charging JEEP CHEROKEE 1988 Service User Guide
[x] Cancel search | Manufacturer: JEEP, Model Year: 1988, Model line: CHEROKEE, Model: JEEP CHEROKEE 1988Pages: 1378, PDF Size: 19.9 MB
Page 201 of 1378
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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hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... (1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ ( 2) Require replacement.
Leaking (vacuum) ........ A .. Require repair or replacement.
Linkage bent,
affecting performance .. A ... Require repair or replacement
of linkage.
Linkage bent, not
affecting performance .. 2 ... Suggest repair or replacement
of linkage.
Linkage binding,
affecting performance .. A ... Require repair or replacement
of linkage.
Linkage binding, not
affecting performance .. 1 .. Suggest repair or replacement
of linkage.
Linkage broken .......... A ... Require repair or replacement
of linkage.
Linkage loose, affecting
performance ............ A ... Require repair or replacement
of linkage.
Linkage loose, not
affecting performance .. 1 ... Suggest repair or replacement
of linkage.
Linkage missing ......... C ............ Require replacement.
Linkage noisy ........... 2 .. Suggest repair or replacement.
Missing ................. C ............ Require replacement.
Noisy ................... 2 .. Suggest repair or replacement.
Out of adjustment ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.
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AIR BAGS
For all air bag components and conditions, refer to vehicle
manufacturer's specifications for diagnosis and parts replacement.
ALTERNATORS AND GENERATORS
NOTE: If components have been added that increase vehicle
electrical load requirement (for example, sound systems,
air conditioning, alarm systems, etc.), charging system
output must meet the increased demand.
ALTERNATOR AND GENERATOR INSPECTION
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Condition Code Procedure
Alternator output meets
OEM specification but is
insufficient for add-on
Page 526 of 1378
Post (top or side)
loose .................. A ............ Require replacement.
Post (top or side) melted,
affecting performance .. A ........... (6) Require repair or
replacement.
Post (top or side) melted,
not affecting
performance ............ 2 ........... ( 6) Suggest repair or
replacement.
Specific gravity low .... B .......... ( 7) Further inspection
required.
State of charge low ..... A .......... ( 7) Further inspection
required.
Top dirty ............... 2 ....... Suggest cleaning battery.
Top wet ................. A ... ( 8) Require cleaning battery.
Further inspection required.
Vent cap loose .......... A ... Require repair or replacement
of vent cap.
Vent cap missing ........ C .......... Require replacement of
vent cap.
( 1) - DO NOT attempt to charge a frozen battery. Allow battery
to warm thoroughly and then performance-test. If battery
fails performance test, require replacement.
( 2) - No service suggested or required unless the battery fails
performance test, in which case, require replacement.
( 3) - This phrase refers to a battery that fails to either
accept and/or retain a charge using appropriate times
listed in the Battery Charging Guide of the BCI Service
Manual, battery charger operating manual, or battery
manufacturer's specifications.
( 4) - Determine cause of low fluid level. Refill to proper
level(s) with water (distilled water preferred). Recharge
battery and performance-test. If battery does not meet
specifications, require replacement. If battery is sealed
type (non-removable filler caps), require replacement.
( 5) - The battery may meet battery manufacturer's specifications
but test below the minimum specification defined by the
vehicle's OEM for that vehicle.
( 6) - Determine cause and correct prior to repair or replacement
of part.
( 7) - Recharge and test to manufacturer's specifications. If
battery fails performance test, require replacement.
( 8) - Check fluid level and adjust to manufacturer's
specification. Suggest checking charging system for
proper operation.
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BATTERY CABLES
See BATTERY CABLES, WIRES AND CONNECTORS .
BATTERY CABLES, WIRES AND CONNECTORS
BATTERY CABLE, WIRE AND CONNECTOR INSPECTION \
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Condition Code Procedure
Application incorrect ... B .. Require repair or replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
Page 550 of 1378
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Wire lead burned ........ A .. Require repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Malfunctioning includes inoperative, intermittent
operation, or failure to perform all functions.
( 3) - Make sure poor sound quality is not caused by
ignition/charging system or other forms of electrical
interference.
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RELAY BOXES
RELAY BOX INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Broken, affecting
performance ............ A ............ Require replacement.
Broken, not affecting
performance ............ .. ........ No service suggested or
required.
Burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Burned, not affecting
performance ............ 2 ........... ( 1) Suggest repair or
replacement.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... ( 1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Cover missing ........... C ... Require replacement of cover.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Melted, affecting
performance ............ A ........ ( 1) Require replacement.
Melted, not affecting
Page 553 of 1378
See HORNS AND SIRENS .
SOLENOIDS
See ACTUATOR MOTORS (SOLENOIDS) (ELECTRIC) .
NOTE: For starter solenoids that are integral to the starter
assembly, see STARTERS.
NOTE: For starter relays, see RELAYS.
SPEAKERS AND MICROPHONES
SPEAKER AND MICROPHONE INSPECTION \
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Condition Code Procedure
Application incorrect ... A ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... ( 1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Inoperative ............. B ........... ( 2) Require repair or
replacement. Further
inspection required.
Membrane torn ........... A ............ Require replacement.
Missing ................. C ............ Require replacement.
Polarity reversed ....... A ................. Require repair.
Sound quality poor ...... A ........... ( 3) Require repair or
replacement. Further
inspection required.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.
( 3) - Make sure poor sound quality is not caused by
ignition/charging system or other forms of electrical
Page 558 of 1378
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector melted ........ A ........... (1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Malfunctioning .......... A ........... ( 2) Require repair or
replacement.
Missing ................. C ............ Require replacement.
Skips ................... A .. Require repair or replacement.
Sound quality poor ...... A ........... ( 3) Require repair or
replacement.
Speed incorrect ......... A .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Wire lead burned ........ A .. Require repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Malfunctioning includes inoperative, intermittent
operation, or failure to perform all functions.
( 3) - Make sure poor sound quality is not caused by
ignition/charging system or other forms of electrical
interference.
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TENSIONERS
TENSIONER INSPECTION \
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Condition Code Procedure
Alignment incorrect ..... B .. Require repair or replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
Page 561 of 1378
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Wire lead burned ........ A .. Require repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Malfunctioning includes inoperative, intermittent
operation, or failure to perform all functions.
( 3) - Make sure poor sound quality is not caused by
ignition/charging system or other forms of electrical
interference.
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TRANSDUCERS
TRANSDUCER INSPECTION \
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... ( 1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Drive mechanism damaged,
affecting performance .. A ........... ( 2) Require repair or
replacement.
Drive mechanism damaged,
not affecting
performance ............ 2 ........... ( 2) Suggest repair or
replacement.
Inoperative ............. A ........... ( 3) Require repair or
replacement.
Leaking
(vacuum/fluid/air) ..... A ............ Require replacement.
Linkage bent, affecting
performance ............ A ... Require repair or replacement
of linkage.
Linkage bent, not
affecting performance .. .. ........ No service suggested or
required.
Linkage binding, affecting
performance ............ A ... Require repair or replacement
of linkage.
Linkage binding, not
affecting performance .. 2 ... Suggest repair or replacement
of linkage.
Linkage broken .......... A ... Require repair or replacement
Page 673 of 1378
Post (top or side) burned,
affecting performance .. A ........... (6) Require repair or
replacement.
Post (top or side) burned,
not affecting
performance ............ 2 ........... ( 6) Suggest repair or
replacement.
Post (top or side)
corroded, affecting
performance ............ A ................. Require repair.
Post (top or side)
corroded, not affecting
performance ............ 2 ................. Suggest repair.
Post (top or side)
loose .................. A ............ Require replacement.
Post (top or side)
melted, affecting
performance ............ A ........... ( 6) Require repair or
replacement.
Post (top or side)
melted, not affecting
performance ............ 2 ........... ( 6) Suggest repair or
replacement.
Specific gravity low .... B .......... ( 7) Further inspection
required.
State of charge low ..... A .......... ( 7) Further inspection
required.
Top dirty ............... 2 ....... Suggest cleaning battery.
Top wet ................. A ... ( 8) Require cleaning battery.
Further inspection required.
Vent cap loose .......... A ... Require repair or replacement
of vent cap.
Vent cap missing ........ C ..... Require replacement of vent
cap.
( 1) - DO NOT attempt to charge a frozen battery. Allow
battery to warm thoroughly and then performance-test.
If battery fails performance test, require replacement.
( 2) - No service suggested or required unless the battery
fails performance test, in which case, require
replacement.
( 3) - This phrase refers to a battery that fails to either
accept and/or retain a charge using appropriate times
listed in the Battery Charging Guide of the BCI Service
Manual, battery charger operating manual, or battery
manufacturer's specifications.
( 4) - Determine cause of low fluid level. Refill to proper
level(s) with water (distilled water preferred).
Recharge battery and performance-test.
( 5) - The battery may meet battery manufacturer's
specifications but test below the minimum
specification defined by the vehicle's OEM for
that vehicle.
( 6) - Determine cause and correct prior to repair or
replacement of part.
( 7) - Recharge and test to manufacturer's specifications.
If battery fails performance test, require replacement.
( 8) - Check fluid level and adjust to manufacturer's
specification. Suggest checking charging system
for proper operation.
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BATTERY CABLES, WIRES AND CONNECTORS
Page 777 of 1378
* Battery connections and specific gravity.
* Engine Compression.
* Electrical connections on components and sensors.
* Emission control devices.
* Ignition system.
* All vacuum line, fuel hose and pipe connections.
General Precautions
In order to prevent injury to operator or damage to system
or component parts, use following techniques:
* Turn ignition off before connecting or disconnecting any
component parts.
* DO NOT apply DC voltage greater than 12 volts or any AC voltage
to system.
* Disconnect battery cables before charging.
* Remove ECU from vehicle if ambient temperature could exceed
176
F (80C).
* DO NOT modify or circumvent any system functions.
SYSTEM TESTING
Fuel System Test
WARNING: Always relieve residual fuel pressure in fuel delivery
system before opening system. To prevent chance of personal
injury, cover fittings with shop towel while disconnecting
fittings.
1) Remove cap from pressure test port located in fuel rail.
See Fig. 3 . Connect Fuel Pressure Gauge (J-34730-1) to pressure
fitting.
2) Start vehicle. Pressure should be approximately 31 psi
(2.1 kg/cm
) with vacuum hose connected to pressure regulator and
39 psi (2.6 kg/cm ) with vacuum hose removed from pressure
regulator.
3) Check fuel pump flow rate. A good fuel pump will deliver
at least one liter of fuel per minute with fuel return line pinched
off. If fuel pump does not pump adequately, inspect fuel system for a
plugged fuel filter or filter sock.
Fig. 3: Fuel System Pressure Test Components
Courtesy of Chrysler Motors.
4) Fuel pump flow rate can be checked by connecting one end
of an old A/C gauge hose to fuel test port on fuel rail and inserting
Page 798 of 1378
3) Return throttle plate to closed throttle position (M/T),
or maintain throttle plate in closed position (A/T). Check sensor
output voltage. To do so, disconnect voltmeter positive lead from
terminal "C" and connect it to terminal "A" (top) of sensor (M/T), o\
r
from terminal "A" and connect it to terminal "B" (A/T).
4) Move and hold throttle plate in wide open throttle
position (M/T), or maintain throttle plate in closed position (A/T).\
Ensure throttle linkage contacts stop. Note voltmeter reading. Output
voltage should be 4.6-4.7 volts (M/T), or .2 volt (A/T).
5) If output voltage is incorrect, loosen bottom sensor
retaining screw and pivot sensor in adjustment slot for a coarse
adjustment. Loosen top sensor retaining screw for fine adjustments.
Tighten screws after adjustment.
TESTING & TROUBLE SHOOTING
PRELIMINARY CHECKS & PRECAUTIONS
Subsystem Checks
Before testing fuel injection system for cause of
malfunction, check that following subsystems and components are in
good operating condition:
* Battery and charging system.
* Engine state of tune.
* Emission control devices.
* Fuel system pressure and delivery volume.
* Wiring connectors at components.
General Precautions
In order to prevent injury to operator or damage to system
or component parts, use following techniques:
* Turn ignition off before connecting or disconnecting any
component parts.
* DO NOT apply DC voltage greater than 12 volts or any AC voltage
to system.
* Disconnect battery cables before charging.
* Remove ECU from vehicle if ambient temperature could exceed
176
F (80C).
* DO NOT modify or circumvent any system functions.
RESISTANCE & VOLTAGE TESTS
MAT Sensor
1) Disconnect wiring from MAT sensor. Using high input
impedance digital volt-ohmmeter (DVOM), check resistance of sensor.
Resistance should be less than 1000 ohms when engine is warm. Replace
sensor if it does not fall within range shown in
TEMPERATURE-TO-RESISTANCE VALUES table.
2) Test resistance in wiring harness between ECU connector
terminal No. 32 and sensor connector terminal. Also test resistance
in wiring harness between ECU harness terminal No. 14 and sensor
connector terminal. See Fig. 5. Repair wiring harness if open circuit
or resistance greater than one ohm is indicated.
Coolant Temperature Sensor (CTS)
1) Disconnect wiring harness from CTS. Using high input
impedance digital volt-ohmmeter (DVOM), check resistance of sensor.
Resistance should be less than 1000 ohms when engine is warm. Replace
sensor if it does not fall within range shown in
TEMPERATURE-to-RESISTANCE VALUES table.