display JEEP CHEROKEE 1988 Service Repair Manual
[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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Ign. Ignition
In. Inches
Inj. Injector
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"J" ABBREVIATION TABLE
"J" ABBREVIATION TABLE \
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ABBREVIATION DEFINITION
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J/B Junction Block
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"K" ABBREVIATION TABLE
"K" ABBREVIATION TABLE \
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ABBREVIATION DEFINITION
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k/ohms 1000 ohms (kilo as in k/ohms)
kg Kilograms (weight)
kg/cm Kilograms Per Square Centimeter
KAM Keep Alive Memory
KAPWR Keep Alive Power
KM/H Kilometers Per Hour
KOEO Key On Engine Off
KOER Key On Engine Running
KS Knock Sensor
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"L" ABBREVIATION TABLE
"L" ABBREVIATION TABLE \
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ABBREVIATION DEFINITION
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L Liter(s)
L/D Light Duty
LCD Liquid Crystal Display
LED Light Emitting Diode
LH Left Hand
LOS Limited Operation Strategy
LT BLU Light Blue
LT GRN Light Green
LUS Lock-Up Solenoid
Lbs. Pounds
Lt(s). Light(s)
Lugg. Luggage
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"M" ABBREVIATION TABLE
"M" ABBREVIATION TABLE \
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ABBREVIATION DEFINITION
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mA Milliamps
mV Millivolts
mfd. Microfarads
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Brake switch is an input device mounted above the brake
pedal. When brake pedal is operated, brake switch delivers an input
signal to the TCM. The TCM uses input signal for controlling No. 3
valve body solenoid for torque converter lock-up.
NEUTRAL SAFETY SWITCH
NOTE: Neutral safety switch may be referred to as park/neutral
safety switch or gear select switch.
Neutral safety switch is an input device mounted on the
transmission manual valve shaft. Neutral safety switch delivers an
input signal to TCM, indicating transmission manual valve gear
position.
SPEED SENSOR
Speed sensor, mounted in adapter housing or extension
housing, is an input device consisting of speed sensor rotor and speed
sensor. Speed sensor rotor is mounted on transmission output shaft.
Input signal is delivered from speed sensor to TCM with each
revolution of transmission output shaft. The TCM uses input signal for
controlling transmission operation.
THROTTLE POSITION SENSOR (TPS)
The TPS, mounted on throttle body, determines throttle
position and delivers an input signal to TCM. The TCM uses input
signal for controlling transmission upshifts and torque converter
lock-up.
SELF-DIAGNOSTIC SYSTEM
DIAGNOSTIC PROCEDURE
When performing vehicle diagnosis:
* Ensure transmission fluid level is correct and fluid is
neither contaminated nor aerated.
* Ensure shift cable is properly adjusted. Refer to the
appropriate TRANSMISSION SERVICING - A/T article in
this section.
* Ensure battery is fully charged.
* Perform visual inspection, ensuring all electrical
connections at transmission, TCM, throttle position sensor,
neutral safety switch, speed sensor and brake switch are
clean and properly installed.
* Perform TEST 1A - VERIFICATION OF THE COMPLAINT under TROUBLE
SHOOTING CHARTS in this article.
* Repair diagnostic trouble codes in order displayed.
* Always perform TEST 2A - VERIFICATION TEST after repair is
completed. See TEST 2A - VERIFICATION TEST under TROUBLE
SHOOTING CHARTS in this article.
RETRIEVING DIAGNOSTIC TROUBLE CODES
NOTE: Manufacturer recommends using Chrysler's Diagnostic Readout
Box-II (DRB-II) with proper cartridge for system diagnosis.
Other after-market scan tools may be used for system
diagnosis. The following procedure is for DRB-II scan tool
usage. Use manufacturer's instruction for operating the
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DRB-II scan tool. When retrieving diagnostic trouble codes
using DRB-II, you must first enter AW4 MENU and then
retrieve diagnostic trouble codes.
NOTE: Ensure TEST 1A - VERIFICATION OF THE COMPLAINT is performed
when trouble shooting the vehicle. This test checks for
diagnostic trouble codes with vehicle stationary and during
road test. See TEST 1A - VERIFICATION OF THE COMPLAINT under
TROUBLE SHOOTING CHARTS.
NOTE: The DRB-II scan tool can be used in several different modes
using manufacturer's instructions to activate system
components and perform several tests on transmission. See
DRB-II OPERATING MODES .
Entering AW4 MENU
1) Ensure ignition is off. Connect DRB-II to 6-pin
transmission diagnostic connector. See Fig. 3. Transmission diagnostic
connector is located to the right of the steering column on driver's
side of instrument panel above accelerator pedal or below glove box on
passenger's side.
Fig. 3: Diagnostic Connector & Terminals I.D. (Cherokee)
Courtesy of Chrysler Corp.
2) Turn ignition on. Copyright date and diagnostic program
will be briefly displayed. If DRB-II displays an error message,
proceed to DRB-II PROBLEMS & ERROR MESSAGES . The following are
possible error messages that may appear.
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* 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
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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
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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
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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
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2) Connect the DRB-II to the transmission diagnostic
connector. See RETRIEVING FAULT CODES under SELF-DIAGNOSTIC SYSTEM for
diagnostic connector location.
CAUTION: If the vehicle is in 3rd or OD position and feels like it
is stuck in 3rd or jumping from 2-1 or 3-1, perform
TEST 10A - TESTING FOR INTERMITTENT SPEED SENSOR test below.
3) With the DRB-II, perform SYSTEM TEST. See SYSTEM TEST MODE
under DRB-II OPERATING MODES .
4) The DRB-II will instruct you to do some actions during the
System Test. The DRB-II will then look for the action to happen and
automatically go to the next test function. If you perform the
required action and the DRB-II does not move to the next function,
press ENTER. The DRB-II will continue the testing.
5) When the DRB-II states "VEHICLE DRIVE", the vehicle be
must be driven at a speed above 4 miles per hour to ensure accurate
testing of the vehicle speed sensor. Afterwards, the DRB-II will
display any fault codes that may be present.
6) When the system test is complete, if there are any fault
codes present, the DRB-II will automatically display the code(s).
7) There are two types of faults for the transmission
solenoids. They are displayed as "FAULT STORED" and "FAULT PRESENT".
Note that the tests are different in the chart below.
8) Perform the tests shown below in response to the indicated
fault codes.
NOTE: ALWAYS start diagnosis with the most recent code.
CODE-TO-TEST MENU
CODE-TO-TEST MENU \
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Code: Solenoid Affected: Fault Status: Perform:
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None None Affected No Faults Test 2A
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700 Solenoid No. 1 Fault Present Test 4A
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700 Solenoid No. 1 Fault Stored Test 3A
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700 Solenoid No. 2 Fault Present Test 4B
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700 Solenoid No. 2 Fault Stored Test 3A
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700 Solenoid No. 3 Fault Present Test 4C
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700 Solenoid No. 3 Fault Stored Test 3A
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702 Speed Sensor Fault Test 5A
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703 Gear Select Fault Test 6A
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705 TPS Fault Test 7A
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708 Wrong TCU Test 9A
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TEST 2A - VERIFICATION TEST
NOTE: Perform TEST 1A - VERIFICATION OF THE COMPLAINT
before proceeding.
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ELE C TR O STA TIC D IS C HAR G E W AR NIN G - B ASIC IN FO RM ATIO N
1988 J e ep C hero ke e
GENERAL INFORMATION
Electrostatic Discharge (ESD) Warning - Basic Information
All Makes amd Models
* PLEASE READ THIS FIRST *
NOTE: This article is intended for general information purposes
only.
INTRODUCTION
All Electrostatic Discharge (ESD) sensitive components
contain solid state circuits (transistors, diodes, semiconductors)
that may become damaged when contacted with an electrostatic charge.
The following information applies to all ESD sensitive devices. The
ESD symbol shown in Fig. 1 may be used on schematics to indicate which
components are ESD sensitive. See Fig. 1. Although different
manufactures may display different symbols to represent ESD sensitive
devices, the handling and measuring precautions and procedures are the
same.
Fig. 1: Sample ESD Symbol
HANDLING STATIC-SENSITIVE CIRCUITS/DEVICES
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If equipped, the EMR light (some models may use a reminder
flag) reminds vehicle operator that an emission system maintenance is
required. This indicator is activated after a predetermined
time/mileage.
When performing a smog check inspection, ensure EMR indicator
is not activated. On models using an EMR light, light should glow when
ignition switch is turned to ON position and should turn off when
engine is running.
If an EMR flag is present or an EMR light stays on with
engine running, fail vehicle and service or replace applicable
emission-related components. To reset an EMR indicator, refer to
appropriate MAINTENANCE REMINDER LIGHTS in the MAINTENANCE section.
MALFUNCTION INDICATOR LIGHT (MIL)
The Malfunction Indicator Light (MIL) is used to alert
vehicle operator that the computerized engine control system has
detected a malfunction (when it stays on all the time with engine
running). On some models, the MIL may also be used to display trouble
codes.
As a bulb and system check, malfunction indicator light will
glow when ignition switch is turned to ON position and engine is not
running. When engine is started, light should go out.