2003 CHRYSLER CARAVAN automatic transmission

RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the starter solenoid field coils. There should be
continuity between the cavity for relay terminal 87
and the starter solenoid terminal at all times. If OK,
go to Step 4. If not OK, repair the open circuit to the
starter solenoid as required.
(4) The coil battery terminal (85) is connected to
the electromagnet in the relay. It is energized when
the ignition switch is held in the Start position and
the clutch pedal is depressed (manual trans). Check
for battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position and the
clutch pedal is depressed (manual trans), and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK, check for
an open or short circuit to the ignition switch and
repair, if required. If the circuit to the ignition switch
is OK, see the Ignition Switch Test procedure in this
group.
(5) The coil ground terminal (86) is connected to
the electromagnet in the relay. It is grounded by the
PCM if the conditions are right to start the car. For
automatic trans. cars the PCM must see Park Neu-
tral switch low and near zero engine speed (rpm).
For manual trans. cars the PCM only needs to see
near zero engine speed (rpm) and low clutch inter-
lock input and see near zero engine speed (rpm). To
diagnose the Park Neutral switch of the trans range
sensor refer to the transaxle section. Check for conti-
nuity to ground while the ignition switch is in the
start position and if equipped the clutch pedal
depressed. If not OK and the vehicle has an auto-
matic trans. verify Park Neutral switch operation. If
that checks OK check for continuity between PCM
and the terminal 86. Repair open circuit as required.
Also check the clutch interlock switch operation if
equipped with a manual transmission. If OK, the
PCM may be defective.
SAFETY SWITCHES
For diagnostics of the Transmission Range Sensor,
refer to the Transaxle section for more information.
If equipped with Clutch Interlock/Upstop Switch,
refer to Diagnosis and Testing in the Clutch section.
IGNITION SWITCH
After testing starter solenoid and relay, test igni-
tion switch and wiring. Refer to the Ignition Section
or Wiring Diagrams for more information. Check all
wiring for opens or shorts, and all connectors for
being loose or corroded.
BATTERY
For battery diagnosis and testing, refer to the Bat-
tery section for procedures.
ALL RELATED WIRING AND CONNECTORS
Refer to Wiring Diagrams for more information.
DIAGNOSIS AND TESTING - FEED CIRCUIT
RESISTANCE TEST
Before proceeding with this operation, review Diag-
nostic Preparation and Starter Feed Circuit Tests.
The following operation will require a voltmeter,
accurate to 1/10 of a volt.
CAUTION: Ignition and Fuel systems must be dis-
abled to prevent engine start while performing the
following tests.
(1) To disable the Ignition and Fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(2) Gain access to battery terminals.
(3) With all wiring harnesses and components
properly connected, perform the following:
(a) Connect the negative lead of the voltmeter to
the battery negative post, and positive lead to the
battery negative cable clamp. Rotate and hold the
ignition switch in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between cable clamp and post.
(b) Connect positive lead of the voltmeter to the
battery positive post, and negative lead to the bat-
tery positive cable clamp. Rotate and hold the igni-
tion switch key in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between the cable clamp and post.
(c) Connect negative lead of voltmeter to battery
negative terminal, and positive lead to engine
block near the battery cable attaching point.
Rotate and hold the ignition switch in the START
position. If voltage reads above 0.2 volt, correct
poor contact at ground cable attaching point. If
voltage reading is still above 0.2 volt after correct-
ing poor contacts, replace ground cable.
(4) Connect positive voltmeter lead to the starter
motor housing and the negative lead to the battery
negative terminal. Hold the ignition switch key in
8F - 32 STARTINGRS
STARTING (Continued)
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the START position. If voltage reads above 0.2 volt,
correct poor starter to engine ground.
(a) Connect the positive voltmeter lead to the
battery positive terminal, and negative lead to bat-
tery cable terminal on starter solenoid. Rotate and
hold the ignition switch in the START position. If
voltage reads above 0.2 volt, correct poor contact at
battery cable to solenoid connection. If reading is
still above 0.2 volt after correcting poor contacts,
replace battery positive cable.
(b) If resistance tests do not detect feed circuit
failures, replace the starter motor.
DIAGNOSIS AND TESTING - FEED CIRCUIT
TEST
NOTE: The following results are based upon the
vehicle being at room temperature.
The following procedure will require a suitable
volt-ampere tester (Fig. 1).
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.(1) Check battery before performing this test. Bat-
tery must be fully charged.
(2) Connect a volt-ampere tester to the battery ter-
minals. Refer to the operating instructions provided
with the tester being used.
(3) To disable the ignition and fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(4) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
and SET parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(5) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
1).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 amps, check for engine seizing
or faulty starter.
²If voltage reads 12.4 volts or greater and amper-
age reads 0 to 10 amps, check for corroded cables
and/or bad connections.
²Voltage below 9.6 volts and amperage draw
above 300 amps, the problem is the starter. Replace
the starter refer to starter removal.
(6) After the starting system problems have been
corrected, verify the battery state-of-charge and
charge battery if necessary. Disconnect all testing
equipment and connect ASD relay. Start the vehicle
several times to assure the problem has been cor-
rected.
SPECIFICATIONS
Torques
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Starter Mounting Bolts 47.4 35
Starter Solenoid Battery
Nut11.3 8.3 100
Fig. 1 Volt Ampere Tester
RSSTARTING8F-33
STARTING (Continued)
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PROGRAMMABLE FEATURES
NOTE: Tire pressure monitoring (TPM) system infor-
mation is not covered in this section of the service
manual. Refer to the tires/wheels section of this
manual for detailed tire pressure monitoring system
information.
²LANGUAGE?- The options include English,
Francaise, Deutsch, Italiana, or Espanol. The default
is English. All EVIC display nomenclature, including
the trip computer functions, warning messages and
the programmable features appear in the selected
language.
²DISPLAY U.S. OR METRIC?- The options
include U.S. and M. The default is U.S. This feature
toggles the trip computer temperature, fuel economy
and odometer display readings between U.S. and
metric units of measure. It also changes the odome-
ter display in the instrument cluster.
²SERVICE INTV. =- The options include from
1000 to 12000 kilometers in 1000 kilometer incre-
ments (2000 to 7500 miles in 500 mile increments).
The default is 12000 kilometers (7500 miles). The
selected distance becomes the interval at which the
Perform Service warning message will be displayed
by the EVIC. If a new distance is selected, a second
programmable feature appears,RESET SERVICE
DISTANCE?- The options include No and Yes. The
default is Yes. When Yes is selected, the accumulated
distance since the last previous Perform Service
warning message will be reset to zero because the
service interval has been changed. When No is
selected, the distance until the next Perform Service
warning message is reduced by the accumulated dis-
tance since the last previous message.
²USE FACTORY SETTINGS?- The options
include Yes and No. The default is Yes. When yes is
selected all the programmable features will return to
there defaults and the rest of the programmable fea-
tures will not be displayed. If No is selected the rest
of the programmable features will be displayed at
there default values. This feature will automatically
return to the Yes default under two conditions. First,
if no programmable features are changed from there
defaults. Second, if all the programmable features
equal there defaults.
²AUTO DOOR LOCKS?- The options include
Yes and No. The default is Yes. When Yes is selected,
all doors and the liftgate lock automatically when
vehicle speed reaches 25 kilometers-per-hour (15
miles-per-hour). If YES is selected, a second program-
mable feature appears,AUTO UNLOCK ON EXIT?
- The options again include Yes and No. The default
is No. When Yes is selected, following each Auto Door
Lock event all doors and the liftgate will automati-
cally unlock when the driver door is opened, if thevehicle is stopped and the transmission gear selector
is in Park or Neutral. The Auto Door Unlock event
will only occur once following each Auto Door Lock
event.
²REMOTE UNLOCK- The options include
Driver Door 1st and All Doors. The default is Driver
Door 1st. When Diver Door 1st is selected, only the
driver door unlocks when the Unlock button of the
Remote Keyless Entry (RKE) transmitter is
depressed once. The Unlock button of the RKE trans-
mitter must be depressed twice to unlock all doors.
When All Doors is selected, all doors unlock when the
Unlock button of the RKE transmitter is depressed
once.
²REMOTE LINKED TO MEMORY?- This pro-
grammable feature only applies to vehicles equipped
with the optional memory / heated system. The
options include Yes and No. The default is No. When
Yes is selected, the memory system will recall the
Driver 1 or Driver 2 memory settings assigned to the
RKE transmitter being used to unlock the vehicle.
When No is selected, the memory system will only
recall memory settings when the Driver 1 or Driver 2
push buttons of the memory switch on the driver side
front door trim panel are depressed.
²SOUND HORN ON LOCK?- The options
include Yes and No. The default is No. When Yes is
selected, a short horn chirp will provide an audible
confirmation when the RKE receiver recognizes a
valid Lock signal from an RKE transmitter. When No
is selected, no horn chirp will occur with the RKE
Lock event. This feature may be selected indepen-
dent of theFLASH LIGHTS WITH LOCKS?pro-
grammable feature.
²FLASH LIGHTS WITH LOCKS?- The options
include Yes and No. The default is Yes. When Yes is
selected, a single flash of the hazard warning lamps
will provide an optical confirmation when the RKE
receiver recognizes a valid Lock signal from an RKE
transmitter, and two flashes of the same lamps will
occur when the RKE receiver recognizes a valid
Unlock signal from an RKE transmitter. When No is
selected, no lamp flash will occur with the RKE Lock
or Unlock event. This feature may be selected inde-
pendent of theSOUND HORN ON LOCK?pro-
grammable feature.
²HEADLAMP DELAY =- The options include
Off, 30 Sec, 60 Sec, and 90 Sec. The default is 90 Sec.
When a time interval is selected, the headlamps will
remain on for that length of time when the head-
lamps are turned off after the ignition is turned off,
or if the Auto mode is selected on vehicles with the
Auto Headlamps option. When Off is selected, the
headlamp delay feature is disabled.
²HEADLAMPS ON WITH WIPERS?- This pro-
grammable feature only applies to vehicles equipped
8M - 8 MESSAGE SYSTEMSRS
ELECTRONIC VEHICLE INFO CENTER (Continued)
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POWER LOCKS
TABLE OF CONTENTS
page page
POWER LOCKS
DESCRIPTION.........................38
OPERATION...........................39
DOOR CYLINDER LOCK SWITCH
DESCRIPTION.........................40
OPERATION...........................40
DIAGNOSIS AND TESTING - DOOR
CYLINDER LOCK SWITCH..............40
REMOVAL.............................41
INSTALLATION.........................41
DOOR LOCK MOTOR
DIAGNOSIS AND TESTING - DOOR LOCK
MOTOR .............................41
DOOR LOCK SWITCH
DIAGNOSIS AND TESTING - DOOR LOCK
SWITCH............................41
REMOVAL.............................42
INSTALLATION.........................42
KEYLESS ENTRY TRANSMITTER
DIAGNOSIS AND TESTING - KEYLESS ENTRY
TRANSMITTER.......................42STANDARD PROCEDURE
STANDARD PROCEDURE - HORN CHIRP
PREFERENCE........................42
STANDARD PROCEDURE - BATTERY
REPLACEMENT.......................42
STANDARD PROCEDURE - RKE
TRANSMITTER PROGRAMING...........43
SPECIFICATIONS
RANGE.............................43
BATTERY...........................43
REMOTE KEYLESS ENTRY MODULE
DESCRIPTION.........................43
OPERATION...........................43
DIAGNOSIS AND TESTING - REMOTE
KEYLESS ENTRY MODULE..............43
REMOVAL.............................44
INSTALLATION.........................44
SLIDING DOOR LOCK MOTOR
REMOVAL.............................44
INSTALLATION.........................44
POWER LOCKS
DESCRIPTION
POWER DOOR LOCK SYSTEM
The front doors, sliding door(s) and liftgate are
equipped with actuator motors to lock or unlock the
latch mechanisms. The door lock actuator motor is
not serviced separately from the door latch, except
for the sliding door(s).
AUTOMATIC DOOR LOCK
The vehicle comes with two options for power door
locks:
²Rolling automatic lock (ENABLE), doors auto-
matically lock at approximately at 25.7 Km/h (16
mph).
²No rolling automatic lock (DISABLE), doors do
not automatically lock when the vehicle is moving.
AUTOMATIC DOOR UNLOCK
The doors will unlock automatically on vehicles
equipped with power door locks if:
²Auto door locks feature is enabled and automatic
unlock is enabled.²The transmission was in gear and speed was
above zero.
²The transmission in park or neutral and speed
is zero.
²Any door (excluding liftgate) opens.
DOOR LOCK INHIBIT
The BCM cancels out the door lock switch actua-
tion, when the key is in the Ignition Switch and
either front door is open.
Pressing the key fob RKE lock/unlock under these
conditions results in normal lock/unlock activation.
CENTRAL LOCKING
If equipped with Vehicle Theft Security System
(VTSS), all the doors can be locked with the key by
using the driver door lock cylinder. Turning the key
to the lock position will lock all the doors.
DOOR LOCK CIRCUIT PROTECTION
The door lock system is protected by a 40 amp fuse
located in the IPM. The BCM receives lock/unlock
input and will turn on the appropriate drivers and
provide a voltage level to the door lock motor for a
specific time. The IPM is located along the side of the
vehicle battery in the engine compartment.
8N - 38 POWER LOCKSRS
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AUTOMATIC DAY / NIGHT
MIRROR
DESCRIPTION
An automatic dimming inside day/night rear view
mirror and an automatic dimming driver side outside
rear view mirror are available factory-installed
options on this model. Following is a general descrip-
tion of this optional equipment.
The automatic day/night mirror is able to automat-
ically change its reflectance. A thin layer of electro-
chromic material between two pieces of conductive
glass make up the face of the mirror. Two photocell
sensors are used to monitor light levels and adjust
the reflectance of the mirror to reduce the glare of
headlamps approaching the vehicle from the rear.
For removal procedures, (Refer to 23 - BODY/IN-
TERIOR/REAR VIEW MIRROR - REMOVAL).
OPERATION
The ambient photocell sensor faces forward, to
detect the outside light levels. A second sensor faces
rearward to detect the light level received through
the vehicles back window. When the difference
between the two light levels becomes too great (the
light level received at the rear of the mirror is much
higher than that at the front of the mirror), the mir-
ror begins to darken.
The mirror switch allows the driver a manual con-
trol of whether the automatic dimming feature is
operational. When AUTO is selected a small Light-
Emitting Diode (LED), to the right of the mirror
switch, is illuminated. The automatic dimming fea-
ture will only operate when the ignition switch is in
the On position. The mirror also senses the backup
lamp circuit, and will automatically disable its self-
dimming feature whenever the transmission gear
selector is in the Reverse position.
NOTE: The mirror always defaults to an ON state
upon ignition.
The driver side automatic dimming mirror is stan-
dard with the automatic dimming inside mirror. The
signal to control the dimming of that mirror is gen-
erated by the automatic day/night inside rear view
mirror circuitry. That signal is then delivered to the
driver side outside rear view mirror on a hard wired
circuit.
The automatic day/night mirror cannot be
repaired. If faulty or damaged, the entire inside rear
view mirror assembly must be replaced.
DIAGNOSIS AND TESTING - AUTOMATIC DAY /
NIGHT MIRROR
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
(1) Check the fuse in the intelligent power module.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fuse in the intelli-
gent power module. If OK, go to Step 3. If not OK,
repair the open circuit to the ignition switch as
required.
(3) Unplug the wire harness connector from the
automatic day/night mirror. Check for battery voltage
at the fused ignition switch output circuit cavity of
the automatic day/night mirror wire harness connec-
tor. If OK, go to Step 4. If not OK, repair the open
circuit to the junction block as required.
(4) Turn the ignition switch to the Off position.
Check for continuity between the ground circuit cav-
ity of the automatic day/night mirror wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 5. If not OK, repair the cir-
cuit to ground as required.
(5) Turn the ignition switch to the On position. Set
the parking brake. Place the transmission gear selec-
tor lever in the Reverse position. Check for battery
voltage at the backup lamp switch output circuit cav-
ity of the automatic day/night mirror wire harness
connector. If voltage is present, reinstall the auto-
matic day/night mirror wire harness connector and
go to Step 6. If not OK, repair the open circuit as
required.
(6) Place the transmission gear selector lever in
the Neutral position. Place the automatic day/night
mirror switch in the On (LED in the switch is
lighted) position. Cover the forward facing ambient
photocell sensor to keep out any ambient light.
NOTE: The ambient photocell sensor must be cov-
ered completely, so that no light reaches the sen-
sor. Use a finger pressed tightly against the sensor,
or cover the sensor completely with electrical tape.
(7)
Shine a light into the rearward facing headlamp
photocell sensor. The automatic day/night mirror
should darken. The automatic day/night mirror should
darken within 2 minutes if testing for the first time.
For immediate response, turn the vehicle OFF and
back ON with the forward-facing light sensor still cov-
RSPOWER MIRRORS8N-47
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The power seat system includes the following com-
ponents:
²Power seat recliners
²Power seat switches
²Power seat tracks
²Circuit breaker
The power seat system with memory and heated
seat options includes the following components:
²Power seat recliner
²Power seat switch
²Power seat track.
²Memory Seat Mirror Module (MSMM)
²Memory set switch
²Heated Seat Module (HSM)
²Heated seat switch
²Electronic Vehicle Information Center (EVIC)
²Programmable Communications Interface (PCI)
data bus network
Refer to Wiring Diagrams for complete circuit dia-
grams. Following are general descriptions and opera-
tions for the major components in the power seat
system and memory seat system.
DESCRIPTION - MEMORY SYSTEM
An electronic memory system is available on some
models. The memory system is able to store and
recall the driver side power seat positions (including
the power recliner position) and both outside side
view mirrors positions for two drivers. On vehicles
equipped with a factory radio, the memory system is
also able to store and recall radio station presets fortwo drivers. The memory system also will store and
recall the last station listened to for each driver, even
if it is not one of the preset stations.
The memory system will automatically return to
its preset settings when the corresponding numbered
button of the memory switch is depressed, or when
the doors are unlocked using the corresponding
Remote Keyless Entry (RKE) transmitter. A customer
programmable feature of the memory system allows
the RKE recall of memory features to be disabled, if
desired. This programmable feature is internal in the
EVIC module, which is located in the overhead con-
sole.
A Memory Seat Mirror Module (MSMM) is used on
some models to control and integrate the many elec-
tronic functions and features included in the memory
seat and mirror systems.
The memory system includes the following compo-
nents:
²Memory Seat Mirror Module (MSMM)
²Memory set switch
²Position potentiometers on both outside side
view mirrors
²Position potentiometers on the driver side power
seat track and power seat recliner motors.
²Electronic Vehicle Information Center (EVIC)
²Radio receiver (if PCI data bus capable).
Certain functions of the memory system rely upon
resources shared with other electronic modules in the
vehicle over the Programmable Communications
Interface (PCI) J1850 data bus network. The PCI
data bus network allows the sharing of sensor infor-
mation. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
Initial diagnosis of these electronic modules or the
PCI data bus network requires the use of a DRBIIIt
scan tool and the proper Diagnostic Procedures man-
ual. If this method does not prove conclusive, the use
of a automotive meter such as the Fluket, the proper
wiring schematics and the service manual diagnostic
routines are required.
The other electronic modules that may affect mem-
ory system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
²Powertrain Control Module (PCM)- Refer to
Powertrain Control Modulein Electronic Control
Modules for more information.
²Transmission Control Module (TCM)- Refer
toTransmission Control Modulein Electronic
Control Modules for more information.
Fig. 1 Identifying a Side Airbag Equipped Seat
1 - Airbag Label
RSPOWER SEAT SYSTEM8N-51
POWER SEAT SYSTEM (Continued)
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NOTE: Turning the system off by 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 rpm (indicates 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 co-efficient 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)
²If the actual speed is greater than 20 mph over
the set speed.
²Autostick shifts into 1st or 2nd gear (autostick,
if equipped)
Once the speed control has been disengaged,
depressing the RESUME switch when speed is
greater than 20 mph allows the vehicle to resume
control to the target speed that was stored in the
PCM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the ACCEL
switch. The new target speed is stored in the PCM
when the ACCEL switch is released. The PCM also
has a9tap-up9feature in which target speed
increases by 2 mph for each momentary switch acti-
vation of the ACCEL switch. The PCM also provides
a means to decelerate to a new lower target speed
without disengaging speed control. Depress and hold
the COAST switch until the desired speed is reached,
then release the switch.
The PCM also has a ªTap Downº feature in which
target speed decreases at 1 mph for each momentary
switch activation of the coast switch.
OPERATION - INTERACTIVE SPEED CONTROL
(4 Speed EATX Only)
Interactive means that communication between the
PCM and the TCM is taking place, this communica-
tion is internal to the PCM on NGC vehicles. Inter-
active speed control avoids unnecessary shifting for
smoother, quieter operation and when downshifts are
required, makes the shifts smoother.
CLIMBING A GRADE
DESCRIPTION
When climbing a grade the interactive speed con-
trol tries to maintain the set speed by increasing the
throttle opening, while inhibiting/delaying down-
shifts.
OPERATION
If opening the throttle alone cannot maintain the
set speed and the vehicle speed drops more than
three mph below the set speed, the transmission will
downshift to third gear. If the vehicle continues to
lose speed, by more than 6 mph, the transmission
will downshift again to maintain the set speed. After
the vehicle encounters a less-steep grade, or has
crested the grade (reduced the load on the power-
train) and can maintain the set speed at a reduced
throttle position, the transmission will upshift, as
appropriate, until the set speed can be maintained in
Overdrive.
GRADE HUNTING
DESCRIPTION
All vehicles equipped with a four speed automatic
transmission have a grade hunting feature for the
2nd to 3rd gear upshift and the 3rd to Overdrive
upshift.
OPERATION
The TCM (on SBEC vehicles) (PCM on NGC vehi-
cles) identifies the powertrain loading conditions and
selects the proper gear to maintain the current vehi-
cle speed. Under moderate loading conditions the
transaxle will stay in 3rd gear until the top of the
grade is reached or the powertrain loading is
reduced.
If powertrain loading is severe, the transaxle may
shift into 2nd gear and remain there until power-
train loading is reduced, then a 2nd to 3rd gear
upshift will be scheduled. Grade hunting features
always operate regardless of whether or not the
interactive speed control is engaged.If the interac-
tive speed control is not engaged and power-
train loading is not reduced, the driver may
have to completely lift off of the throttle before
an upshift will occur. If the driver does lift off the
throttle to induce an upshift under these conditions,
vehicle speed will reduce and the Overdrive to 3rd
and 3rd to 2nd gear downshifts will reoccur when the
throttle is reapplied. If grade hunting is repeatedly
induced by the driver, transaxle damage may result.
8P - 2 SPEED CONTROLRS
SPEED CONTROL (Continued)
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AUTOMATIC SPEED CONTROL OVERSPEED
REDUCTION
DESCRIPTION
Transmission control software includes an auto-
matic speed control overspeed reduction feature. This
maintains vehicle speed at the selected set point
when descending a grade.
OPERATION
The TCM (on SBEC vehicles) (PCM on NGC vehi-
cles) first senses that the speed control is set. If the
set speed is exceeded by more than 4 mph (6.5
km/hr) and the throttle is closed, the TCM (on SBEC
vehicles) (PCM on NGC vehicles) causes the trans-
axle to downshift to THIRD gear. After downshifting,
the automatic speed control resumes normal opera-
tion. To ensure that an upshift is appropriate after
the set speed is reached, the TCM (on SBEC vehi-
cles) (PCM on NGC vehicles) waits until the speed
control system opens the throttle at least 6 degrees
before upshifting to OVERDRIVE again.
If the driver applies the brakes, canceling auto-
matic speed control operation with the transaxle still
in THIRD gear, the TCM (on SBEC vehicles) (PCM
on NGC vehicles) maintains this gear until the driver
opens the throttle at least 6 degrees to avoid an inap-
propriate upshift. The upshift is also delayed for 2.5
seconds after reaching the 6 degrees throttle opening
in anticipation that the driver might open the throt-
tle enough to require THIRD gear. This will avoid
unnecessary and disturbing transmission cycling. If
the automatic speed control RESUME feature is used
after braking, the upshift is delayed until the set
speed is achieved to reduce cycling and provide bet-
ter response.
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. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to the Instru-
ment Cluster for speedometer diagnosis.
If a road test verifies an inoperative system, and
the speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose or corroded electrical connections 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 at both ends of the speed
control servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Conduct electrical test at PCM.
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.
SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Servo Mounting Bracket
Nuts14 10.3 123.9
Servo Mounting Bracket
Bolts14 10.3 123.9
Servo Mounting Nuts 6.7 60
RSSPEED CONTROL8P-3
SPEED CONTROL (Continued)
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