four wheel drive CHRYSLER CARAVAN 2003 Owner's Manual

TEST TWO-SELECTOR IN DRIVE (2nd GEAR)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the 3 position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph.
(4) In second gear the underdrive clutch pressure
should read 110 to 145 psi.
TEST TWO A±SELECTOR IN OD (4th Gear)
NOTE: This test checks the underdrive clutch
hydraulic circuit as well as the shift schedule.
(1) Attach gauge to the underdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow wheels to rotate freely and increase
throttle opening to achieve an indicated speed of 40
mph.
(4) Underdrive clutch pressure should read below
5 psi. If not, then either the solenoid assembly or
PCM/TCM is at fault.
TEST THREE-OVERDRIVE CLUTCH CHECK (3rd and
2nd Gear)
(1) Attach gauge to the overdrive clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 20 mph. Vehicle should be in 3rd gear.(4) Overdrive clutch pressure should read 74 to 95
psi.
(5) Move selector lever to the (3) position and
increase indicated vehicle speed to 30 mph.
(6) The vehicle should be in second gear and over-
drive clutch pressure should be less than 5 psi.
(7) This test checks the overdrive clutch hydraulic
circuit as well as the shift schedule.
TEST FOUR-SELECTOR IN OVERDRIVE (4th Gear)
(1) Attach gauge to the 2/4 clutch tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle front wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 30 mph. Vehicle should be in 4th gear.
(4) The 2/4 clutch pressure should read 75 to 95
psi.
(5) This test checks the 2/4 clutch hydraulic cir-
cuit.
TEST FIVE-SELECTOR IN OVERDRIVE (4th Gear-CC
on)
(1) Attach gauge to the torque converter clutch off
pressure tap.
(2) Move selector lever to the (OD) position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle speed
of 50 mph. Vehicle should be in 4th gear, CC on.
CAUTION: Both wheels must turn at the same
speed.
(4) Torque converter clutch off pressure should be
less than 5 psi.
(5) This test checks the torque converter clutch
hydraulic circuit.
TEST SIX-SELECTOR IN REVERSE
(1) Attach gauges to the reverse and LR clutch
tap.
(2) Move selector lever to the (R) position.
(3) Read reverse clutch pressure with output sta-
tionary (foot on brake) and throttle opened to achieve
1500 rpm.
(4) Reverse and LR clutch pressure should read
165 to 235 psi.
(5) This test checks the reverse clutch hydraulic
circuit.
TEST RESULT INDICATIONS
(1) If proper line pressure is found in any one test,
the pump and pressure regulator are working prop-
erly.
(2) Low pressure in all positions indicates a defec-
tive pump, a clogged filter, or a stuck pressure regu-
lator valve.
Fig. 4 Pressure Taps
1 - OVERDRIVE CLUTCH
2 - TORQUE CONVERTER OFF
3 - LOW/REVERSE CLUTCH
4 - 2/4 CLUTCH
5 - REVERSE CLUTCH
6 - UNDERDRIVE CLUTCH
RS41TE AUTOMATIC TRANSAXLE21 - 121
41TE AUTOMATIC TRANSAXLE (Continued)
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(4) Install andlightly tightenthe three remain-
ing wheel mounting nuts, securing the wheel cover in
place (Fig. 12).
(5) Progressively tighten all five wheel mounting
nuts in the proper sequence (Fig. 16). Tighten wheel
nuts to a torque of 135 N´m (100 ft. lbs.).
(6) Lower the vehicle.
TIRE PRESSURE MONITORING
DESCRIPTION
Some versions of this vehicle are equipped with a
Tire Pressure Monitoring (TPM) system. It monitors
air pressure in the four road tires (excludes spare).
Pressure in the spare tire is not monitored.
There is a sensor (transmitter) in each of the vehi-
cle's four road wheels. The system alerts the driver
when tire pressure falls outside predetermined
thresholds (pressure too low or too high). A message
is then displayed on the Electronic Vehicle Informa-
tion Center (EVIC) located in the overhead console.
For further information, refer to the Owners Man-
ual or the appropriate diagnostic information.
OPERATION
The Tire Pressure Monitoring (TPM) system uses
radio and sensor technology to monitor tire air pres-
sure levels. Sensors, mounted to each road wheel as
part of the valve stem, transmit tire pressure read-
ings to a receiver located in the overhead console.
These transmissions occur once every minute at
speeds over 20 mph (32 km/h). The Tire Pressure
Monitoring system remains active even if no tire
pressure related message is displayed in the EVIC.
If any road tire pressure has exceeded the low or
high pressure threshold (refer to chart below), the
TPM system will display a message in the EVIC and
sound a chime. This message will be displayed for
the rest of the ignition cycle, or until either the Low/
High Tire pressure condition has been corrected. If
the C/T, MENU, STEP or RESET button is pressed,
the message is replaced by the new message
requested; however, if the Low/High Tire condition
has not been corrected, the Low/High Tire pressure
message will again be displayed.
Fig. 14 TWO WHEEL MOUNTING NUTS INSTALLED
1 - WHEEL
2 - VALVE STEM
3 - HUB PILOT
4 - NUTS
Fig. 15 WHEEL COVER INSTALLATION OVER TWO
NUTS
1 - RETAINING TABS
2 - VALVE STEM
3 - BOLT-ON WHEEL COVER
Fig. 16 NUT TIGHTENING SEQUENCE
RSTIRES/WHEELS22-9
TIRES/WHEELS (Continued)
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damaged, the clutch electromagnetic coil unit must
be replaced.
OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch plate into contact with the clutch pulley and
drives the compressor shaft. When the coil is not
energized, the pulley freewheels on the clutch hub
bearing, which is part of the pulley.
A zener diode is connected in parallel with the
clutch electromagnetic coil. This diode controls the
dissipation of voltage induced into the coil windings
by the collapsing of the electromagnetic fields that
occurs when the compressor clutch is disengaged.
The zener diode dissipates this induced voltage by
regulating a current path to ground. This arrange-
ment serves to protect other circuits and components
from potentially damaging voltage spikes in the vehi-
cle electrical system that might occur if the voltage
induced in the clutch coil windings could not be dis-
sipated.
The compressor clutch engagement is controlled by
several components: the heater-A/C controls in the
passenger compartment, the A/C pressure transducer
on the liquid line, the evaporator temperature sensor
on the expansion valve, the Powertrain Control Mod-
ule (PCM) in the engine compartment, and the com-
pressor clutch relay in the Intelligent Power Module
(IPM). The PCM may delay compressor clutch
engagement for up to thirty seconds. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION - PCM OPERATION).
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPRESSOR
CLUTCH AIR GAP
If a new clutch plate and/or clutch pulley are being
used, the air gap between the clutch plate and clutch
pulley must be checked using the following proce-
dure:
(1) Using feeler gauges, measure the air gap
between the clutch plate and the clutch pulley fric-
tion surfaces.
(2) If the air gap is not between 0.5 and 0.9 mm
(0.020 and 0.035 in.), add or subtract shims until the
desired air gap is obtained.
NOTE: The shims may compress after tightening
the compressor shaft bolt. Check the air gap in four
or more places on the clutch plate to verify that the
air gap is still correct. Spin the clutch pulley before
making the final air gap check.
STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
check that the compressor clutch coil is performing to
specifications. (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS - FRONT/COMPRESSOR
CLUTCH COIL - DIAGNOSIS AND TESTING). If
the clutch coil is performing to specifications, per-
form the compressor clutch break-in procedure. This
procedure (burnishing) will seat the opposing friction
surfaces and provide a higher compressor clutch
torque capability.
(1) Set the heater-A/C controls to the A/C mode,
with the blower switch in the highest speed position.
(2) Start the engine and hold the engine speed at
1500 to 2000 rpm.
(3) Cycle the compressor clutch On and Off about
twenty times (seven seconds On, then seven seconds
Off).
REMOVAL
The refrigerant system can remain fully charged
during compressor clutch, pulley, or coil replacement.
Although the compressor assembly must be removed
from its mounting, the compressor clutch can be ser-
vice with the compressor in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Raise and support the vehicle.
Fig. 11 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (SOME MODELS)
3 - PULLEY AND BEARING
4 - CLUTCH COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
RSCONTROLS - FRONT24-17
COMPRESSOR CLUTCH (Continued)
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