1994 JEEP CHEROKEE sensor

The speedometer assembly used in XJ models is the
new unit type (one-piece) speed sensor (Fig. 16). How-
ever, YJ models may be equipped with either the new
unit style, or the older style that has a two-piece speed
sensor and a metal adapter (Fig. 16). Service procedures
for both styles are described in the following procedures.
SPEEDOMETER ASSEMBLY REMOVAL (WITH
UNIT STYLE SENSOR)
(1) Raise vehicle.
(2) Disconnect wires from vehicle speed sensor.
(3) Remove adapter clamp and screw (Fig. 16).
(4) Remove speed sensor and speedometer adapter
as assembly.
(5) Remove speed sensor retaining screw and re-
move sensor from adapter.
(6) Remove speedometer pinion from adapter.
(7) Inspect sensor and adapter O-rings (Fig. 16).
Remove and discard O-rings if worn or damaged.
(8) Inspect terminal pins in vehicle speed sensor.
Clean pins with Mopar electrical spray cleaner if
dirty or oxidized. Replace sensor if faulty, or pins are
loose, severely corroded, or damaged.
SPEEDOMETER INSTALLATION AND
INDEXING (UNIT STYLE)
(1) Thoroughly clean adapter flange and adapter
mounting surface in housing. Surfaces must be clean
for proper adapter alignment and speedometer oper-
ation.
(2) Install new O-rings on speed sensor and speed-
ometer adapter if necessary (Fig. 17).
(3) Lubricate sensor and adapter O-rings with
transmission fluid.(4) Install vehicle speed sensor in speedometer
adapter. Tighten sensor attaching screw to 2-3 Nzm
(15-27 in. lbs.) torque.
(5) Install speedometer pinion in adapter.
(6) Count number of teeth on speedometer pinion.
Do this before installing assembly in housing. Then
lubricate pinion teeth with transmission fluid.
(7) Note index numbers on adapter body (Fig. 17).
These numbers will correspond to number of teeth on
pinion.
(8) Install speedometer assembly in housing.
(9) Rotate adapter until requiredrange numbers
are at 6 o-clock position. Be sure range index num-
bers correspond to number of teeth on pinion gear.
Fig. 16 Speedometer Components (With Unit Style Sensor)
Fig. 17 Location Of Index Numbers On Speedometer
Adapter (Unit Style Sensor)
21 - 104 30RH/32RH IN-VEHICLE SERVICEJ

(10) Install speedometer adapter clamp and retain-
ing screw. Tighten clamp screw to 10-12 Nzm (90-110
in. lbs.) torque.
(11) Connect wires to vehicle speed sensor.
(12) Lower vehicle and top off transmission fluid
level if necessary.
SPEEDOMETER COMPONENT REMOVAL
(TWO-PIECE SENSOR)
(1) Raise vehicle.
(2) Disconnect speed sensor wires.
(3) Remove bolt attaching vehicle speed sensor to
sensor adapter. Then slide sensor out of adapter.
(4) Inspect speed sensor mounting area in sensor
adapter. If transmission fluid is found in this area,
oil seal in metal speedometer adapter is leaking and
will have to be replaced.
(5) Remove speedometer adapter clamp bolt and
remove clamp (Fig. 18).
(6) Remove speedometer adapter, sensor adapter
and speedometer pinion as assembly.
SPEEDOMETER COMPONENT INSTALLATION
AND INDEXING (TWO-PIECE SENSOR)
(1) Replace speedometer O-ring if cut, torn, or worn.
(2) If oil seal in metal speedometer adapter needs
replacement, remove old seal with pointed tool. Then
install new seal with Special Tool C-4004. Push seal
into place with tool until tool bottoms (Fig. 19).
(3) Clean speedometer adapter mounting surface of
transmission, or transfer case thoroughly.
(4) Lubricate adapter seals with transmission fluid.
(5) Count number of teeth on speedometer pinion.
Do this before installing pinion and adapter.
(6) Note range numbers on face of speedometer
adapter (Fig. 20). These numbers correspond to num-
ber of teeth on speedometer pinion.
(7) Install pinion in adapter and install assembled
pinion and adapter in transmission or transfer case.
(8) Rotate speedometer adapter until required
range numbers are at 6 o'clock position (Fig. 20).
Verify that range numbers correspond to num-
ber of teeth on pinion.
(9) Push speedometer adapter into place until seated.
(10) Install speedometer adapter clamp and bolt.
Tighten bolt to 11 Nzm (100 in. lbs.) torque.
(11) Install sensor adapter on speedometer adapter
(Fig. 18). Tighten sensor adapter coupling nut to 17
Nzm (150 in. lbs.) torque.
(12) Carefully align and insert vehicle speed sensor
into sensor adapter.
(13) Install bolt that attaches speed sensor to
adapter. Tighten bolt to 5-8 Nzm (48-72 in. lbs.)
(14) Connect wires to speed sensor.
(15) Lower vehicle.
(16) Check top off transmission fluid level if necessary.
TRANSMISSION COOLER REVERSE FLUSHING
The transmission main cooler is located in the ra-
diator lower tank. The cooler is not a serviceable
component. If the cooler is damaged in any way, the
radiator will have to be replaced.
On models with an auxiliary cooler, the cooler is
mounted in front of the radiator or air conditioningFig. 18 Speedometer Components (With Two-Piece
Sensor)
Fig. 19 Installing Speedometer Adapter Seal (With
Two-Piece Sensor And Metal Adapter)
Fig. 20 Indexing Speedometer Adapter (With Two-
Piece Sensor)
J30RH/32RH IN-VEHICLE SERVICE 21 - 105

30RH/32RH TRANSMISSION REMOVAL AND INSTALLATION
INDEX
page page
ConverterÐPump SealÐDrive Plate Service . . . 109
Transmission and Converter Installation....... 109Transmission and Converter Removal........ 108
TRANSMISSION AND CONVERTER REMOVAL
(1) Remove fan shroud attaching bolts.
(2) Disconnect transmission fill tube at upper
bracket.
(3) Raise vehicle.
(4) Remove inspection cover from converter hous-
ing and remove skid plate for access, if necessary.
(5) Remove transmission fill tube and fill tube
O-ring.
(6) Remove starter motor.
(7) Mark propeller shafts and axle yokes for align-
ment reference.
(8) Disconnect propeller shafts at yokes. Secure
shafts to frame rails with wire.
(9) Disconnect exhaust pipes at exhaust manifolds,
if necessary.
(10) Drain transfer case lubricant.
(11) Disconnect vehicle speed sensor wires.
(12) Disconnect transfer case shift linkage.
(13) Disconnect gearshift linkage and throttle ca-
ble at transmission levers.
(14) Disconnect park/neutral position switch wires.
(15) Disconnect and remove crankshaft position
sensor. Retain sensor bolt for reinstallation.
CAUTION: The crankshaft position sensor can be
damaged during transmission removal (or installa-
tion) if the sensor is still bolted to the engine block.
To avoid damage, remove the sensor before remov-
ing the transmission.
(16) Remove converter housing access cover and
mark drive plate and converter for alignment refer-
ence.
(17) Remove bolts attaching converter to drive
plate.
(18) Support engine with support stand.
(19) Support transmission-transfer case assembly
with transmission jack. Secure transmission to jack
with safety chain.
(20) Remove bolts/nuts attaching cushion and
torque arm bracket to skid plate (Fig. 1).
(21) Remove skid plate, or rear crossmember, if
equipped.
(22) Lower transmission slightly and disconnect
cooler lines at transmission.Refer to In-Vehicle
Service section for procedures.(23) Remove bolts attaching transmission to en-
gine.
(24) Move transmission and converter rearward
until clear of crankshaft.
(25) Hold converter in position and lower transmis-
sion until converter housing clears engine.
(26) Remove converter from transmission.
(27) Remove transfer case from transmission.
(28) If necessary, following components can now be
serviced:
²torque converter
²torque converter drive plate
²oil pump seal
²engine rear core hole plugs
²engine rear oil galley plugs
Fig. 1 Transmission Rear Mount
21 - 108 30RH/32RH TRANSMISSION REMOVAL AND INSTALLATIONJ

(1) Lubricate converter drive hub and pump seal
with Mopar ATF Plus, or Dexron II transmission
fluid. Then install converter. Turn converter back
and forth to align drive slots in converter hub with
pump gear lugs. Be sure converter is fully seated in
pump (Fig. 5).
(2) Temporarily secure converter with C-clamp or
metal strap attached across converter housing.
(3) Position transmission on jack and secure it
with safety chains.
(4) Raise transmission and align converter with
drive plate.
(5) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.
(6) Install two converter housing lower attaching
bolts and tighten bolts to draw housing toward en-
gine.
(7) Install and tighten converter attaching bolts.
(8) Install and tighten bolts that attach transmis-
sion to engine (Fig. 6).
(9) Install crankshaft position sensor as follows:
CAUTION: Clearance between the sensor pickup
face and driveplate ring gear must be correctly es-
tablished before engine startup. A cardboard
spacer, attached to the sensor face, is used for thispurpose. Failure to establish correct clearance will
result in sensor breakage.
(a) Remove any remaining fragments of original
cardboard spacer from sensor pickup face.
Fig. 5 Checking Torque Converter Seating
Fig. 6 Transmission Attachment
21 - 110 30RH/32RH TRANSMISSION REMOVAL AND INSTALLATIONJ

(b) Align and install new spacer on sensor
pickup face. Spacer has adhesive backing so it will
adhere to sensor face.
(c) Insert sensor into housing until it just
touches ring gear teeth. Then install and tighten
sensor attaching bolt. Correct clearance is estab-
lished when spacer is peeled off by ring gear dur-
ing engine startup.
(10) Install transmission fill tube and O-ring (Fig.
6).
(11) Connect transmission cooler lines to fittings.
Refer to Figure 7 for cooler line identification.(12) Position support stand under transmission
and remove transmission jack.
(13) Install transfer case on transmission adapter.
Tighten attaching nuts to 41 Nzm (30 ft. lbs.) torque.
(14) Install rear crossmember and attach transmis-
sion rear support to crossmember.
(15) Connect vehicle speed sensor wires.
(16) Install inspection cover on converter housing.
(17) Install exhaust pipes and support brackets, if
removed.
(18) Install starter motor.
(19) Connect wires to park/neutral position switch.
(20) Connect gearshift and linkage and throttle ca-
ble.
(21) Connect transfer case shift linkage.
(22) Connect propeller shafts to transfer case
yokes.
(23) Connect front exhaust pipes and catalytic con-
verter support bracket bolts (if removed).
(24) Install skid plate, rear cushion and bracket, if
removed.
(25) Fill transfer case to bottom edge of fill plug
hole with Mopar Dexron II.
(26) Lower vehicle and fill transmission to correct
level with ATF Plus, type 7176 fluid.
(27) Install fan shroud and bolts (if removed).
(28) Check and adjust gearshift linkage if neces-
sary. Then check and adjust throttle cable if neces-
sary.
Fig. 7 Transmission Cooler Line Location And
Identification
J30RH/32RH TRANSMISSION REMOVAL AND INSTALLATION 21 - 111

The valve body solenoids are controlled by signals
from the transmission control module (TCM). Signal
sequence is determined by vehicle speed and throttle
position.
Fourth gear is an 0.75:1 ratio overdrive range.
First, second, third and reverse gear are conventional
ranges. Third gear ratio is 1:1. A separate planetary
gear set provides overdrive operation in fourth gear.
TRANSMISSION RANGES AND SHIFT LEVER
POSITIONS
The AW-4 transmission has six ranges and shift le-
ver positions. Park, Reverse and Neutral are conven-
tional and mechanically operated. The 1-2, 3 and D
ranges provide electronically controlled shifting.
The 1-2 position provides first and second gear
only. The 3 position provides first, second and third
gear.
The D range provides first through fourth gear.
Overdrive fourth gear range is available only when
the shift lever is in D position (Fig. 2).
TRANSMISSION IDENTIFICATION
The transmission I.D. plate is attached to the case
(Fig. 3). The plate contains the transmission serial
and model numbers. Refer to the information on this
plate when ordering service parts.
COMPONENTS AND OPERATION
ELECTRONIC CONTROLS
The AW-4 is electronically controlled in the 1, 2, 3
and D ranges. Controls consist of the transmission
control module (TCM), valve body solenoids and var-ious sensors. The sensors monitor vehicle speed,
throttle opening, shift lever position and brake pedal
application.
TRANSMISSION CONTROL MODULE (TCM)
The module determines shift and converter clutch
engagement timing based on signals from the sen-
sors. The valve body solenoids are activated, or deac-
tivated accordingly.
The module has a self diagnostic program. Compo-
nent and circuitry malfunctions can be diagnosed
with the DRB II scan tool. Once a malfunction is
noted and stored in control module memory, it is re-
tained even after the problem has been corrected. To
cancel a stored malfunction, simply disconnect and
reconnect the9Trans.9fuse in the module harness.
TRANSMISSION VALVE BODY SOLENOIDS
The solenoids are mounted on the valve body and
operated by the transmission control module. The so-
lenoids control operation of the converter clutch and
shift valves in response to input signals from the
module.
SENSORS
The sensors include the throttle position sensor
(TPS), transmission output speed sensor, vehicle
speed sensor, park/neutral position switch and brake
switch.
The throttle position sensor is mounted on the
throttle body. It electronically determines throttle po-
sition and relays this information to the transmission
control module to determine shift points and con-
verter clutch engagement.
The transmission speed sensor consists of a rotor
and magnet on the transmission output shaft and a
switch in the extension housing or adapter. The sen-
sor switch is activated each time the rotor and mag-
Fig. 2 AW-4 Shift Lever Positions And Transmission
Ranges
Fig. 3 Transmission Identification
JAW-4 AUTOMATIC TRANSMISSION 21 - 157

net complete one revolution. Sensor signals are sent
to the transmission control module.
The park/neutral position switch is mounted on the
valve body manual shaft. The switch signals shift
linkage and manual valve position to the transmis-
sion control module through an interconnecting har-
ness. The switch prevents engine starting in all gears
other than Park or Neutral.
The brake switch is in circuit with the torque con-
verter clutch solenoid. The switch disengages the
converter clutch whenever the brakes are applied.
The switch is mounted on the brake pedal bracket
and signals the transmission control module when
the pedal is pressed or released.
TORQUE CONVERTER
A four element torque converter is used for all ap-
plications. The converter consists of the front cover
and pump, stator, turbine, and an electronic modu-
lated converter clutch mechanism.
The converter clutch mechanism consists of a slid-
ing clutch piston, clutch springs and the clutch disc
material (Fig. 4). The clutch provides optimum
torque transfer and economy when engaged.
The clutch disc is attached to the converter front
cover. The clutch piston and clutch springs are at-
tached to the turbine hub. The springs dampen en-
gine firing impulses and loads during the initial
phase of converter clutch engagement.
Clutch engagement is controlled by transmission
valve body solenoid number three and by the con-
verter clutch relay valve. The solenoid channels line
pressure to the clutch through the relay valve at
clutch engagement speeds.
Torque converter clutch engagement occurs in sec-
ond gear in 1-2 position; third gear in 3 position and
third and fourth gear in D position.
FOURTH GEAR OVERDRIVE COMPONENTS
The overdrive system consists of the input shaft, one-
way clutch, planetary sun gear, ring gear, planetary car-
rier, direct clutch and overdrive brake (Fig. 5). The
overdrive elements are controlled and applied through
transmission valve body solenoid number two.
In overdrive fourth gear, the brake prevents the
overdrive sun gear from turning. During operation,
the overdrive elements operate as follows:
The overdrive input shaft and planetary carrier ro-
tate as a unit. The sun gear and overdrive direct
clutch drum are in mesh and operate as a single
unit. The direct clutch splines function as the hub for
the overdrive brake. The one-way clutch outer race is
in mesh with the planetary carrier. The inner race is
fixed to the sun gear shaft.
Fig. 5 Fourth Gear Overdrive Components
Fig. 4 Torque Converter With Modulated Clutch
21 - 158 AW-4 AUTOMATIC TRANSMISSIONJ

(2) Verify transmission throttle cable operation.
Repair or replace cable if necessary.
(3) Check engine throttle operation. Operate accel-
erator pedal and observe injector throttle plate move-
ment. Adjust linkage if throttle plate does not reach
wide open position.
(4) Check transmission fluid level when fluid is at
normal operating temperature. Start engine. Shift
transmission through all gear ranges then back to
Neutral. Correct level is to Full or Add mark on dip-
stick with engine at curb idle speed.
(5) Check and adjust park/neutral position switch
if necessary.
(6) Check throttle position sensor adjustment and
operation. Adjust the sensor if necessary.
MANUAL SHIFTING TEST
(1) This test determines if problem is related to
mechanical or electrical component.
(2) Stop engine and disconnect transmission con-
trol module or module fuse.
(3) Road test vehicle. Shift transmission into each
gear range. Transmission should operate as follows:
²lock in Park
²back up in Reverse
²not move in Neutral
²provide first gear only with shift lever in 1-2 posi-
tion
²operate in third gear only with shift lever in 3 po-
sition
²operate in overdrive fourth gear in D position
(4) If transmission operates as described, proceed
to next step. However, if forward gear ranges were
difficult to distinguish (all feel the same), or vehicle
would not back up, refer to diagnosis charts. Do not
perform stall or time lag tests.
CAUTION: Do not overspeed the engine during the
next test step. Ease off the throttle and allow the
vehicle to slow before downshifting.
(5) Continue road test. Manually downshift trans-
mission from D to 3, and from 3 to 1-2 position. Then
manually upshift transmission through forward
ranges again.
(6) If transmission operation is OK, perform stall,
time lag and pressure tests. If transmission shifting
problem is encountered, refer to diagnosis charts.
(7) If a problem still exists, continue testing with
DRB II scan tool.
HYDRAULIC PRESSURE TEST
PRESSURE TEST PROCEDURE
(1) Connect pressure test gauge to test port on pas-
senger side of transmission. Use Adapter 7554 to con-
nect gauge. Be sure test gauge has minimum
capacity of 300 psi (2100 kPa).(2) Be sure transmission fluid is at normal operat-
ing temperature.
(3) Apply parking brakes and block wheels.
WARNING: DO NOT ALLOW ANYONE TO STAND AT
THE FRONT OR REAR OF THE VEHICLE WHILE
PERFORMING THE FOLLOWING STEPS IN THE
PRESSURE TEST.
(4) Check and adjust engine curb idle speed.
(5) Apply service brakes.
(6) Shift transmission into D range and note line
pressure with engine at curb idle speed. Pressure
should be 61-to-70 psi (421-to-481 kPa).
(7) Press accelerator pedal to wide open throttle
position and note line pressure. Pressure should be
173-to-209 psi (1196-to-1442 kPa).
CAUTION: Do not maintain wide open throttle for
more than three or four seconds at a time.
(8) Shift transmission into Reverse and note line
pressure with engine at curb idle speed. Pressure
should be 75-to-90 psi (519-to-618 kPa).
(9) Press accelerator to wide open throttle position
and note line pressure in Reverse. Pressure should
be 213-to-263 psi (1471-to-1814 kPa).
CAUTION: Do not maintain wide open throttle for
more than three or four seconds at a time.
(10) If line pressure is not within specifications,
adjust transmission throttle cable and repeat pres-
sure test.
Fig. 27 Pressure Test Gauge Connection
21 - 168 AW-4 TRANSMISSION DIAGNOSISJ