2003 DODGE RAM display

then sends the proper ambient temperature mes-
sages to the EVIC, CMTC over the PCI J1850 data
bus.
The temperature function is supported by the
ambient temperature sensor, a wiring circuit, the
Front Control Module, the Programmable Communi-
cations Interface (PCI) data bus, and a portion of the
Electronics module. If any portion of the ambient
temperature sensor circuit fails, the Front Control
Module will self-diagnose the circuit.
For complete circuit diagrams, refer toWiring.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At 24É C (75É F), the sensor resistance
should be approximately 10.3 kilohms. At 30É C (86É
F), the sensor resistance should be approximately
7.57 kilohms. The sensor resistance should decrease
as the temperature rises. If OK, refer toDiagnosis
and Testing - Ambient Temperature Sensor Cir-
cuitin this group. If not OK, replace the faulty
ambient temperature sensor.
NOTE: The ambient temperature sensor is a very
sensitive device. When testing, be certain the tem-
perature sensor has had time to stabilize (room
temperature) before attempting to read the sensor
resistance. Failure to let the ambient temperature
sensor temperature stabilize could result in a mis-
leading test.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Front Control Module wire
harness connector.
(2) Connect a jumper wire between the two termi-
nals of the ambient temperature sensor wire harness
connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the Front Control Module wire har-
ness connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return or
signal circuit as required.(4) Remove the jumper wire from the ambient tem-
perature sensor wire harness connector. Check for
continuity between the sensor return circuit cavity of
the Front Control Module wire harness connector
and a good ground. There should be no continuity. If
OK, go to Step 5. If not OK, repair the shorted sen-
sor return circuit as required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the Front
Control Module wire harness connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing - Overhead Consolein
this group. If not OK, repair the shorted ambient
temperature sensor signal circuit as required.
REMOVAL
(1) Open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Working on the underside of the hood, remove
screw holding sensor to hood panel.
(4) Disconnect the sensor electrical connector and
remove sensor from vehicle.
INSTALLATION
(1) Connect the sensor electrical connector.
(2) Working on the underside of the hood, install
screw holding sensor to hood panel.
(3) Connect the battery negative cable.
(4) Close the hood.
UNIVERSAL TRANSMITTER
DESCRIPTION
Some DR models are equipped with a universal
transmitter transceiver. The universal transmitter is
integral to the Electronic Vehicle Information Center
(EVIC) and the Compass Mini-Trip Computer
(CMTC), which is located in the overhead console.
The only visible component of the universal transmit-
ter are the three transmitter push buttons centered
between the modules push buttons located just rear-
ward of the display screen in the overhead console.
The three universal transmitter push buttons are
identified with one, two or three light indicators so
that they be easily identified.
Each of the three universal transmitter push but-
tons control an independent radio transmitter chan-
nel. Each of these three channels can be trained to
transmit a different radio frequency signal for the
remote operation of garage door openers, motorized
gate openers, home or office lighting, security sys-
tems or just about any other device that can be
equipped with a radio receiver in the 286 to 399
MegaHertz (MHz) frequency range for remote opera-
DRMESSAGE SYSTEMS 8M - 11
AMBIENT TEMP SENSOR (Continued)

tion. The universal transmitter is capable of operat-
ing systems using either rolling code or non-rolling
code technology.
The electronics module displays messages and a
small house-shaped icon with one, two or three dots
corresponding to the three transmitter buttons to
indicate the status of the universal transmitter. The
EVIC messages are:
²Clearing Channels- Indicates that all of the
transmitter codes stored in the universal transmitter
have been successfully cleared.
²Channel ªXº Training- Indicates that the uni-
versal transmitter is in its transmitter learning
mode.
²Channel ªXº Trained- Indicates that the uni-
versal transmitter has successfully acquired a new
transmitter code.
²Channel ªXº Transmitting- Indicates that a
trained universal transmitter button has been
depressed and that the universal transmitter is
transmitting.
The universal transmitter cannot be repaired, and
is available for service only as a unit with the EVIC
or CMTC modules. If any part of the universal trans-
mitter is faulty or damaged, the complete EVIC or
CMTC module must be replaced.
OPERATION
The universal transmitter operates on a non-
switched source of battery current so the unit will
remain functional, regardless of the ignition switch
position. For more information on the features, pro-
gramming procedures and operation of the universal
transmitter, see the owner's manual in the vehicle
glove box.
DIAGNOSIS AND TESTING - UNIVERSAL
TRANSMITTER
If the Universal Transmitter is inoperative, but the
Electronic Vehicle Information Center (EVIC) is oper-
ating normally, see the owner's manual in the vehicle
glove box for instructions on training the Transmit-
ter. Retrain the Transmitter with a known good
transmitter as instructed in the owner's manual and
test the Transmitter operation again. If the unit is
still inoperative, test the universal transmitter with
Radio Frequency Detector special tool. If both the
Transmitter and the EVIC module are inoperative,
refer toElectronic Vehicle Information Center
Diagnosis and Testingin this group for further
diagnosis. For complete circuit diagrams, refer to
Wiring Diagrams. (Fig. 8) as described below:
(1) Turn the Radio Frequency (RF) Detector ON. A
ªchirpº will sound and the green power LED will
light. If the green LED does not light, replace the
battery.(2) Hold the RF detector within one inch of the
TRAINED universal transmitter and press any of the
transmitters buttons.
(3) The red signal detection LEDs will light and
the tool will beep if a radio signal is detected. Repeat
this test three times.
STANDARD PROCEDURE
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES
To erase the universal transmitter codes, simply
hold down the two outside buttons until the display
confirms the operation.
NOTE: Individual channels cannot be erased. Eras-
ing the transmitter codes will erase ALL pro-
grammed codes.
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES
(1) Turn off the engine.
(2) Erase the codes by pressing the two outside
buttons. Release the buttons when the display con-
firms the operation (about 20 seconds).
(3) Choose one of the three buttons to train. Place
the hand-held transmitter within one inch of the uni-
Fig. 8 RADIO FREQUENCY DETECTOR
1 - SIGNAL DETECTION LED'S
2 - POWER LED
3 - ON/OFF SWITCH
4 - 9V BATTERY
8M - 12 MESSAGE SYSTEMSDR
UNIVERSAL TRANSMITTER (Continued)

The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
A speed control servo is not used with any
5.7L V-8 engine, or with the 5.9L diesel engine
when equipped with a manual transmission.
The Powertrain Control Module (PCM) controls the
solenoid valve body. The solenoid valve body controls
the application and release of vacuum to the dia-
phragm of the vacuum servo. The servo unit cannot
be repaired and is serviced only as a complete assem-
bly.
Power is supplied to the servo's by the PCM
through the brake switch. The PCM controls the
ground path for the vacuum and vent solenoids.
The dump solenoid is energized anytime it receives
power. If power to the dump solenoid is interrupted,
the solenoid dumps vacuum in the servo. This pro-
vides a safety backup to the vent and vacuum sole-
noids.
The vacuum and vent solenoids must be grounded
at the PCM to operate. When the PCM grounds the
vacuum servo solenoid, the solenoid allows vacuum
to enter the servo and pull open the throttle plate
using the cable. When the PCM breaks the ground,
the solenoid closes and no more vacuum is allowed to
enter the servo. The PCM also operates the vent sole-
noid via ground. The vent solenoid opens and closes a
passage to bleed or hold vacuum in the servo as
required.
The PCM duty cycles the vacuum and vent sole-
noids to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. When
the brake is released, if vehicle speed exceeds 30
mph to resume, 35 mph to set, and the RES/ACCEL
switch has been depressed, ground for the vent and
vacuum circuits is restored.
REMOVAL
The speed control servo assembly is attached to the
bottom of the battery tray (Fig. 8).
(1) Disconnect negative battery cable at battery
(both cables at both batteries if diesel).
(2) To gain access to servo, remove plastic wheel-
house splash shield over left-front wheel.
(3) Disconnect vacuum line at servo (Fig. 8).
(4) Disconnect electrical connector at servo (Fig. 8).
(5) Remove 3 servo mounting screws (Fig. 8).
Depending on engine application, different sets of
mounting lugs (Fig. 8) are used to support servo to
battery tray. While removing, note proper lugs.(6) Disconnect servo cable at throttle body. Refer to
Servo Cable Removal/Installation.
(7) Remove 2 mounting nuts holding servo cable
sleeve to bracket (Fig. 9).
(8) Pull speed control cable sleeve and servo away
from servo mounting bracket to expose cable retain-
ing clip (Fig. 9) and remove clip. Note: The servo
mounting bracket displayed in (Fig. 9) is a typical
bracket and may/may not be applicable to this model
vehicle.
(9) Remove servo from mounting bracket. While
removing, note orientation of servo to bracket.
INSTALLATION
(1) Position servo to mounting bracket (Fig. 9).
(2) Align hole in cable connector with hole in servo
pin. Install cable-to-servo retaining clip (Fig. 9).
(3) Insert servo mounting studs through holes in
servo mounting bracket.
(4) Install 2 servo-to-mounting bracket nuts and
tighten. Refer to torque specifications.
(5) Position servo assembly to correct mounting
lugs on battery tray (Fig. 8) and install 3 screws.
Tighten 3 screws. Refer to torque specifications.
(6) Connect vacuum line at servo.
(7) Connect electrical connector at servo.
Fig. 8 SPEED CONTROL SERVO LOCATION
1 - BATTERY TRAY
2 - MOUNTING LUGS
3 - SERVO
4 - ELEC. CONNEC.
5 - MOUNTING SCREWS (3)
6 - MOUNTING BRACKET
7 - VACUUM LINE
DRSPEED CONTROL 8P - 7
SERVO (Continued)

NOTE: If a PCM is replaced, the unique ªSecret
Keyº data must be transferred from the SKIM to the
PCM. This procedure requires the SKIM to be
placed in SECURED ACCESS MODE using the four
digit PIN code.
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER PROGRAMMING
Two programmed Sentry Key transponders are
included with the Sentry Key Immobilizer System
(SKIS) when it is shipped from the factory. The Sen-
try Key Immobilizer Module (SKIM) can be pro-
grammed to recognize up to six additional
transponders, for a total of eight Sentry Keys. The
following ªCustomer Learnº programming procedure
for the programming of additional transponders
requires access to at least two of the valid Sentry
Keys. If two valid Sentry Keys are not available, Sen-
try Key programming will require the use of a
DRBIIItscan tool.
CUSTOMER LEARN PROGRAMMING
(1) Obtain the additional Sentry Key transponder
blank(s) that are to be programmed for the vehicle.
Cut the additional Sentry Key transponder blanks to
match the ignition lock cylinder mechanical key
codes.
(2) Insert one of the two valid Sentry Key tran-
sponders into the ignition switch and turn the igni-
tion switch to the ON position.
(3) After the ignition switch has been in the ON
position for about three seconds, but no more than
fifteen seconds, cycle the ignition switch back to the
OFF position. Replace the first valid Sentry Key in
the ignition lock cylinder with the second valid Sen-
try Key and turn the ignition switch back to the ON
position. Both operations must be performed within
15 seconds.
(4) In approximately ten seconds the VTSS indica-
tor LED will start to flash to indicate that the sys-
tem has entered the ªCustomer Learnº programming
mode.
(5) Within approximately sixty seconds of entering
the ªCustomer Learnº programming mode, turn the
ignition switch to the OFF position, replace the valid
Sentry Key with a blank Sentry Key transponder,
and turn the ignition switch back to the ON position.
(6) In approximately ten seconds, the VTSS indica-
tor LED will stop flashing and stay on solid for
approximately three seconds and then turn OFF to
indicate that the blank Sentry Key transponder has
been successfully programmed. The SKIS will imme-
diately return to normal system operation following
exit from the ªCustomer Learnº programming mode.(7) Repeat this process for each additional Sentry
Key transponder blank to be programmed.
If any of the above steps is not completed in the
proper sequence, or within the allotted time, the
SKIS will automatically exit the ªCustomer Learnº
programming mode. The SKIS will also automatically
exit the ªCustomer Learnº programming mode if it
sees a non-blank Sentry Key transponder when it
should see a blank, if it has already programmed
eight valid Sentry Keys, or if the ignition switch is
turned to the OFF position for more than about fifty
seconds.
NOTE: While in Customer Learn mode (LED flash-
ing), the engine will not START and RUN.
PROGRAMMING BLANK SENTRY KEY
TRANSPONDERS WITH A DRBIIITSCAN TOOL
When programming a blank Sentry Key transpon-
der, the key blank must first be cut to match the
ignition lock cylinder. It will also be necessary to
enter the vehicle's four digit PIN code into the
DRBIIItscan tool to enter the Sentry Key Immobi-
lizer Module's (SKIM's) secured access mode.
NOTE: Once a Sentry Key is programmed to a par-
ticular vehicle, it cannot be transferred to another
vehicle.
Insert the blank key into the ignition and turn it to
the RUN position. Using the DRBIIItscan tool,
select ªTheft Alarm,º then ªSKIM,º then ªMiscella-
neous.º Select ªProgram New Key.º Enter the four
digit PIN code using the DRBIIIt. When program-
ming is completed, the SKIM will exit secured access
mode and the DRBIIItwill display the status of the
key. One of five different status messages may be dis-
played as follows:
²ªProgramming Successfulº is displayed if SKIM
Sentry Key programming succeeds.
²ªLearned Key in Ignitionº is displayed if the key
in the ignition has already been programmed into
that vehicle's SKIM.
²ª8 Keys Already Learned (At The Maximum)
Programming Not Doneº is displayed if eight keys
have already been programmed into the SKIM. In
this case, if a new key needs to be added due to a
lost or defective key, the ªErase All Keysº function
(requires entering secured access mode) has to be
performed. Then the customer's seven keys plus the
new key MUST be reprogrammed into the SKIM.
²ªProgramming Not Attemptedº is displayed after
an ªErase All Keysº function is executed.
²ªProgramming Key Failedº is displayed if fur-
ther diagnosis is required.
8Q - 4 VEHICLE THEFT SECURITYDR
VEHICLE THEFT SECURITY (Continued)

tank. The valve prevents fluid drainback when the
vehicle is parked for lengthy periods. The valve check
ball is spring loaded and has an opening pressure of
approximately 2 psi.
The valve is serviced as an assembly; it is not repair-
able. Do not clean the valve if restricted, or contami-
nated by sludge, or debris. If the valve fails, or if a
transmission malfunction occurs that generates signifi-
cant amounts of sludge and/or clutch particles and
metal shavings, the valve must be replaced.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheating condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way flow
device. It must be properly oriented in terms of flow
direction for the cooler to function properly. The
valve must be installed in the pressure line. Other-
wise flow will be blocked and would cause an over-
heating condition and eventual transmission failure.
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) (Fig. 258)
has 3 primary functions:
²Provide a PARK/NEUTRAL start signal to the
engine controller and the starter relay.
²Turn the Back-up lamps on when the transmis-
sion is in REVERSE and the engine (ignition) is on.
²Provide a transmission range signal to the
instrument cluster.
The sensor is mounted in the transmission housing
near the valve body, just above the pan rail. It's in the
same position as the Park/Neutral switch on other
transmissions. The TRS contacts a cammed surface on
the manual valve lever. The cammed surface translates
the rotational motion of the manual lever into the linear
motion of the sensor. The cammed surface on the man-
ual lever is comprised of two parts controlling the TRS
signal: The insulator portion contacts the switch poppet
when the manual lever is not in PARK or NEUTRAL.
The manual lever itself contacts the poppet when the
lever is in PARK or NEUTRAL; providing a ground for
the signal from the starter relay and the JTEC engine
controller.
OPERATION
As the switch moves through its linear motion (Fig.
259) contacts slide across a circuit board which changes
the resistance between the range sensing pins of the
switch. A power supply on the instrument cluster pro-
vides a regulated voltage signal to the switch. The
return signal is decoded by the cluster, which then con-
trols the PRNDL display to correspond with the correct
transmission range. A bus message of transmission
range is also sent by the cluster. In REVERSE range a
second contact set closes the circuit providing power to
the reverse lamps.
Fig. 258 Transmission Range Sensor
Fig. 259 Transmission Range Sensor
Linear Movement
DRAUTOMATIC TRANSMISSION - 46RE 21 - 263
TORQUE CONVERTER DRAINBACK VALVE (Continued)

Mechanical State Electronic Display
(Ignition Unlocked)Electronic Display
(Ignition On)
Indicated Gear Position Transmission
StatusColumn Shifter
Position
P P P Vehicle is in PARK
with the pawl
engaged.In the PARK gate.
R The PARK pawl is
disengaged and the
vehicle is free to
roll, but REVERSE
is not engaged.Between the PARK
and REVERSE
gates.
R R R The transmission is
hydraulically in
REVERSE.In the REVERSE
gate.
N The transmission is
transitioning
between REVERSE
and NEUTRAL.Between the
REVERSE and
NEUTRAL gates.
N N N The vehicle is in
NEUTRAL.In the NEUTRAL
gate.
N The transmission is
transitioning
between NEUTRAL
and DRIVE, but is
not in DRIVE.Between the
NEUTRAL and
DRIVE gates.
D D D The transmission is
hydraulically in
DRIVE.In the DRIVE gate,
2 2 2 The transmission is
hydraulically in
Manual SECOND.In the SECOND
gate.
1 1 1 The transmission is
hydraulically in
Manual FIRST.In the FIRST gate.
DIAGNOSIS AND TESTING - TRANSMISSION
RANGE SENSOR (TRS)
NOTE: For all circuit identification in the following
steps, Refer to the appropriate Wiring Information.
(1) Raise vehicle on suitable hoist.
(2) Disconnect the vehicle's shift cable from the
manual lever.
(3) With the manual lever in the PARK position
(the PARK position is with the manual lever moved
to the full rearward position), measure the resistance
between the Park/Neutral Position Sense pin of the
TRS and the transmission case. The resistance
should be less than 5 ohms.(4) With the manual lever in the NEUTRAL posi-
tion (the NEUTRAL position is with the manual
lever moved two detents forward of the full rearward
position), measure the resistance between the Park/
Neutral Position Sense pin of the TRS and the trans-
mission case. The resistance should be less than 5
ohms.
(5) If the resistance is greater than 5 ohms in
either of the previous steps, check for a dirty contact
between the tip of the TRS rod and the valve body
manual lever. If the contact is OK, replace the TRS.
(6) With the manual lever in the REVERSE posi-
tion (the REVERSE position is with the manual lever
moved one detent forward of the full rearward posi-
tion), measure the resistance between the Fused
Ignition Switch Output and the Back-up Lamp feed
pins of the TRS. The resistance should be less than 5
21 - 264 AUTOMATIC TRANSMISSION - 46REDR
TRANSMISSION RANGE SENSOR (Continued)

TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) (Fig. 242)
has 3 primary functions:
²Provide a PARK/NEUTRAL start signal to the
engine controller and the starter relay.
²Turn the Back-up lamps on when the transmis-
sion is in REVERSE and the engine (ignition) is on.
²Provide a transmission range signal to the
instrument cluster.
The sensor is mounted in the transmission housing
near the valve body, just above the pan rail. It's in
the same position as the Park/Neutral switch on
other transmissions. The TRS contacts a cammed
surface on the manual valve lever. The cammed sur-
face translates the rotational motion of the manual
lever into the linear motion of the sensor. The
cammed surface on the manual lever is comprised of
two parts controlling the TRS signal: The insulator
portion contacts the switch poppet when the manual
lever is not in PARK or NEUTRAL. The manual
lever itself contacts the poppet when the lever is in
PARK or NEUTRAL; providing a ground for the sig-
nal from the starter relay and the JTEC engine con-
troller.
OPERATION
As the switch moves through its linear motion (Fig.
243) contacts slide across a circuit board which
changes the resistance between the range sensing
pins of the switch. A power supply on the instrument
cluster provides a regulated voltage signal to the
switch. The return signal is decoded by the cluster,
which then controls the PRNDL display to corre-
spond with the correct transmission range. A bus
message of transmission range is also sent by the
cluster. In REVERSE range a second contact set
closes the circuit providing power to the reverse
lamps.
Fig. 242 Transmission Range Sensor
Fig. 243 Transmission Range Sensor Linear
Movement
DRAUTOMATIC TRANSMISSION - 48RE 21 - 441

Mechanical State Electronic Display
(Ignition Unlocked)Electronic Display
(Ignition On)
Indicated Gear Position Transmission
StatusColumn Shifter
Position
P P P Vehicle is in PARK
with the pawl
engaged.In the PARK gate.
R The PARK pawl is
disengaged and the
vehicle is free to
roll, but REVERSE
is not engaged.Between the PARK
and REVERSE
gates.
R R R The transmission is
hydraulically in
REVERSE.In the REVERSE
gate.
N The transmission is
transitioning
between REVERSE
and NEUTRAL.Between the
REVERSE and
NEUTRAL gates.
N N N The vehicle is in
NEUTRAL.In the NEUTRAL
gate.
N The transmission is
transitioning
between NEUTRAL
and DRIVE, but is
not in DRIVE.Between the
NEUTRAL and
DRIVE gates.
D D D The transmission is
hydraulically in
DRIVE.In the DRIVE gate,
2 2 2 The transmission is
hydraulically in
Manual SECOND.In the SECOND
gate.
1 1 1 The transmission is
hydraulically in
Manual FIRST.In the FIRST gate.
DIAGNOSIS AND TESTING - TRANSMISSION
RANGE SENSOR (TRS)
NOTE: For all circuit identification in the following
steps, Refer to the appropriate Wiring Information.
(1) Raise vehicle on suitable hoist.
(2) Disconnect the vehicle's shift cable from the
manual lever.
(3) With the manual lever in the PARK position
(the PARK position is with the manual lever moved
to the full rearward position), measure the resistance
between the Park/Neutral Position Sense pin of the
TRS and the transmission case. The resistance
should be less than 5 ohms.(4) With the manual lever in the NEUTRAL posi-
tion (the NEUTRAL position is with the manual
lever moved two detents forward of the full rearward
position), measure the resistance between the Park/
Neutral Position Sense pin of the TRS and the trans-
mission case. The resistance should be less than 5
ohms.
(5) If the resistance is greater than 5 ohms in
either of the previous steps, check for a dirty contact
between the tip of the TRS rod and the valve body
manual lever. If the contact is OK, replace the TRS.
(6) With the manual lever in the REVERSE posi-
tion (the REVERSE position is with the manual lever
moved one detent forward of the full rearward posi-
tion), measure the resistance between the Fused
Ignition Switch Output and the Back-up Lamp feed
pins of the TRS. The resistance should be less than 5
21 - 442 AUTOMATIC TRANSMISSION - 48REDR
TRANSMISSION RANGE SENSOR (Continued)