1988 JEEP CHEROKEE key battery

Removal
1) Remove PCV valve hose at valve cover. Remove valve cover
bolts. Using a razor knife, cut RTV sealant along valve cover. Pry
upward on valve cover in areas marked "PRY HERE" near bolt hole areas.
2) Remove valve cover. Alternately loosen each rocker arm
bolt one turn at a time. Remove rocker arm assemblies and push rods.
Mark components for reassembly. Components must be installed in
original location.
Installation
Reverse removal procedures. Install rocker arm components in
original location. Tighten bolts to specification. Apply RTV sealant
on valve cover prior to installation.
VALVE SPRINGS
Valve springs can be removed without removing cylinder head.
Valve Spring Installed Height
Information not available from manufacturer.
HYDRAULIC VALVE LIFTERS
Removal
Remove rocker arms and push rods. See ROCKER ARMS & BRIDGE.
Using Lifter Remover/Installer (J-21884), remove lifter through push
rod openings of cylinder head. Mark lifter location for reassembly
reference. Replace lifters as an assembly if damaged. Internal
components cannot be interchanged.
Inspection
Inspect lifter and camshaft mating surfaces for wear. Check
cylinder block lifter bore diameter. Lifter bore diameter should be
within .9055-.9065" (22.999-23.025 mm). Replace parts as necessary.
Installation
Soak lifter assembly in engine oil supplement prior to
installation. Reverse removal procedures for installation. Install
lifter in original location.
ENGINE FRONT COVER
Removal
1) Disconnect negative battery cable. Remove drive belts, fan
and hub assembly. Remove pulley from vibration damper. Remove
vibration damper retaining bolt and washer.
2) Using Puller (J-21719-01), remove vibration damper and
key. Remove oil pan-to-front cover bolts. Remove cover-to-block
retaining bolts. Remove front cover.
3) Cut oil pan gasket even with face of cylinder block.
Remove gasket from oil pan. Pry crankshaft oil seal from cover.
Installation
1) Ensure all gasket surfaces are clean. Ensure oil slinger
is installed on crankshaft. Apply sealing compound on both sides of
front cover gasket. Install gasket on cylinder block. Replace front
section of oil pan seal with similar section fabricated from new seal.
2) Coat seal with RTV sealant and place in position. Apply
sealant to the joint area of oil pan and cylinder block. Place front
cover on cylinder block. Place Front Cover Seal Installer (J-22248) in\
front cover seal area.
3) Install all retaining bolts. Tighten bolts to

VALVE SPRING
Valve springs can be removed without removing cylinder head.
Valve Spring Installed
For 4.0L the Valve Spring Installed Height Specification is
1.625 inches or 41.29 mm. For the 4.2L the information is not
available from manufacturer.
HYDRAULIC VALVE LIFTER
Removal
Remove cylinder head. See CYLINDER HEAD. Using Lifter
Remover/Installer (J-21884), remove lifter. Mark lifter location for
reassembly reference. Replace lifters as an assembly if damaged.
Internal components cannot be interchanged.
Inspection
Inspect lifter and camshaft mating surfaces for wear. Check
cylinder block lifter bore diameter. Lifter bore diameter should be
within .9055-.9065" (22.999-23.025 mm). Replace parts as necessary.
Installation
Soak lifter assembly in engine oil prior to installation.
Reverse removal procedure for installation. Install lifter in original
location.
ENGINE FRONT COVER
Removal
1) Disconnect negative battery cable. Remove drive belts, fan
and hub assembly. Remove pulley from vibration damper. Remove
vibration damper retaining bolt and washer.
2) Using Puller (J-21719-01), remove vibration damper and
key. Remove alternator and A/C compressor bracket (if equipped).
Remove oil pan-to-front cover bolts. Remove cover-to-block retaining
bolts. Remove front cover.
3) Cut oil pan gasket tabs even with face of cylinder block.
Remove tabs. Remove gasket from oil pan. Pry crankshaft oil seal from
cover.
Installation
1) Ensure all gasket surfaces are clean. Ensure oil slinger
is installed on crankshaft. Apply sealing compound on both sides of
front cover gasket. Install gasket on cylinder block. Replace front
section of oil pan seal with similar section fabricated from new seal.
2) Coat seal with RTV sealant and place in position. Apply
sealant to the joint area of oil pan and cylinder block. Apply engine
oil on seal-to-oil pan contact areas.
3) Place front cover on cylinder block. Place Front Cover
Seal Installer (J-22248) in front cover seal area. Install all
retaining bolts. Tighten bolts to specification.
4) Install front cover oil seal. See FRONT COVER OIL SEAL in
this article. Remove front cover seal installer. Reverse removal
procedure for remaining components. Lubricate vibration damper
retaining bolt with oil prior to installation. Tighten bolts to
specification.
FRONT COVER OIL SEAL
1) Remove vibration damper. Pry seal from front cover. Use

* CARTRIDGE ERROR
* HIGH BATTERY
* KEYPAD TEST FAILURE
* LOW BATTERY
* RAM TEST FAILURE
3) If no error messages appear, display will read as follows
after a few seconds: 1) VEHICLES TESTED, 2) HOW TO USE, 3) CONFIGURE
and 4) SELECT SYSTEM.
4) Select 4) SELECT SYSTEM to enter diagnostic system. Once
in SELECT SYSTEM, select 2) TRANSMISSION to enter transmission.
Display will read 1) EATX and 2) AW4.
5) Select 2) AW4. After a few seconds display will change to
read AW4, VERSION 01. After a few seconds, display will read AW4 MENU,
1) SYSTEM TEST and 2) READ FAULTS. If DOWN ARROW is depressed 3 times,\
display will read as follows: 3) STATE DISPLAY, 4) ACTUATOR TESTS and
5) ADJUSTMENTS.
NOTE: The ACTUATOR TESTS and ADJUSTMENTS cannot be used when
diagnosing the AW-4 transmission.
Retrieving Diagnostic Trouble Codes
1) Select 2) READ FAULTS from AW4 MENU. If no diagnostic
trouble code exists, display will read as follows: AW4 FAULTS, NO
FAULTS DETECTED.
2) If diagnostic trouble code exists, the following message
will be displayed: 1 OF 3 FAULTS. This number will vary depending on
number of diagnostic trouble codes stored in the TCM memory.
3) Diagnostic trouble code and message will be displayed.
Press DOWN ARROW key to display next diagnostic trouble code. To
identify diagnostic trouble code, see DIAGNOSTIC TROUBLE CODE
IDENTIFICATION table.
NOTE: See TROUBLE SHOOTING CHARTS to diagnose faults indicated by
trouble codes.
NOTE: Valve body solenoid diagnostic trouble code 700 may appear
in a FAULT PRESENT or FAULT STORED status. Status will be
displayed along with diagnostic trouble code. Diagnostic
trouble code must be diagnosed depending on the status. See
TEST 1A - VERIFICATION OF THE COMPLAINT under TROUBLE
SHOOTING CHARTS.
DIAGNOSTIC TROUBLE CODE IDENTIFICATION









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Trouble Code Problem Area
700 ( 1) .............................. Valve Body Solenoid
702 ......................................... Speed Sensor
703 ............................... ( 2) Gear Select Switch
705 ............................. Throttle Position Sensor
706 ......................................... Brake Switch
707 ..................................... Wrong TCM Or TCU
( 1) - Trouble code may apply to individual valve body
solenoids. Valve body solenoid may be referred to
as S1 for No. 1, S2 for No. 2 and S3 for No. 3.
( 2) - Gear select switch is the same as the neutral
safety switch.









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CLEARING DIAGNOSTIC TROUBLE CODES

1) Once all diagnostic trouble codes have been obtained,
diagnostic trouble code(s) can be erased from TCM memory by
disconnecting electrical connector from TCM for at least 15 seconds.
CAUTION: DO NOT disconnect battery, as data stored in other vehicle
control modules will be lost.
2) The TCM is located behind right side of instrument panel
on Cherokee. See Fig. 1.
DRB-II OPERATING MODES
NOTE: The DRB-II can be operated in several different modes to
perform various tests. Except for voltmeter/ohmmeter and HOW
TO USE modes, all other operating modes are selected from
AW4 MENU. See ENTERING AW4 MENU under RETRIEVING DIAGNOSTIC
TROUBLE CODES.
VOLTMETER/OHMMETER MODE
To access voltmeter/ohmmeter mode, connect Red volt-ohmmeter
test lead to Red port at top right corner of DRB-II. There are 2
different ports on top of DRB-II; ensure test lead is connected to
proper port. Access voltmeter or ohmmeter mode using manufacturer's
instructions.
NOTE: The DRB-II is grounded through transmission diagnostic
connector and only one test lead is required. When
diagnosing transmission, an external volt-ohmmeter may
sometimes be required.
HOW TO USE MODE
1) This mode gives instructions on DRB-II usage. To enter
this mode, see steps 1) through 4) of ENTERING AW4 MENU under
RETRIEVING DIAGNOSTIC TROUBLE CODES . Select 2) HOW TO USE.
2) A series of screens will be displayed explaining DRB-II
key usage for system diagnosing.
SYSTEM TEST MODE
NOTE: SYSTEM TEST mode consists of a stationary test and a road
test. The SYSTEM TEST mode must be selected from AW4 MENU.
See ENTERING AW4 MENU under RETRIEVING DIAGNOSTIC TROUBLE
CODES.
1) Stationary test monitors transmission system data, current
valve body solenoid failures, switch failures, correct TCM
application, calibration and operation. Road test checks all valve
body solenoids and speed sensor.
2) Technician will be instructed to place shift lever in each
gear position, starting by shifting into 1-2 position. Once
transmission is in Park, brake pedal must be depressed to check brake
switch.
3) After brake switch is checked, technician will be
instructed to slowly depress throttle. DRB-II will display 7 asterisks
( ******* ) corresponding to throttle position. While depressing
accelerator, Throttle Position Sensor (TPS) sweeps through entire
range of positions required by the TCM.
4) A corresponding asterisk will be cleared from DRB-II
display as each throttle position is sensed by TCM. Several attempts
may be required to clear all asterisks from the display, depending on

how fast accelerator is depressed.
5) After throttle position is checked, technician will be
instructed to drive the vehicle. The DRB-II will indicate if a
requested action is seen by the TCM. If technician is requested to
perform a particular operation and TCM does not acknowledge the
action, press ENTER key to continue testing.
6) The TCM will instruct technician to accelerate vehicle at
light throttle to ensure transmission shifts through all gears,
indicating proper valve body solenoid operation.
7) During road test, ensure vehicle can be accelerated slowly
and evenly to allow transmission to enter all gear ranges without
downshifting or braking. If a failure is sensed, a diagnostic trouble
code will be displayed on DRB-II.
NOTE: If TCM senses a failure, control logic activates a specified
valve body solenoid to obtain a certain gear depending on
failure. Because transmission diagnostic trouble codes are
displayed one at a time, multiple diagnostic trouble codes
must be identified by retesting transmission.
STATE DISPLAY MODE
NOTE: STATE DISPLAY mode must be selected from AW4 MENU. See
ENTERING AW4 MENU under RETRIEVING DIAGNOSTIC TROUBLE CODES .
Select 3) STATE DISPLAY on DRB-II.
Module Information
When selecting module information option, the TCM version
will be indicated by a 2-digit number. Information can be used to
verify proper TCM application.
Sensor
1) When selecting sensor option, TPS and RPM indications will
be shown. The TPS indicator will display a 7 segment bar graph,
indicating TPS position and throttle plate angle.
2) A properly operating TPS should indicate 7 segments
through full throttle travel. The RPM indicator will display
transmission output shaft revolutions per minute.
Brake Switch Or Input/Output
Display indicates brake switch status, indicating whether
brake pedal is applied or released. Display also indicates shift lever
position, whether a valve body solenoid is on or off and present
transmission operating gear.
DRB-II PROBLEMS & ERROR MESSAGES
CARTRIDGE ERROR
1) If CARTRIDGE ERROR message is displayed, disconnect DRB-II
from transmission diagnostic connector. DO NOT touch keys on DRB-II
keypad. Reconnect DRB-II to transmission diagnostic connector and note
display.
2) If CARTRIDGE ERROR message is displayed, replace DRB-II
cartridge and proceed with diagnostics. If KEYPAD TEST FAILURE message
is displayed, replace DRB-II and proceed with diagnostics.
HIGH BATTERY
If HIGH BATTERY message is displayed, use external voltmeter
to check battery voltage at battery terminals. If battery voltage is
11.7-13.0 volts, replace DRB-II. If battery voltage is not 11.7-13.0

volts, check charging system.
KEYPAD TEST FAILURE
1) If KEYPAD TEST FAILURE message is displayed, disconnect
DRB-II from transmission diagnostic connector. DO NOT touch keys on
DRB-II keypad. Reconnect DRB-II to transmission diagnostic connector
and note display.
2) If KEYPAD TEST FAILURE message is not displayed, proceed
with diagnostics. If KEYPAD TEST FAILURE message is displayed, replace
DRB-II and proceed with diagnostics.
LOW BATTERY
If LOW BATTERY message is displayed, use external voltmeter
to check battery voltage at battery terminals. If battery voltage is
11.7-13.0 volts, replace DRB-II. If battery voltage is not 11.7-13.0
volts, check charging system.
RAM TEST FAILURE
1) If RAM TEST FAILURE message is displayed, disconnect DRB-
II from transmission diagnostic connector. DO NOT touch keys on DRB-II
keypad. Reconnect DRB-II to transmission diagnostic connector and note
display.
2) If RAM TEST FAILURE message is not displayed, proceed with
diagnostics. If RAM TEST FAILURE message is displayed, replace DRB-II
and proceed with diagnostics. If KEYPAD TEST FAILURE message is
displayed, replace DRB-II and proceed with diagnostics.
COMPONENT TESTING
BRAKE SWITCH
Brake switch is mounted above brake pedal. When brake pedal
is operated, brake switch delivers an input signal to TCM. The TCM
uses input signal for controlling No. 3 valve body solenoid for torque
converter lock-up. No other information is available from
manufacturer.
NOTE: For proper brake switch adjustment, see BRAKE SWITCH under
REMOVAL & INSTALLATION .
NEUTRAL SAFETY SWITCH
NOTE: Neutral safety switch may be referred to as park/neutral or
gear select switch. For proper neutral safety switch
adjustment, see NEUTRAL SAFETY SWITCH under REMOVAL &
INSTALLATION.
Disconnect electrical connector. Note terminal
identification. See Fig. 4. Using ohmmeter, check continuity between
specified terminals in relation to shift lever position. See NEUTRAL
SAFETY SWITCH CONTINUITY SPECIFICATIONS table. Replace neutral safety
switch if continuity is not as specified.
NEUTRAL SAFETY SWITCH CONTINUITY SPECIFICATIONS









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Shift Lever Continuity
Position Between Terminals

CO M PU TE R R ELE A R N P R O CED URES

1988 J e ep C hero ke e
GENERAL INFORMATION
Computer Relearn Procedures
All Models
* PLEASE READ THIS FIRST *
The following general procedures are to be used if
driveability problems are encountered after power loss or battery has
been disconnected. These procedures may provide an aid in eliminating
these problems.
To reduce the possibility of complaints, after any service
which requires battery power to be disconnected, vehicle should be
road tested.
COMPUTER RELEARN PROCEDURES
Vehicles equipped with engine or transmission computers may
require a relearn procedure after vehicle battery is disconnected.
Many vehicle computers memorize and store vehicle operation patterns
for optimum driveability and performance. When vehicle battery is
disconnected, this memory is lost. The computer will use default data
until new data from each key start is stored. As computer memorizes
vehicle operation for each new key start, driveability is restored.
Vehicle computers may memorize vehicles operation patterns for 40 of
more key starts.
Customers often complain of driveability problems during
relearn stage because vehicle acts differently then before being
serviced. Depending on type and make of vehicle and how it is
equipped, the following complaints (driveability problems) may exist:
* Harsh Or Poor Shift Quality
* Rough Or Unstable Idle
* Hesitation Or Stumble
* Rich Or Lean Running
* Poor Fuel Mileage
These symptoms and complaints should disappear after a number
of drive cycles have been memorized. To reduce the possibility of
complaints, after any service which requires battery power to be
disconnected, vehicle should be road tested. If a specific relearn
procedure is not available, the following procedure may be used:
Automatic Transmission
* Set parking brake, start engine in "P" or "N" position.
Warm-up vehicle to normal operating temperature or until
cooling fan cycles.
* Allow vehicle to idle for one minute in "N" position. Select
"D" and allow engine to idle for one minute.
* Accelerate at normal throttle position (20-50%) until vehicle
shifts into top gear.
* Cruise at light to medium throttle.
* Decelerate to a stop, allowing vehicle to downshift, and use
brakes normally.
* Process may be repeated as necessary.
Manual Transmission

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 the COMPUTER RELEARN PROCEDURES article in GENERAL
INFORMATION section.
ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
WARNING: Many solid state electrical components can be damaged by
static electricity (ESD). Some will display a warning label,
but many will not. Discharge personal static electricity by
touching a metal ground point on the vehicle prior to
servicing any ESD sensitive component.
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if
overheated. DO NOT touch glass portion of bulb with bare hands. Eye
protection should be worn when handling or working around halogen
bulbs.
RADIATOR CAP
CAUTION: Always disconnect the fan motor when working near the
radiator fan. The fan is temperature controlled and could
start at any time even when the ignition key is in the OFF
position. DO NOT loosen or remove radiator cap when cooling
system is hot.