ECO mode JEEP CHEROKEE 1988 Service Owner's Guide
[x] Cancel search | Manufacturer: JEEP, Model Year: 1988, Model line: CHEROKEE, Model: JEEP CHEROKEE 1988Pages: 1378, PDF Size: 19.9 MB
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FU EL P U M P - E LE C TR IC
1988 J e ep C hero ke e
1988 Electric Fuel Pump
JEEP
2.5L TBI, 4.0L MPFI
DESCRIPTION & OPERATION
Fuel system on 2.5L TBI models operate under constant fuel
pressure of 14.5 psi (1.02 kg/cm ). Fuel pressure regulator is
mounted on throttle body assembly. Excess fuel pressure is returned
to fuel tank. ECU has no control over fuel pressure relief valve.
Fuel pump is immersible type with permanent magnet electric motor.
A frame mounted in-line fuel filter is used. Fuel pump is
attached to fuel gauge sending unit in fuel tank. Voltage to operate
pump is controlled by Electronic Control Unit (ECU). A ballast
resistor is used in the fuel pump control circuit.
Ballast resistor is by-passed during start mode. During
running mode, ballast resistor reduces speed of pump by lowering pump
voltage. This ensures normal speed in running mode. The 1-ohm ballast
resistor is mounted on right side of plenum chamber.
Fuel pump control relay is located on front of right strut
tower. Battery voltage is supplied to relay from ignition switch.
Relay is energized when ECU provides a circuit to ground.
A multi-cell, roller type pump is used on all 4.0L MPFI
models. Pump and fuel filter are located on a plate, forward of rear
axle. Fuel pump control relay location for 4.0L models is on right
inner front fenderwell. Battery voltage is supplied to relay from
ignition switch. Relay is energized when ECU provides a circuit to
ground.
Pump contains 2 check valves. One valve relieves internal
pump pressure and regulates maximum pump output. Second valve,
located near pump outlet, restricts fuel movement in either direction
when pump is not in operation. System operates under a constant fuel
pressure of 31 psi (2.17 kg/cm
).
Fig. 1: 2.5L Fuel Pump & Fuel Gauge Sending Unit
Courtesy of Chrysler Motors.
Page 900 of 1378
2) To determine if front axle has completed a shift out of
4WD into 2WD, position mode select switch back to "4WD" position while
operating vehicle at slow speed. If vehicle shifts into 2WD, axle will
ratchet. If shift is not completed, transfer case will shift into 4WD
and hissing sound will come from mode select switch.
FRONT AXLE SHIFT MOTOR TEST
1) Disconnect vacuum harness from front axle shift motor.
Connect vacuum pump to shift motor front port. Apply 15 in. Hg vacuum
to shift motor. Rotate right front wheel to disengage axle.
2) Shift motor should hold vacuum at least 30 seconds. If
not, replace motor. If motor does hold vacuum, disconnect vacuum pump
from shift motor front port. Connect pump to shift motor rear port and
cap transfer case connecting port. Apply 15 in. Hg vacuum to motor.
3) Shift motor should hold vacuum for at least 30 seconds. If
not, replace motor. If motor does hold vacuum, remove cap from shift
motor transfer case connecting port and check for vacuum. If no vacuum
is present, rotate right front wheel to ensure axle has shifted
completely. Axle must completely shift to open shift motor connecting
port.
4) Recheck vacuum at shift motor transfer case port. If
vacuum is present, transfer case requires diagnosis. Command-Trac uses
Model 207 transfer case. Selec-Trac uses Model 228 transfer case.
REMOVAL & INSTALLATION
LOCKING HUB
Removal
1) Remove cover to outer clutch housing. Remove bearing race
spring assembly. Remove sealing ring and seal bridge retainer. Remove
bearing components.
2) Squeeze tangs of wire retaining ring together with needle-
nose pliers. Pull remaining components of automatic hub from wheel.
Installation
1) Ensure lock ring is in position. Using Bearing Nut Wrench
(J-6893-D), tighten wheel bearing adjusting nut to 50 ft. lbs. (60 N.\
m) to seat bearings.
2) Back off nut and tighten to 35 ft. lbs. (47 N.m) while
rotating hub. Finally, back off nut a maximum of 3/8 turn. Assemble
lock ring (with tab in keyway) over axle shaft, against bearing
adjustment nut.
3) Adjustment nut pin must pass through one of the washer
holes. Tighten outer adjusting nut to 183 ft. lbs. (248 N.m). Align
outer clutch housing splines with splines of wheel hub.
4) Loosen cover screws 3 or 4 turns, and push in on cover to
allow retaining ring to expand into rotor hub groove. Tighten cover
cap screws to 40-50 INCH lbs. (4.5-5.6 N.m).
Fig. 2: Selec-Trac Vacuum Control System
AXLE SHIFT MOTOR & HOUSING
Page 903 of 1378
5 - Transmission/(Transfer Case)
A * Auto Column Shift (2WD)
B * Auto Floor Shift (Part Time 4WD)
C * Auto Floor Shift (Full Time 4WD)
D * Auto Floor Shift (2WD)
E * Auto Column Shift (Part Time 4WD)
J * Auto Column Shift (Full Time 4WD)
L * 5-Speed Manual Floor Shift (Part Time 4WD)
N * 5-Speed Manual Floor Shift (Full Time 4WD)
S * 4-Speed Manual Floor Shift (2WD)
W * 5-Speed Manual Shift (2WD)
X * 4-Speed Manual Floor Shift (Part Time 4WD)
6-7 - Body Style
73 * Cherokee Wagon 2-Door (2WD)
74 * Cherokee Wagon 4-Door (2WD)
75 * Wagoneer Wagon 4-Door (4WD)
77 * Cherokee Wagon 2-Door (4WD)
78 * Cherokee Wagon 4-Door (4WD)
8 - Trim Package
1 * Custom
2 * Pioneer
3 * Chief
4 * Laredo
5 * Base
5 * Wagoneer
6 * Limited
K * Cherokee Base (2WD)
L * Pioneer (2WD)
M * Laredo (2WD)
9 - Check Digit
* Manufacturer Assigned
10 - Model Year
E * 1984
F * 1985
G * 1986
H * 1987
J * 1988
11 - Assembly Plant
T * Toledo, Ohio
12-17 - Sequential Serial Number
* Production Sequence
MAINTENANCE SERVICE INFORMATION
SEVERE & NORMAL SERVICE DEFINITION
NOTE: Use the Severe Service schedule if the vehicle to be serviced
is operated under ANY (one or more) of these conditions:
Service is recommended at specified mileage intervals of
vehicle operation. Service schedules are based on the following
primary operating conditions:
Severe Service
* Short Trips (About 15 Miles)
Page 914 of 1378
Command-Trac .............................. 2.2 Pts. (1.0L)
Drive Axles (3)
Front ....................................... 2.5 Pts. (1.2L)
Front (Disconnect Housing) ( 4) ............. 5.0 Ozs. (0.15L)
Rear ........................................ 2.5 Pts. (1.2L)
Rear (Trac-Lok) ( 5) ......................... 2.5 Pts. (1.2L)
( 1) - Capacities are recommended or calculated levels. Always use
dipstick (if available) to measure level.
( 2) - Includes 2.3 Qts. for coolant recovery bottle.
( 3) - Fill to bottom of filler plug hole.
( 4) - Add 5 Ozs. of gear lubricant through indicator switch hole.
( 5) - Add 2 Ozs. of Limited-Slip differential lubricant additive
first, then add new fluid.
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WHEEL & TIRE SPECIFICATIONS
WHEEL & TIRE SPECIFICATIONS TABLE\
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Wheel Size Tire Size
Cherokee
15x6 & 15x7 (Aluminum Or Steel) ............. P195/75R15
15x6 & 15x7 (Aluminum Or Steel) ............. P205/75R15
15x6 & 15x7 (Aluminum Or Steel) ............. P215/75R15
15x6 & 15x7 (Aluminum Or Steel) ............. P225/75R15
Wagoneer
15x6 (Aluminum/Steel) ....................... P205/75R15
All Models
16-Inch Wheels ...................... Compact Spare Tire
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TIRE REPLACEMENT
CAUTION: Always ensure all 4 tires on the vehicle are the same size,
except when using the temporary spare. The use of
mismatched tires may cause unpredictable handling.
Replacing original tires with tires of a different size may
result in false speedometer and odometer indications.
TIRE INFLATION
The tire specification decal is located in the glove box.
WHEEL TIGHTENING
Tighten the lug nuts firmly in a crisscross pattern as shown
in Fig. 11 . Tighten to 95 ft. lbs (129 N.m). Always position wheel
locking nut opposite valve stem in position indicated. See Fig. 11.
Fig. 11: Wheel Locking Nut Location
Courtesy of American Motors Corp.
Page 915 of 1378
BATTERY SPECIFICATIONS
CAUTION: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in the GENERAL INFORMATION
section.
All gasoline engine equipped models use group 58 batteries
with 390 or 475 amp cold crank rating. Models with 2.1L Turbo Diesel
engine use group 24 batteries with a 815 amp cold crank rating.
CAUTIONS & WARNINGS
REPLACING BLOWN FUSES
Before replacing a blown fuse, remove ignition key, turn off
all lights and accessories to avoid damaging the electrical system. Be
sure to use fuse with the correct indicated amperage rating. The use
of an incorrect amperage rating fuse may result in a dangerous
electrical system overload.
BATTERY WARNING
WARNING: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in GENERAL INFORMATION section.
BRAKE PAD WEAR INDICATOR
Indicator will cause a squealing or scraping noise, warning
that brake pads need replacement.
DIESEL FUEL ANTI-FUNGAL ADDITIVES
CAUTION: If fuel contamination due to fungi or other microorganisms is
suspected a fuel additive with a biocide may be used. Follow
the manufacturers dosage as recommended on product label. Use
biocides ONLY when necessary, excessive use can may cause
other fuel system problems.
DIESEL FUEL CONTAMINATION
WARNING: Diesel fuel system may be contaminated with fungi or other
microorganisms. Keep contaminated fuel away from open skin
cuts or sores to prevent skin irritation or infection.
DIESEL FUEL REQUIREMENTS
CAUTION: All diesel engines are to use Diesel Fuel #2 when the outside
temperature is above 20\bF (-7\bC). In temperatures that are
below 20\bF (-7\bC) use Diesel Fuel #1, this will reduce the
chance of the fuel thickening and forming wax.
Note: A Diesel Fuel #1 & #2 combination (Blended Fuel) may be\
used, and is recommended for mild winter driving.
Page 917 of 1378
WARNING: DO NOT USE starting fluids (ether) or flammable liquids to
aid the starting of a Cummins Turbo-Diesel. NEVER pour diesel
fuel, flammable liquids or starting fluids into the air
cleaner canister, air intake or turbocharger housing in an
attempt to start the vehicle. A flash fire may result causing
personal injury.
TRANSFER CASE
CAUTION: Both drive axles are disengaged when transmission gear is
in Neutral position. Always set parking brake when leaving
vehicle unattended.
CAUTION: Never attempt to engage Low range when vehicle is moving
faster than 2-3 MPH (3-5 KM/H). Transfer case damage may
result.
GASOLINES CONTAINING ALCOHOL
CAUTION: Exclusive use of gasohol is not recommended. Vehicle test
results have shown that significant fuel system corrosion
can result when gasohol is used exclusively. Fuel additives
which are now being sold as octane enhancers are not
recommended. Most of these products contain high
concentrations of methanol.
WARRANTY INFORMATION
CAUTION: Due to the different warranties offered in various regions
and the variety of after-market extended warranties
available, please refer to the warranty package that came
with the vehicle to verify all warranty options.
BASIC NEW CAR WARRANTY
Jeep Corporation warrants to the original purchaser that the
vehicle is free from defects under normal use and service for 12
months or 12,000 miles, whichever comes first.
POWERTRAIN PROTECTION LIMITED WARRANTY
Begins at 12 months or 12,000 miles and lasts for 7 years or
70,000 miles, whichever comes first. Warranty covers Engine,
Transmission, Transfer Case, and Drive Shaft/Drive Axle(s) for RWD &
4WD.
Items not covered include, normal scheduled maintenance,
tune-ups, clutch adjustments, lack of proper maintenance, and vehicles
on which the mileage cannot readily be determined. A 100.00 deductible
on 2WD models and a 150.00 deductible on 4WD models applies to each
repair visit.
Powertrain Warranty also covers cost of towing to nearest
Jeep Dealer if vehicle cannot be driven due to failure of a covered
powertrain part.
ANTI-CORROSION PERFORATION WARRANTY
Warrants the sheet metal parts of the vehicle against
perforation (rust-through) due to corrosion. It covers any body sheet
metal panel for unlimited mileage during the first 36 months. Outer-
body sheet metal panels are covered for 7 years or 100,000 miles,
Page 928 of 1378
PO W ER S TE ER IN G G EN ER AL S ER VIC IN G
1988 J e ep C hero ke e
1988 STEERING
Jeep Power Steering General Servicing
Cherokee, Comanche, Grand Wagoneer, Pickup, Wagoneer,
Wrangler
LUBRICATION
SERVICE INTERVALS
Check fluid at every oil change.
CHECKING FLUID LEVEL
Check fluid level with engine stopped and fluid hot or cold.
Fluid level must be at "FULL-HOT" or "FULL-COLD" mark on dipstick. On
models with remote reservoir, keep fluid level 0.5-1.0" from top of
reservoir with wheels turned fully to left.
RECOMMENDED FLUID TABLE
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Application Part Number
Jeep ............................................. 8993342
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REFILLING & BLEEDING SYSTEM
1) Fill reservoir to correct level. Operate engine until
fluid reaches normal operating temperature. Stop engine. Add fluid (if
necessary). Turn wheels to full left position. Add fluid to reservoir
to fill to "FULL-COLD" mark on dipstick.
2) Start and operate engine at fast idle. Recheck reservoir
level. Add to "FULL-COLD" mark on dipstick. Turn wheels from side to
side without contacting stops. Maintain fluid level just above pump
body.
3) When air is removed, return wheels to straight-ahead
position. Operate engine 2-3 minutes. Stop engine. Road test vehicle.
Recheck fluid level. Level should be at "FULL-HOT" position after
system has stabilized. Add fluid (if necessary). DO NOT overfill.
BELT TENSION (Tension in Lbs. Using Boroughs Tension Gauge)
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Application New Belt Used Belt
Jeep ................ ( 1) 125-155 ............... 90-115
( 1) - Cherokee, Comanche and Wagoneer is 120-140 lbs.
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TROUBLE SHOOTING
Refer to TROUBLE SHOOTING - BASIC PROCEDURES article in the
GENERAL TROUBLE SHOOTING section.
TESTING
Page 943 of 1378
To test crankcase ventilation system, start engine and allow
it to reach normal operating temperature. Make sure engine is idling
at normal curb idle, and perform following checks:
1) Remove PCV valve from its mounting. If valve is
functioning properly, hissing noise will be heard as air passes
through it. Strong vacuum should be felt when your finger is placed
over valve inlet.
2) While finger is over inlet, check for presence of vacuum
leaks in hose line and at all connections. Reinstall PCV valve,
remove crankcase air inlet hose at air cleaner.
3) Loosely hold piece of stiff paper over opening at end of
inlet hose. Paper should be sucked against hose opening with
noticeable force after sufficient time has elapsed for crankcase
pressure to lower (usually about a minute). For final check, stop
engine, remove PCV valve and shake it. Metallic clicking noise should
be heard, indicating valve is free.
4) If system passes both engine running and stopped tests,
it is functioning properly. No further tests are required. If it has
failed either test, replace appropriate components and retest. If it
does not pass on second try, clean system.
MAINTENANCE
Engine may idle slow or rough due to clogged ventilator
valve or system. Therefore, never adjust carburetor idle without
first checking valve and system.
If ventilator valve or system becomes clogged, all crankcase
ventilation will stop, and serious engine damage could result.
Although following manufacturers' service procedures give
specific intervals, it is recommended the crankcase ventilation
system be checked more frequently if vehicle is operated under severe
conditions (extreme dust, prolonged idling, trailer hauling or short
trips in cold weather).
PCV VALVE
Replace PCV valve every 30,000 miles. Valve is located on
rocker arm cover of 4-cylinder, 6-cylinder and V6 models and on
intake manifold of V8 models.
FILTER ELEMENT
Clean filter element every 30,000 miles. Filter is located
inside air cleaner of 4-cylinder, 6-cylinder and V6 models and in oil
filler cap of V8 models.
Page 947 of 1378
![JEEP CHEROKEE 1988 Service Owners Guide \
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EMISSIONS RECALL - OXYGEN SENSOR](/img/16/57037/w960_57037-946.png "JEEP CHEROKEE 1988 Service Owners Guide \
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EMISSIONS RECALL - OXYGEN SENSOR")
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EMISSIONS RECALL - OXYGEN SENSOR REPLACEMENT
Dear Chrysler Vehicle Owner:
Chrysler Corporation and the Environmental Protection Agency has
determined that the oxygen sensor on certain Cherokee, Wagoneer and
Comanche models may be susceptible to failure. Failure of the oxygen
sensor may cause your vehicle to be in violation of Federal Emissions
Standards. For this reason, we are asking you to return your vehicle,
identified by the Vehicle Identification Number on the enclosed form,
to your dealer for a special service repair. This service will be
provided free of charge.
The needed instructions have been sent to all involved dealers. The
service will not hurt your engine performance or fuel economy. To
obtain this service:
* Contact your Jeep/Eagle dealer as soon as possible to make an
appointment for the free service.
* Take the enclosed Owner Notification Form with you at the time of
your appointment and give it to your dealer. The form identifies
the vehicle and recall for which service is required.
* The dealer will inspect and replace the oxygen sensor if
necessary. The service will take about one-half hour, but
additional time may be required depending on how service
appointments are scheduled and processed.
In order to ensure your full protection under the emission warranty
made applicable to your vehicle under Federal law, and your right to
participate in future recalls, it is recommended that you have your
vehicle serviced as soon as possible. Failure to do so could legally
be determined to be a lack of proper maintenance of your vehicle.
Further, without this repair your vehicle may fail a state or local
emission inspection test.
If you have any problem obtaining the service, please contact the
Chrysler Zone Service Office in your area. (It is listed under
"Service Assistance" in your Owner's Manual.} A Zone representative
will arrange for prompt servicing of your vehicle. If you are still
unable to obtain the repair as described in this letter within a
reasonable time, you may also contact the Manufacturers Operations
Division of the Environmental Protection Agency (6405d), 401 M Street
S. W., Washington, D. C. 20460.
We regret any inconvenience this action may cause, but trust you
understand our interest in clean air and in your continuing
satisfaction with our product. Thank you for your prompt attention to
this important matter.
Customer Services Field Operations
Chrysler Corporation
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COMPLETION REPORTING & REIMBURSEMENT
Claims for vehicles which have been serviced must be submitted on
the DIAL System. Claims submitted will be used by Chrysler to record
recall service completions and provide dealer payments.
Page 950 of 1378
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SC HED ULE D S ER VIC ES - G ASO LIN E
1988 J e ep C hero ke e
1984-88 MAINTENANCE
AMC/Jeep Maintenance & Service Intervals - Gasoline
Jeep; Cherokee, Wagoneer
* PLEASE READ THIS FIRST *
NOTE: All SERVICE SCHEDULES are listed for normal service
vehicles. If vehicle is operated under severe service
conditions, see SEVERE SERVICE REQUIREMENTS (PERFORM
W/SERVICE SCHEDULES) for items requiring additional
maintenance.
NOTE: This article contains scheduled maintenance service
information. Fluid types and capacities listed with each
service in this article are only those necessary to perform
that scheduled service. For specifications pertaining to
fluid capacities for the entire vehicle, fuse and circuit
breaker identification, wheel and tire size, battery type,
warranty information, or model identification refer to the
MAINTENANCE INFORMATION article in this section.
CAUTIONS & WARNINGS
AIR CONDITIONING MAINTENANCE
WARNING: NEVER add A/C refrigerant to correct a non-cooling problem
unless pressure gauges are connected to the system by a
certified technician. Lack of cooling may be caused by a
restriction, therefore adding refrigerant can cause a
dangerous pressure rise.
ANTI-LOCK BRAKE SYSTEM (If Equipped)
The anti-lock brake system contains electronic equipment that
can be susceptible to interference caused by improperly installed or
high output radio transmitting equipment. Since this interference
could cause the possible loss of the anti-lock braking capability,
such equipment should be installed by qualified professionals.
On models equipped with anti-lock brake systems, ALWAYS
observe the following cautions:
* DO NOT attempt to bleed hydraulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES Section.
* DO NOT mix tire sizes. As long as tires remain close to the
original diameter, increasing the width is acceptable.
Rolling diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* Use ONLY recommended brake fluids. DO NOT use silicone brake
fluids in an ABS-equipped vehicle.
BATTERY WARNING
WARNING: When battery is disconnected, vehicles equipped with