ECO mode DODGE RAM 2003 Service Owners Manual

OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 120). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be
illuminated. Pressing the switch a second time
causes normal overdrive operation to be restored and
the overdrive lamp to be turned off. The overdrive
OFF mode defaults to ON after the ignition switch is
cycled OFF and ON. The normal position for the con-
trol switch is the ON position. The switch must be in
this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates
only when the overdrive switch is turned to the OFF
position, or when illuminated by the transmission
control module.
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The overdrive off switch, valve body solenoid, case
connectors and related wiring can all be tested with
a 12 volt test lamp or a volt/ohmmeter. Check conti-
nuity of each component when diagnosis indicates
this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
REMOVAL
(1) Using a plastic trim tool, remove the overdrive
off switch retainer from the shift lever (Fig. 121).(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 122)
INSTALLATION
NOTE: There is enough slack in the wire to pull out
the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the
overdrive off switch. Use care when installing the
switch, as it is not indexed, and can be accidentally
installed incorrectly.
Fig. 120 Overdrive Off Switch
Fig. 121 Overdrive Off Switch Retainer
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH RETAINER
3 - PLASTIC TRIM TOOL
Fig. 122 Remove the Overdrive Off Switch
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH
DRAUTOMATIC TRANSMISSION - 48RE 21 - 397

The label gives additional information which may
also be necessary for identification purposes.
GEAR RATIOS
The 45RFE gear ratios are:
1st .................................3.00:1
2nd.................................1.67:1
2nd Prime...........................1.50:1
3rd.................................1.00:1
4th .................................0.75:1
Reverse.............................3.00:1
GEAR RATIOS
The 545RFE gear ratios are:
1st .................................3.00:1
2nd.................................1.67:1
2nd Prime...........................1.50:1
3rd.................................1.00:1
4th .................................0.75:1
5th .................................0.67:1
Reverse.............................3.00:1
OPERATION
The 45RFE/545RFE offers full electronic control of
all automatic up and downshifts, and features real-
time adaptive closed-loop shift and pressure control.
Electronic shift and torque converter clutch controls
help protect the transmission from damage due to
high temperatures, which can occur under severe
operating conditions. By altering shift schedules, line
pressure, and converter clutch control, these controls
reduce heat generation and increase transmission
cooling.
To help reduce efficiency-robbing parasitic losses,
the transmissions includes a dual-stage transmission
fluid pump with electronic output pressure control.
Under most driving conditions, pump output pres-
sure greatly exceeds that which is needed to keep the
clutches applied. The 45RFE/545RFE pump-pressure
control system monitors input torque and adjusts the
pump pressure accordingly. The primary stage of the
pump works continuously; the second stage is
bypassed when demand is low. The control system
also monitors input and output speed and, if incipi-
ent clutch slip is observed, the pressure control sole-
noid duty cycle is varied, increasing pressure in
proportion to demand.
A high-travel torque converter damper assembly
allows earlier torque converter clutch engagement to
reduce slippage. Needle-type thrust bearings reduce
internal friction. The 45RFE/545RFE is packaged in
a one-piece die-cast aluminum case. To reduce NVH,
the case has high lateral, vertical and torsional stiff-
ness. It is also designed to maximize the benefit of
the structural dust cover that connects the bottom of
the bell housing to the engine bedplate, enhancing
overall power train stiffness. Dual filters protect the
pump and other components. A pump return filter is
added to the customary main sump filter. Indepen-
dent lubrication and cooler circuits assure ample
pressure for normal transmission operation even if
the cooler is obstructed or the fluid cannot flow due
to extremely low temperatures.
The hydraulic control system design (without elec-
tronic assist) provides the transmission with PARK,
REVERSE, NEUTRAL, SECOND, and THIRD gears,
based solely on driver shift lever selection. This
design allows the vehicle to be driven (in ªlimp-inº
mode) in the event of a electronic control system fail-
ure, or a situation that the Transmission Control
Module (TCM) recognizes as potentially damaging to
the transmission.
The TCM also performs certain self-diagnostic
functions and provides comprehensive information
(sensor data, DTC's, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRBtscan tool.
Fig. 1 Transmission Part And Serial Number
Location
1 - IDENTIFICATION NUMBERS (STAMPED)
21 - 490 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 106). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be
illuminated. Pressing the switch a second time
causes normal overdrive operation to be restored and
the overdrive lamp to be turned off. The overdrive
OFF mode defaults to ON after the ignition switch is
cycled OFF and ON. The normal position for the con-trol switch is the ON position. The switch must be in
this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates
only when the overdrive switch is turned to the OFF
position, or when illuminated by the transmission
control module.
REMOVAL
(1) Using a plastic trim tool, remove the overdrive
off switch retainer from the shift lever (Fig. 107).
(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 108)
Fig. 105 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
Fig. 106 Overdrive Off Switch
Fig. 107 Overdrive Off Switch Retainer
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH RETAINER
3 - PLASTIC TRIM TOOL
Fig. 108 Remove the Overdrive Off Switch
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH
21 - 568 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
OVERDRIVE SWITCH (Continued)

(9) Fill the transmission with the recommended
fluid.
TRANSMISSION CONTROL
RELAY
DESCRIPTION
The relay is supplied fused B+ voltage, energized
by the TCM, and is used to supply power to the sole-
noid pack when the transmission is in normal oper-
ating mode.
OPERATION
When the relay is ªoffº, no power is supplied to the
solenoid pack and the transmission is in ªlimp-inº
mode. After a controller reset, the TCM energizes the
relay. Prior to this, the TCM verifies that the con-
tacts are open by checking for no voltage at the
switched battery terminals. After this is verified, the
voltage at the solenoid pack pressure switches is
checked. After the relay is energized, the TCM mon-
itors the terminals to verify that the voltage is
greater than 3 volts.
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is part of
the solenoid module, which is mounted to the top of
the valve body inside the transmission.
The Transmission Range Sensor (TRS) has five
switch contact pins that:
²Determine shift lever position
²Supply ground to the Starter Relay in Park and
Neutral only.
²Supply +12 V to the backup lamps in Reverse
only.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transmission
temperature to the TCM and PCM.
OPERATION
The Transmission Range Sensor (TRS) communi-
cates shift lever position to the TCM as a combina-
tion of open and closed switches. Each shift lever
position has an assigned combination of switch states
(open/closed) that the TCM receives from four sense
circuits. The TCM interprets this information and
determines the appropriate transmission gear posi-
tion and shift schedule.
There are many possible combinations of open and
closed switches (codes). Seven of these possible codes
are related to gear position and five are recognized
as ªbetween gearº codes. This results in many codes
which shouldnever occur. These are called
ªinvalidº codes. An invalid code will result in a DTC,
and the TCM will then determine the shift lever
position based on pressure switch data. This allows
reasonably normal transmission operation with a
TRS failure.
GEAR C5 C4 C3 C2 C1
ParkCL OP OP CL CL
Temp 1CL OP OP CL OP
ReverseOP OP OP CL OP
Temp 2OP OP CL CL OP
Neutral 1OP OP CL CL CL
Neutral 2OP CL CL CL CL
Temp 3OP CL CL CL OP
DriveOP CL CL OP OP
Temp 4OP CL OP OP OP
Manual 2CL CL OP OP OP
Temp 5CL OP OP OP OP
Manual 1CL OP CL OP OP
Fig. 125 Checking Torque Converter Seating-Typical
1 - SCALE
2 - STRAIGHTEDGE
DRAUTOMATIC TRANSMISSION - 45RFE/545RFE 21 - 581
TORQUE CONVERTER (Continued)

REAR RETAINER COMPONENTS
Inspect the retainer components. Replace the bear-
ing if rough or noisy. Check the retainer for cracks or
wear in the bearing bore.
Inspect the retaining rings and washers. Replace
any part if distorted, bent, or broken. Reuse is not
recommended.
Inspect rear extension bushing. Replace if worn or
scored.
DRIVE CHAIN
Examine the drive chain and shaft bearings.
replace the chain if stretched, distorted, or if any of
the links bind. Replace the bearings if rough, or
noisy.
Fig. 40 Input Gear And Carrier Components
1 - PLANETARY CARRIER 4 - CARRIER LOCK RING
2 - REAR THRUST WASHER 5 - CARRIER LOCK RETAINING RING
3 - FRONT THRUST WASHER 6 - INPUT GEAR
Fig. 41 Shift Forks
1 - RANGE FORK
2 - MODE FORK AND RAIL
3 - MODE SPRING
Fig. 42 Shift Fork And Wear Pad Locations
1 - RANGE FORK
2 - MODE FORK
3 - WEAR PADS (SERVICEABLE)
4 - WEAR PADS (SERVICEABLE)
DRTRANSFER CASE - NV241 GENII 21 - 603
TRANSFER CASE - NV241 GENII (Continued)

(6) Align and install low range/input gear assem-
bly in front case (Fig. 53). Be sure low range gear
pinions are engaged in annulus gear and that input
gear shaft is fully seated in front bearing.
(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 54).
(8) Install a new input gear seal using Installer
8841 and Handle C-4171.SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Install the mode hub (Fig. 55) onto the output
shaft.
(3) Install the mode hub retaining ring (Fig. 56)
onto the output shaft.
Fig. 53 Install Input Planetary Assembly
1 - FRONT CASE
2 - INPUT PLANETARY ASSEMBLY
Fig. 54 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 55 Install Mode Hub
1 - OUTPUT SHAFT
2 - MODE HUB
Fig. 56 Install Mode Hub Retaining Ring
1 - OUTPUT SHAFT
2 - RETAINING RING
3 - MODE HUB
DRTRANSFER CASE - NV241 GENII 21 - 607
TRANSFER CASE - NV241 GENII (Continued)

(4) Insert front sprocket in drive chain.
(5) Install drive chain around mainshaft sprocket
(Fig. 73). Then position front sprocket over front
shaft.
(6) Raise mainshaft about 2.54 cm (one inch) and
seat front sprocket on front output shaft.
(7) If mainshaft and mode sleeve were unseated
during chain installation, align and reseat mainshaft
in input gear and hub.
(8) Install front sprocket retaining ring (Fig. 74).(9) Install spring and cup on shift rail (Fig. 75).
(10) Insert magnet in front case pocket (Fig. 76).
OIL PUMP AND REAR CASE
CAUTION: Do not remove the bolts holding the oil
pump cover to the rear case half. The oil pump
cover is aligned to the rear output shaft inner bear-
ing race and will become mis-aligned if the bolts
are loosened. If the transfer case failure has gener-
ated any debris which may have become trapped in
the oil pump. the rear case and oil pump assembly
MUST be replaced.
(1) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of front case. Keep sealer
bead width to maximum of 3/16 inch. Do not use
excessive amount of sealer as excess will be displaced
into case interior.
Fig. 73 Install Front Sprocket and Drive Chain
1 - FRONT DRIVE SPROCKET
2 - DRIVE CHAIN
3 - MAINSHAFT
Fig. 74 Front Sprocket Retaining Ring Installation
1 - FRONT SPROCKET
2 - RETAINING RING
Fig. 75 Shift Rail Spring And Cup Installation
1 - CUP
2 - SPRING
Fig. 76 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
21 - 612 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)

SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Coat the interior of the drive sprocket hub with
ATF+4 and install the drive sprocket drive hub (Fig.
63) onto the mainshaft.(3) Install the mode hub (Fig. 64) onto the main-
shaft.
(4) Install the mode hub retaining ring (Fig. 65)
onto the mainshaft.
(5) Install the clutch gear (Fig. 66) onto the output
shaft. Verify that the pointed ends of the clutch gear
teeth are pointing to the front of the mainshaft.
Fig. 64 Install Mode Hub
1 - MAINSHAFT
2 - MODE HUB
Fig. 63 Install the Drive Sprocket Drive Hub
1 - MAINSHAFT
2 - DRIVE SPROCKET DRIVE HUB
Fig. 65 Install Mode Hub Retaining Ring
1 - MAINSHAFT
2 - MODE HUB
3 - RETAINING RING
Fig. 66 Install Clutch Gear
1 - OUTPUT SHAFT
2 - CLUTCH GEAR
3 - MODE HUB
21 - 642 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

SHIFT FORKS AND MAINSHAFT
(1) Lubricate mainshaft splines with recommended
transmission fluid.
(2) Install the mode hub (Fig. 54) onto the output
shaft.
(3) Install the mode hub retaining ring (Fig. 55)
onto the output shaft.(4) Install the sprocket hub (Fig. 56) onto the out-
put shaft.
(5) Install the clutch gear (Fig. 57) onto the output
shaft.
(6) Install the drive sprocket (Fig. 58) onto the out-
put shaft.
Fig. 54 Install Mode Hub
1 - OUTPUT SHAFT
2 - MODE HUB
Fig. 55 Install Mode Hub Retaining Ring
1 - OUTPUT SHAFT
2 - RETAINING RING
3 - MODE HUB
Fig. 56 Install Sprocket Hub
1 - OUTPUT SHAFT
2 - SPROCKET HUB
Fig. 57 Install Clutch Gear
1 - OUTPUT SHAFT
2 - CLUTCH GEAR
3 - MODE HUB
21 - 674 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)

(9) Install spring and cup on shift rail (Fig. 71).
(10) Insert magnet in front case pocket (Fig. 72).
OIL PUMP AND REAR CASE
Lubricate the oil pump components with transmis-
sion fluid before installation. Prime the oil pickup
tube by pouring a little oil into the tube before instal-
lation.
CAUTION: Do not remove the bolts holding the oil
pump cover to the rear case half. The oil pump
cover is aligned to the rear output shaft inner bear-
ing race and will become mis-aligned if the bolts
are loosened. If the transfer case failure has gener-
ated any debris which may have become trapped in
the oil pump. the rear case and oil pump assembly
MUST be replaced.
(1) Install new o-ring in pickup tube inlet of oil
pump.
(2) Insert oil pickup tube into the oil pump.
(3) Apply bead of MopartGasket Maker, or equiv-
alent, to mating surface of front case. Keep sealer
bead width to maximum of 3/16 inch. Do not use
excessive amount of sealer as excess will be displaced
into case interior.(4) Align oil pump with mainshaft and align shift
rail with bore in rear case. Then install rear case and
oil pump assembly (Fig. 73).
(5) Install 4-5 rear case-to front case bolts (Fig. 74)
to hold rear case in position. Tighten bolts snug but
not to specified torque at this time.
CAUTION: Verify that shift rail, and case alignment
dowels are seated before installing any bolts. Case
could be cracked if shaft rail or dowels are mis-
aligned.
(6) Apply LoctiteŸ 242 to remainder of rear case-
to-front case bolt threads and install bolts. Tighten
bolts to 20-27 N´m (15-24 ft. lbs.),
(7) Install rear output bearing snap-ring (Fig. 75)
to output shaft.
SEAL BOOT AND SHIFT MOTOR ASSEMBLY
(1) Install the front output shaft seal slinger with
Installer 8840. Install the slinger onto the shaft until
the tool contacts the rear of the output shaft.
(2) Install a new seal boot clamp onto the seal
boot.
(3) Install the seal boot and clamp onto the slinger
hub and tighten the clamp with Crimp Tool
C-4975-A.
(4) Position the shift motor and mode sensor
assembly onto the transfer case.
(5) Install the bolts to hold the shift motor and
mode sensor assembly to the transfer case. Tighten
the bolts to 16-25 N´m (12-18 ft. lbs.).
REAR EXTENSION
(1) Install new seal in rear extension housing seal
with Installer D-163 and Handle C-4171..
Fig. 71 Shift Rail Spring And Cup Installation
1 - CUP
2 - SPRING
Fig. 72 Case Magnet Installation
1 - MAGNET
2 - CASE POCKET
Fig. 73 Install Rear Case
1 - REAR CASE
2 - FRONT CASE
21 - 678 TRANSFER CASE - NV243DR
TRANSFER CASE - NV243 (Continued)