ACC key position JEEP CHEROKEE 1988 Service Repair Manual

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

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

Vibration can come from many sources. Before overhauling
driveline, check other sources of possible vibration as follows:
* Tires and wheels - Check tire inflation and wheel balance.
Check for foreign objects in tread, damaged tread, mismatched
tread patterns or incorrect tire size.
* Center Bearing - Tighten drive shaft center bearing
mounting bolts. If bearing insulator is deteriorated or
oil-soaked, replace it.
* Engine & Transmission Mountings - Tighten mounting bolts.
If mountings are deteriorated, replace them.
* Drive Shaft - Check drive shaft for damage or dents that
could affect balance. Check for undercoating adhering to
shafts. If present, clean shafts thoroughly.
* Universal Joints - Check for foreign material stuck in
joints. Check for loose bolts and worn bearings.
ADJUSTMENTS
DRIVE SHAFT PHASING
One-Piece Shafts
Check that flanges on either end of drive shaft are in same
plane. Often there are arrows on slip joint and drive shaft to aid in
alignment. See Fig. 2. If flanges are not in same plane, disassemble
universal joint and align.
Fig. 2: Slip Joint Alignment Arrows
Align arrows for proper shaft phasing.
2-Piece Shafts
1) All General Motors models with 32 splines use keys on
spline and slip joint, which can only mate in correct position. On
most models with 2-piece shafts, proper phasing is accomplished by
keys on spline and slip joint.

IG NIT IO N S W IT C H & L O CK C YLIN DER

1988 J e ep C hero ke e
1988 Ignition Switch & Lock Cylinders
JEEP
DESCRIPTION
The ignition switch and lock cylinder is typically mounted on
the steering column and actuated by an ignition key.
SERVICING
To gain access to ignition components on Jeep vehicles, the
steering column must be removed or lowered and the turn signal switch
must be removed.
CAUTION: The lock plate is held by high spring pressure. DO NOT
remove snap ring without using a compressor tool. If the
steering shaft has standard threads, use Compressor Tool
(J-23653); if the shaft has metric threads use Metric
Forcing Screw (J-23653-4).
CAUTION: Special care must be taken to avoid bumping, jolting or
hammering on the steering shaft and gearshift tube.
REMOVAL & INSTALLATION
LOCK CYLINDER
Removal
Turn lock cylinder clockwise 2 detent positions beyond
"OFF-LOCK" position. Compress lock cylinder retaining tab using a thin
bladed screwdriver and remove lock cylinder.
Fig. 1: Typical Column Type Ignition Switch Lock Cylinder Removal
On most vehicles, push in to release lock retainer.
Installation
Insert key in lock. Hold cylinder sleeve, and turn key

clockwise until key stops. Insert cylinder lock into bore with
cylinder tab aligned with keyway in housing. Push cylinder in until it
bottoms. Rotate cylinder counterclockwise to engage lock sector, and
push in until cylinder tab engages in housing groove.
IGNITION SWITCH
Removal
Lower column and remove switch mounting screws. Disconnect
harness connector. Remove switch.
Installation
Move switch slider to "ACC" position. Move switch slider back
2 clicks to "OFF-UNLOCK" position. Insert remote rod in switch slider,
and position switch on column. Do not move slider. Install and tighten
screws.
Fig. 2: Rod-Actuated Ignition Switch

TAILGATE WINDOW REGULATOR & MOTOR
Removal (Grand Wagoneer)
1) Remove carpet (if equipped) and tailgate access cover.
Remove retainers attaching regulator arms to channel. Disengage
regulator arm pins from channel, and raise glass.
2) Carefully support glass in raised position. Disconnect
wiring harness from safety switch. If regulator attaching screws are
covered by sector gears, place a jumper wire between terminals of
safety switch connector.
NOTE: If regulator attaching screws are accessible, remove
regulator attaching screws and regulator.
3) Place key in tailgate switch and operate motor until
regulator attaching screws are accessible. Hold regulator in this
position, and wedge a screw between meshing teeth.
4) Remove regulator attaching screws and regulator. Using a
large screwdriver, release spring tension from tension bracket. Remove
motor attaching screws and motor.
Installation
To install, reverse removal procedure.
SIDE WINDOW MASTER SWITCH
Removal
1) Disconnect battery negative cable. Remove retaining screws
and escutcheon. Remove switch housing screws.
2) Pull switch out to expose wires. Disconnect terminal plate
from switch. Depress retainer clips through holes in switch housing,
and remove switch.
Installation
To install, reverse removal procedure.
FRONT & REAR DOOR REGULATORS & MOTORS
Removal
1) Raise window half way up. Disconnect battery negative
cable. Remove door trim panel and water shield.
2) Insert a drift punch into hole in door inner panel, or use
masking tape to hold window half way up. Remove regulator arm retainer
clip, and remove arm from bottom window channel.
3) Disconnect wires from motor. Remove inner door panel-to-
regulator nuts and bolts. Remove regulator and motor assembly.
Installation
To install, reverse removal procedure.

cylinder. Turn cylinder to "OFF-UNLOCK" position. Disconnect switch
from remote rod. Disconnect harness connectors at switch. Remove
switch.
Installation
Move switch slider to "ACC" position. Engage remote rod in
switch slider. Position switch on column, taking care not to move
slider. Hold key in "ACC" position while pushing switch down slightly
to remove slack in actuator rod. Install attaching screws. Connect
harness connectors.
IGNITION SWITCH
Removal (Comanche & Grand Wagoneer)
Remove lower instrument panel trim panel. Insert key in lock
cylinder. Turn cylinder 2 positions beyond the "OFF-UNLOCK" position.
Disconnect switch from remote rod. Disconnect harness connectors at
switch. Remove switch.
Installation
Move switch slider to "ACC" position. Move switch slider back
2 clicks to "OFF-UNLOCK" position. Engage remote rod in switch slider.
Position switch on column. DO NOT move slider while positioning
switch. Install attaching screws. Connect harness connectors.
Fig. 2: Exploded View of Jeep Steering Column Switch Assemblies
Courtesy of Chrysler Motors
TROUBLE SHOOTING
Refer to TROUBLE SHOOTING - BASIC PROCEDURES article in the
GENERAL TROUBLE SHOOTING section.

1) Remove lower bracket assembly-to-lower bearing support
bolts. On column shift models, remove shift housing cover. On floor
shift models, unsnap and remove shroud extensions. Remove wiring
protector from column jacket.
2) Mount column in vise at capsule bracket. Mount Holding
Fixture (C-4132) onto column. Mount holding fixture and column in
vise.
3) Remove tilt lever. To remove hazard warning knob, push in
knob while unscrewing. Remove ignition key light assembly. Pull knob
off wiper/washer switch assembly. Pull hider up switch lever. Remove 2
sleeve-to-wiper/washer switch retaining screws. Remove sleeve.
4) Rotate shaft in wiper switch fully clockwise. Remove shaft
by pulling straight out of wiper/washer switch. Carefully remove
plastic cover from lock plate. Using Lock Plate Depressor (J-23653-A
for Jeep), depress lock plate. Pry retaining ring from groove.
5) Remove lock plate, canceling cam and upper bearing plate.
Remove switch actuator screw and arm. Remove 3 turn signal switch
attaching screws. Place shift bowl in "LOW" position. Wrap a piece of
tape around wires to prevent snagging when removing switch. Remove
switch and wiring.
6) Remove key light. Place lock cylinder in "LOCK" position.
Insert a small screwdriver into slot next to switch mounting screw
boss. Depress spring latch at bottom of slot. Remove lock.
7) Using a paper clip, remove key warning switch. Bend one
end of clip into a hook. Insert hook into exposed loop of wedge
spring. Pull clip. Remove spring and switch. DO NOT allow spring to
fall into steering column.
8) Remove 3 housing cover screws. Remove housing cover.
Remove wiper/washer switch. Using a punch, press out wiper switch
pivot pin (if necessary). Tilt lever opening shield and dimmer switch
actuator rod may be removed from cap (if necessary).
9) Place column in fully upright position. Using a large
Phillips screwdriver, remove tilt spring retainer. Insert screwdriver
in opening. Push in approximately 3/16". Turn approximately 1/8 turn
clockwise until ears align with grooves in housing. Remove spring and
guide.
10) Remove dimmer switch mounting screws. Remove dimmer
switch. Separate dimmer switch from rod by pulling on rod. Push upper
steering shaft in far enough to remove steering shaft inner race seat
and inner race. With ignition switch in "ACC" position, remove
ignition switch mounting screws and switch. Place Pivot Pin Remover
(J-21854-01 for Jeep) over pivot pin. Thread small portion of screw
firmly into pin.
11) Hold screw from turning with one wrench while turning nut
clockwise with a second wrench to withdraw pivot pin from support.
Remove opposite pivot pin in same manner. Use tilt release lever to
disengage lock shoes. Remove bearing housing assembly by pulling
upward to extend rack fully.
12) Move housing assembly left to disengage rack from
actuator. Rotate housing clockwise to free dimmer switch actuator rod.
Remove activator assembly. Remove coupling from lower end of steering
shaft. Double coupling is retained to shaft with a roll pin. Remove
shaft assembly from upper end.
CAUTION: DO NOT drop or bump steering shaft as plastic pins may shear.
13) Disassemble steering shaft assembly by removing center
spheres and anti-lash springs. See Fig. 9. Remove 4 bolts securing
support to lock plate. Remove support from end of column jacket.
Remove 2 attaching screws and shift gate from support (if necessary).
Dimmer switch is removed with support.

opening. Remove wave washer. Remove bowl from jacket. Remove shift
lever spring from bowl by winding spring up with pliers and pulling
out.
16) By removing spring retaining screw and moving spring
clockwise, remove lock bolt spring. Using a hammer and punch, lightly
tap drive shaft from sector. Remove drive shaft, sector and bolt.
Remove rack, spring and shim (if used). Remove tilt release lever pin.\
17) Relieve load on lever release by holding shoes inward.
Wedge a block between top of shoes and bearing housing. Remove release
lever and release lever spring. Using punch and hammer, remove lock
shoe pin. Remove lock shoes and lock shoe springs.
18) Remove bearings from bearing housing only if they are to
be replaced. Remove separator and ball from bearing. Place housing on
work bench. Using a punch against back surface of race, hammer race
from housing. DO NOT reuse bearings.
Reassembly
1) During reassembly, coat all friction surfaces with
multipurpose grease. Clamp column in vise so that both ends of column
are accessible. Install bearings in bearing housing (if removed).
2) Install lock shoe springs, lock shoes and shoe pin in
bearing housing. Use a .180" rod to line up shoes for pin
installation. With tilt lever opening on left side and with the shoes
facing up, the 4 slot shoe should also face up.
3) Install spring, release lever and pin in bearing housing.
Install drive shaft in housing. Lightly tap sector onto drive shaft
far enough to bottom on shaft. Install lock bolt. Engage lock bolt
with sector cam surface. Install rack and spring. Block tooth on rack
should engage block tooth on sector.
4) Install external tilt release lever. Install bolt spring
and spring retaining screw. Tighten to 35 INCH lbs. (4 N.m). Install
shift lever spring in bowl by winding up with pliers and pushing in.
Slide bowl into jacket. Install wave washer and jacket mounting plate.
5) Work jacket mounting plate into jacket notches by tipping
jacket mounting plate toward bowl hub at 12 o'clock position and under
jacket opening. Slide jacket mounting plate in jacket notches.
Carefully install shift tube in lower end of jacket.
6) Align key in tube with keyway in bowl. Using Puller (J-
23073-01 for Jeep), pull shift tube into bowl. See Fig. 11. DO NOT
push or tap on end of shift tube. By pulling bowl up and compressing
wave washer, install thrust washer and retaining pin.
Fig. 11: Installing Shift Tube on Models With Tilt Wheel
7) Slide dimmer switch actuator rod through hole in support.
Feed rod between bowl and jacket. Install support by aligning notch in
support with notch in jacket. Insert 4 screws through support into