DODGE RAM 2001 Service Repair Manual

Page 701 of 2889

(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)

Page 702 of 2889

(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)

Page 703 of 2889

(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 is
secured 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.
8O - 28 RESTRAINTSBR/BE
REAR SEAT BELT BUCKLE (Continued)

Page 704 of 2889

(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
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)

Page 705 of 2889

TURNING LOOP HEIGHT
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 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) 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

Page 706 of 2889

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION............................1
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
VACUUM SUPPLY.......................2
ROAD TEST............................3
SPECIFICATIONS.........................4
CABLE
DESCRIPTION............................4
OPERATION.............................4
REMOVAL...............................4
INSTALLATION............................4
SPEED CONTROL SERVO
DESCRIPTION............................5OPERATION.............................5
REMOVAL...............................6
INSTALLATION...........................10
SWITCH
DESCRIPTION...........................12
OPERATION.............................12
REMOVAL..............................13
INSTALLATION...........................13
VACUUM RESERVOIR
DESCRIPTION...........................13
REMOVAL..............................13
INSTALLATION...........................14
SPEED CONTROL
DESCRIPTION - SPEED CONTROL SYSTEM
Gas Engines and/or Diesel With Automatic Trans.
The speed control system is operated by the use of
a cable and a vacuum controlled servo. Electronic
control of the speed control system is integrated into
the Powertrain Control Module (PCM). The controls
consist of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
Diesel With Manual Trans.
The speed control system is fully electronically con-
trolled by the Engine Control Module (ECM).A
cable and a vacuum controlled servo are not
used if the vehicle is equipped with a manual
transmission and a diesel engine. This is a ser-
vo-less system.The controls consist of two steering
wheel mounted switches. The switches are labeled:
ON/OFF, RES/ACCEL, SET, COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
DESCRIPTION - VEHICLE SPEED INPUT
Gas Engines and/or Diesel With Automatic Trans.
The Vehicle Speed Sensor (VSS) is no longer used
for any Dodge Truck.
Vehicle speed and distance covered are measured by
the Rear Wheel Speed Sensor. The sensor is mounted
to the rear axle. A signal is sent from this sensor to the
Controller Antilock Brake (CAB) computer. A signal is
then sent from the CAB to the Powertrain Control
Module (PCM) to determine vehicle speed and distance
covered. The PCM will then determine strategies for
speed control system operation.
Diesel With Manual Trans.
The Vehicle Speed Sensor (VSS) is no longer used
for any Dodge Truck.
Vehicle speed and distance covered are measured
by the Rear Wheel Speed Sensor. The sensor is
mounted to the rear axle. A signal is sent from this
sensor to the Controller Antilock Brake (CAB) com-
puter. A signal is then sent from the CAB to the
Engine Control Module (ECM) to determine vehicle
speed and distance covered. The ECM will then
determine strategies for speed control system opera-
tion.
BR/BESPEED CONTROL 8P - 1

Page 707 of 2889

OPERATION - SPEED CONTROL SYSTEM
Gas Engines and/or Diesel With Automatic Trans.
When speed control is selected by depressing the
ON switch, the PCM allows a set speed to be stored
in PCM RAM for speed control. To store a set speed,
depress the SET switch while the vehicle is moving
at a speed between 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.
²Depressing the clutch pedal (if equipped)
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the PCM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²An indication of Park or Neutral
²A rapid increase of rpm (indication that the
clutch has been disengaged)
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM when the RES/ACCEL is released. The PCM
also has a9tap-up9feature in which vehicle speed
increases at a rate of approximately 2 mph for each
momentary switch activation of the RES/ACCEL
switch.
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.
Diesel With Manual Trans.
When speed control is selected by depressing the
ON switch, the Engine Control Module (ECM) allows
a set speed to be stored in ECM RAM for speed con-trol. To store a set speed, depress the SET switch
while the vehicle is moving at a speed between 35
and 85 mph. In order for the speed control to engage,
the brakes cannot be applied.The speed control can
be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
²Depressing the clutch pedal
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the ECM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²A rapid increase of rpm (indication that the
clutch has been disengaged)
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the ECM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
ECM when the RES/ACCEL is released. The ECM also
has a9tap-up9feature in which vehicle speed increases
at a rate of approximately 2 mph for each momentary
switch activation of the RES/ACCEL switch.
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.
DIAGNOSIS AND TESTING - VACUUM SUPPLY
Gas Powered Engines
On gasoline powered engines: actual engine vac-
uum, a vacuum reservoir, a one-way check valve and
vacuum lines are used to supply vacuum to the speed
control servo.
(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.
8P - 2 SPEED CONTROLBR/BE
SPEED CONTROL (Continued)

Page 708 of 2889

(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.
(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 the
fitting at opposite end of valve with a finger and
apply vacuum. If vacuum will not hold, diaphragm
within check valve has ruptured. Replace valve.
Diesel Engines With Automatic Trans.
On diesel powered engines equipped with an auto-
matic transmission: an engine driven vacuum pump,
a one-way check valve and vacuum lines are used to
supply vacuum to the speed control servo. A vacuum
reservoir is not used.
(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. For
vacuum testing and vacuum specifications, refer to
Vacuum Pump OutputÐDiesel Engine in 9, Engines.
(3) If vacuum pump output is OK, determine other
source of leak. Check all vacuum lines to: speed con-
trol servo, engine vacuum pump and heating/air con-
ditioning system for leaks.
(4) Verify operation of one-way check valve and
check it for leaks.(a) Locate one-way check valve. The valve is
located in vacuum line between speed control servo
and engine vacuum pump. 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 the
fitting at opposite end of valve with a finger and
apply vacuum. If vacuum will not hold, diaphragm
within check valve has ruptured. Replace valve.
Diesel Engine With Manual Trans.
Vacuum is not used for any part of the speed con-
trol system if equipped with a diesel engine and a
manual transmission.
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 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.
BR/BESPEED CONTROL 8P - 3
SPEED CONTROL (Continued)

Page 709 of 2889

SPECIFICATIONS
TORQUE - SPEED CONTROL SYSTEM
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Servo Mounting Bracket
Nuts8.5 75
Switch Module Mounting
Screws326
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 - 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.
(4) Squeeze 2 tabs on sides of speed control cable
at throttle body mounting bracket (locking plate) and
push out of bracket.
(5) Remove servo cable from servo. Refer to Speed
Control Servo Removal/Installation in this group.
REMOVAL - DIESEL WITH AUTO. TRANS.
(1) Disconnect both negative battery cables at both
batteries.
(2) Remove cable/lever/linkage cover. Refer to
Speed Control Servo Removal/Installation.
(3) Remove (disconnect) servo cable from servo.
Refer to Speed Control Servo Removal/Installation.
(4) Using finger pressure only, disconnect end of
servo cable from throttle lever pin by pulling forward
on connector while holding lever rearward (Fig.
3).DO NOT try to pull connector off perpendic-
ular to lever pin. Connector will be broken.
(5) Squeeze 2 pinch tabs (Fig. 3) on sides of speed
control cable at mounting bracket and push cable
rearward out of bracket.
(6) Remove cable from vehicle.
INSTALLATION - GAS ENGINES
(1) Install end of cable to speed control servo.
Refer to Speed Control Servo Removal/Installation.
(2) Install cable into throttle body mounting
bracket (injection pump bracket on diesel engine).
Cable snaps into bracket.
(3) Install speed control cable connector at throttle
body bellcrank pin (injection pump bellcrank pin on
diesel engine). Connector snaps onto pin.
(4) Connect negative battery cable to battery.
(5) Before starting engine, operate accelerator
pedal to check for any binding.
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.
Fig. 1 Servo Cable at Throttle BodyÐV-6/V-8 Engine
1 - VEHICLE SPEED CONTROL CABLE
8P - 4 SPEED CONTROLBR/BE
SPEED CONTROL (Continued)

Page 710 of 2889

(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:
²Vacuum
²Vent
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
Fig. 2 Servo Cable at Throttle BodyÐV-10 Engine
1 - THROTTLE CABLE
2 - THROTTLE VALVE CABLE
3 - SPEED CONTROL SERVO CABLE
BR/BESPEED CONTROL 8P - 5
CABLE (Continued)

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