2002 DODGE RAM service

(6) Remove the passenger airbag on/off switch and
face plate from the instrument panel as a unit.
(7) Remove the three screws that secure the pas-
senger airbag on/off switch to the back of the switch
face plate (Fig. 22).(8) Remove the passenger airbag on/off switch
from the face plate.
INSTALLATION
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) Position the passenger airbag on/off switch to
the back of the face plate (Fig. 22).
(2) Install and tighten the three screws that secure
the passenger airbag on/off switch to the face plate.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Route the passenger airbag on/off switch pigtail
wires through the switch opening of the instrument
panel.
(4) Reach through the glove box opening to access
and reconnect the two passenger airbag on/off switch
pigtail wire connectors to the instrument panel wire
harness connectors. These connectors are retained on
a bracket located on the inboard glove box opening
reinforcement (Fig. 20). Be certain that both connec-
tors are fully engaged and latched.
Fig. 20 Passenger Airbag On/Off Switch Connectors
1 - PASSENGER SIDE AIRBAG ON/OFF SWITCH WIRE
HARNESS CONNECTORS
2 - INSTRUMENT PANEL WIRE HARNESS CONNECTORS
3 - BRACKET
4 - REINFORCEMENT
Fig. 21 Passenger Airbag On/Off Switch Remove/
Install
1 - SCREWS (3)
2 - PASSENGER AIRBAG ON/OFF SWITCH BEZEL
Fig. 22 Passenger Airbag On/Off Switch Face Plate
Remove/Install
1 - PASSENGER SIDE AIRBAG ON/OFF SWITCH
2 - SCREW (3)
3 - SWITCH BEZEL
BR/BERESTRAINTS 8O - 25
PASSENGER AIRBAG ON/OFF SWITCH (Continued)

(5) Position the passenger airbag on/off switch and
face plate unit to the opening in the instrument
panel (Fig. 21).
(6) Install and tighten the three screws that secure
the passenger airbag on/off switch face plate to the
instrument panel. Tighten the screws to 2.2 N´m (20
in. lbs.).
(7) Reinstall the glove box onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - INSTALLATION).
(8) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(9) Do not reconnect the battery negative cable at
this time. The airbag system verification test proce-
dure should be performed following service of any
airbag system component. (Refer to 8 - ELECTRI-
CAL/RESTRAINTS - STANDARD PROCEDURE -
VERIFICATION TEST).
REAR SEAT BELT &
RETRACTOR
REMOVAL
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Remove the rear seat from the passenger com-
partment. (Refer to 23 - BODY/SEATS/REAR SEAT -
REMOVAL).
(2) Remove the trim cover from the door sill.
(Refer to 23 - BODY/INTERIOR/DOOR SILL TRIM -
REMOVAL).
(3) Remove the screw that secures the lower seat
belt anchor plate to the quarter inner panel near the
base of the C-pillar (Fig. 23).
(4) Unsnap and lift the rear shoulder belt turning
loop cover to access the screw that secures the turn-
ing loop to the quarter inner panel near the top of
the C-pillar.(5) Remove the screw that secures the shoulder
belt turning loop to the quarter inner panel.
(6) Remove the trim from the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(7) Disengage the rear seat shoulder belt turning
loop and lower seat belt anchor plate from the quar-
ter trim panel.
(8) Remove the screw that secures the retractor to
the quarter inner panel near the C-pillar.
(9) Remove the rear shoulder belt and retractor
from the quarter inner panel.
INSTALLATION
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Position the rear shoulder belt retractor onto
the quarter inner panel (Fig. 23).
Fig. 23 Rear Seat Belt & Retractor - Typical
1 - TURNING LOOP
2 - REAR SEAT BELT AND RETRACTOR
3 - QUARTER TRIM PANEL
8O - 26 RESTRAINTSBR/BE
PASSENGER AIRBAG ON/OFF SWITCH (Continued)

(2) Install and tighten the screw that secures the
retractor to the quarter inner panel. Tighten the
screw to 40 N´m (29 ft. lbs.).
(3) Engage the rear seat shoulder belt turning loop
and lower seat belt anchor plate with the quarter
trim panel.
(4) Reinstall the trim onto the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - INSTALLATION).
(5) Position the shoulder belt turning loop onto the
quarter inner panel near the top of the C-pillar.
(6) Install and tighten the screw that secures the
shoulder belt turning loop to the quarter inner panel.
Tighten the screw to 40 N´m (29 ft. lbs.).
(7) Fold and snap the cover over the rear shoulder
belt turning loop to conceal the screw that secures
the turning loop to the quarter inner panel.
(8) Position the lower seat belt anchor plate onto
the quarter inner panel near the base of the C-pillar.
(9) Install and tighten the screw that secures the
lower seat belt anchor plate to the quarter inner
panel near the base of the C-pillar. Tighten the screw
to 40 N´m (29 ft. lbs.).
(10) Reinstall the trim cover onto the door sill.
(Refer to 23 - BODY/INTERIOR/DOOR SILL TRIM -
INSTALLATION).
(11) Reinstall the rear seat into the passenger
compartment. (Refer to 23 - BODY/SEATS/REAR
SEAT - INSTALLATION).
REAR SEAT BELT BUCKLE
REMOVAL
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Disengage the rear seat latch by pulling the
release handle on the underside of the rear seat
cushion.(2) Fold the rear seat unit up and back against the
cab back panel (stowed position) for access to the
rear seat belt buckle anchors.
(3) Reach through the opening between the rear
seat back and the floor panel to access and remove
the nut that secures the rear seat belt buckle/buckle
unit (right side) or lap belt/buckle unit (left side)
anchor plate to the stud on the rear floor panel (Fig.
24).
(4) Remove the rear seat belt buckle/buckle unit
(right side) or lap belt/buckle unit (left side) from the
rear floor panel.INSTALLATION
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
Fig. 24 Rear Seat Belt Buckle Remove/Install
1 - CAB BACK PANEL
2 - REAR FLOOR PANEL
3 - REAR SEAT BUCKLE/BUCKLE UNIT
4 - REAR SEAT LAP BELT/BUCKLE UNIT
BR/BERESTRAINTS 8O - 27
REAR SEAT BELT & RETRACTOR (Continued)

(1) Reach through the opening between the rear
seat back and the floor panel to position the rear seat
belt buckle/buckle unit (right side) or lap belt/buckle
unit (left side) onto the stud on the rear floor panel
(Fig. 24).
(2) Install and tighten the nut that secures the
rear seat belt buckle/buckle unit (right side) or lap
belt/buckle unit (left side) anchor plate to the stud on
the rear floor panel. Tighten the nut to 40 N´m (29 ft.
lbs.).
(3) Route the lap belt and buckles between the
rear seat back and rear seat cushion.
(4) Disengage the rear seat from its stowed posi-
tion by pulling the release handle on the underside of
the rear seat cushion.
(5) Fold the rear seat cushion down toward the
rear floor panel until the unit is latched in its open
position.
SEAT BELT SWITCH
DESCRIPTION
The seat belt switch is a small, normally closed,
single pole, single throw, leaf contact, momentary
switch. Only one seat belt switch is installed in the
vehicle, and it is integral to the buckle of the driver
seat belt buckle-half, located near the inboard side of
the driver side front seating position. The seat belt
switch is connected to the vehicle electrical system
through a two-wire pigtail wire and connector on the
seat belt buckle-half, which is connected to a wire
harness connector and take out of the body wire har-
ness.
The seat belt switch cannot be adjusted or repaired
and, if faulty or damaged, the entire driver seat belt
buckle-half unit must be replaced.
OPERATION
The seat belt switch is designed to control a path
to ground for the seat belt switch sense input of the
Electro-Mechanical Instrument Cluster (EMIC).
When the driver side seat belt tip-half is inserted in
the seat belt buckle, the switch opens the path to
ground; and, when the driver side seat belt tip-half is
removed from the seat belt buckle, the switch closes
the ground path. The switch is actuated by the latch
mechanism within the seat belt buckle. The EMIC
monitors the driver seat belt switch status, then con-
trols the seatbelt indicator and sends hard wired
chime requests to the Central Timer Module (CTM)
based upon that input.
The seat belt switch receives ground through its
pigtail wire connection to the body wire harness from
another take out of the body wire harness. An eyelet
terminal connector on that ground take out issecured under a nut to a ground stud on the left
lower B-pillar (standard cab models) or the left lower
cowl side inner panel (club cab and quad cab models).
The seat belt switch is connected in series between
ground and the seat belt switch sense input of the
EMIC.
DIAGNOSIS AND TESTING - SEAT BELT
SWITCH
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the seat belt switch from the seat belt switch pigtail
wire connector located near the floor panel under the
driver side front seat cushion. Check for continuity
between the seat belt switch sense circuit and the
ground circuit cavities in the seat belt switch pigtail
wire connector. There should be continuity with the
driver side seat belt tip-half and buckle-half unfas-
tened, and no continuity with tip-half and buckle-half
fastened. If OK, go to Step 2. If not OK, replace the
faulty driver side seat belt buckle-half unit.
(2) Check for continuity between the ground cir-
cuit cavity in the body wire harness connector for the
seat belt switch and a good ground. There should be
continuity. If OK, go to Step 3. If not OK, repair the
open ground circuit to ground (G301 - standard cab,
or G300 - club/quad cab) as required.
(3) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the seat
belt switch sense circuit cavity in the instrument
panel wire harness connector (Connector C2) for the
instrument cluster and a good ground. There should
be no continuity. If OK, go to Step 4. If not OK,
repair the shorted seat belt switch sense circuit
8O - 28 RESTRAINTSBR/BE
REAR SEAT BELT BUCKLE (Continued)

between the seat belt switch and the instrument
cluster as required.
(4) Check for continuity between the seat belt
switch sense circuit cavities in the body wire harness
connector for the seat belt switch and the instrument
panel wire harness connector (Connector C2) for the
instrument cluster. There should be continuity. If
OK, proceed to the diagnosis for the instrument clus-
ter. (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). If not OK,
repair the open seat belt switch sense circuit between
the seat belt switch and the instrument cluster as
required.
SEAT BELT TURNING LOOP
ADJUSTER
REMOVAL
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Remove the knob from the lever of the seat belt
turning loop adjuster. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/TURNING LOOP HEIGHT ADJUSTER
KNOB - REMOVAL).
(2) Remove the screw that secures the shoulder
belt turning loop to the height adjuster.
(3) Remove the trim from the B-pillar. (Refer to 23
- BODY/INTERIOR/B-PILLAR TRIM - REMOVAL).
(4) Remove the screw that secures the upper end
of the height adjuster to the B-pillar.(5) Pull the upper end of the height adjuster away
from the B-pillar far enough to disengage the hooks
on the lower end of the adjuster from the slots in the
pillar.
(6) Remove the adjuster from the B-pillar.
INSTALLATION
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Position the height adjuster to the B-pillar
with the hook formations oriented toward the lower
end of the adjuster.
(2) Engage the hooks on the lower end of the
adjuster into the slots in the B-pillar.
(3) Tilt the upper end of the height adjuster up
into position against the B-pillar.
(4) Install and tighten the screw that secures the
upper end of the height adjuster to the B-pillar.
Tighten the screw to 41 N´m (30 ft. lbs.).
(5) Reinstall the trim onto the B-pillar. (Refer to
23 - BODY/INTERIOR/B-PILLAR TRIM - INSTAL-
LATION).
(6) Install and tighten the anchor screw that
secures the seat belt turning loop to the adjuster.
Tighten the screw to 30 N´m (22 ft. lbs.).
(7) Reinstall the knob onto the lever of the seat
belt turning loop adjuster. (Refer to 8 - ELECTRI-
CAL/RESTRAINTS/TURNING LOOP HEIGHT
ADJUSTER KNOB - INSTALLATION).
BR/BERESTRAINTS 8O - 29
SEAT BELT SWITCH (Continued)

TURNING LOOP HGT
ADJUSTER KNOB
REMOVAL
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Unsnap and lift the seat belt turning loop cover
to expose the anchor screw that secures the turning
loop to the height adjuster.
(2) Using the head of the turning loop anchor
screw as a fulcrum, carefully pry the knob from the
height adjuster lever with a suitable trim tool (Fig.
25).
INSTALLATION
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE ORRETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Fold and snap the seat belt turning loop cover
back into place over the anchor screw that secures
the turning loop to the adjuster.
(2) Position the height adjuster knob to the seat
belt turning loop height adjuster lever.
(3) Using hand pressure, push the knob firmly and
evenly onto the lever until it is fully engaged.
Fig. 25 Turning Loop Height Adjuster Knob
Removal - Typical
1 - KNOB
2 - ADJUSTER LEVER
3 - SEAT BELT TURNING LOOP
4 - TRIM TOOL (SNAP-ON A179A)
8O - 30 RESTRAINTSBR/BE

DIAGNOSIS AND TESTING - ROAD TEST
Perform a vehicle road test to verify reports of
speed control system malfunction. The road test
should include attention to the speedometer.
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 Mopart
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 SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Servo Mounting Bracket
Nuts8.5 - 75
Switch Module Mounting
Screws3-26
Vacuum Reservoir
Mounting Screws2.2 -
20
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
REMOVAL - GAS ENGINES
(1) Disconnect negative battery cable at battery.
(2) Remove air cleaner (all except 8.0L V-10
engine).(3) Using finger pressure only, remove speed con-
trol cable connector at bellcrank by pushing connec-
tor off the bellcrank pin (Fig. 1) or (Fig. 2).DO NOT
try to pull connector off perpendicular to the
bellcrank pin. Connector will be broken.Fig. 1 Servo Cable at Throttle BodyÐV6/V-8 Engine
1 - VEHICLE SPEED CONTROL CABLE
8P - 4 SPEED CONTROLBR/BE
SPEED CONTROL (Continued)

INSTALLATION - DIESEL WITH AUTO. TRANS.
(1) Install (connect) end of speed control servo
cable to speed control servo. Refer to Speed Control
Servo Removal/Installation.
(2) Install cable through mounting hole on mount-
ing bracket. Cable snaps into bracket.
(3) Connect servo cable to throttle lever by push-
ing cable connector rearward onto lever pin while
holding lever forward.
(4) Connect negative battery cables to both batter-
ies.
(5) Before starting engine, operate accelerator
pedal to check for any binding.
(6) Install cable/lever cover.
SPEED CONTROL SERVO
DESCRIPTION
A speed control servo is not used if equipped
with both a diesel engine and a manual trans-
mission.
The servo unit consists of a solenoid valve body,
and a vacuum chamber. The solenoid valve body con-
tains three solenoids:
²Vacuum²Vent
²Dump
The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
A speed control servo is not used if equipped
with both a diesel engine and a manual trans-
mission.
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
REMOVAL
V-8 ENGINE
(1) Disconnect negative battery cable at battery.
(2) Disconnect electrical connector at servo (Fig. 4).
(3) Disconnect vacuum hose at servo.
(4) Disconnect servo cable at throttle body. Refer to
Servo Cable Removal/Installation in this group.
Fig. 3 Servo Cable at Throttle Lever
1 - PINCH (2) TABS
2 - CABLE MOUNTING BRACKET
3 - PINCH TABS (2)
4 - OFF
5 - THROTTLE CABLE
6 - THROTTLE LEVER
7 - THROTTLE LEVER PIN
8 - OFF
9 - CONNECTOR
10 - SPEED CONTROL CABLE
8P - 6 SPEED CONTROLBR/BE
CABLE (Continued)