Because R-134a is not interchangeable with R-12, separate
sets of hoses, gauges, and recovery/recycling equipment are required
to service vehicles. This is necessary to avoid cross-contamination
and damaging system.
All equipment used to service systems using R-134a must meet
SAE standard J2210. The service hoses on the manifold gauge set must
have manual (turn wheel) or automatic back-flow valves at the service
port connector ends. This will prevent refrigerant from being released
into the atmosphere.
For identification purposes, R-134a service hoses must have a
Black stripe along their length and be clearly labeled SAE J2196/134a.
The low pressure test hose is Blue with a Black stripe. The high-side
test hose is Red with a Black stripe. The center test hose is Yellow,
or White, with a Black stripe.
NOTE: Refrigerant R-12 service hoses will ONLY be labeled SAE
J2196.
All R-134a manifold gauge sets can be identified by one or
all of the following:
* Labeled FOR USE WITH R-134a on set.
* Labeled HFC-134 or R-134a on gauge face.
* Light Blue color on gauge face. In addition,
pressure/temperature scales on R-134a gauge sets are
different from R-12 manifold gauge sets.
MANIFOLD GAUGE SET
A manifold gauge set is used to determine the system's high-
side and low-side pressures, correct refrigerant charge, and operating
efficiency. High (discharge) and low (suction) pressures must be
compared to determine system operation. Manifold gauge sets for the 2
refrigerant types are basically the same except for fittings at ends
of hoses. Fittings are different to ensure connection only to
appropriate refrigerant system.
Low-Side Gauge
Low-side gauge, which may have a Blue identifying feature, is
used to measure low-side (suction) pressure. Low-side gauge is also
called a compound gauge because it can measure pressure and vacuum.
Pressure scale ranges from 0 to 150 psi; vacuum scale ranges from 0 to
30 in. Hg.
High-Side Gauge
High-side gauge, which may have a Red identifying feature, is
used to measure high-side (discharge) pressure. Gauge scale ranges
from 0 to 500 psi.
CONNECTING GAUGE SET
NOTE: R-134a quick disconnect service couplings are connected in
the same sequence as Schrader-type service valves.
Schrader-Type Valves
1) Put on safety goggles, and cover vehicle's fender. Slowly
remove protective caps from Schrader valves to check for leaky valves.
CAUTION: Ensure hand valves on manifold gauge set and the hose-end
shutoff valves are closed before attaching test hoses to
Schrader valves.
NOTE: All active codes must be resolved before diagnosing store
codes.
1) Raise and support vehicle. Start engine and let idle with
transmission in PARK position. Wiggle wiring harness and connectors of
air bag system and rotate steering wheel from stop to stop.
2) Visually inspect related wire harness connectors. Look for
broken, bent, pushed out, spread, corroded or contaminated terminals.
Also, look for chafed, pierced, pinched or partially broken wires.
3) Check for trouble codes as you work through system. If
stored trouble code becomes active, perform appropriate diagnostic
test. If stored code is reproducible, repair or replace wiring
harness, harness connector or terminals or replace component as
necessary.
CLUSTER MESSAGE MISMATCH
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) If AIR BAG warning light is on, go to next step. If AIR
BAG warning light is not on, go to step 5).
2) Using DRB, select PASSIVE RESTRAINTS, AIRBAG and MONITOR
DISPLAY. Read WARNING LAMP STATUS. If DRB does not display MIC LAMP
STATUS ON, replace instrument cluster. If DRB displays MIC LAMP STATUS
ON, go to next step.
3) If DRB displays ACM LAMP REQUEST: ON, go to next step. If
DRB does not display ACM LAMP REQUEST: ON, replace instrument cluster.
4) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
NOTE: If AIR BAG warning light is defective, instrument cluster
will flash seat belt light for 30 seconds starting 10 seconds
after bulb check stops.
5) Using DRB, read air bag control module active codes
(messages). If CLUSTER MISMATCH is only active message, go to next
step. If other messages are present, go to appropriate diagnostic test
to continue diagnosis.
6) If seat belt warning light flashes for 30 seconds after
bulb check is complete, replace instrument cluster. If seat belt
warning light does not flashes for 30 seconds after bulb check is
complete, go to next step.
7) Using DRB, select PASSIVE RESTRAINTS, AIRBAG and MONITOR
DISPLAY. Read WARNING LAMP STATUS. If DRB displays ACM LAMP REQUEST:
OFF, go to next step. If DRB does not display ACM LAMP REQUEST: OFF,
replace instrument cluster.
8) If DRB displays MIC LAMP REQUEST: OFF, go to next step. If
DRB does not display MIC LAMP REQUEST: OFF, replace instrument
cluster.
9) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
DRIVER SQUIB CIRCUIT OPEN
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
4) Locate Central Timer Module (CTM). CTM is located under
left side of instrument panel. Using an external voltmeter, measure
voltage between ground and backprobe of CTM 14-pin Green connector C1
terminal No. 11 (Dark Green wire). Wipers should be operating at low
speed. If voltage does not cycle between zero and 12 volts, repair
open Dark Green wire between CTM and wiper relay or wiper motor. If
voltage cycles between zero and 10 volts, replace CTM.
5) Using scan tool, monitor intermittent wiper voltage level.
Rotate wiper switch from low intermittent to high intermittent level.
If voltage changes from approximately 2.5 to 12 volts, replace CTM. If
voltage does not change from approximately 2.5 to 12 volts, go to next
step.
6) Disconnect 24-pin multifunction switch connector. Using an
external ohmmeter, measure resistance of White/Dark Blue wire between
multifunction switch connector terminal No. 1 and CTM 14-pin Green
connector C1 terminal No. 12. if resistance is less than 5 ohms,
replace multifunction switch. If resistance is 5 ohms or more, repair
open White/Dark Blue wire between multifunction switch and CTM.
NO WIPER ACTUATION AFTER WASH BUTTON PUSHED
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) Using scan tool select Central Timer Module (CTM). If sca\
n
tool displays NO RESPONSE, go to appropriate VEHICLE COMMUNICATIONS
article. If scan tool displays any CCD bus failure message, go to
SYMPTOM IDENTIFICATION. If scan tool does not display NO RESPONSE or
any CCD bus failure message, go to next step.
2) Turn ignition on. If washer system works, go to next step.
If washer system does not work, see appropriate WIPER/WASHER SYSTEMS
article.
3) Using scan tool, actuate washer. If washer pump sense
displays ON, replace CTM. If washer pump sense does not display ON,
repair open Brown wire between CTM 14-pin connector C1 terminal No. 10
and multifunction switch.
WIPER SPEED SENSITIVE FEATURE 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) Using scan tool select Central timer module (CTM). If sca\
n
tool display is not blank or have a CCD bus failure message, go to
next step. If scan tool display is blank or has a CCD bus failure
message, see appropriate VEHICLE COMMUNICATIONS article.
2) Using scan tool, select Powertrain Control Module (PCM).
If scan tool display is not blank or have a CCD bus failure message,
go to next step. If scan tool display is blank or has a CCD bus
failure message, see appropriate VEHICLE COMMUNICATIONS article.
3) Raise and support vehicle. Turn wipers on to lowest
intermittent position. Time interval between wipes. Spin rear wheels
to more than 15 MPH. If interval between wipes decreased to
approximately 18 seconds, system is currently functioning properly. If
interval between wipes did not decrease to approximately 18 seconds,
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
voltage. If voltage is less than one volt, go to next step. If voltage
is one volt or more, condition to set FTC is not present at this time.
Test is complete.
2) While observing scan tool, disconnect S/C ON/OFF switch.
If S/C switch voltage changes to 5 volts, replace S/C ON/OFF switch.
Perform TEST VER-4A under VERIFICATION TESTS. If voltage does not
change to 5 volts, go to next step.
3) While observing scan tool, disconnect S/C RESUME/ACCEL
switch. If S/C switch voltage changes to 5 volts, replace S/C
RESUME/ACCEL switch. Perform TEST VER-4A under VERIFICATION TESTS. If
voltage does not change to 5 volts, go to next step.
4) Turn ignition off. Ensure both S/C switches are still
disconnected. Using an ohmmeter, check resistance between S/C switch
connector terminals (S/C switch signal circuit and S/C switch ground
circuit). If resistance is less than 5 ohms, repair short circuit.
Perform TEST VER- 4A under VERIFICATION TESTS. If resistance is 5 ohms
or more, go to next step.
5) Disconnect clockspring 4-pin connector. Clockspring 4-pin
connector is located behind steering wheel. Inspect connector. Clean
or repair as necessary. Using an ohmmeter, check resistance between
ground and S/C switch signal circuit at clockspring connector (Dark
Green/Red wire on all models except Ram Van and Ram Wagon; wire color
is not available for Ram Van and Ram Wagon). If resistance is less
than 5 ohms, repair short to ground. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is 5 ohms or more, go to next step.
6) Disconnect PCM. Inspect connectors. Clean or repair as
necessary. Using an ohmmeter, check resistance between ground and S/C
switch signal circuit at either S/C switch connector (Dark Green/Red
wire on all models except Ram Van and Ram Wagon; wire color is not
available for Ram Van and Ram Wagon). If resistance is less than 5
ohms, repair short to ground. Perform TEST VER-4A under VERIFICATION
TESTS. If resistance is 5 ohms or more, replace PCM. Perform TEST VER-
4A under VERIFICATION TESTS.
FTC P1683: SPEED CONTROL POWER RELAY CIRCUIT
FTC P1683 will set if Speed Control (S/C) power supply
circuit is open or shorted when S/C is turned on.
Possible Causes:
* Brake switch out of adjustment.
* S/C brake switch output circuit open or shorted.
* Defective S/C servo.
* Defective brake switch.
* S/C vacuum or vent solenoid control circuits open or
shorted.
* Defective PCM.
* Ground circuit open.
* S/C power supply circuit open.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
NOTE: Ensure brake pedal is not depressed during the following
steps.
1) Turn ignition off. Disconnect S/C servo connector. Inspect
connector. Clean or repair as necessary. Turn ignition on. Using scan
tool, actuate S/C relay. Using a 12-volt test light, probe S/C brake
switch output circuit at S/C servo connector terminal No. 3 (Dark
Blue/Red wire). If test light is illuminated and bright, go to next
1) On drive shafts greater than 30" in length, measure runout
3" from transmission flange/yoke, center bearing yoke and pinion
flange using dial indicator. Maximum runout for Ram Pickup is .030" (.
76 mm) at front and rear end of drive shaft and .035" (.89 mm) at
center of drive shaft. Maximum runout for all other models is .010" (.
25 mm) at front and rear end of drive shaft and .015" (.38 mm) at
center of drive shaft.
2) For drive shafts less than 30" in length, maximum runout
for Pickup is .030" (.76 mm). Maximum runout for all other models is .\
020" (.51 mm). Replace drive shaft if maximum runout is exceeded.
BALANCING DRIVE SHAFT
1) Perform following procedure only after inspecting all
other possible causes of vibration. See INSPECTION. Drive shaft
imbalance may often be cured by disconnecting shaft, rotating it 180
degrees and reconnecting shaft to flange. Test drive to check results.
NOTE: DO NOT run engine for prolonged periods without forced
airflow across radiator. Engine or transmission may
overheat.
2) To balance drive shaft(s), begin by raising rear wheels
off ground and turning drive shaft with engine. Balance testing may be
done by marking drive shaft in 4 positions, 90 degrees apart around
shaft. Place marks about 6" forward of rear flange/yoke weld. Number
marks 1-4.
3) Install large diameter screw-type hose clamp around drive
shaft so clamp's head is in No. 1 position. Spin drive shaft with
engine and note vibrations. If there is little or no change in
vibration intensity, move clamp head to No. 2 position, and repeat
test.
4) Continue procedure until vibration is at lowest level. If
no difference is noted with clamp head moved to all 4 positions,
vibrations may not be due to drive shaft imbalance.
5) If vibration decreases but is not completely eliminated,
place a second clamp at same position, and repeat test. Combined
weight of both clamps in one position may increase vibration. If so,
rotate clamps 1/2" apart, above and below lowest vibration level
position, and repeat test.
6) Continue to rotate clamps, as necessary, until vibration
is at lowest point. If vibration can be eliminated or reduced to
acceptable level, bend back slack end of clamp so screw cannot loosen.
If vibration level is still unacceptable, leave rear clamp(s) in
place, and repeat procedure at front end of drive shaft. Road test
vehicle. On 4WD models, perform procedure on each shaft.
CHECKING VERTICAL ANGLE
One-Piece Drive Shafts
1) Raise and support vehicle so rear wheels can be rotated.
Rotate drive shaft so a pinion flange bearing cap faces downward.
Attach Inclinometer (C-4224) magnet to bearing cap, and measure drive
shaft vertical angle. See Fig. 4. Remove inclinometer.
2) Rotate drive shaft 90 degrees until drive shaft rear yoke
bearing cap faces downward. Attach inclinometer magnet to bearing cap,
and measure drive shaft vertical angle. Difference between 2 measured
angles is drive shaft rear angle. See Fig. 5. Remove inclinometer.
3) Rotate drive shaft until a slip joint yoke bearing cap
faces downward. Attach inclinometer magnet to bearing cap, and note
angle. Remove inclinometer. Rotate drive shaft 90 degrees until drive
shaft front yoke bearing cap faces downward. Attach inclinometer
magnet to bearing cap, and note angle. Remove inclinometer.
Fig. 7: Checking Vertical Alignment Of 2-Piece Drive Shaft
Courtesy of Chrysler Corp.
ADJUSTING VERTICAL ANGLE
If front angle minus rear angle is greater than one degree
positive (+1 degree), rear angle is too small and must be increased.
If front angle minus rear angle is greater than one degree negative (-
1 degree), rear angle is too large and must be decreased.
1) Raise and support rear of vehicle. Position a jack under
differential housing. Remove rear wheel assemblies. Loosen rear spring
"U" bolt nuts. Insert tapered shim between spring and axle spring pad.
If increasing angle, insert shim with taper facing front of vehicle.
If decreasing angle, insert shim with taper facing rear of vehicle.
NOTE: If encountering difficulty in making drive shaft vertical
adjustments on one-piece drive shafts, drive shaft may be out
of horizontal alignment. See CHECKING HORIZONTAL ALIGNMENT.
NOTE: On 2-piece drive shafts, center angle is adjusted by use of
shims between center support mounting bracket and frame
crossmember. Center angle may need adjusting if rear angle is
changed.
2) Tighten spring "U" bolt nuts to specification. See TORQUE
SPECIFICATIONS table. Recheck drive shaft angle measurements. See
CHECKING VERTICAL ANGLE.
CHECKING HORIZONTAL ALIGNMENT
1) Drive shaft horizontal alignment should be checked if
frame damage is suspected or when major components have been replaced.
See Fig. 8 .
2) Clamp a long straightedge (12" longer than width of rear
wheel track) at 90 degrees to frame side rails. See Fig. 9. Use large
framing squares to align straightedge with side rails.
BR3500 (8 Stud Dual Wheel)........................ 145 (195)\
\
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BATTERY SPECIFICATIONS
Vehicle is factory equipped with a maintenance free battery.
The top of the battery is permanently sealed, and water never has to
be added, and periodic maintenance is not required either. But,
periodically check the battery terminals and battery hold-down bracket
for corrosion. Replace with a battery of the same group number as
shown on original battery's label.
CAUTION: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in the GENERAL INFORMATION
section.
CAUTIONS & WARNINGS
SUPPLEMENTAL RESTRAINT SYSTEM (AIR BAG)
NOTE: See the AIR BAGS article in the ACCESSORIES/SAFETY EQUIPMENT
Section.
Modifications or improper maintenance, including incorrect
removal and installation of the Supplemental Restraint System (SRS),
can adversely affect system performance. DO NOT cover, obstruct or
change the steering wheel horn pad in any way, as such action could
cause improper function of the system. Use only plain water when
cleaning the horn pad. Solvents or cleaners could adversely affect the
air bag cover and cause improper deployment of the system.
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all warnings and service precautions. See
appropriate AIR BAGS article in ACCESSORIES/SAFETY EQUIPMENT.
WARNING: Any maintenance performed on or near the components of the
SRS must be performed only by an authorized dealer.
Do not permit anyone else to service, inspect maintain, or
service any SRS components or wiring. Similarly, no part of
the SRS should ever be handled or disposed of by anyone
except an authorized dealer.
Improper work on the SRS components or wiring could result in
inadvertent deployment of the airbags or could render the SRS
system inoperative. Either situation could result in serious
injury
WARNING: If the car has had any front-end damage, have the SRS system
inspected by an authorized dealer to ensure it is working
properly.
WARNING: If any of the following conditions occur, the SRS is not
working properly. Immediately have it inspected by an
authorized dealer:
* The SRS warning light does not illuminate when you start
the car.
* The SRS warning light does not go off after about 7 seconds.
* The SRS warning light illuminates while driving.