Servo Mounting Bracket-to-Body Bolts 12 - 105
Speed Control Switch Mounting Screws 1.5 - 14
Vacuum Reservoir Mounting Screws 3 - 20
8P - 2 SPEED CONTROLKJ
SPEED CONTROL (Continued)

CABLE
DESCRIPTION
The speed control servo cable is connected between
the speed control vacuum servo diaphragm and the
throttle body control linkage.
OPERATION
This cable causes the throttle control linkage to
open or close the throttle valve in response to move-
ment of the vacuum servo diaphragm.
REMOVAL - 3.7L
(1) Disconnect negative battery cable at battery.
(2) Remove air filter resonator at throttle body.
The accelerator cable must be partially removed to
gain access to speed control cable.
(3) Hold throttle in wide open position. While held
in this position, slide throttle cable pin (Fig. 1) from
throttle body bellcrank.
(4) Using a pick or small screwdriver, press release
tab (Fig. 2) to release plastic cable mount from
bracket.Press on tab only enough to release
cable from bracket. If tab is pressed too much,
it will be broken.Slide plastic mount (Fig. 2)
towards right side of vehicle to remove throttle cable
from throttle body bracket.(5) Using finger pressure only, disconnect servo
cable connector (Fig. 3) at throttle body bellcrank pin
by pushing connector off bellcrank pin towards front
of vehicle.DO NOT try to pull connector off per-
pendicular to the bellcrank pin. Connector will
be broken.
Fig. 1 THROTTLE CABLE PIN
1 - THROTTLE CABLE PIN
2 - THROTTLE BODY BELLCRANK
3 - PUSH UP HERE
Fig. 2 THROTTLE CABLE RELEASE TAB
1 - THROTTLE CABLE
2 - RELEASE TAB
3 - PICK OR SCREWDRIVER
4 - PLASTIC CABLE MOUNT
Fig. 3 SPEED CONTROL CABLE AT BELLCRANK
1 - THROTTLE BODY BELLCRANK
2 - SPEED CONTROL CABLE CONNECTOR
KJSPEED CONTROL 8P - 3

(6) Slide speed control cable plastic mount towards
right of vehicle to remove cable from throttle body
bracket (Fig. 4).
(7) Remove servo cable from servo. Refer to Servo
Removal/Installation.
INSTALLATION - 3.7L
(1) Install end of cable to speed control servo.
Refer to Servo Removal/Installation.
(2) Slide speed control cable plastic mount into
throttle body bracket.
(3) Install speed control cable connector onto throt-
tle body bellcrank pin (push rearward to snap into
location).
(4) Slide throttle (accelerator) cable plastic mount
into throttle body bracket. Continue sliding until
cable release tab is aligned to hole in throttle body
mounting bracket.
(5) While holding throttle to wide open position,
place throttle cable pin into throttle body bellcrank.
(6) Install air filter resonator box to throttle body.
(7) Connect negative battery cable at battery.
(8) Before starting engine, operate accelerator
pedal to check for any binding.
SERVO
DESCRIPTION
The servo unit consists of a solenoid valve body,
and a vacuum chamber. The solenoid valve body con-
tains three solenoids:²Vacuum
²Vent
²Dump
The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
The Powertrain Control Module (PCM) controls the
solenoid valve body. The solenoid valve body controls
the application and release of vacuum to the dia-
phragm of the vacuum servo. The servo unit cannot
be repaired and is serviced only as a complete assem-
bly.
Power is supplied to the servo's by the PCM
through the brake switch. The PCM controls the
ground path for the vacuum and vent solenoids.
The dump solenoid is energized anytime it receives
power. If power to the dump solenoid is interrupted,
the solenoid dumps vacuum in the servo. This pro-
vides a safety backup to the vent and vacuum sole-
noids.
The vacuum and vent solenoids must be grounded
at the PCM to operate. When the PCM grounds the
vacuum servo solenoid, the solenoid allows vacuum
to enter the servo and pull open the throttle plate
using the cable. When the PCM breaks the ground,
the solenoid closes and no more vacuum is allowed to
enter the servo. The PCM also operates the vent sole-
noid via ground. The vent solenoid opens and closes a
passage to bleed or hold vacuum in the servo as
required.
The PCM duty cycles the vacuum and vent sole-
noids to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. When
the brake is released, if vehicle speed exceeds 30
mph to resume, 35 mph to set, and the RES/ACCEL
switch has been depressed, ground for the vent and
vacuum circuits is restored.
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Disconnect vacuum line at servo (Fig. 5).
(3) Disconnect electrical connector at servo (Fig. 5).
(4) Remove coolant bottle nuts/bolts. Position bot-
tle forward a few inches.
(5) Disconnect servo cable at throttle body. Refer to
servo Cable Removal/Installation.
(6) Remove servo bracket mounting nuts (Fig. 5).
(7) Remove 2 mounting nuts holding servo cable
sleeve to bracket (Fig. 6).
(8) Pull speed control cable sleeve and servo away
from servo mounting bracket to expose cable retain-
ing clip (Fig. 6) and remove clip. Note: The servo
Fig. 4 SPEED CONTROL CABLE AT BRACKET
1 - THROTTLE CABLE BRACKET
2 - PLASTIC CABLE MOUNT
3 - SPEED CONTROL CABLE
8P - 4 SPEED CONTROLKJ
CABLE (Continued)

mounting bracket displayed in (Fig. 6) is a typical
bracket and may/may not be applicable to this model
vehicle.
(9) Remove servo from mounting bracket. While
removing, note orientation of servo to bracket.INSTALLATION
(1) Position servo to mounting bracket.
(2) Align hole in cable connector with hole in servo
pin. Install cable-to-servo retaining clip.
(3) Insert servo mounting studs through holes in
servo mounting bracket.
(4) Install servo-to-mounting bracket nuts and
tighten. Refer to torque specifications.
(5) Install servo mounting bracket-to-body nuts
and tighten. Refer to torque specifications.
(6) Connect vacuum line at servo.
(7) Connect electrical connector at servo.
(8) Connect servo cable to throttle body. Refer to
servo Cable Removal/Installation.
(9) Install coolant bottle.
(10) Connect negative battery cable to battery.
(11) Before starting engine, operate accelerator
pedal to check for any binding.
SWITCH
DESCRIPTION
There are two separate switch pods that operate
the speed control system. The steering-wheel-
mounted switches use multiplexed circuits to provide
inputs to the PCM for ON, OFF, RESUME, ACCEL-
ERATE, SET, DECEL and CANCEL modes. Refer to
the owner's manual for more information on speed
control switch functions and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
OPERATION
When speed control is selected by depressing the
ON, OFF switch, the PCM allows a set speed to be
stored in its RAM for speed control. To store a set
speed, depress the SET switch while the vehicle is
moving at a speed between approximately 35 and 85
mph. In order for the speed control to engage, the
brakes cannot be applied, nor can the gear selector
be indicating the transmission is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²An indication of Park or Neutral
²The VSS signal increases at a rate of 10 mph
per second (indicates that the co-efficient of friction
between the road surface and tires is extremely low)
²Depressing the clutch pedal.
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
Fig. 5 SPEED CONTROL SERVO
1-9T9FITTING
2 - VACUUM LINE
3 - SERVO BRACKET MOUNTING NUTS
4 - SERVO MOUNTING BRACKET
5 - SERVO
6 - SERVO ELECTRICAL CONNECTOR
Fig. 6 SERVO CABLE CLIP REMOVE/INSTALL
TYPICAL
1 - SERVO MOUNTING NUTS (2)
2 - SERVO
3 - CABLE RETAINING CLIP
4 - SERVO CABLE AND SLEEVE
KJSPEED CONTROL 8P - 5
SERVO (Continued)

²The VSS signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
²If the actual speed is not within 20 mph of the
set speed
The previous disengagement conditions are pro-
grammed for added safety.
Once the speed control has been disengaged,
depressing the ACCEL switch restores the vehicle to
the target speed that was stored in the PCM's RAM.
NOTE: Depressing the OFF switch will erase the set
speed stored in the PCM's RAM.
If, while the speed control is engaged, the driver
wishes to increase vehicle speed, the PCM is pro-
grammed for an acceleration feature. With the
ACCEL switch held closed, the vehicle accelerates
slowly to the desired speed. The new target speed is
stored in the PCM's RAM when the ACCEL switch is
released. The PCM also has a9tap-up9feature in
which vehicle speed increases at a rate of approxi-
mately 2 mph for each momentary switch activation
of the ACCEL switch.
The PCM also provides a means to decelerate with-
out disengaging speed control. To decelerate from an
existing recorded target speed, depress and hold the
COAST switch until the desired speed is reached.
Then release the switch. The ON, OFF switch oper-
ates two components: the PCM's ON, OFF input, and
the battery voltage to the brake switch, which powers
the speed control servo.
Multiplexing
The PCM sends out 5 volts through a fixed resistor
and monitors the voltage change between the fixed
resistor and the switches. If none of the switches are
depressed, the PCM will measure 5 volts at the sen-
sor point (open circuit). If a switch with no resistor is
closed, the PCM will measure 0 volts (grounded cir-
cuit). Now, if a resistor is added to a switch, then the
PCM will measure some voltage proportional to the
size of the resistor. By adding a different resistor to
each switch, the PCM will see a different voltage
depending on which switch is pushed.
Another resistor has been added to the 'at rest cir-
cuit' causing the PCM to never see 5 volts. This was
done for diagnostic purposes. If the switch circuit
should open (bad connection), then the PCM will see
the 5 volts and know the circuit is bad. The PCM will
then set an open circuit fault.
REMOVAL
WARNING: BEFORE ATTEMPTING TO DIAGNOSE,
REMOVE OR INSTALL ANY AIRBAG SYSTEM OR
RELATED STEERING WHEEL AND STEERING COL-
UMN COMPONENTS YOU MUST FIRST DISCON-
NECT AND ISOLATE THE NEGATIVE (GROUND)
BATTERY CABLE. WAIT 2 MINUTES FOR SYSTEM
CAPACITOR TO DISCHARGE BEFORE FURTHER
SYSTEM SERVICE. FAILURE TO DO SO COULD
RESULT IN ACCIDENTAL DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
(1) Disconnect and isolate negative battery cable
from battery.
(2) Remove airbag module. Refer to Restraint Sys-
tems.
(3) Unplug electrical connector (Fig. 7).
(4) Remove speed control switch mounting screw
(Fig. 7) and remove switch from steering wheel.
INSTALLATION
(1) Position switch to steering wheel.
(2) Install switch mounting screw and tighten.
Refer to torque specifications.
(3) Plug electrical connector into switch.
(4) Install airbag module. Refer to Restraint Sys-
tems.
(5) Connect negative battery cable to battery.
Fig. 7 SPEED CONTROL SWITCH
1 - SWITCH
2 - SCREW
3 - ELECTRICAL CONNECTOR
8P - 6 SPEED CONTROLKJ
SWITCH (Continued)

VACUUM RESERVOIR
DESCRIPTION
The vacuum reservoir is a plastic storage tank con-
nected to an engine vacuum source by vacuum lines.
OPERATION
The vacuum reservoir is used to supply the vac-
uum needed to maintain proper speed control opera-
tion when engine vacuum drops, such as in climbing
a grade while driving. A one-way check valve is used
in the vacuum line between the reservoir and the
vacuum source. This check valve is used to trap
engine vacuum in the reservoir. On certain vehicle
applications, this reservoir is shared with the heat-
ing/air-conditioning system. The vacuum reservoir
cannot be repaired and must be replaced if faulty.
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR
(1) Disconnect vacuum hose at speed control servo
and install a vacuum gauge into the disconnected
hose.
(2) Start engine and observe gauge at idle. Vac-
uum gauge should read at least ten inches of mer-
cury.
(3) If vacuum is less than ten inches of mercury,
determine source of leak. Check vacuum line to
engine for leaks. Also check actual engine intake
manifold vacuum. If manifold vacuum does not meet
this requirement, check for poor engine performance
and repair as necessary.
(4) If vacuum line to engine is not leaking, check
for leak at vacuum reservoir. To locate and gain
access to reservoir, refer to Vacuum Reservoir Remov-
al/Installation in this group. Disconnect vacuum line
at reservoir and connect a hand-operated vacuum
pump to reservoir fitting. Apply vacuum. Reservoir
vacuum should not bleed off. If vacuum is being lost,
replace reservoir.
(5) Verify operation of one-way check valve and
check it for leaks.Certain models may be
equipped with 2 check-valves.
(a) Locate one-way check valve. The valve is
located in vacuum line between vacuum reservoir
and engine vacuum source. Disconnect vacuum
hoses (lines) at each end of valve.
(b) Connect a hand-operated vacuum pump to
reservoir end of check valve. Apply vacuum. Vac-
uum should not bleed off. If vacuum is being lost,
replace one-way check valve.
(c) Connect a hand-operated vacuum pump to
vacuum source end of check valve. Apply vacuum.
Vacuum should flow through valve. If vacuum is
not flowing, replace one-way check valve. Seal thefitting at opposite end of valve with a finger and
apply vacuum. If vacuum will not hold, diaphragm
within check valve has ruptured. Replace valve.
REMOVAL
The vacuum reservoir is located behind, and at the
outer end of the instrument panel (Fig. 8). To gain
access for testing or removal, remove glovebox assem-
bly. Also remove fuse box access cover panel at end of
instrument panel. On vehicles equipped with LHD
(Left Hand Drive), this fuse access panel is located at
right end of instrument panel. On vehicles equipped
with RHD (Right Hand Drive), this access panel is
located at left end of instrument panel.
(1) Remove glovebox assembly. Access to reservoir
vacuum line and fitting can now be made.
(2) Remove vacuum line at reservoir.
(3) Remove fuse access cover panel at end of
instrument panel.
(4) Through fuse access opening, remove 2 horizon-
tally mounted screws (Fig. 8).
(5) From bottom of instrument panel, remove 1
vertically mounted screw (Fig. 9).
(6) Remove reservoir from instrument panel.
Fig. 8 VACUUM RESERVOIR LOCATION
1 - VACUUM RESERVOIR
2 - HORIZONTAL MOUNTING SCREWS
3 - OUTBOARD END OF I.P.
KJSPEED CONTROL 8P - 7

INSTALLATION
The vacuum reservoir is located behind, and at the
outer end of the instrument panel. To gain access for
testing or removal, remove glovebox assembly. Also
remove fuse box access cover panel at end of instru-
ment panel. On vehicles equipped with LHD (Left
Hand Drive), this fuse access panel is located at right
end of instrument panel. On vehicles equipped with
RHD (Right Hand Drive), this access panel is located
at left end of instrument panel.
(1) Position reservoir to instrument panel.
(2) Install 3 mounting screws and tighten. Refer to
torque specifications.
(3) Connect vacuum line to reservoir fitting.
(4) Install glovebox assembly.
(5) Install fuse box access cover panel.
Fig. 9 VACUUM RESERVOIR REMOVE/INSTALL
1 - VACUUM RESERVOIR
2 - HORIZONTAL MOUNTING SCREWS (2)
3 - VERTICAL MOUNTING SCREW (1)
8P - 8 SPEED CONTROLKJ
VACUUM RESERVOIR (Continued)

VEHICLE THEFT SECURITY
TABLE OF CONTENTS
page page
VEHICLE THEFT SECURITY
DESCRIPTION..........................1
OPERATION............................3
DIAGNOSIS AND TESTING - VEHICLE THEFT
SECURITY SYSTEM....................6
STANDARD PROCEDURE
STANDARD PROCEDURE - SKIS
INITIALIZATION........................8
STANDARD PROCEDURE - SENTRY KEY
TRANSPONDER PROGRAMMING..........8
DOOR CYLINDER LOCK SWITCH
DESCRIPTION..........................9
OPERATION...........................10
DIAGNOSIS AND TESTING - DOOR
CYLINDER LOCK SWITCH..............10
REMOVAL.............................10
INSTALLATION.........................10
HOOD AJAR SWITCH
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - HOOD AJAR
SWITCH............................12REMOVAL.............................12
INSTALLATION.........................12
HOOD AJAR SWITCH BRACKET
REMOVAL.............................13
INSTALLATION.........................13
HOOD AJAR SWITCH STRIKER
REMOVAL.............................13
INSTALLATION.........................14
INTRUSION TRANSCEIVER MODULE
DESCRIPTION.........................14
OPERATION...........................15
REMOVAL.............................15
INSTALLATION.........................16
SIREN
DESCRIPTION.........................16
OPERATION...........................17
REMOVAL.............................17
INSTALLATION.........................17
TRANSPONDER KEY
DESCRIPTION.........................18
OPERATION...........................18
VEHICLE THEFT SECURITY
DESCRIPTION
The Vehicle Theft Security System (VTSS) is an
available factory-installed option on this model (Fig.
1). The VTSS is comprised of two primary sub-
systems: Vehicle Theft Alarm (VTA) and Sentry Key
Immobilizer System (SKIS). The VTA is an active
system that provides visual and audible responses as
deterrents to and warnings of unauthorized vehicle
tampering. The SKIS is a passive system that effec-
tively immobilizes the vehicle against unauthorized
operation. Following are paragraphs which describe
the various components that are included in each of
these subsystems of the VTSS.
Hard wired circuitry connects many of the VTSS
components to each other through the electrical sys-
tem of the vehicle. These hard wired circuits are
integral to several wire harnesses, which are routed
throughout the vehicle and retained by many differ-
ent methods. These circuits may be connected to each
other, to the vehicle electrical system and to the
VTSS components through the use of a combination
of soldered splices, splice block connectors, and many
different types of wire harness terminal connectorsand insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
VEHICLE THEFT ALARM The VTA is available in
two different configurations for this vehicle: One con-
figuration is designed for vehicles manufactured for
sale in North America; while, the other configuration
is designed for vehicles manufactured for sale in
markets outside of North America, also referred to as
Rest-Of-World or ROW. In addition, the VTA for
ROW is available in two versions: base and premium.
All vehicles equipped with VTA are also equipped
with the Remote Keyless Entry (RKE) system and
the Sentry Key Immobilizer System (SKIS), regard-
less of their market destination. The North American
and ROW base version of the VTA provides perimeter
vehicle protection by monitoring the vehicle doors,
the tailgate, the rear flip-up glass and, for vehicles
built for certain markets where it is required equip-
ment, the hood. If unauthorized vehicle use or tam-
pering is detected, these systems respond by pulsing
the horn and flashing certain exterior lamps. The
ROW premium version of the VTA is only available
KJVEHICLE THEFT SECURITY 8Q - 1