four wheel drive JEEP CHEROKEE 1995 Service Owner's Manual
[x] Cancel search | Manufacturer: JEEP, Model Year: 1995, Model line: CHEROKEE, Model: JEEP CHEROKEE 1995Pages: 2198, PDF Size: 82.83 MB
Page 600 of 2198

ANTI-LOCK BRAKES
INDEX
page page
ABS Power Relay.......................... 1
ABS Pump Motor Relay..................... 1
ABS Warning Lamp........................ 2
Acceleration Switch......................... 1
Brake Switch Input......................... 2
Data Link Connector........................ 2Diagram Index............................ 3
General Information........................ 1
Hydraulic Control Unit....................... 2
Pump Motor Speed Sensor................... 2
Wheel Speed Sensors...................... 1
GENERAL INFORMATION
Three fuses supply power for the Anti-Lock Brake
System (ABS); fuses 8 and 10 in the Power Distribu-
tion Center (PDC) and fuse 7 in the fuse block. Fuses
8 and 10 in the PDC are connected directly to battery
voltage and are HOT all times. Fuse 7 in the fuse
block is HOT when the ignition switch is the RUN
Position.
In the RUN position, the ignition switch connects
circuit A1 from fuse 6 in the PDC with circuit A38.
Circuit A38 connects to a bus bar in the fuse block.
The bus bar feeds circuit B236 through fuse 7. Fuse 7
is a 2 amp fuse.
Circuit B236 connects to the coil side of the ABS
power relay and cavity 53 of the ABS control module.
Circuit Z1 provides ground for the ABS control mod-
ule. Circuit Z1 connects to cavities 1 and 19 of the
ABS control module.
Refer to group 5, Brakes for operational descrip-
tions of ABS system components.
WHEEL SPEED SENSORS
The all wheel anti-lock system uses four wheel
speed sensors; one for each wheel. Each sensor con-
verts wheel speed into an electrical signal that it
transmits to the ABS control module. A pair of
twisted wires connect to each sensor to provide sig-
nals to the ABS control module.
Circuits B6 and B7 provide signals to ABS control
module from right front wheel speed sensor. Circuit
B6 which provides the LOW signal connects to cavity
29 of the ABS control module. Circuit B7 connects to
cavity 47 of the module and provides the HIGH sig-
nal.
Circuits B8 and B9 provide signals to ABS control
module from left front wheel speed sensor. Circuit B8,
which provides the LOW signal, connects to cavity 30
of the ABS control module. Circuit B9 connects to
cavity 48 of the module and provides the HIGH sig-
nal.
Circuits B1 and B2 provide signals to ABS control
module from right rear wheel speed sensor. Circuit
B1 which provides the LOW signal connects to cavity45 of the ABS control module. Circuit B2 connects to
cavity 27 of the module and provides the HIGH sig-
nal.
Circuits B4 and B3 provide signals to ABS control
module from left rear wheel speed sensor. Circuit B3,
which provides the LOW signal, connects to cavity 28
of the ABS control module. Circuit B4 connects to
cavity 46 of the module and provides the HIGH sig-
nal.
ACCELERATION SWITCH
During four-wheel drive operation, the acceleration
(G) switch provides deceleration data to the ABS con-
trol module. Refer to Group 5, Brakes for additional
information.
Circuits B515, B516, and B517 connect the accel-
eration sensor to the ABS control module. Circuits
B515 and B516 provide switch states while circuit
B517 provides ground. At the ABS control module
circuit B515 connects to cavity 25, circuit B516 con-
nects to cavity 43 and circuit B517 connects to cavity
26.
ABS POWER RELAY
The ABS power relay is located in the power distri-
bution center (PDC). When the ABS module grounds
the ABS power relay on circuit B207, the relay
switches to connect circuit A20 from PDC fuse 10 to
circuit B235. Circuit B236 from fuse 7 in the fuse
block splices to feed the coil side of the ABS power
relay. Circuit B207 connects to cavity 34 of the ABS
control module.
Circuit B235 is double crimped at the ABS power
relay. One branch of circuit B235 supplies power to
the coil side of the ABS pump motor relay. The other
branch of circuit B235 splices to cavities 3 and 33 of
the ABS control module and to the hydraulic control
unit.
ABS PUMP MOTOR RELAY
The ABS pump motor relay in the power distribu-
tion center (PDC) supplies voltage to the ABS pump
motor. When the ABS power relay energizes, circuit
B235 supplies battery voltage to the coil side of the
J8W-32 ANTI-LOCK BRAKESÐXJ VEHICLES 8W - 32 - 1
Page 614 of 2198

CHARGING SYSTEM INDICATOR LAMP
The Powertrain Control Module (PCM) illuminates
the charging system indicator lamp by providing
ground for the lamp on circuit G12. Circuit G12 con-
nects to cavity 36 of the PCM. Circuit F87 supplies
battery voltage to the lamp.
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit 107 connects the indicator lamp to the
4WD switch. Circuit 106 connects the lamp to the in-
strument cluster and circuit F87.
CLUSTER GROUND
Circuit Z1 from the instrument cluster left connec-
tor provides ground for the illumination lamps and
indicator lamps.
HELPFUL INFORMATION
²If the warning lamps don't operate, check fuse 14
in the fuse block.
²If the indicator lamps and illumination lamps
don't operate, check fuse 13 in the fuse block.
²Inspect the ground at the instrument panel lower
right reinforcement support.
DIAGRAM INDEX
Component Page
4WD Switch............................8W-40-9
4WD Indicator Lamp......................8W-40-9
ABS Control Module......................8W-40-9
Brake Warning Switch.....................8W-40-10
Chime/Buzzer Module......................8W-40-8
Daytime Running Lamps Module.............8W-40-5, 6
Engine Coolant Temperature Sending Unit.........8W-40-6
Engine Oil Pressure Sending Unit..............8W-40-6
Fuse 3 (PDC)...........................8W-40-8
Fuse 5 (PDC)...........................8W-40-4
Fuse 6 (PDC).........................8W-40-4, 8
Fuse 11 (PDC)..........................8W-40-8
Fuse 16 (PDC)..........................8W-40-8
Fuse 9 (Fuse Block).......................8W-40-8
Fuse 15 (Fuse Block)......................8W-40-4
Fuse 17 (Fuse Block)....................8W-40-4, 8
Fuse 19 (Fuse Block)......................8W-40-4
Headlamp Switch.......................8W-40-4, 5
Headlamp Delay Module....................8W-40-8
Headlamp Dimmer Switch...................8W-40-5
Ignition Switch......................8W-40-4, 8, 10
Instrument Cluster......................8W-40-4, 5
Low Washer Fluid Lamp Switch...............8W-40-8
Park Brake Switch.......................8W-40-10
Powertrain Control Module..................8W-40-6
Remote Keyless Entry Module................8W-40-8
Telltale Connector (Instrument Cluster).....8W-40-7 thru 10
J8W-40 INSTRUMENT CLUSTERÐXJ VEHICLES 8W - 40 - 3
Page 868 of 2198

TRANSMISSION CONTROLS
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit 107 connects the indicator lamp to the
4WD switch. Circuit 106 connects the lamp to the in-
strument cluster and circuit F87.
TRANSMISSION COMFORT SWITCH
Circuit T17 from fuse 12 in the Power Distribution
Center (PDC) supplies battery voltage to the trans-
mission comfort switch. Circuit Z1 provides ground
for the switch. Circuit T177 Connects the switch to
the Transmission Control Module (TCM).
TRANSMISSION CONTROL MODULE
Vehicles equipped with the 4.0L engine have elec-
tronically controlled solenoids in the automatic trans-
mission valve body.
The transmission control module (TCM) receives
inputs from the throttle position sensor (TPS) on cir-
cuit K22 and the stop lamp switch on circuit K29.
Circuit K4 connects to the TCM to provide ground for
the TPS signal.
The TCM receives the transmission output speed
sensor signal on circuit 505. Circuit A14 from fuse 2
in the Power Distribution Center (PDC) supplies bat-
tery voltage to the TCM. Circuit T17 from fuse 12 in
the PDC also connects to the TCM. Circuit Z12 pro-
vides ground for the TCM.The TCM powers the S1 solenoid on circuit 510,
the S2 solenoid on circuit 509, and the S3 solenoid on
circuit 508. Circuit Z12 provides ground for the S1,
S2, and S3 solenoids.
Circuits 506 and 507 from the Park/Neutral posi-
tion switch connect to the TCM. Circuits 506 and 507
tell the TCM what drive range the transmission is in.
DATA LINK CONNECTOR
Circuit 137 from the TCM connects to the data link
connector. Circuit F39 from fuse 5 in the PDC sup-
plies power to the data link connector. Circuit Z12
provides ground for the data link connector.
DIAGRAM INDEX
Component Page
ABS Data Link Connector...................8W-31-3
4-WD Indicator Lamp......................8W-31-4
4-WD Indicator Switch.....................8W-31-4
Fuse 2 (PDC)...........................8W-31-4
Fuse 6 (PDC).........................8W-31-2, 3
Fuse 11 (PDC)..........................8W-31-3
Fuse 12 (PDC)..........................8W-31-2
Ignition Switch........................8W-31-2, 3
Park/Neutral Position Switch.................8W-31-3
Telltale Connector (Instrument Cluster)...........8W-31-4
Transmission Comfort Switch.................8W-31-2
Transmission Control Module.............8W-31-2, 3, 4
Transmission Valve Body Solenoids.............8W-31-4
J8W-31 TRANSMISSION CONTROLSÐXJ-RHD 8W - 31 - 1
Page 872 of 2198

ANTI-LOCK BRAKES
INDEX
page page
ABS Power Relay.......................... 1
ABS Pump Motor Relay..................... 1
ABS Warning Lamp........................ 2
Acceleration Switch......................... 1
Brake Pedal Travel Sensor................... 2
Brake Switch Input......................... 2Data Link Connector........................ 2
Diagram Index............................ 3
General Information........................ 1
Hydraulic Control Unit....................... 2
Pump Motor Speed Sensor................... 2
Wheel Speed Sensors...................... 1
GENERAL INFORMATION
Three fuses supply power for the Anti-Lock Brake
System (ABS); fuses 6 and 10 in the Power Distribu-
tion Center (PDC) and fuse 2 in the fuse block. Fuses
6 and 10 in the PDC are connected directly to battery
voltage and are HOT all times. Fuse 2 in the fuse
block is HOT when the ignition switch is the RUN
Position.
In the RUN position, the ignition switch connects
circuit A1 from fuse 6 in the PDC with circuit A38.
Circuit A38 connects to a bus bar in the fuse block.
The bus bar feeds circuit B236 through fuse 2. Fuse
2 is a 2 amp fuse.
Circuit B236 connects to the coil side of the ABS
power relay and cavity 53 of the ABS control module.
Circuit Z1 provides ground for the ABS control
module. Circuit Z1 connects to cavities 1 and 19 of
the ABS control module.
Refer to group 5, Brakes for operational descrip-
tions of ABS system components.
WHEEL SPEED SENSORS
The all wheel anti-lock system uses four wheel
speed sensors; one for each wheel. Each sensor con-
verts wheel speed into an electrical signal that it
transmits to the ABS control module. A pair of
twisted wires connect to each sensor to provide sig-
nals to the ABS control module.
Circuits B6 and B7 provide signals to ABS control
module from the right front wheel speed sensor. Cir-
cuit B6 which provides the LOW signal connects to
cavity 29 of the ABS control module. Circuit B7 con-
nects to cavity 47 of the module and provides the
HIGH signal.
Circuits B8 and B9 provide signals to ABS control
module from the left front wheel speed sensor. Cir-
cuit B8, which provides the LOW signal, connects to
cavity 30 of the ABS control module. Circuit B9 con-
nects to cavity 48 of the module and provides the
HIGH signal.
Circuits B1 and B2 provide signals to ABS control
module from the right rear wheel speed sensor. Cir-
cuit B1 which provides the LOW signal connects tocavity 45 of the ABS control module. Circuit B2 con-
nects to cavity 27 of the module and provides the
HIGH signal.
Circuits B4 and B3 provide signals to ABS control
module from the left rear wheel speed sensor. Circuit
B3, which provides the LOW signal, connects to cav-
ity 28 of the ABS control module. Circuit B4 connects
to cavity 46 of the module and provides the HIGH
signal.
ACCELERATION SWITCH
During four-wheel drive operation, the acceleration
switch provides deceleration data to the ABS control
module. Refer to Group 5, Brakes for additional in-
formation.
Circuits B515, B516, and B517 connect the acceler-
ation sensor to the ABS control module. Circuits
B515 and B516 provide switch states while circuit
B517 provides ground. At the ABS control module cir-
cuit B515 connects to cavity 25, circuit B516 connects
to cavity 43 and circuit B517 connects to cavity 26.
ABS POWER RELAY
The ABS power relay is located in the power distri-
bution center (PDC). When the ABS module grounds
the ABS power relay on circuit B207, the relay
switches to connect circuit A20 from PDC fuse 10 to
circuit B235. Circuit B236 from fuse 7 in the fuse
block splices to feed the coil side of the ABS power
relay. Circuit B207 connects to cavity 34 of the ABS
control module.
Circuit B235 is double crimped at the ABS power
relay. One branch of circuit B235 supplies power to
the coil side of the ABS pump motor relay. The other
branch of circuit B235 splices to cavities 3 and 33 of
the ABS control module and to the hydraulic control
unit.
ABS PUMP MOTOR RELAY
The ABS pump motor relay in the power distribu-
tion center (PDC) supplies voltage to the ABS pump
motor. When the ABS power relay energizes, circuit
B235 supplies battery voltage to the coil side of the
J8W-32 ANTI-LOCK BRAKESÐXJ-RHD 8W - 32 - 1
Page 885 of 2198

LOW WASHER FLUID WARNING LAMP
Circuit G29 connects the low washer fluid switch to
the warning lamp in the instrument cluster. Circuit
F12 supplies battery voltage to the switch.
When the low washer fluid switch closes, it con-
nects circuits G29 and F12. Battery voltage from cir-
cuit F12 powers the low washer fluid lamp. Circuit
Z1 at the instrument cluster provides ground to illu-
minate the warning lamp.
SEAT BELT INDICATOR WARNING LAMP
The seat belt indicator warning lamp is activated
by the chime/buzzer on circuit G11. Circuit G11 sup-
plies power to instrument cluster for the lamp. Cir-
cuit Z1 provides ground for the lamp at the cluster.
The chime/buzzer module powers circuit G11 after
it receives an input on circuit G10 indicating the seat
belt switch is open.
HIGH-BEAM INDICATOR LAMP
Circuit L3 supplies power for the high beam indi-
cator lamp. The ground path for the lamp is through
circuit Z1. Circuit Z1 provides ground for the indica-
tor lamp at the cluster.
ABS WARNING LAMP
Circuit F87 provides power for the ABS warning
lamp at the instrument cluster. Ground for the ABS
warning lamp is provided by either the ABS control
module or by the ABS power relay when the relay is
not energized. The ABS control module illuminates
the lamp by providing ground on circuit B205.
Circuit B205 splices to connect to circuit B235
through a diode. When the ABS power relay is not
energized, it connects circuit B235 to circuit Z12. The
ground path for the warning lamp is through the di-
ode to circuit B235, through the ABS power relay to
ground on circuit Z12.
The diode between circuits B205 and B235 pre-
vents voltage from flowing to the ABS control module
when the ABS power relay switches to supply power
on circuit B235.
TURN SIGNAL INDICATOR LAMPS
Circuits L61 and L60 power for the turn signal in-
dicator lamps. Circuit L61 powers the left indicator
lamp. Circuit L60 powers the right indicator lamp.
Circuit Z1 provides ground for the lamps.
BRAKE WARNING LAMP
Circuit F87 supplies power to the park brake lamp.
Ground for the park brake lamp is supplied through
the case grounded park brake switch or brake warn-
ing switch on circuit G9. Circuit G9 connects to the
brake warning lamp at the instrument cluster.
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit G107 connects the indicator lamp to
the 4WD switch. Circuit G106 connects the lamp to
the instrument cluster and circuit F87.
TACHOMETER
The Powertrain Control Module (PCM) supplies the
signal to the tachometer on circuit G21. Circuit G21
connects to cavity 43 of the PCM.
CLUSTER GROUND
Circuit Z1 from the instrument cluster left connec-
tor provides ground for the illumination lamps and
indicator lamps.
HELPFUL INFORMATION
²If the warning lamps don't operate, check fuse 26
in the fuse block.
²If the indicator lamps don't operate, check fuse 14
in the fuse block.
²If the illumination lamps don't operate, check fuse
25 in the fuse block.
8W - 40 - 2 8W-40 INSTRUMENT CLUSTERÐXJ-RHDJ
Page 1286 of 2198

SERVICE DIAGNOSIS
INDEX
page page
Runout.................................. 4
Unbalance............................... 3Universal Joint Angle Measurement............. 4
Vibration................................. 3
VIBRATION
Tires that are out-of-round or wheels that are un-
balanced will cause a low frequency vibration. Refer
to Group 22, Wheels and Tires for additional infor-
mation.
Brake drums that are unbalanced will cause a
harsh, low frequency vibration. Refer to Group 5,
Brakes for additional information.
Driveline vibration can also result from loose or
damaged engine mounts. Refer to Group 21, Trans-
missions for additional information.
Propeller shaft vibration will increase as the vehi-
cle speed is increased. A vibration that occurs within
a specific speed range is not caused by propeller
shaft unbalance. Defective universal joints or an in-
correct propeller shaft angle are usually the cause.
UNBALANCE
If propeller shaft unbalance is suspected, it can be
verified with the following procedure.
Removing and re-indexing the propeller shaft
180É may eliminate some vibrations.
²Clean all the foreign material from the propeller
shaft and the universal joints.²Inspect the propeller shaft for missing balance
weights, broken welds, and bent areas.If the pro-
peller shaft is bent, it must be replaced.
²Ensure the universal joints are not worn, are prop-
erly installed, and are correctly aligned with the
shaft.
²Check the universal joint clamp screws torque
(1) Raise the vehicle.
(2) Remove the wheel and tires assembly. Install
the wheel lug nuts to retain the brake drums.
(3) Mark and number the shaft six inches from the
yoke end at four positions 90É apart.
(4) Run and accelerate the vehicle until vibration
occurs. Note the intensity and speed the vibration oc-
curred. Stop the engine.
(5) Install a screw clamp at position 1 (Fig. 1).
(6) Start the engine and re-check for vibration. If
there is little or no change in vibration, move the
clamp to one of the other three positions. Repeat the
vibration test.
(7) If there is no difference in vibration at the
other positions, the vibration may not be propshaft
unbalance.
DRIVELINE VIBRATION
JPROPELLER SHAFTS 16 - 3
Page 1410 of 2198

AX 15 MANUAL TRANSMISSION
INDEX
page page
General Information....................... 33
Service Diagnosis......................... 34
Transmission Assembly and Adjustment......... 52
Transmission Disassembly and Overhaul........ 37
Transmission Gear Ratios................... 34
Transmission Identification.................. 33Transmission Installation.................... 36
Transmission Lubricant..................... 34
Transmission Removal..................... 35
Transmission Shift Pattern................... 34
Transmission Switch and Plug Locations........ 34
GENERAL INFORMATION
The AX 15 is a 5-speed, synchromesh, manual
transmission. Fifth gear is an overdrive range with a
ratio of 0.79:1. The shift mechanism is integral and
mounted in the shift tower portion of the adapter
housing (Fig. 1).
An adapter housing is used to attach the transmis-
sion to the transfer case on 4-wheel drive models. A
standard extension housing is used on 2-wheel drive
models.
The AX 15 is used in XJ and YJ models with a 4.0L
engine. The AX 15 is used for two and four-wheel
drive applications.
TRANSMISSION IDENTIFICATION
The AX 15 identification code numbers are on the
bottom surface of the transmission gear case (Fig. 2).
Fig. 1 AX 15 Manual Transmission
Fig. 2 Identification Code Number Location
JAX 15 MANUAL TRANSMISSION 21 - 33
Page 1411 of 2198

The first number is year of manufacture. The sec-
ond and third numbers indicate month of manufac-
ture. The next series of numbers is the transmission
serial number.
TRANSMISSION SHIFT PATTERN
The AX 15 shift pattern is shown in Figure 3. First
and second and third and fourth gear ranges are in
line for improved shifting. Fifth and reverse gear
ranges are also in line at the extreme right of the
pattern (Fig. 3).
The AX 15 is equipped with a reverse lockout
mechanism. The shift lever must be moved through
the Neutral detent before making a shift to reverse.
TRANSMISSION LUBRICANT
Recommended lubricant for AX 15 transmissions is
Mopar 75W-90, API Grade GL-5 gear lubricant, or
equivalent.
Correct lubricant level is from the bottom edge, to
no more than 6 mm (1/4 in.) below the bottom edge of
the fill plug hole.
Approximate dry fill lubricant capacity is:
²3.10 liters (3.27 qts.) in 4-wheel drive models
²3.15 liters (3.32 qts.) in 2-wheel drive models
TRANSMISSION SWITCH AND PLUG LOCATIONS
The fill plug is at the driver side of the gear case
(Fig. 4).
The drain plug and backup light switch are on the
passenger side of the gear case (Fig. 5).
TRANSMISSION GEAR RATIOS
AX 15 gear ratios are:
First gear - 3.83:1
Second gear - 2.33:1
Third gear - 1.44:1
Fourth gear - 1.00:1
Fifth gear - 0.79:1
Reverse - 4.22:1
SERVICE DIAGNOSIS
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill, or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, intermediate plate and adapter or extension
housing, or from the front/rear seals. A suspected
leak could also be the result of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will usually be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening, or use of a non-recommended sealer.
A leak at the front of the transmission will be from
either the front bearing retainer or retainer seal. Lu-
bricant may be seen dripping from the clutch housing
after extended operation. If the leak is severe, it may
also contaminate the clutch disc causing slip, grab
and chatter.
Transmissions filled from air or electrically pow-
ered lubricant containers can be underfilled. This
Fig. 3 AX 15 Shift Pattern
Fig. 4 Fill Plug Location
Fig. 5 Drain Plug/Backup Light Switch Location
21 - 34 AX 15 MANUAL TRANSMISSIONJ
Page 1554 of 2198

(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 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 (and hold) 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 hold wide open throttle for more
than 3-4 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 hold wide open throttle for more
than 4 seconds.
(10) If line pressure is not within specifications,
adjust transmission throttle cable and repeat pres-
sure test.
Fig. 27 Pressure Test Gauge Connection
JAW-4 TRANSMISSION DIAGNOSIS 21 - 177
Page 1722 of 2198

WHEELS AND TIRES
CONTENTS
page page
SPECIFICATIONS........................ 12
TIRES.................................. 1VEHICLE VIBRATION..................... 10
WHEELS................................ 6
TIRES
INDEX
page page
Cleaning of Tires.......................... 2
General Information........................ 1
Pressure Gauges.......................... 2
Repairing Leaks........................... 3
Replacement Tires......................... 2Rotation................................. 3
Tire Inflation Pressures...................... 2
Tire Noise or Vibration...................... 4
Tire Wear Patterns......................... 4
Tread Wear Indicators....................... 3
GENERAL INFORMATION
Tires are designed for each specific vehicle. They
provide the best overall performance for normal oper-
ation. The ride and handling characteristics match
the vehicle's requirements. With proper care they
will give excellent reliability, traction, skid resis-
tance, and tread life. These tires have specific load
carrying capacities. When correctly inflated, they will
operate properly.
Tires used in cool climates, and with light loads
will have a longer life than tires used in hot climates
with heavy loads. Abrasive road surfaces will acceler-
ate tire wear.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain much
greater mileage than careless drivers.
Driving habits that shorten the life of any tire;
²Rapid acceleration and deceleration
²Severe application of brakes
²High-speed driving
²Taking turns at excessive speeds
²Striking curbs and other obstacles
It is very important to follow the tire rotation in-
terval
IDENTIFICATION
Tire type, size, aspect ratio and speed rating are
encoded in the letters and numbers imprinted on the
side wall of the tire. Refer to the chart to decipher
the tire identification code (Fig. 1).Performance tires will have a speed rating letter
after the aspect ratio number. The speed rating is not
always printed on the tire sidewall. The letterSin-
dicates that the tire is speed rated up to 112 mph.
²Qup to 100 mph
²Tup to 118 mph
²Uup to 124 mph
²Hup to 130 mph
²Vup to 149 mph
²Zmore than 149 mph (consult the tire manufac-
turer for the specific speed rating)
An All Season type tire will have eitherM+S,M
&SorMÐS(indicating mud and snow traction) im-
printed on the side wall.
RADIAL-PLY TIRES
Radial-ply tires improve handling, tread life, ride
quality and decrease rolling resistance.
Radial-ply tires must always be used in sets of
four. Under no circumstances should they be used on
the front only. They may be mixed with temporary
spare tires when necessary, but reduced speeds are
recommended.
Radial-ply tires have the same load-carrying capac-
ity as other types of tires of the same size. They use
the same recommended inflation pressures.
SPARE TIRE (TEMPORARY)
The compact spare tire is designed for emergency
use only. The original tire should be repaired and re-
installed at the first opportunity. Refer to Owner's
Manual for complete details.
JWHEELS AND TIRES 22 - 1