4WD DODGE RAM 2001 Service User Guide
[x] Cancel search | Manufacturer: DODGE, Model Year: 2001, Model line: RAM, Model: DODGE RAM 2001Pages: 2889, PDF Size: 68.07 MB
Page 63 of 2889
(8) Install a new cotter pin in hub nut. Tighten the
nut as needed to align cotter pin hole in shaft with
the opening in the nut.
(9) Install the rotor, brake caliper with adapter,
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - INSTALLATION).
(10) Install the ABS wheel speed sensor if
equipped, (Refer to 5 - BRAKES/ELECTRICAL/
FRONT WHEEL SPEED SENSOR - INSTALLA-
TION).
(11) Install the wheel and tire assemblies, (Refer
to 22 - TIRES/WHEELS/WHEELS - STANDARD
PROCEDURE).
(12) Remove the support and lower the vehicle.
(13) Apply the brakes several times to seat the
brake shoes and the caliper piston. Do not move the
vehicle until a firm brake pedal is obtained.
KNUCKLE
DESCRIPTION
The knuckles are a single casting with legs
machined for the upper and lower ball joints. The
knuckles also has machined mounting locations for
the front brake calipers adapters and hub bearing
assembly.
OPERATION
The steering knuckles pivots between the upper
and lower ball joints. The steering linkage is
attached to the knuckles controls vehicle steering.
REMOVAL
(1) Remove hub bearing and axle shaft.
(2) Remove tie-rod or drag link end from the steer-
ing knuckle arm.
(3) Remove the ABS sensor wire and bracket from
knuckle.
(4) Remove the cotter pin from the upper ball stud
nut. Remove the upper and lower ball stud nuts.
(5) Strike the steering knuckle with a brass ham-
mer to loosen. Remove knuckle from axle tube yokes.
REMOVAL
(1) Remove hub bearing and axle shaft.
(2) Remove tie-rod or drag link end from the steer-
ing knuckle arm.
(3) Remove the ABS sensor wire and bracket from
knuckle. Refer to Brakes, for proper procedures.
(4) Remove the cotter pin from the upper ball stud
nut. Remove the upper and lower ball stud nuts.
(5) Strike the steering knuckle with a brass ham-
mer to loosen.
(6) Remove knuckle from axle tube yokes.
INSTALLATION
(1) Position the steering knuckle on the ball studs.
(2) Install and tighten lower ball stud nut to 108
N´m (80 ft. lbs.) torque. Advance nut to next slot to
line up hole and install new cotter pin.
(3) Install and tighten upper ball stud nut to 101
N´m (75 ft. lbs.) torque. Advance nut to next slot to
line up hole and install new cotter pin.
(4) Install the hub bearing and axle shaft.
(5) Install tie-rod or drag link end onto the steer-
ing knuckle arm.
(6) Install the ABS sensor wire and bracket to the
knuckle. Refer to Brakes, for proper procedures.
INSTALLATION
(1) Position the steering knuckle on the ball studs.
(2) Install and tighten lower ball stud nut to 47
N´m (35 ft. lbs.) torque. Do not install cotter pin at
this time.
(3) Install and tighten upper ball stud nut to 94
N´m (70 ft. lbs.) torque. Advance nut to next slot to
line up hole and install new cotter pin.
(4) Retorque lower ball stud nut to 190±217 N´m
(140±160 ft. lbs.) torque. Advance nut to next slot to
line up hole and install new cotter pin.
(5) Install the hub bearing and axle shaft.
(6) Install tie-rod or drag link end onto the steer-
ing knuckle arm.
(7) Install the ABS sensor wire and bracket to the
knuckle. Refer to Brakes, for proper procedure.
LOWER CONTROL ARM
REMOVAL
(1) Raise and support the vehicle.
(2) Paint or scribe alignment marks on the cam
adjusters and suspension arm for installation refer-
ence (Fig. 15).
(3) Remove the lower suspension arm nut, cam
and cam bolt from the axle.
(4) Remove the nut and bolt from the frame rail
bracket and remove the lower suspension arm (Fig.
22).
INSTALLATION
(1) Position the lower suspension arm at the axle
bracket and frame rail bracket.
(2) Install the rear bolt and finger tighten the nut.
(3) Install the cam bolt, cam and nut in the axle
and align the reference marks.
(4) Remove support and lower the vehicle.
(5) Tighten cam nut at the axle bracket to 190
N´m (140 ft. lbs.). Tighten rear nut at the frame
bracket to 190 N´m (140 ft. lbs.).
2 - 20 FRONT - 4WDBR/BE
HUB / BEARING (Continued)
Page 64 of 2889
SHOCK
DESCRIPTION
The shocks are mounted inside the springs and
attached at the top to brackets with grommets. These
brackets are bolted on the frame with three studs on
a ring. The shock is mounted at the bottom of the
axle below the spring seat.
OPERATION
The shock absorbers dampen the jounce and
rebound of the vehicle over various road conditions.
DIAGNOSIS AND TESTING - SHOCK
A knocking or rattling noise from a shock absorber
may be caused by movement between mounting
bushings and metal brackets or attaching compo-
nents. These noises can usually be stopped by tight-
ening the attaching nuts. If the noise persists,
inspect for damaged and worn bushings, and attach-
ing components. Repair as necessary if any of these
conditions exist.
A squeaking noise from the shock absorber may be
caused by the hydraulic valving and may be intermit-
tent. This condition is not repairable and the shock
absorber must be replaced.
The shock absorbers are not refillable or adjust-
able. If a malfunction occurs, the shock absorbermust be replaced. To test a shock absorber, hold it in
an upright position and force the piston in and out of
the cylinder four or five times. The action throughout
each stroke should be smooth and even.
The shock absorber bushings do not require any
type of lubrication. Do not attempt to stop bushing
noise by lubricating them. Grease and mineral oil-
base lubricants will deteriorate the bushing.
REMOVAL
(1) Remove the nut, retainer and grommet from
the upper stud in the engine compartment.
(2) Remove three nuts from the upper shock
bracket (Fig. 16) .
(3) Remove the lower bolt from the axle bracket
(Fig. 17) . Remove the shock absorber from engine
compartment.
INSTALLATION
(1) Position the lower retainer and grommet on the
upper stud. Insert the shock absorber through the
spring from engine compartment.
(2) Install the lower bolt and tighten to 135 N´m
(100 ft. lbs.).
(3) Install the upper shock bracket and three nuts.
Tighten nuts to 75 N´m (55 ft. lbs.).
Fig. 15 Cam Adjuster
1 - ADJUSTMENT CAM
2 - AXLE BRACKET
3 - BRACKET REINFORCEMENT
4 - LOWER SUSPENSION ARM
Fig. 16 Shock Absorber and Bracket
1 - GROMMET
2 - RETAINER
3 - BRACKET
4 - RETAINER
5 - SHOCK
6 - GROMMET
BR/BEFRONT - 4WD 2 - 21
LOWER CONTROL ARM (Continued)
Page 65 of 2889
(4) Install upper grommet and retainer. Install
upper shock nut and tighten to 47 N´m (35 ft. lbs).
SPRING
DESCRIPTION
The springs use a rubber isolators between the
frame bracket and spring. The isolators help prevent
road noise. The bottom of the spring sits on a seat
mounted to the axle.
OPERATION
The coil springs control ride quality and maintain
proper ride height.
REMOVAL
(1) Raise and support the vehicle. Position a
hydraulic jack under the axle to support it.
(2) Paint or scribe alignment marks on lower sus-
pension arm cam adjusters and axle bracket for
installation reference.
(3) Remove the upper suspension arm and loosen
lower suspension arm bolts.
(4) Mark and disconnect the front propeller shaft
from the axle 4x4 models.
(5) Disconnect the track bar from the frame rail
bracket.
(6) Disconnect the drag link from pitman arm.
(7) Disconnect the stabilizer bar link and shock
absorber from the axle.(8) Lower the axle until the spring is free from the
upper mount. Remove the coil spring.
INSTALLATION
(1) Position the coil spring on the axle pad.
(2) Raise the axle into position until the spring
seats in the upper mount.
(3) Connect the stabilizer bar links and shock
absorbers to the axle bracket. Connect the track bar
to the frame rail bracket.
(4) Install the upper suspension arm.
(5) Install the front propeller shaft to the axle 4x4
model.
(6) Install drag link to pitman arm and tighten
nut to specifications. Install new cotter pin.
(7) Remove the supports and lower the vehicle.
(8) Tighten the following suspension components
to specifications:
²Link to stabilizer bar nut.
²Lower shock bolt.
²Track bar bolt at axle shaft tube bracket.
²Upper suspension arm nut at axle bracket.
²Upper suspension nut at frame bracket.
²Align lower suspension arm reference marks and
tighten cam nut.
²Lower suspension nut at frame bracket.
STABILIZER BAR
DESCRIPTION
The stabilizer bar extends across the front under-
side of the chassis and connects to the frame rails.
Links are connected from the bar to the axle brack-
ets. Stabilizer bar mounts are isolated by teflon lined
rubber bushings.
OPERATION
The stabilizer bar is used to minimize vehicle front
sway during turns. The spring steel bar helps to con-
trol the vehicle body in relationship to the suspen-
sion.
REMOVAL
(1) Raise and support the vehicle.
(2) Hold the stabilizer link shafts with a wrench
and remove the link nuts at the stabilizer bar.
(3) Remove the retainers and grommets from the
stabilizer bar links.
(4) Remove the stabilizer bar link nuts from the
axle brackets.
(5) Remove the links from the axle brackets with
Puller C-3894-A (Fig. 18).
(6) Remove the stabilizer bar clamps from the
frame rails and remove the stabilizer bar.
Fig. 17 Shock Absorber Axle Mount
1 - SHOCK
2 - SPRING
3 - FLAG NUT
4 - SHOCK BOLT
2 - 22 FRONT - 4WDBR/BE
SHOCK (Continued)
Page 66 of 2889
INSTALLATION
(1) Position the stabilizer bar on the frame rail
and install the clamps and bolts. Ensure the bar is
centered with equal spacing on both sides.
(2) Tighten the clamp bolts to 54 N´m (40 ft. lbs.).
(3) Install links to the axle bracket and tighten
nut to 47 N´m (35 ft. lbs.).
(4) Install links, retainers, grommets and nuts to
the stabilizer bar. Hold the link shaft with a wrench
and tighten the nuts to 37 N´m (27 ft. lbs.).
(5) Remove the supports and lower the vehicle.
TRACK BAR
DESCRIPTION
The bar is attached to a frame rail bracket with a
ball stud and is isolated with a bushing at the axle
bracket.
OPERATION
The track bar is used to control front axle side-to-
side movement.
DIAGNOSIS AND TESTING - TRACK BAR
(1) Turn the front wheel 90É to the left of center.
(2) Mount a dial indicator to the left frame rail in
front of the track bar ball joint (Fig. 19).
(3) Position the dial indicator plunger on the ball
joint end cap next to the grease fitting and zero the
indicator.
NOTE: Dial indicator plunger must be perpendicular
to the ball joint end cap.(4) Turn the front wheel 180É to the right and
record the dial indicator reading. Repeat this step
three times and record all readings.
(5) If any of the readings exceed 2.03 mm (0.080
in) replace the track bar.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the cotter pin and nut from the ball
stud end at the frame rail bracket (Fig. 20) .
(3) Remove ball stud from bracket with Puller
C-4150A (Fig. 21) .
(4) Remove the bolt and flag nut from the axle
bracket and remove the track bar (Fig. 20) .
INSTALLATION
(1) Install the track bar at axle bracket. Loosely
install the retaining bolt and flag nut.
(2) Pry the axle assembly over to install the track
bar at the frame rail bracket.
(3) Install the retaining nut on the stud. Tighten
the ball stud nut to 95 N´m (70 ft. lbs.). Install a new
cotter pin.
(4) Remove the supports and lower the vehicle.
(5) Tighten the bolt at the axle bracket to 176 N´m
(130 ft. lbs.).
UPPER CONTROL ARM
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the upper suspension arm nut and bolt
at the axle bracket (Fig. 22) .
Fig. 18 Stabilizer Link
1 - PULLER
2 - LINK
Fig. 19 Dial Indicator Location
1 - TRACK BAR BALL JOINT
BR/BEFRONT - 4WD 2 - 23
STABILIZER BAR (Continued)
Page 67 of 2889
(3) Remove the nut and bolt at the frame rail and
remove the upper suspension arm.
INSTALLATION
(1) Position the upper suspension arm at the axle
and frame rail.
(2) Install the bolts and finger tighten the nuts.
(3) Remove the supports and lower the vehicle.
(4) Tighten nut at the axle bracket to 163 N´m
(120 ft. lbs.). Tighten nut at frame bracket to 163
N´m (120 ft. lbs.).
LOWER BALL JOINT
REMOVAL -
(1) Remove lower snap ring from the lower ball
joint (Fig. 23).
Fig. 20 Track Bar
1 - AXLE BRACKET
2 - FRAME BRACKET
3 - TRACK BAR
4 - FLAG NUT
Fig. 21 Track Bar Puller
1 - TRACK BAR
2 - PULLER
Fig. 22 Upper and Lower Suspension Arm
1 - STABILIZER BAR
2 - SHOCK ABSORBER
3 - COIL SPRING
4 - UPPER SUSPENSION ARM
5 - LOWER SUSPENSION ARM
6 - TRACK BAR
Fig. 23 Lower Snap Ring
2 - 24 FRONT - 4WDBR/BE
UPPER CONTROL ARM (Continued)
Page 68 of 2889
(2) Position tools as shown to remove lower ball
stud (Fig. 24).
INSTALLATION
(1) Position tools as shown to install lower ball
stud (Fig. 25).
UPPER BALL JOINT
REMOVAL -
(1) Position tools as shown to remove upper ball
stud (Fig. 26).
INSTALLATION
(1) Position tools as shown to install upper ball
stud (Fig. 27).
Fig. 24 Lower Ball Joint Removal
1 - SPECIAL TOOL C4212-F
2 - SPECIAL TOOL 8445-3
3 - SPECIAL TOOL 8445-1
Fig. 25 Lower Ball Joint Install
1 - SPECIAL TOOL C4212-F
2 - SPECIAL TOOL 8445-2
3 - BALL JOINT
4 - KNUCKLE
Fig. 26 Upper Ball Joint Removal
1 - SPECIAL TOOL C4212-F
2 - SPECIAL TOOL 6761
3 - KNUCKLE
4 - SPECIAL TOOL 8445-3
Fig. 27 Upper Ball Joint Installation
1 - SPECIAL TOOL C4212-F
2 - SPECIAL TOOL 8445-2
3 - BALL JOINT
4 - KNUCKLE
BR/BEFRONT - 4WD 2 - 25
LOWER BALL JOINT (Continued)
Page 385 of 2889
(4) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL) (Fig. 17).
(5) Remove two generator mounting bolts. Do not
remove any wiring at generator. If equipped with
4WD, unplug 4WD indicator lamp wiring harness
(located near rear of generator).
(6) Remove generator. Position generator to gain
access for thermostat gasket removal.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20)
MAY BE USED FOR LARGER CLAMPS. ALWAYS
WEAR SAFETY GLASSES WHEN SERVICING CON-
STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 18). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
(7) Remove radiator upper hose clamp and upper
hose at thermostat housing.
(8) Position wiring harness (behind thermostat
housing) to gain access to thermostat housing.
(9) Remove thermostat housing mounting bolts,
thermostat housing, gasket and thermostat (Fig. 19).
Discard old gasket.
INSTALLATION
(1) Clean mating areas of intake manifold and
thermostat housing.(2) Install thermostat (spring side down) into
recessed machined groove on intake manifold (Fig.
19).
(3) Install gasket on intake manifold and over
thermostat (Fig. 19).
Fig. 16 Generator Support BracketÐ3.9L and 5.9L
Engine
1 - IDLER PULLEY BUSHING
2 - A/C AND/OR GENERATOR MOUNTING BRACKET
3 - IDLER PULLEY
4 - SCREW AND WASHER
Fig. 17 Automatic Belt TensionerÐ3.9L and 5.9L
Engines
1 - IDLER PULLEY
2 - TENSIONER
3 - FAN BLADE
Fig. 18 SPRING CLAMP SIZE LOCATION
1 - SPRING CLAMP SIZE LOCATION
7 - 50 ENGINEBR/BE
ENGINE COOLANT THERMOSTAT - 3.9L/5.2L/5.9L (Continued)
Page 462 of 2889
the module attempts to have the CCD chip re-send
the message.
DIAGNOSIS AND TESTING - CCD DATA BUS
CCD BUS FAILURE
The CCD data bus can be monitored using the
DRBIIItscan tool. However, it is possible for the
data bus to pass all tests since the voltage parame-
ters will be in ªrangeª and false signals are being
sent. There are essentially 12 ªhard failuresª that
can occur with the CCD data bus:
²Bus Shorted to Battery
²Bus Shorted to 5 Volts
²Bus Shorted to Ground
²Bus (+) Shorted to Bus (±)
²Bus (±) and Bus (+) Open
²Bus (+) Open
²Bus (±) Open
²No Bus Bias
²Bus Bias Level Too High
²Bus Bias Level Too Low
²No Bus Termination
²Not Receiving Bus Messages Correctly
Refer to the appropriate diagnostic procedures for
details on how to diagnose these faults using a
DRBIIItscan tool.
BUS FAILURE VISUAL SYMPTOM DIAGNOSIS
The following visible symptoms or customer com-
plaints, alone or in combination, may indicate a CCD
data bus failure:
²Airbag Indicator Lamp and Malfuntion Indicator
Lamp (MIL) Illuminated
²Instrument Cluster Gauges (All) Inoperative
²No Compass Mini-Trip Computer (CMTC) Oper-
ation
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controller Antilock Brakes (CAB) is a micro-
processor which handles testing, monitoring and con-
trolling the ABS brake system operation (Fig. 10).
The CAB functions are:
²Perform self-test diagnostics.
²Monitor the RWAL brake system for proper oper-
ation.
²Control the RWAL valve solenoids.
NOTE: If the CAB needs to be replaced, the rear
axle type and tire revolutions per mile must be pro-
gramed into the new CAB. For axle type refer to
Group 3 Differential and Driveline. For tire revolu-tions per mile,(Refer to 22 - TIRES/WHEELS/TIRES -
SPECIFICATIONS) . To program the CAB refer to the
Chassis Diagnostic Manual.
OPERATION
SYSTEM SELF-TEST
When the ignition switch is turned-on the micro-
processor RAM and ROM are tested. If an error
occurs during the test, a DTC will be set into the
RAM memory. However it is possible the DTC will
not be stored in memory if the error has occurred in
the RAM module were the DTC's are stored. Also it
is possible a DTC may not be stored if the error has
occurred in the ROM which signals the RAM to store
the DTC.
CAB INPUTS
The CAB continuously monitors the speed of the
differential ring gear by monitoring signals generated
by the rear wheel speed sensor. The CAB determines
a wheel locking tendency when it recognizes the ring
gear is decelerating too rapidly. The CAB monitors
the following inputs to determine when a wheel lock-
ing tendency may exists:
²Rear Wheel Speed Sensor
²Brake Lamp Switch
²Brake Warning Lamp Switch
²Reset Switch
²4WD Switch (If equipped)
CAB OUTPUTS
The CAB controls the following outputs for antilock
braking and brake warning information:
²RWAL Valve
Fig. 10 RWAL CAB
1-RWALCAB
BR/BEELECTRONIC CONTROL MODULES 8E - 11
COMMUNICATION (Continued)
Page 588 of 2889
SHIFT INDICATOR (TRANSFER
CASE)
DESCRIPTION
A four-wheel drive indicator is standard equipment
on all instrument clusters. However, on vehicles not
equipped with the optional four-wheel drive system,
this indicator is mechanically disabled. The four-
wheel drive indicator is located near the lower edge
of the instrument cluster overlay, to the right of cen-
ter. The four-wheel drive indicator consists of a sten-
cilled cutout of the text ª4WDº in the opaque layer of
the instrument cluster overlay. The dark outer layer
of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the ª4WDº text to appear in amber
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by a
Light Emitting Diode (LED) soldered onto the instru-
ment cluster electronic circuit board. The four-wheel
drive indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The four-wheel drive indicator lamp gives an indi-
cation to the vehicle operator that a four-wheel drive
operating mode is engaged. The indicator will be illu-
minated when either high range (4H) or low range
(4L) have been selected with the transfer case shift
lever. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon the
cluster programming, and a hard wired input from
the four-wheel drive switch on the front axle discon-
nect housing. The four-wheel drive indicator Light
Emitting Diode (LED) receives battery current on the
instrument cluster electronic circuit board through
the fused ignition switch output (st-run) circuit
whenever the ignition switch is in the On or Start
positions; therefore, the lamp will always be off when
the ignition switch is in any position except On or
Start. The LED only illuminates when it is switched
to ground by the instrument cluster transistor.
The four-wheel drive switch is connected in series
between ground and the four-wheel drive switch
sense input to the instrument cluster. For further
information on the transfer case and the transfer
case operating ranges, (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/TRANSFER CASE - OPERA-
TION. For further information on the front axle
disconnect mechanism, (Refer to 3 - DIFFERENTIAL
& DRIVELINE/FRONT AXLE/AXLE VACUUM
MOTOR - OPERATION). The four-wheel drive switch
input to the instrument cluster circuitry can be diag-nosed using conventional diagnostic tools and meth-
ods.
DIAGNOSIS AND TESTING - FOUR-WHEEL
DRIVE INDICATOR
The diagnosis found here addresses an inoperative
four-wheel drive indicator condition. If the problem
being diagnosed is related to indicator accuracy, be
certain to confirm that the problem is with the indi-
cator and not with a damaged or inoperative front
axle disconnect mechanism. (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/FRONT AXLE/AXLE VACUUM
MOTOR - DIAGNOSIS AND TESTING). If no front
axle disconnect problem is found, the following proce-
dure will help locate a short or open in the four-
wheel drive switch input to the instrument cluster.
Refer to the appropriate wiring information. The wir-
ing 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.
INDICATOR DOES NOT ILLUMINATE WITH FOUR-WHEEL
DRIVE MODE SELECTED
(1) Disconnect and isolate the battery negative
cable. Disconnect the engine wire harness connector
for the four-wheel drive switch from the switch con-
nector receptacle. Check for continuity between the
ground circuit cavity of the engine wire harness con-
nector for the four-wheel drive switch and a good
ground. There should be continuity. If OK, go to Step
2. If not OK, repair the open ground circuit to ground
(G100) as required.
(2) Reconnect the battery negative cable. Turn the
ignition switch to the On position. Install a jumper
wire between the 4WD switch sense circuit cavity of
the engine wire harness connector for the four-wheel
drive switch and a good ground. The four-wheel drive
indicator should light. If OK, replace the faulty four-
wheel drive switch. If not OK, go to Step 3.
BR/BEINSTRUMENT CLUSTER 8J - 29
Page 589 of 2889
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the instrument cluster from the instrument
panel. Check for continuity between the 4WD switch
sense circuit cavities of the instrument panel wire
harness connector (Connector C2) for the instrument
cluster and the engine wire harness connector for the
four-wheel drive switch. There should be continuity.
If OK, replace the faulty instrument cluster. If not
OK, repair the open 4WD switch sense circuit
between the instrument cluster and the four-wheel
drive switch as required.
INDICATOR STAYS ILLUMINATED WITH FOUR-WHEEL DRIVE
MODE NOT SELECTED
(1) Disconnect and isolate the battery negative
cable. Disconnect the engine wire harness connector
for the four-wheel drive switch from the switch con-
nector receptacle. Check for continuity between the
ground circuit terminal and the 4WD switch sense
circuit terminal in the four-wheel drive switch con-
nector receptacle. There should be no continuity. If
OK, repair the shorted 4WD switch sense circuit
between the four-wheel drive switch and the instru-
ment cluster as required. If not OK, replace the
faulty four-wheel drive switch.
SPEEDOMETER
DESCRIPTION
A speedometer is standard equipment on all instru-
ment clusters. The speedometer is located just to the
right of the tachometer near the center of the instru-
ment cluster. The speedometer consists of a movable
gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 210 degree primary scale
on the gauge dial face that reads left-to-right either
from 0 to 120 mph, or from 0 to 200 km/h, depending
upon the market for which the vehicle is manufac-
tured. Each version also has a secondary inner scale
on the gauge dial face that provides the equivalent
opposite units from the primary scale. Text appearing
on the cluster overlay just below the hub of the
speedometer needle abbreviates the unit of measure
for the primary scale in all upper case letters (i.e.:
MPH or KM/H), followed by the unit of measure for
the secondary scale in all lower case letters (i.e.: mph
or km/h). The speedometer graphics are white (pri-
mary scale) and red (secondary scale) against a black
field, making them clearly visible within the instru-
ment cluster in daylight. When illuminated from
behind by the panel lamps dimmer controlled cluster
illumination lighting with the exterior lamps turned
On, the white graphics appear blue-green, while the
red graphics still appear red. The orange gauge nee-
dle is internally illuminated. Gauge illumination isprovided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The speedometer is serviced as a
unit with the instrument cluster.
OPERATION
The speedometer gives an indication to the vehicle
operator of the vehicle road speed. This gauge is con-
trolled by the instrument cluster circuit board based
upon the cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Chrysler Collision
Detection (CCD) data bus. The speedometer is an air
core magnetic unit that receives battery current on
the instrument cluster electronic circuit board
through the fused ignition switch output (st-run) cir-
cuit whenever the ignition switch is in the On or
Start positions. The cluster is programmed to move
the gauge needle back to the low end of the scale
after the ignition switch is turned to the Off position.
The instrument cluster circuitry controls the gauge
needle position and provides the following features:
²Message Failure- If the cluster fails to receive
a speedometer message, it will hold the gauge needle
at the last indication for about four seconds, or until
the ignition switch is turned to the Off position,
whichever occurs first. If a new speedometer message
is not received after about four seconds, the gauge
needle will return to the far left (low) end of the
scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the vehicle speed
sensor to determine the vehicle road speed, then
sends the proper vehicle speed messages to the
instrument cluster. For further diagnosis of the
speedometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the vehicle speed
sensor, the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the
speedometer, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
TACHOMETER
DESCRIPTION
A tachometer is standard equipment on all instru-
ment clusters. The tachometer is located just to the
left of the speedometer near the center of the instru-
8J - 30 INSTRUMENT CLUSTERBR/BE
SHIFT INDICATOR (TRANSFER CASE) (Continued)