1998 DODGE RAM 1500 ECO mode

(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.
²
Supply +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 - 405
TORQUE CONVERTER (Continued)

INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear (Fig. 40). Minor nicks
can be dressed off with an oilstone but replace the
gear if any teeth are broken, cracked, or chipped. The
bearing surface on the gear can be smoothed with
300-400 grit emery cloth if necessary.
Examine the carrier body and pinion gears for
wear or damage. The carrier will have to be replaced
as an assembly if the body, pinion pins, or pinion
gears are damaged.
Check the lock ring and both thrust washers for
wear or cracks. Replace them if necessary. Also
replace the lock retaining ring if bent, distorted, or
broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork
shift rail (Fig. 41). Minor nicks on the shift rail can
be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 42). The
mode fork pads are serviceable and can be replaced if
necessary. The range fork pads are not serviceable.
The fork must be replaced as an assembly if the pads
are worn or damaged.
Check both of the sleeves for wear or damage,
especially on the interior teeth. Replace the sleeves if
wear or damage is evident.
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.
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
DRTRANSFER CASE - NV241 GENII 21 - 427
TRANSFER CASE - NV241 GENII (Continued)

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.
(4) Install the sprocket hub (Fig. 57) onto the out-
put shaft.
(5) Install the clutch gear (Fig. 58) onto the output
shaft.
(6) Install the drive sprocket (Fig. 59) onto the out-
put shaft.
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
Fig. 57 Install Sprocket Hub
1 - OUTPUT SHAFT
2 - SPROCKET HUB
Fig. 58 Install Clutch Gear
1 - OUTPUT SHAFT
2 - CLUTCH GEAR
3 - MODE HUB
Fig. 59 Install Drive Sprocket
1 - OUTPUT SHAFT
2 - DRIVE SPROCKET
21 - 432 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)

(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 - 436 TRANSFER CASE - NV241 GENIIDR
TRANSFER CASE - NV241 GENII (Continued)

(7) Install snap-ring to hold input/low range gear
into front bearing (Fig. 62).
(8) Install a new input gear seal using Installer
8841 and Handle C-4171.
(9) Install a new input gear oil seal with Installer
9036 and Handle C-4171.
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.
Fig. 62 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 63 Install the Drive Sprocket Drive Hub
1 - MAINSHAFT
2 - DRIVE SPROCKET DRIVE HUB
Fig. 64 Install Mode Hub
1 - MAINSHAFT
2 - MODE HUB
Fig. 65 Install Mode Hub Retaining Ring
1 - MAINSHAFT
2 - MODE HUB
3 - RETAINING RING
21 - 466 TRANSFER CASE - NV271DR
TRANSFER CASE - NV271 (Continued)

(6) Align and install low range/input gear assem-
bly in front case (Fig. 52). 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. 53).
(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. 54) onto the output
shaft.
(3) Install the mode hub retaining ring (Fig. 55)
onto the output shaft.
Fig. 52 Install Input Planetary Assembly
1 - FRONT CASE
2 - INPUT PLANETARY ASSEMBLY
Fig. 53 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
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
DRTRANSFER CASE - NV243 21 - 499
TRANSFER CASE - NV243 (Continued)

MODE SENSOR
DESCRIPTION
The transfer case mode sensor (Fig. 83) is an elec-
tronic device whose output can be interpreted to indi-
cate the shift motor shaft's rotary position. The
sensor consists of a magnetic ring and four Hall
Effect Transistors to create a 4 channel digital device
(non-contacting) whose output converts the motor
shaft position into a coded signal. The TCCM must
supply 5VDC (+/- 0.5v) to the sensor and monitor the
shift motor position. The four channels are denoted
A, B, C, and D. The sensor is mechanically linked to
the shaft of the cam which causes the transfer case
shifting. The mode sensor draws less than 53 mA.
OPERATION
During normal vehicle operation, the Transfer Case
Control Module (TCCM) monitors the mode sensor
outputs at least every 250 (+/-50) milliseconds when
the shift motor is stationary and 400 microseconds
when the shift motor is active. A mode sensor signal
between 3.8 Volts and 0.8 Volts is considered to be
undefined.
Refer to SECTOR ANGLES vs. TRANSFER CASE
POSITION for the relative angles of the transfer case
shift sector versus the interpreted transfer case gear
operating mode. Refer to MODE SENSOR CHAN-
NEL STATES for the sensor codes returned to the
TCCM for each transfer case mode sensor position.
The various between gears positions can also be
referred as the transfer case's coarse position. These
coarse positions come into play during shift attempts.SECTOR ANGLES VS. TRANSFER CASE POSITION
Shaft Angle (Degrees) Transfer Case Position
+40 4LO
+20 N
0 2WD/AWD
-20 4HI
MODE SENSOR CHANNEL STATES
Transfer Case
Angle (degrees)Sensor Channel A Sensor Channel B Sensor Channel C Sensor Channel D
Between Gears H H L H
+40 (4LO) H H L L
Between Gears H H L H
Between Gears H L L H
+20 (NEUTRAL) H L L L
Between Gears H L L H
Between Gears H L H H
0 (2WD/AWD) H L H L
Between Gears H L H H
Between Gears L L H H
-20 (4HI) L L H L
Between Gears L L H H
Between Gears L H H H
Fig. 83 Mode Sensor
1 - MODE SENSOR
DRTRANSFER CASE - NV243 21 - 509

(4) Install remaining thrust washer in low range
gear and on top of input gear. Be sure washer tabs
are properly aligned in gear notches.
(5) Install retainer on input gear and install snap-
ring.
(6) Align and install low range/input gear assem-
bly in front case (Fig. 49). 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. 50).
(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.
NOTE: Replace the mode hub retainer if the legs
were distorted during removal.
(2) Install the mode hub retainer (Fig. 51) onto the
mode hub.
(3) Install the mode hub (Fig. 52) and mode hub
retainer onto the differential assembly. Make sure
the retainer is fully seated onto the differential.
Fig. 49 Install Input Planetary Assembly
1 - FRONT CASE
2 - INPUT PLANETARY ASSEMBLY
Fig. 50 Install Input Gear Retaining Ring
1 - INPUT GEAR
2 - RETAINING RING
Fig. 51 Install Retainer onto Mode Hub
1 - MODE HUB RETAINER
2 - MODE HUB
Fig. 52 Install the Mode Hub and Retainer
1 - DIFFERENTIAL ASSEMBLY
2 - MODE HUB AND RETAINER
DRTRANSFER CASE - NV244 GENII 21 - 527
TRANSFER CASE - NV244 GENII (Continued)