warning DODGE RAM 1999 Service Owner's Manual

Page 290 of 1691

outlet port. See Fig. 7. Start engine. Outlet pressure should not be
more 5 psi (0.4 kg/cm) less than inlet pressure. If pressure drop is
more than 5 psi (0.4 kg/cm), replace fuel filter and retest pressure.
If pressure drop is less than 5 psi (0.4 kg/cm), check for fuel
supply restriction.
NOTE: Due to very small vacuum specifications, use a scan tool and
Periphal Expansion Port (PEP) module with 0-15 psi transducer\
to perform following test.
Fuel Supply Restriction Test
Ensure transfer pump pressure is okay. Disconnect fuel supply
line at fuel transfer pump inlet. Remove plastic clip from pump inlet
and install in end of fuel supply line. Install 3/8" Adapter Hose
(6631) between fuel supply line and pump inlet. Install transducer
from PEP module to "T" fitting on adapter. Connect scan tool to
module. Start engine. Check vacuum reading with engine at full
throttle with no load. If vacuum reading is less than 6 in. Hg, check
for fuel supply air leaks. If vacuum reading is 6 in. Hg or more,
check fuel line for damage, dents and kinks. Repair as necessary. If
no problem is found, remove fuel module from fuel tank and check for
obstructions. Repair as necessary.
NOTE: A 3' section of 1/4" I.D. clear tubing and a 1/8" NPT fitting
are required for the following test.
Fuel Supply Air Leak Test
Clean area around filter inlet fitting plug, then remove
plug. See Fig. 7. Install 1/8" NPT fitting with 1/4" nipple fitting in
test port. Attach clear hose with a clamp to fitting. Place other end
of hose in a fuel container. Turn ignition switch to START position,
then release to RUN position without starting engine. Fuel transfer
pump should run for 25 seconds. After hose has been purged, watch for
any air bubbles in hose. If no bubbles exist, system is okay. If
bubbles exist, check fuel line, fittings and fuel module in tank.
Repair as necessary.
OVERFLOW VALVE
1) Fuel transfer pump delivers more fuel to fuel injection
pump than needed. Surplus fuel is routed back to fuel tank by overflow
valve. Overflow valve is used to secure fuel return line to side of
fuel injection pump. See Fig. 1. A sticking check valve in the
overflow valve may result in low power. Pressure release is set at 14
psi. (1.0 kg/cm
). If outlet valve is stuck closed, a FTC may set.
2) Clean area around outlet valve and fuel return line.
Remove valve from pump and fitting. Using regulated air pressure, test
valve by blowing into valve inlet. Valve should open at 14-16 psi. (1.
0-1.1 kg/cm
). If valve does not open, replace valve. Reduce air
pressure to 10 psi. (0.7 kg/cm). Valve should close. If valve does
not close, replace valve. Using NEW gaskets, install valve through
banjo fitting into fuel injection pump. Tighten valve to 24 ft. lbs.
(30 N.m).
FUEL INJECTOR & HIGH-PRESSURE FUEL LINES
WARNING: DO NOT allow diesel fuel to contact hot engine when checking
fuel injector, as high exhaust temperatures could cause fire.
Use care when working around high-pressure fuel lines, as
fuel is under extreme pressure and could penetrate skin,
causing personal injury. Wear safety goggles and protective
clothing when checking fuel injectors.

Page 293 of 1691

Minimum Compression Pressure
Dakota
2.5L ........................................................ (1)
3.9L, 5.2L & 5.9L ............................. 100 psi (690 kPa)\
Durango ........................................ 100 psi (690 kPa)\
Ram Pickup ..................................... 100 psi (690 kPa)\
Ram Van Ram Wagon .............................. 100 psi (690 kPa)\
Maximum Variation Between Cylinders ............................ ( 1)
( 1) - Information is not available from manufacturer.
\
\
\
\
\
\
\

FUEL SYSTEM
FUEL PRESSURE RELEASE
WARNING: Fuel system is under high pressure. ALWAYS release fuel
pressure before attempting to open system for testing or
component replacement. DO NOT allow fuel to flow onto engine
or electrical parts while testing fuel system components.
Vehicles With Fuel Rail Test Port
1) Loosen fuel tank filler cap. Ensure ignition is off.
Remove protective cap from fuel rail test port.
2) Place one end of Fuel Pressure Release Hose (C-4799-1)
into an approved fuel container. Attach remaining end of hose to fuel
rail test port. Use care, as fuel system may be under pressure. Fuel
pressure will be released from fuel system. Remove hose, reinstall
protective cap, and fuel tank filler cap.
3) Wait 5 seconds. Use care when disconnecting fuel lines, as
some fuel pressure may still exist in fuel lines.
NOTE: One or more DTCs may set when fuel pump relay is removed.
Clear DTCs from PCM after fuel pressure release procedure. To
clear DTCs from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC
SYSTEM in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
Vehicles Without Fuel Rail Test Port
1) Remove gas cap. Using a non-metallic tool, open flapper
valve in filler neck to relieve pressure. Remove fuel pump relay from
Power Distribution Center (PDC). Relays are identified on label under
PDC cover. Start and run engine until it stalls. Attempt to start
engine. Continue restarting engine until it will no longer run. Turn
ignition off.
CAUTION: DO NOT supply power to fuel injector for more than 4 seconds,
or fuel injector may be damaged.
2) Disconnect any fuel injector connector. Connect a jumper
wire between either fuel injector terminal and positive battery
terminal. Connect another jumper wire to other fuel injector terminal.
Momentarily touch other end of jumper wire to negative battery
terminal.
3) Place a shop towel under fuel line quick-connector at fuel
rail. Use care when disconnecting fuel lines, as some fuel pressure
may still exist in fuel lines. Disconnect fuel line quick-connector.
Reinstall fuel pump relay in PDC. Clear DTCs from PCM. To clear DTCs
from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC SYSTEM in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
FUEL PRESSURE TEST

Page 297 of 1691

BO DY C O NTR O L C O M PU TE R

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Body Control Computer Tests
Ram Pickup
NOTE: See BODY CONTROL COMPUTER - INTRODUCTION article before
proceeding with following test. Body control computer in RWD
trucks is the Central Timer Module (CTM).
SYMPTOM IDENTIFICATION
IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS
NOTE: For connector terminal identification wiring diagrams, see
BODY CONTROL COMPUTER - INTRODUCTION article.
NOTE: Perform a visual inspection before proceeding with this test.
Ensure battery is fully charged.
1) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector located under left side of dash, to left of steering
wheel. Turn ignition switch to ON position. If scan tool display is
not blank, go to next step. If scan tool display is blank, see
appropriate VEHICLE COMMUNICATIONS article.
2) Using scan tool, select SYSTEM MONITORS, then CCD BUS
TEST. Scan tool will perform a CCD bus test. If scan tool displays BUS
OPERATIONAL, go to next step. If scan tool displays any message except
BUS OPERATIONAL, see appropriate VEHICLE COMMUNICATIONS article.
3) Using scan tool, select READ DTCs. If any Diagnostic
Trouble Codes (fault messages) are present, go to appropriate fault
message. If no fault messages are present, identify customer
complaint. See following list for possible fault messages and customer
complaint symptoms. Problems listed are diagnosed using a scan tool.
These problems may occur separately or in various combinations. When
diagnosing a system with many apparent problems, a sequence of tests
may be required. After repairs, ensure problem(s) or failure(s) have\
been corrected.
CHIME SYSTEM
* CHIME INOPERATIVE - ENGINE TEMPERATURE CRITICAL
* CHIME INOPERATIVE - KEY IN IGNITION & LF DOOR OPEN
* CHIME INOPERATIVE AT ALL TIMES
* CHIME INOPERATIVE WITH EXTERIOR LIGHTS ON
* CHIME INOPERATIVE WITH LOW OIL PRESSURE
* CHIME INOPERATIVE WITH DRIVER DOOR OPEN
DOOR AJAR SYSTEM
* OPEN LEFT DOOR AJAR CIRCUIT
* OPEN RIGHT DOOR AJAR CIRCUIT
* SHORTED LEFT DOOR AJAR CIRCUIT
* SHORTED RIGHT DOOR AJAR CIRCUIT
INSTRUMENT CLUSTER
* ALL GAUGES INOPERATIVE
* ANY CCD CLUSTER WARNING LIGHT INOPERATIVE
* ANY HARD WIRED CLUSTER WARNING LIGHT INOPERATIVE

Page 304 of 1691

PCM INACTIVE ON BUS, go to appropriate VEHICLE COMMUNICATIONS article.
If scan tool does not display PCM INACTIVE ON BUS, go to next step.
4) Turn ignition off. Remove instrument cluster. See
appropriate INSTRUMENT PANELS article. Turn ignition on. Using
external voltmeter, measure voltage between ground and instrument
cluster connector C1 terminal No. 6 (Yellow wire). If voltage is 10
volts or less, repair open Yellow wire. If voltage is more than 10
volts, replace instrument cluster.
ANY CCD CLUSTER LIGHT INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Turn ignition on. Using scan tool, select ELECTRO/MECH
CLUSTER. If scan tool displays BUS OPERATIONAL, go to next step. If
scan tool does not display BUS OPERATIONAL, go to appropriate VEHICLE
COMMUNICATIONS article and follow appropriate symptom diagnostics.
2) If scan tool displays NO RESPONSE, go to appropriate
VEHICLE COMMUNICATIONS article. If scan tool does not display NO
RESPONSE, go to next step.
3) Using scan tool, select SYSTEM TEST. If scan tool displays
PCM INACTIVE ON BUS, go to appropriate VEHICLE COMMUNICATIONS article.
If scan tool does not display PCM INACTIVE ON BUS, go to next step.
4) Push and hold RESET button while cycling ignition key.
Release RESET button when CHEC appears in odometer display. Observe
inoperative light during self-test. If inoperative light did not
illuminate during self-test, go to next step. If inoperative light
illuminated during self-test, verify if light is controlled by an
input to instrument cluster. See appropriate wiring diagram in BODY
CONTROL COMPUTER - INTRODUCTION article. If light is controlled by an
input to instrument cluster, go to appropriate circuits article or
symptom test. See IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS. If
light is not controlled by an input to instrument cluster, system is
currently functioning correctly.
5) Gain access to instrument cluster. See appropriate
INSTRUMENT PANELS article. If defective light is a LED, replace
instrument cluster. If defective light is a bulb, go to next step.
6) Remove and inspect defective bulb. If bulb is burned out,
replace bulb. If bulb is not burned out, replace instrument cluster.
ANY HARD WIRED CLUSTER WARNING LIGHT INOPERATIVE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting or connecting any module connector.
1) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Remove inoperative bulb. If bulb is burned out,
replace bulb. If bulb is not burned out, go to next step.
2) Inspect wiring diagram and evaluate which instrument
cluster provides; power or ground for inoperative bulb. See
appropriate wiring diagram in BODY CONTROL COMPUTER - INTRODUCTION
article. Using external ohmmeter or voltmeter, check appropriate power
or ground circuit. If circuit is okay, replace instrument cluster. If
power or ground is not available at appropriate circuit, repair open

Page 306 of 1691

multiple engine sensors have failed, repair ground between splice and
PCM.
12) Connect jumper wire between OPS connector terminals. If
oil pressure warning indicator illuminates, replace OPS. If oil
pressure warning indicator does not illuminate, go to next step.
13) Do not remove jumper wire. Disconnect PCM Black connector
C2. PCM is located in engine compartment on right inner fender. Using
an external ohmmeter, measure resistance between ground and PCM White
connector C2 terminal No. 23 (Gray/Orange wire). If resistance is less\
than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open
Gray/Orange wire.
14) Check cooling system operation. If cooling system is
operating properly, go to next step. If cooling system is not
operating properly, repair engine cooling problem.
15) Using scan tool, select PCM MONITOR under SYSTEM TESTS.
If scan tool displays PCM ACTIVE ON BUS, system is currently
functioning properly. If scan tool does not display PCM ACTIVE ON BUS,
go to appropriate VEHICLE COMMUNICATIONS article.
16) Using scan tool, select MODULE ENGINE CONTROLLER. Read
PCM DTCs. If scan tool displays any charging system related DTCs, go
to appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section
and repair DTC as necessary. If scan tool does not display any
charging system related DTCs, go to next step.
17) Check charging system operation. If charging system is
operating properly, replace instrument cluster. If charging system is
not operating properly, repair engine charging problem.
18) Using scan tool, select BODY COMPUTER MONITORS. Read CCD
BUS ENGINE INFO. If scan tool displays engine RPM, replace instrument
cluster. If scan tool does not display engine RPM, replace PCM.
OVERHEAD CONSOLE CONCERNS
AVERAGE MPH/FUEL ECON INOPERATIVE OR WRONG (CMTC FAILS TO
RESPOND TO INSTRUMENT CLUSTER DIMMING, DISTANCE TO EMPTY
INOPERATIVE OR WRONG, ELAPSED TIME INOPERATIVE/WRONG, SWITCH
ON CMTC INOPERATIVE, TRIP ODOMETER INOPERATIVE/WRONG)
NOTE: If any listed symptoms exist, Compass Mini-Trip computer
(CMTC) is defective. Replace CMTC. Perform VERIFICATION TEST
VER- 1A after each repair.
CMTC SHOWS FAILED
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
Using scan tool, perform AUTO SELF TEST. If CMTC shows
failed, replace CMTC. If CMTC does not show failed, system is
currently functioning properly.
CMTC SEGMENTS FAIL TO LIGHT UP
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
Using scan tool, perform AUTO SELF TEST. If CMTC segments
fail to illuminate, replace CMTC. If CMTC segments all illuminate
properly, system is currently functioning properly.
INCORRECT READING BEYOND +/- 5

Page 323 of 1691

and make an informed decision about how to proceed.
BRAKES
SERVICE PROCEDURES REQUIRED & SUGGESTED FOR PROPER
VEHICLE OPERATION
Some states may have specifications that differ from OEM.
Check your local/state regulations. Where state or local laws are
stricter, they take precedence over these guidelines.
ACCELEROMETERS (G SENSOR OR LATERAL)
ACCELEROMETER INSPECTION\
\
\
\
\
\
\

Condition Code Procedure
Broken .................. A ............ Require replacement.
Connector loose ......... A .. Require repair or replacement.
Loose ................... B .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Out of position ......... B ....... Require re-positioning to
vehicle manufacturer's
specifications.
Output signal incorrect . B ............ Require replacement.
\
\
\
\
\
\
\

ACCUMULATORS
ACCUMULATOR INSPECTION\
\
\
\
\
\
\

Condition Code Procedure
Leaking ................. B ............ Require replacement.
Missing ................. C ............ Require replacement.
Pre-charge incorrect .... B ............ Require replacement.
\
\
\
\
\
\
\

ANCHOR PINS
See BACKING PLATES .
ANTI-LOCK BRAKE SYSTEMS
NOTE: Anti-lock brakes are an integral part of the brake system. It
is essential that the anti-lock brakes function properly when
brake service is performed.
Anti-lock brake systems are commonly referred to as "ABS" and
will be referred to as "ABS" throughout these guidelines. Some ABS
components also function as part of a traction control system (TCS).
WARNING: When diagnosing and servicing high pressure components,
observe safety procedures and equipment requirements
established by the vehicle manufacturer to reduce the
possibility of serious personal injury.
NOTE: Intermittent electrical conditions are often caused by a loss
of ground, poor connection, or water intrusion into the
wiring harness.

Page 355 of 1691

1) Start engine, and check booster vacuum hose connections. A
hissing noise indicates a vacuum leak. Repair any vacuum leaks before
proceeding. Stop engine, and shift transmission into Neutral. Pump
brake pedal until all vacuum reserve in booster is depleted.
2) Hold brake pedal under light pressure. If pedal does not
hold firm and falls away, master cylinder may be faulty. Bleed system
using appropriate method, and repeat step 1). See BLEEDING PROCEDURES
under BLEEDING BRAKE SYSTEM.
3) If pedal still does not hold firm, master cylinder is
faulty. If pedal holds firm, start engine and observe pedal height. If
pedal height change is not apparent, power booster or vacuum check
valve is faulty. Install good check valve, and repeat steps 1) and 2).\
If pedal falls away slightly under light pressure and then holds firm,
go to next step .
4) Start engine. Release brake pedal. Increase engine speed
to 1500 RPM. Close throttle and immediately turn off ignition. Wait at
least 90 seconds, and try brake action again. Booster should provide 2
or more vacuum assisted pedal applications. If vacuum assist is not
provided, perform booster and check valve vacuum tests.
POWER BRAKE BOOSTER VACUUM TEST
Connect vacuum gauge to booster check valve using "T"
fitting. Start engine, and run at idle speed for one minute. Clamp
hose shut between vacuum source and check valve. Stop engine, and
observe vacuum gauge. If vacuum drops more than one in. Hg within 15
seconds, booster diaphragm or check valve is faulty.
POWER BRAKE BOOSTER CHECK VALVE TEST
Disconnect vacuum hose from check valve. Remove check valve
and valve seal from booster. Use a hand-operated vacuum pump for
testing. Apply 15-20 in. Hg at large end of check valve. Vacuum should
hold steady. If gauge on pump indicates vacuum loss, check valve is
faulty and should be replaced.
COMBINATION VALVE METERING VALVE TEST
Metering valve operation can be checked visually with aid of
an assistant. While an assistant applies and releases brake pedal,
observe metering valve stem. If valve is operating correctly, stem
will extend slightly when brakes are applied, and contract when brakes
are released. If valve is faulty, replace combination valve assembly.
COMBINATION VALVE PRESSURE DIFFERENTIAL SWITCH TEST
1) Using an assistant, apply brake pedal. Observe brake
warning light. Raise and support vehicle, and connect a bleed hose to
one rear wheel cylinder. Submerge other end of hose into container
partially filled with brake fluid. Have assistant press and hold brake
pedal down while observing brake warning light. Open bleeder screw. If
warning light glows, switch is operating properly.
2) If warning light fails to glow, check circuit fuse, bulb
and wiring. Repair as necessary. Repeat step 1). If warning light
fails to glow, check brakelight, parking brake switches and related
wiring. Repair as necessary. Repeat step 1). If warning light fails to
glow, pressure differential switch is faulty. Replace combination
valve assembly, and bleed brake system. Verify proper valve operation.
REMOVAL & INSTALLATION

Page 358 of 1691

pads at this time. On models with removable hub, install hub on rotor.
Install wheel and tire assembly. Tighten lug nuts so they are snug,
but DO NOT tighten to final torque specifications.
3) While rotating wheel, tighten adjuster nut sufficiently to
seat bearing. Loosen nut and retighten while still rotating wheel.
Back off adjuster nut to completely release bearing preload torque.
Ensure endplay of .001-.003" (.025-.076 mm). Install lock nut and NEW
cotter pin. If necessary, tighten lock nut slightly to align cotter
pin hole. Install grease cap. Tighten caliper bolts and lug nuts to
specification. See TORQUE SPECIFICATIONS table. To complete
installation, reverse remove procedure.
Removal (Ram Pickup With 8 Studs)
1) Raise and support vehicle. Remove wheel. Remove hub
extension, if equipped. Remove brake caliper. Support caliper aside.
2) On models with removable adapter hub, remove hub from
rotor. On models with one-piece hub and rotor assembly, remove cotter
pin from rotor hub nut. Remove nut. Disconnect ABS wheel speed sensor
wire (if equipped), and remove from frame and steering knuckle. Remove\
bolts securing hub to steering knuckle from inboard side of steering
knuckle. Remove rotor and hub assembly.
Installation
1) Apply anti-seize compound to drive shaft splines. Replace
grease seal in steering knuckle, if necessary. Insert 2 rearmost top
and bottom rotor hub bolts in steering knuckle so they extend through
back of knuckle. Install hub spacer, ensuring flat on space is
positioned to rear. Use chassis grease to hold spacer in position, if
necessary.
NOTE: If equipped with wheel speed sensor, brake shield must be
positioned on hub bearing, and sensor wire must be at top of
knuckle.
2) Align rotor hub with drive shaft and install hub assembly.
Align bolt holes in hub flange with bolts previously installed. Start
nuts on flange bolts sufficiently to hold assembly in place. Install
remaining bolts, and tighten all bolts to specification. See TORQUE
SPECIFICATIONS table.
3) Install washer and hub nut. Tighten nut securely. Install
NEW cotter pin. Install grease cap. Install caliper. Tighten caliper
bolts and lug nuts to specification. See TORQUE SPECIFICATIONS table.
To complete installation, reverse remove procedure.
REAR BRAKE SHOES
WARNING: Use water or brake cleaner to clean brake parts. DO NOT use
compressed air to remove dirt and dust.
Removal (Dakota & Ram Van)
1) Remove wheel and drum. Note how secondary spring overlaps
primary return spring. Using spring remover, remove brake shoe return
springs. Slide automatic adjuster cable off anchor. Disconnect cable
from adjusting lever.
2) Remove cable, cable guide and anchor plate. See Figs. 3,
4, and 5. Disconnect adjusting lever return spring from lever. Remove
lever and return spring from pivot pin. Remove shoe-to-shoe spring.
Spread shoes, and remove adjustment star wheel.
3) Remove shoe retainers, springs and pins. Remove parking
brake lever from secondary shoe. Remove shoes and parking brake strut
with spring.

Page 363 of 1691

being replaced, remove booster check valve and seal.
Installation
1) If new booster is being installed, install check valve and
seal. Position booster on dash, and install lock nuts on booster
mounting studs finger tight. Install booster push rod on brake pedal
pin, and secure rod with NEW retaining clip.
2) Tighten booster lock nuts to specification. Install master
cylinder on booster, and tighten mounting nuts to specification. See
TORQUE SPECIFICATIONS table. Connect vacuum hose to booster check
valve. Start vehicle and check booster operation.
COMBINATION VALVE
Removal & Installation
Raise and support vehicle. Mark brakelines for assembly
reference. Disconnect parking brake cable from clip on valve, if
necessary. Disconnect brake warning light connection at switch.
Disconnect all brake hydraulic lines at valve. Cap brakelines to
prevent dirt from entering system. Remove valve. To install, reverse
removal procedures. Bleed brake system. See BLEEDING PROCEDURES under
BLEEDING BRAKE SYSTEM.
AXLE BEARING & SEAL (FULL FLOATING AXLE)
Removal & Installation (Ram Pickup With 12" & 13" Drums)
1) Raise and support vehicle. Remove wheel. Remove axle shaft
nuts and washers. Strike center of axle flange to free cones. Remove
axle shaft and gasket.
2) Straighten and remove nut lock. Remove adjustment nut and
outer bearing. Remove drum assembly. Remove seal and inner bearing
from drum assembly.
3) Pack inner bearing, and install inner bearing and seal in
drum. Install drum assembly, outer bearing and adjustment nut. While
rotating drum, tighten adjustment nut to specification. See TORQUE
SPECIFICATIONS table.
4) Back off adjustment nut 1/8 turn to obtain .001-.010" (0.
025-0.254 mm) end play. Bend nut lock into spindle keyway. Install
gasket and axle shaft. Install wheel, and lower vehicle. See TORQUE
SPECIFICATIONS table.
OVERHAUL
NOTE: Use illustrations when overhauling components. See
Figs. 2-6.
DISC BRAKE SPECIFICATIONS
DISC BRAKE SPECIFICATIONS\
\
\
\
\
\
\

Application In. (mm)\
Disc Diameter
Dakota ............................................... 11.30 (287)\
Ram Pickup
1/2 Ton ............................................. 11.57 (294)\
3/4 & 1 Ton ......................................... 12.50 (318)\
Ram Van
1/2 & 3/4 Ton ....................................... 11.75 (299)\
1 Ton ............................................... 12.82 (326)\
Lateral Runout

Page 385 of 1691

operator's foot off accelerator pedal, S/C compensates for excessive
S/C cable slack. If lift foot sets are continually used, speed control
overshoot/undershoot condition will develop.
To "unlearn" overshoot/undershoot condition, operator must
press and release set button while maintaining desired speed with
accelerator pedal, then turn S/C switch to OFF position after waiting
10 seconds. This procedure must be repeated 10-15 times to completely
unlearn overshoot/undershoot condition.
COMPONENT TESTS
WARNING: Vehicle is equipped with an air bag. Air bag must be
deactivated before servicing speed control components on or
around steering column. See appropriate AIR BAG RESTRAINT
SYSTEMS article.
NOTE: For component locations, See COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
BRAKE SWITCH
Disconnect brake switch 6-pin connector. Using an ohmmeter,
check for continuity at brake switch. See Fig. 1. If continuity is not
as specified in BRAKE SWITCH CONTINUITY table, check brake switch
adjustment. See BRAKE SWITCH under REMOVAL & INSTALLATION. If brake
switch adjustment is okay, replace defective brake switch.
BRAKE SWITCH CONTINUITY
\
\
\
\
\
\
\
 
Switch Plunger  Check Between  Continuity 


Position  Terminals  

\
\
\b\
\
\
\b\
\


Released  5 & 6  Yes 

\
\
\b\
\
\
\b\
\


Depressed  1 & 2  Yes 


\
\
\
\b\
\


 3 & 4  Yes 


\
\
 \
\
\
 \
\
\f

SPEED CONTROL SERVO
1) Start engine. Disconnect Speed Control (S/C) servo 4-pin
connector. Turn S/C on. Using a voltmeter, check voltage at S/C servo
connector terminal No. 3 (Dark Blue/Red wire). Battery voltage should
exist when brake pedal is not depressed. If battery voltage exists, go
to next step. If battery voltage does not exist, check circuit between
brake switch and S/C servo. See WIRING DIAGRAMS.
2) Connect a jumper wire between S/C servo pin No. 3 and S/C
servo connector terminal No. 3. Check voltage at S/C servo pins No. 1,
2 and 4. If battery voltage does not exist, replace S/C servo. If
battery voltage exists, go to next step.
3) Turn ignition off. Check for continuity between S/C servo
connector terminal No. 4 and ground. If continuity exists, test is
complete. If continuity does not exist, repair open ground circuit as
necessary.
VACUUM SUPPLY
Gasoline Engines
1) Disconnect vacuum hose at speed control servo. Install
vacuum gauge to disconnected vacuum hose. Start engine and observe

Page:   < prev 1-10 11-20 21-30 31-40 41-50 51-60 61-70 ... 100 next >