2003 JEEP GRAND CHEROKEE 02 sensors

INSTALLATION........................253
OUTPUT SPEED SENSOR
DESCRIPTION........................254
OPERATION..........................254
REMOVAL............................254
INSTALLATION........................254
OVERDRIVE SWITCH
DESCRIPTION........................254
OPERATION..........................254
PARK LOCK CABLE
REMOVAL............................255
INSTALLATION........................255
PISTONS
DESCRIPTION........................256
OPERATION..........................256
PLANETARY GEARTRAIN
DESCRIPTION........................258
OPERATION..........................260
DISASSEMBLY........................260
CLEANING...........................260
INSPECTION.........................260
ASSEMBLY...........................261
SHIFT MECHANISM
DESCRIPTION........................261
OPERATION..........................261
REMOVAL............................261
INSTALLATION........................263
SOLENOID SWITCH VALVE
DESCRIPTION........................263
OPERATION..........................263
SOLENOIDS
DESCRIPTION........................263OPERATION..........................264
TORQUE CONVERTER
DESCRIPTION........................264
OPERATION..........................268
REMOVAL............................269
INSTALLATION........................269
TRANSMISSION CONTROL RELAY
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION RANGE SENSOR
DESCRIPTION........................270
OPERATION..........................270
TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION........................271
OPERATION..........................271
REMOVAL............................272
INSTALLATION........................272
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION........................272
OPERATION..........................272
VALVE BODY
DESCRIPTION........................273
OPERATION..........................273
REMOVAL............................274
DISASSEMBLY........................275
CLEANING...........................277
INSPECTION.........................277
ASSEMBLY...........................278
INSTALLATION........................279
AUTOMATIC TRANSMISSION -
545RFE
DESCRIPTION
The 545RFE automatic transmission is a sophisti-
cated, multi-range, electronically controlled transmis-
sion which combines optimized gear ratios for
responsive performance, state of the art efficiency
features and low NVH. Other features include driver
adaptive shifting and three planetary gear sets to
provide wide ratio capability with precise ratio steps
for optimum driveability. The three planetary gear
sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between
1st and 3rd gears for normal through-gear accelera-
tions. The alternate second gear ratio (2prime) allows
smoother 4-2 kickdowns at high speeds to provide
2nd gear passing performance over a wider highway
cruising range. An additional overdrive ratio (0.67:1)
is also provided for greater fuel economy and less
NVH at highway speeds.The hydraulic portion of the transmission consists
of the transmission fluid, fluid passages, hydraulic
valves, and various line pressure control components.
The primary mechanical components of the trans-
mission consist of the following:
²Three multiple disc input clutches
²Three multiple disc holding clutches
²Five hydraulic accumulators
²Three planetary gear sets
²Dual Stage Hydraulic oil pump
²Valve body
²Solenoid pack
The TCM is the ªheartº or ªbrainº of the electronic
control system and relies on information from vari-
ous direct and indirect inputs (sensors, switches, etc.)
to determine driver demand and vehicle operating
conditions. With this information, the TCM can cal-
culate and perform timely and quality shifts through
various output or control devices (solenoid pack,
transmission control relay, etc.).
21 - 178 AUTOMATIC TRANSMISSION - 545RFEWJ

TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
(1) Leaks at the weld joint around the outside
diameter weld (Fig. 7).
(2) Leaks at the converter hub weld (Fig. 7).
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
CAUTION: The transmission and torque converter
must be removed as an assembly to avoid compo-
nent damage. The converter driveplate, converter
hub o-ring, or oil seal can be damaged if the con-
verter is left attached to the driveplate during
removal. Be sure to remove the transmission and
converter as an assembly.
(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle
(3) Mark propeller shaft and axle yokes for assem-
bly alignment.
(4) Remove the rear propeller shaft
(5) Remove the front propeller shaft.
(6) Remove the engine to transmission collar (Fig.
8).
(7) Remove the exhaust support bracket from the
rear of the transmission.
(8) Disconnect and lower or remove any necessary
exhaust components.
(9) Remove the starter motor.
(10) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(11) Disconnect wires from solenoid and pressure
switch assembly, input and output speed sensors, and
line pressure sensor.
Fig. 7 Torque Converter Assembly
1 - TURBINE ASSEMBLY
2-STATOR
3 - CONVERTER HUB
4 - O-RING
5 - IMPELLER ASSEMBLY
6 - CONVERTER CLUTCH PISTON
7 - TURBINE HUB
Fig. 8 Transmission Collar
1 - ENGINE
2 - ENGINE TO TRANSMISSION COLLAR
3 - TRANSMISSION
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 183
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(26) To remove torque converter, carefully slide
torque converter out of the transmission.
DISASSEMBLY
(1) Drain fluid from transmission.
(2) Clean exterior of transmission with suitable
solvent or pressure washer.
(3) Remove the torque converter from the trans-
mission.
(4) Remove the manual shift lever from the trans-
mission.
(5) Remove the input, output, and line pressure
sensors from the transmission case (Fig. 14).(6) Inspect the ends of the sensors for debris,
which may indicate the nature of the transmission
failure.
(7) Install Support Stand 8257 onto the transmis-
sion case (Fig. 15).
(8) Using Adapter 8266-1 from End-Play Tool Set
8266 and Dial Indicator C-3339, measure and record
the input shaft end-play (Fig. 16).
Fig. 13 Remove NV242 Transfer Case
1 - NV242 TRANSFER CASE
Fig. 14 Remove Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
Fig. 15 Install Support Stand - Tool 8257
1 - TOOL 8257
Fig. 16 Measure Input Shaft End Play
1 - TOOL 8266
2 - TOOL C-3339
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 185
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(51) Install a new primary oil filter seal in the oil
pump inlet bore. Seat the seal in the bore with the
butt end of a hammer, or other suitable tool.
CAUTION: The primary oil filter seal MUST be fully
installed flush against the oil pump body. DO NOT
install the seal onto the filter neck and attempt to
install the filter and seal as an assembly. Damage to
the transmission will result.
(52) Install the primary oil filter and the oil cooler
return filter (Fig. 50). Tighten the screw to hold the
primary oil filter to the valve body to 4.5 N´m (40
in.lbs.). Using Oil Filter Wrench 8321, tighten the
cooler return oil filter to the transmission case to 14
N´m (125 in.lbs.).
(53) Apply RTV silicone to the oil pan and install
the transmission oil pan. Tighten the bolts to 12 N´m
(105 in.lbs.).
(54) Install the input, output, and line pressure
sensors (Fig. 51). Tighten the bolts to 12 N´m (105
in.lbs.).
(55) Install the manual shift lever from the trans-
mission. Torque the retaining cross-bolt to 16 N´m
(140 in.lbs.).
INSTALLATION
(1) Check torque converter hub and hub drive flats
for sharp edges burrs, scratches, or nicks. Polish the
hub and flats with 320/400 grit paper and crocus
cloth if necessary. Verify that the converter hub
o-ring is properly installed and is free of any debris.
The hub must be smooth to avoid damaging pump
seal at installation.(2) If a replacement transmission is being
installed, transfer any components necessary, such as
the manual shift lever and shift cable bracket, from
the original transmission onto the replacement trans-
mission.
(3) Lubricate oil pump seal lip with transmission
fluid.
(4) Align converter and oil pump.
Fig. 49 Install Valve Body Assembly
1 - VALVE BODY TO CASE BOLT (6)
Fig. 50 Install Primary Oil and Cooler Filters
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
Fig. 51 Install Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 197
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 52). Surface of converter lugs
should be at least 13 mm (1/2 in.) to rear of straight-
edge when converter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Apply a light coating of MopartHigh Temp
Grease to the torque converter hub pocket in the rear
pocket of the engine's crankshaft.
(11) Raise transmission and align the torque con-
verter with the drive plate and the transmission con-
verter housing with the engine block.
(12) Move transmission forward. Then raise, lower,
or tilt transmission to align the converter housing
with the engine block dowels.
(13) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft. Verify that no wires, or the transmission
vent hose, have become trapped between the engine
block and the transmission.
(14) Install two bolts to attach the transmission to
the engine.(15) Install remaining torque converter housing to
engine bolts. Tighten to 68 N´m (50 ft.lbs.).
(16) Install rear transmission crossmember.
Tighten crossmember to frame bolts to 68 N´m (50
ft.lbs.).
(17) Install rear support to transmission. Tighten
bolts to 47 N´m (35 ft.lbs.).
(18) Lower transmission onto crossmember and
install bolts attaching transmission mount to cross-
member. Tighten clevis bracket to crossmember bolts
to 47 N´m (35 ft.lbs.). Tighten the clevis bracket to
rear support bolt to 68 N´m (50 ft.lbs.).
(19) Remove engine support fixture.
(20) Install new plastic retainer grommet on any
shift cable that was disconnected. Grommets should
not be reused. Use pry tool to remove rod from grom-
met and cut away old grommet. Use pliers to snap
new grommet into cable and to snap grommet onto
lever.
(21) Connect gearshift cable to transmission.
(22) Connect wires to solenoid and pressure switch
assembly connector, input and output speed sensors,
and line pressure sensor. Be sure transmission har-
nesses are properly routed.
CAUTION: It is essential that correct length bolts be
used to attach the converter to the driveplate. Bolts
that are too long will damage the clutch surface
inside the converter.
(23) Install all torque converter-to-driveplate bolts
by hand.
(24) Verify that the torque converter is pulled
flush to the driveplate. Tighten bolts to 31 N´m (270
in. lbs.).
(25) Install starter motor and cooler line bracket.
(26) Connect cooler lines to transmission.
(27) Install transmission fill tube.
(28) Install exhaust components.
(29) Install transfer case. Tighten transfer case
nuts to 35 N´m (26 ft.lbs.).
(30) Install the transfer case shift cable to the
cable support bracket and the transfer case shift
lever.
(31) Install the transmission collar onto the trans-
mission and the engine. Tighten the bolts to 54 N´m
(40 ft.lbs.).
(32) Align and connect propeller shaft(s).
(33) Adjust gearshift cable if necessary.
(34) Lower vehicle.
(35) Fill transmission with MopartATF +4, type
9602, Automatic Transmission fluid.
Fig. 52 Checking Torque Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
21 - 198 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and accumulator opera-
tion. Foaming can also result in fluid escaping from the
transmission vent where it may be mistaken for a leak.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
The torque converter fills in both the P (PARK)
and N (NEUTRAL) positions. Place the selector lever
in P (PARK) to be sure that the fluid level check is
accurate.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.At normal operating temperature(approximately 82 C. or 180 F.), the fluid level is cor-
rect if it is in the HOT region (cross-hatched area) on
the oil level indicator. The fluid level will be approx-
imately at the upper COLD hole of the dipstick at
70É F fluid temperature.
NOTE: Engine and Transmission should be at nor-
mal operating temperature before performing this
procedure.
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.
(5)
Hook up DRBtscan tool and select transmission.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
chart. (Fig. 59)
(9) Adjust transmission fluid level shown on the
dipstick according to the chart.
NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
Fig. 59 Transmission Fluid Temperature Chart
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 229
FLUID AND FILTER (Continued)

(23) Install the reverse clutch pack into the input
clutch retainer (Fig. 77).
(24) Install the reverse reaction plate into the
input clutch retainer.
(25) Install the reverse reaction plate selective
snap-ring into the input clutch retainer.
(26) Mount a dial indicator to the assembly, push
down on the clutch discs, pull up on the reaction
plate to ensure the plate is properly seated and zero
the indicator against the reverse clutch discs (Fig.
81). Apply 20 psi of air pressure to the reverse clutch
and record the dial indicator reading. Measure and
record Reverse clutch pack measurement in four (4)
places, 90É apart. Take average of four measurements
and compare with Reverse clutch pack clearance
specification. The correct clutch clearance is 0.58-1.47
mm (0.023-0.058 in.). Adjust as necessary. Install the
chosen snap-ring and re-measure to verify selection.
(27) Remove the reverse clutch pack from the
input clutch retainer.
(28) Install the number 2 bearing onto the under-
drive hub with outer race against the hub with petro-
leum jelly.
(29) Install the underdrive hub into the input
clutch retainer.
(30) Install the number 3 bearing into the over-
drive hub with the outer race against the hub with
petroleum jelly.
(31) Install the overdrive hub into the input clutch
retainer.
(32) Install the number 4 bearing into the reverse
hub with outer race against the hub with petroleum
jelly.(33) Install the reverse hub into the input clutch
retainer.
(34) Install the complete reverse clutch pack.
(35) Install the reverse reaction plate and snap-
ring.
(36) Push up on reaction plate to allow reverse
clutch to move freely.
INPUT SPEED SENSOR
DESCRIPTION
The Input and Output Speed Sensors are two-wire
magnetic pickup devices that generate AC signals as
rotation occurs. They are mounted in the left side of
the transmission case and are considered primary
inputs to the Transmission Control Module (TCM).
OPERATION
The Input Speed Sensor provides information on
how fast the input shaft is rotating. As the teeth of
the input clutch hub pass by the sensor coil, an AC
voltage is generated and sent to the TCM. The TCM
interprets this information as input shaft rpm.
The Output Speed Sensor generates an AC signal
in a similar fashion, though its coil is excited by rota-
tion of the rear planetary carrier lugs. The TCM
interprets this information as output shaft rpm.
The TCM compares the input and output speed
signals to determine the following:
²Transmission gear ratio
²Speed ratio error detection
²CVI calculation
The TCM also compares the input speed signal and
the engine speed signal to determine the following:
²Torque converter clutch slippage
²Torque converter element speed ratio
REMOVAL
(1) Raise vehicle.
(2) Place a suitable fluid catch pan under the
transmission.
(3) Remove the wiring connector from the input
speed sensor (Fig. 82).
(4) Remove the bolt holding the input speed sensor
to the transmission case.
(5) Remove the input speed sensor from the trans-
mission case.
INSTALLATION
(1) Install the input speed sensor into the trans-
mission case.
(2) Install the bolt to hold the input speed sensor
into the transmission case. Tighten the bolt to 11.9
N´m (105 in.lbs.).
Fig. 81 Measuring Reverse Clutch Clearance
1 - TOOL C-3339
2 - REVERSE CLUTCH PACK
21 - 244 AUTOMATIC TRANSMISSION - 545RFEWJ
INPUT CLUTCH ASSEMBLY (Continued)

OUTPUT SPEED SENSOR
DESCRIPTION
The Input and Output Speed Sensors are two-wire
magnetic pickup devices that generate AC signals as
rotation occurs. They are mounted in the left side of
the transmission case and are considered primary
inputs to the Transmission Control Module (TCM).
OPERATION
The Input Speed Sensor provides information on
how fast the input shaft is rotating. As the teeth of
the input clutch hub pass by the sensor coil, an AC
voltage is generated and sent to the TCM. The TCM
interprets this information as input shaft rpm.
The Output Speed Sensor generates an AC signal
in a similar fashion, though its coil is excited by rota-
tion of the rear planetary carrier lugs. The TCM
interprets this information as output shaft rpm.
The TCM compares the input and output speed
signals to determine the following:
²Transmission gear ratio
²Speed ratio error detection
²CVI calculation
The TCM also compares the input speed signal and
the engine speed signal to determine the following:
²Torque converter clutch slippage
²Torque converter element speed ratio
REMOVAL
(1) Raise vehicle.
(2) Place a suitable fluid catch pan under the
transmission.
(3) Remove the wiring connector from the output
speed sensor (Fig. 96).
(4) Remove the bolt holding the output speed sen-
sor to the transmission case.
(5) Remove the output speed sensor from the
transmission case.
INSTALLATION
(1) Install the output speed sensor into the trans-
mission case.
(2) Install the bolt to hold the output speed sensor
into the transmission case. Tighten the bolt to 11.9
N´m (105 in.lbs.).
(3) Install the wiring connector onto the output
speed sensor
(4) Verify the transmission fluid level. Add fluid as
necessary.
(5) Lower vehicle.
OVERDRIVE SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shifter handle. The switch is a momentary con-
tact device that signals the PCM to toggle current
status of the overdrive function.
OPERATION
At key-on, fourth and fifth gear operation is
allowed. Pressing the switch once causes the over-
drive 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 control switch is the ON position. The switch
must be in this position to energize the solenoids and
allow upshifts to fourth and fifth gears. The control
switch indicator light illuminates only when the over-
drive switch is turned to the OFF position, or when
illuminated by the transmission control module.
Fig. 96 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
21 - 254 AUTOMATIC TRANSMISSION - 545RFEWJ