2002 JEEP LIBERTY turn

indicator on and off. If the SKIS indicator flashes
upon ignition On or stays on solid after the bulb test,
it signifies a SKIS fault. If the SKIM detects a sys-
tem malfunction and/or the SKIS has become inoper-
ative, the SKIS indicator will stay on solid. If the
SKIM detects an invalid key or if a key transponder-
related fault exists, the SKIS indicator will flash. If
the vehicle is equipped with the Customer Learn
transponder programming feature, the SKIM will
also send messages to the EMIC to flash the SKIS
indicator and to generate a single audible chime tone
whenever the Customer Learn programming mode is
being utilized. (Refer to 8 - ELECTRICAL/VEHICLE
THEFT SECURITY - STANDARD PROCEDURE -
SENTRY KEY TRANSPONDER PROGRAMMING).
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store fault information in the form of Diagnostic
Trouble Codes (DTC's) in SKIM memory if a system
malfunction is detected. The SKIM can be diagnosed,
and any stored DTC's can be retrieved using a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) If the vehicle is equipped with the optional tilt
steering column, move the tilt steering column to the
fully lowered position and leave the tilt release lever
in the released (down) position.
(3) From below the steering column, remove the
two screws that secure the lower shroud to the upper
shroud (Fig. 11).
(4) Using hand pressure, push gently inward on
both sides of the upper shroud near the parting line
between the upper and lower shrouds to release thesnap features that secure the two halves to each
other.
(5) Remove both the upper and lower shrouds from
the steering column.
(6) Disconnect the instrument panel wire harness
connector for the SKIM from the module connector
receptacle.
(7) The SKIM mounting bracket features a clip for-
mation that secures the SKIM to the right lower
flange of the steering column jacket. Pull downward
on the connector end of the SKIM mounting bracket
to release this clip from the steering column jacket.
(8) Rotate the SKIM and its mounting bracket
downwards and then to the side away from the steer-
ing column to slide the SKIM antenna ring from
around the ignition switch lock cylinder housing. Lift
the multi-function switch upward off of the upper
steering column housing far enough to remove the
SKIM antenna ring formation from between the igni-
tion key release button and the multi-function switch
housing.
(9) Remove the SKIM from the steering column.
Fig. 11 Sentry Key Immobilizer Module Remove/
Install
1 - UPPER SHROUD
2 - STEERING COLUMN
3 - WIRE HARNESS CONNECTOR
4 - SENTRY KEY IMMOBILIZER MODULE
5 - LOWER SHROUD
6 - SCREW (2)
7 - IGNITION LOCK CYLINDER HOUSING
KJELECTRONIC CONTROL MODULES 8E - 17
SENTRY KEY IMMOBILIZER MODULE (Continued)

Certain mechanical problems within the input
clutch assembly (broken return springs, out of posi-
tion snap rings, excessive clutch pack clearance,
improper assembly, etc.) can cause inadequate or out-
of-range element volumes. Also, defective Input/Out-
put Speed Sensors and wiring can cause these
conditions. The following chart identifies the appro-
priate clutch volumes and when they are monitored/
updated:
CLUTCH VOLUMES
Clutch When UpdatedProper Clutch
Volume
L/R2-1 or 3-1
downshift45 to 134
2C3-2 kickdown
shift25 to 85
OD 2-3 upshift 30 to 100
CLUTCH VOLUMES
4C 3-4 upshift 30 to 85
UD4-3 kickdown
shift30 to 100
SHIFT SCHEDULES
As mentioned earlier, the TCM has programming
that allows it to select a variety of shift schedules.
Shift schedule selection is dependent on the follow-
ing:
²Shift lever position
²Throttle position
²Engine load
²Fluid temperature
²Software level
As driving conditions change, the TCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Schedule Condition Expected Operation
Extreme ColdOil temperature below -16É F -Park, Reverse, Neutral and 1st and
3rd gear only in D position, 2nd
gear only in Manual 2 or L
-No EMCC
Super ColdOil temperature between -12É F and
10É F- Delayed 2-3 upshift
- Delayed 3-4 upshift
- Early 4-3 coastdown shift
- High speed 4-2, 3-2, 2-1 kickdown
shifts are prevented
-Shifts at high throttle openings willl
be early.
- No EMCC
ColdOil temperature between 10É F and
36É F-Shift schedule is the same as
Super Cold except that the 2-3
upshifts are not delayed.
WarmOil temperature between 40É F and
80É F- Normal operation (upshift,
kickdowns, and coastdowns)
- No EMCC
HotOil temperature between 80É F and
240É F- Normal operation (upshift,
kickdowns, and coastdowns)
- Normal EMCC operation
8E - 20 ELECTRONIC CONTROL MODULESKJ
TRANSMISSION CONTROL MODULE (Continued)

controls the ground for the heated seat switch indi-
cator lamps (LED's).
When a heated seat switch (Driver or Passenger) is
depressed a signal is received by the heated seat
module, the module energizes the proper indicator
LED (Low or High) in the switch by grounding the
indicator lamp circuit to indicate that the heated seat
system is operating. At the same time, the heated
seat module energizes the selected heated seat sensor
circuit and the sensor provides the module with an
input indicating the surface temperature of the
selected seat cushion.
The Low heat set point is about 36É C (96.8É F),
and the High heat set point is about 42É C (107.6É F).
If the seat cushion surface temperature input is
below the temperature set point for the selected tem-
perature setting, the heated seat module energizes
an N-channel Field Effect Transistor (N-FET) within
the module which energizes the heated seat elements
in the selected seat cushion and back. When the sen-
sor input to the module indicates the correct temper-
ature set point has been achieved, the module
de-energizes the N-FET which de-energizes the
heated seat elements. The heated seat module will
continue to cycle the N-FET as needed to maintain
the selected temperature set point.
If the heated seat module detects a heated seat
sensor value input that is out of range or a shorted
or open heated seat element circuit, it will notify the
vehicle operator or the repair technician of this con-
dition by flashing the High and/or Low indicator
lamps in the affected heated seat switch. Refer to
Diagnosis and Testing Heated Seat Systemin
Heated Systems for flashing LED diagnosis and test-
ing procedures. Refer toDiagnosis and Testing
Heated Seat Modulein this section for heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE
If a heated seat fails to heat and one or both of the
indicator lamps on a heated seat switch flash, refer
toHeated Seat System Diagnosis and Testingin
Heated Systems for flashing LED failure identifica-
tion. Refer toWiring Diagramsin for complete
heated seat system wiring diagrams.
(1) Remove the heated seat module from its
mounting location (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/MEMORY HEATED
SEAT/MIRROR MODULE - REMOVAL).NOTE: ANY RESISTANCE VALUES (OHMSV) GIVEN
IN THE FOLLOWING TEXT ARE SUPPLIED USING
THE AUTOMATIC RANGE GENERATED BY A
FLUKETAUTOMOTIVE METER. IF ANOTHER TYPE
OF MEASURING DEVICE IS USED THE VALUES
GENERATED MAY NOT BE THE SAME AS THE
RESULTS SHOWN HERE, OR MAY HAVE TO BE
CONVERTED TO THE RANGE USED HERE.
RIGHT SEAT HEATER INOPERATIVE
(1) If a heated seat heats but one or both indicator
lamps (LED's) on the heated seat switch fail to illu-
minate, check the driver circuit with the inoperative
LED for a short to ground. If OK, replace the heated
seat switch. If NOT OK repair the short to ground as
required and than replace the heated seat switch.
NOTE: IF THE RIGHT SEAT CUSHION IS ALREADY
WARM THE FOLLOWING STEP WILL NOT PROVE
CONCLUSIVE.
(2) Back-probe the heated seat module wire har-
ness connector (Fig. 15), do not disconnect. Check
cavity #3 for battery voltage when the right heated
seat switch is turned ªONº, voltage should be
present, If OK go to Step 3 If NOT OK, test the right
heated seat switch (Refer to 8 - ELECTRICAL/
HEATED SEATS/PASSENGER HEATED SEAT
SWITCH - DIAGNOSIS AND TESTING). If the
switch tests OK, check for continuity between the
switch and control module on the MUX circuit, If OK
replace the heated seat control module. If NOT OK,
repair the open or shorted MUX circuit as required.
Fig. 15 Heated Seat Module Electrical Connector
8E - 22 ELECTRONIC CONTROL MODULESKJ
HEATED SEAT MODULE (Continued)

NOTE: BE CERTAIN THE BATTERY IS FULLY
CHARGED BEFORE TESTING. FAILURE TO DO SO
CAN RESULT IN INCORRECT READINGS.
(3) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #10
for battery voltage, while observing the voltmeter
depress the right heated seat switchlowsetting
twice, voltage should toggle between approx.12v and
8v, If OK go to Step 4. If NOT OK check for continu-
ity between the switch and control module on the low
heat driver circuit, If OK replace the heated seat con-
trol module.
(4) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #11
for battery voltage, while observing the voltmeter
depress the right heated seat switchhighsetting
twice, voltage should toggle between approx.12v and
8v, If OK go to Step 5. If NOT OK check for continu-
ity between the switch and control module on the
high heat driver circuit, If OK replace the heated
seat control module.
(5) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #2 for
approx. 5v, voltage should be present, If OK go to
Step 6. If NOT OK replace the heated seat control
module.
(6) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #7 for
a range in voltage from 1.72v (warm seat) ± 3.0v
(cold seat). It should be within this range, If OK
replace the heated seat module. If NOT OK test the
Heated Seat Sensor. If NOT OK, replace the right
heated seat element and sensor assembly. If the
heated seat sensor tests OK, check for continuity
between the right heated seat cushion connector and
control module connector on the 5v supply circuit, If
NOT OK, repair the open or shorted 5v supply circuit
as required. If OK check for continuity between the
right heated seat cushion connector and control mod-
ule connector on the temperature sensor input cir-
cuit. If NOT OK, repair the open or shorted
temperature sensor input circuit as required. If OK
replace the heated seat control module.
LEFT SEAT HEATER INOPERATIVE
(1) If a heated seat heats but one or both indicator
lamps (LED's) on the heated seat switch fail to illu-
minate, check the driver circuit with the inoperative
LED for a short to ground. If OK, replace the heated
seat switch. If NOT OK repair the short to ground as
required and than replace the heated seat switch.
NOTE: IF THE LEFT SEAT CUSHION IS ALREADY
WARM THE FOLLOWING STEP WILL NOT PROVE
CONCLUSIVE.(2) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #5 for
battery voltage when the left heated seat switch is
turned ªONº, voltage should be present, If OK go to
Step 3 If NOT OK, test the left heated seat switch
(Refer to 8 - ELECTRICAL/HEATED SEATS/
DRIVER HEATED SEAT SWITCH - DIAGNOSIS
AND TESTING). If the switch tests OK, check for
continuity between the switch and control module on
the MUX circuit, If OK replace the heated seat con-
trol module. If NOT OK, repair the open or shorted
MUX circuit as required.
(3) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #12
for battery voltage, while observing the voltmeter
depress the left heated seat switchlowsetting twice,
voltage should toggle between approx.12v and 8v, If
OK go to Step 4. If NOT OK check for continuity
between the switch and control module on the low
heat driver circuit, If OK replace the heated seat con-
trol module.
(4) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #14
for battery voltage, while observing the voltmeter
depress the left heated seat switchhighsetting
twice, voltage should toggle between approx.12v and
8v, If OK go to Step 5. If NOT OK check for continu-
ity between the switch and control module on the
high heat driver circuit, If OK replace the heated
seat control module.
(5) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #2 for
approx. 5v, 5 voltage should be present, If OK go to
Step 6. If NOT OK replace the heated seat control
module.
(6) Back-probe the heated seat module wire har-
ness connector, do not disconnect. Check cavity #8 for
a range in voltage from 1.72v (warm seat) ± 3.0v
(cold seat). It should be within this range, If OK
replace the heated seat control module. If NOT OK,
test the Heated Seat Sensor. If NOT OK, replace the
left heated seat element and sensor assembly. If the
heated seat sensor tests OK, check for continuity
between the left heated seat cushion connector and
control module connector on the 5v supply circuit, If
NOT OK, repair the open or shorted 5v supply circuit
as required. If OK check for continuity between the
left heated seat cushion connector and control mod-
ule connector on the temperature sensor input cir-
cuit. If NOT OK, repair the open or shorted
temperature sensor input circuit as required. If OK
replace the heated seat control module.
KJELECTRONIC CONTROL MODULES 8E - 23
HEATED SEAT MODULE (Continued)

²Battery Thermal Guard- The battery thermal
guard insulates the battery to protect it from engine
compartment temperature extremes.
²Battery Tray- The battery tray provides a
secure mounting location in the vehicle for the bat-
tery and an anchor point for the battery holddown
hardware.
For battery system maintenance schedules and
jump starting procedures, see the owner's manual in
the vehicle glove box. Optionally, refer to Lubrication
and Maintenance for the proper battery jump start-
ing procedures. While battery charging can be consid-
ered a maintenance procedure, the battery charging
procedures and related information are located in the
service procedures section of this service manual.
This was done because the battery must be fully-
charged before any battery system diagnosis or test-
ing procedures can be performed. Refer to Standard
Procedures for the proper battery charging proce-
dures.
OPERATION
The battery system is designed to provide a safe,
efficient, reliable and mobile means of delivering and
storing electrical energy. This electrical energy is
required to operate the engine starting system, as
well as to operate many of the other vehicle acces-
sory systems for limited durations while the engine
and/or the charging system are not operating. The
battery system is also designed to provide a reserve
of electrical energy to supplement the charging sys-
tem for short durations while the engine is running
and the electrical current demands of the vehicle
exceed the output of the charging system. In addition
to delivering, and storing electrical energy for the
vehicle, the battery system serves as a capacitor and
voltage stabilizer for the vehicle electrical system. It
absorbs most abnormal or transient voltages caused
by the switching of any of the electrical components
or circuits in the vehicle.
DIAGNOSIS AND TESTING - BATTERY SYSTEM
The battery, starting, and charging systems in the
vehicle operate with one another and must be testedas a complete system. In order for the engine to start
and the battery to maintain its charge properly, all of
the components that are used in these systems must
perform within specifications. It is important that
the battery, starting, and charging systems be thor-
oughly tested and inspected any time a battery needs
to be charged or replaced. The cause of abnormal bat-
tery discharge, overcharging or early battery failure
must be diagnosed and corrected before a battery is
replaced and before a vehicle is returned to service.
The service information for these systems has been
separated within this service manual to make it eas-
ier to locate the specific information you are seeking.
However, when attempting to diagnose any of these
systems, it is important that you keep their interde-
pendency in mind.
The diagnostic procedures used for the battery,
starting, and charging systems include the most
basic conventional diagnostic methods, to the more
sophisticated On-Board Diagnostics (OBD) built into
the Powertrain Control Module (PCM). Use of an
induction-type milliampere ammeter, a volt/ohmme-
ter, a battery charger, a carbon pile rheostat (load
tester) and a 12-volt test lamp may be required. All
OBD-sensed systems are monitored by the PCM.
Each monitored circuit is assigned a Diagnostic Trou-
ble Code (DTC). The PCM will store a DTC in elec-
tronic memory for any failure it detects. Refer to
Charging System for the proper charging system on-
board diagnostic test procedures.
MIDTRONICS ELECTRICAL SYSTEM TESTER
The Midtronicstautomotive battery and charging
system tester is designed to help the dealership tech-
nicians diagnose the cause of a defective battery or
charging system. Follow the instruction manual sup-
plied with the tester to properly diagnose a vehicle. If
the instruction manual is not available refer to the
standard procedure in this section, which includes
the directions for using the midtronics electrical sys-
tem tester.
8F - 2 BATTERY SYSTEMKJ
BATTERY SYSTEM (Continued)

battery reduces battery gassing and water loss, at
normal charge and discharge rates. Therefore, the
battery should not require additional water in nor-
mal service. If the electrolyte level in this battery
does become low, water must be added. However,
rapid loss of electrolyte can be caused by an over-
charging condition. Be certain to diagnose the charg-
ing system after replenishing the water in the
battery for a low electrolyte condition and before
returning the vehicle to service. Refer to Charging
System for the proper charging system diagnosis and
testing procedures.
DIAGNOSIS AND TESTING - BATTERY
The battery must be completely charged and the
top, posts and terminal clamps should be properly
cleaned and inspected before diagnostic procedures
are performed. Refer to Battery System Cleaning for
the proper cleaning procedures, and Battery System
Inspection for the proper battery inspection proce-
dures. Refer to Standard Procedures for the proper
battery charging procedures.
WARNING: IF THE BATTERY SHOWS SIGNS OF
FREEZING, LEAKING OR LOOSE POSTS, DO NOT
TEST, ASSIST-BOOST, OR CHARGE. THE BATTERY
MAY ARC INTERNALLY AND EXPLODE. PERSONAL
INJURY AND/OR VEHICLE DAMAGE MAY RESULT.
WARNING: EXPLOSIVE HYDROGEN GAS FORMS IN
AND AROUND THE BATTERY. DO NOT SMOKE,
USE FLAME, OR CREATE SPARKS NEAR THE BAT-
TERY. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT.
WARNING: THE BATTERY CONTAINS SULFURIC
ACID, WHICH IS POISONOUS AND CAUSTIC. AVOID
CONTACT WITH THE SKIN, EYES, OR CLOTHING.
IN THE EVENT OF CONTACT, FLUSH WITH WATER
AND CALL A PHYSICIAN IMMEDIATELY. KEEP OUT
OF THE REACH OF CHILDREN.
WARNING: IF THE BATTERY IS EQUIPPED WITH
REMOVABLE CELL CAPS, BE CERTAIN THAT EACH
OF THE CELL CAPS ARE IN PLACE AND TIGHT
BEFORE THE BATTERY IS RETURNED TO SER-
VICE. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT FROM LOOSE OR MISSING
CELL CAPS.
The condition of a battery is determined by two cri-
teria:
²State-Of-Charge- This can be determined by
checking the specific gravity of the battery electrolyte
(built-in indicator test or hydrometer test), or bychecking the battery voltage (open-circuit voltage
test).
²Cranking Capacity- This can be determined
by performing a battery load test, which measures
the ability of the battery to supply high-amperage
current.
First, determine the battery state-of-charge. This
can be done in one of three ways. If the battery has a
built-in test indicator, perform the built-in indicator
test to determine the state-of-charge. If the battery
has no built-in test indicator but does have remov-
able cell caps, perform the hydrometer test to deter-
mine the state-of-charge. If the battery cell caps are
not removable, or a hydrometer is not available, per-
form the open-circuit voltage test to determine the
state-of-charge. Refer to open-circuit voltage test in
the Standard Procedures section of this group.
Second, determine the battery cranking capacity by
performing a load test. The battery must be charged
before proceeding with a load test if:
²The battery built-in test indicator has a black or
dark color visible.
²The temperature corrected specific gravity of the
battery electrolyte is less than 1.235.
²The battery open-circuit voltage is less than 12.4
volts.
A battery that will not accept a charge is faulty,
and must be replaced. Further testing is not
required. A fully-charged battery must be load tested
to determine its cranking capacity. A battery that is
fully-charged, but does not pass the load test, is
faulty and must be replaced.
NOTE: Completely discharged batteries may take
several hours to accept a charge. Refer to Standard
Procedures for the proper battery charging proce-
dures.
A battery is fully-charged when:
²All battery cells are gassing freely during charg-
ing.
²A green color is visible in the sight glass of the
battery built-in test indicator.
²Three corrected specific gravity tests, taken at
one-hour intervals, indicate no increase in the spe-
cific gravity of the battery electrolyte.
²Open-circuit voltage of the battery is 12.4 volts
or greater.
STANDARD PROCEDURE
STANDARD PROCEDURE - BATTERY
CHARGING
Battery charging can be performed fast or slow, it
terms of time.Slowbattery charging is the best
means of restoring a battery to full potential. Fast
8F - 8 BATTERY SYSTEMKJ
BATTERY (Continued)

battery charging should only be performed when
absolutely necessary due to time restraints. A battery
is fully-charged when:
²All of the battery cells are gassing freely during
battery charging.
²A green color is visible in the sight glass of the
battery built-in test indicator.
²Three hydrometer tests, taken at one-hour inter-
vals, indicate no increase in the temperature-cor-
rected specific gravity of the battery electrolyte.
²Open-circuit voltage of the battery is 12.65 volts
or above.
WARNING: NEVER EXCEED TWENTY AMPERES
WHEN CHARGING A COLD (-1É C [30É F] OR
LOWER) BATTERY. THE BATTERY MAY ARC INTER-
NALLY AND EXPLODE. PERSONAL INJURY AND/OR
VEHICLE DAMAGE MAY RESULT.
CAUTION: Always disconnect and isolate the bat-
tery negative cable before charging a battery. Do
not exceed sixteen volts while charging a battery.
Damage to the vehicle electrical system compo-
nents may result.
CAUTION: Battery electrolyte will bubble inside the
battery case during normal battery charging. Elec-
trolyte boiling or being discharged from the battery
vents indicates a battery overcharging condition.
Immediately reduce the charging rate or turn off the
charger to evaluate the battery condition. Damage
to the battery may result from overcharging.
CAUTION: The battery should not be hot to the
touch. If the battery feels hot to the touch, turn off
the charger and let the battery cool before continu-
ing the charging operation. Damage to the battery
may result.
NOTE: Models equipped with the diesel engine
option are equipped with two 12-volt batteries, con-
nected in parallel (positive-to-positive and negative-
to-negative). In order to ensure proper charging of
each battery, these batteries MUST be disconnected
from each other, as well as from the vehicle electri-
cal system, while being charged.
Some battery chargers are equipped with polarity-
sensing circuitry. This circuitry protects the battery
charger and the battery from being damaged if they
are improperly connected. If the battery state-of-
charge is too low for the polarity-sensing circuitry to
detect, the battery charger will not operate. This
makes it appear that the battery will not acceptcharging current. See the instructions provided by
the manufacturer of the battery charger for details
on how to bypass the polarity-sensing circuitry.
After the battery has been charged to 12.4 volts or
greater, perform a load test to determine the battery
cranking capacity. Refer to Standard Procedures for
the proper battery load test procedures. If the battery
will endure a load test, return the battery to service.
If the battery will not endure a load test, it is faulty
and must be replaced.
Clean and inspect the battery hold downs, tray,
terminals, posts, and top before completing battery
service. Refer to Battery System Cleaning for the
proper battery system cleaning procedures, and Bat-
tery System Inspection for the proper battery system
inspection procedures.
CHARGING A COMPLETELY DISCHARGED
BATTERY
The following procedure should be used to recharge
a completely discharged battery. Unless this proce-
dure is properly followed, a good battery may be
needlessly replaced.
(1) Measure the voltage at the battery posts with a
voltmeter, accurate to 1/10 (0.10) volt (Fig. 6). If the
reading is below ten volts, the battery charging cur-
rent will be low. It could take some time before the
battery accepts a current greater than a few milliam-
peres. Such low current may not be detectable on the
ammeters built into many battery chargers.
(2) Disconnect and isolate the battery negative
cable. Connect the battery charger leads. Some bat-
tery chargers are equipped with polarity-sensing cir-
cuitry. This circuitry protects the battery charger and
the battery from being damaged if they are improp-
erly connected. If the battery state-of-charge is too
low for the polarity-sensing circuitry to detect, the
battery charger will not operate. This makes it
appear that the battery will not accept charging cur-
rent. See the instructions provided by the manufac-
Fig. 6 Voltmeter - Typical
KJBATTERY SYSTEM 8F - 9
BATTERY (Continued)

To read the built-in indicator, look into the sight
glass and note the color of the indication (Fig. 8). The
battery condition that each color indicates is
described in the following list:
²Green- Indicates 75% to 100% battery state-of-
charge. The battery is adequately charged for further
testing or return to service. If the starter will not
crank for a minimum of fifteen seconds with a fully-
charged battery, the battery must be load tested.
Refer to Standard Procedures for the proper battery
load test procedures.
²Black or Dark- Indicates 0% to 75% battery
state-of-charge. The battery is inadequately charged
and must be charged until a green indication is visi-
ble in the sight glass (12.4 volts or more), before the
battery is tested further or returned to service. Refer
to Standard Procedures for the proper battery charg-
ing procedures. Also refer to Diagnosis and Testing
for more information on the possible causes of the
discharged battery condition.
²Clear or Bright- Indicates a low battery elec-
trolyte level. The electrolyte level in the battery is
below the built-in indicator. A maintenance-free bat-
tery with non-removable cell caps must be replaced if
the electrolyte level is low. Water must be added to a
low-maintenance battery with removable cell caps
before it is charged. Refer to Standard Procedures for
the proper battery filling procedures. A low electro-
lyte level may be caused by an overcharging condi-
tion. Refer to Charging System for the proper
charging system diagnosis and testing procedures.
STANDARD PROCEDURE - HYDROMETER TEST
The hydrometer test reveals the battery state-of-
charge by measuring the specific gravity of the elec-
trolyte.This test cannot be performed on
maintenance-free batteries with non-removable
cell caps.If the battery has non-removable cell caps,
refer to Diagnosis and Testing for alternate methods
of determining the battery state-of-charge.
Specific gravity is a comparison of the density of
the battery electrolyte to the density of pure water.Pure water has a specific gravity of 1.000, and sulfu-
ric acid has a specific gravity of 1.835. Sulfuric acid
makes up approximately 35% of the battery electro-
lyte by weight, or 24% by volume. In a fully-charged
battery the electrolyte will have a temperature-cor-
rected specific gravity of 1.260 to 1.290. However, a
specific gravity of 1.235 or above is satisfactory for
the battery to be load tested and/or returned to ser-
vice.
Before testing, visually inspect the battery for any
damage (a cracked case or cover, loose posts, etc.)
that would cause the battery to be faulty. Then
remove the battery cell caps and check the electrolyte
level. Add distilled water if the electrolyte level is
below the top of the battery plates. Refer to Battery
System Cleaning for the proper battery inspection
procedures.
See the instructions provided by the manufacturer
of the hydrometer for recommendations on the cor-
rect use of the hydrometer that you are using.
Remove only enough electrolyte from the battery cell
so that the float is off the bottom of the hydrometer
barrel with pressure on the bulb released. To read
the hydrometer correctly, hold it with the top surface
of the electrolyte at eye level (Fig. 9).
CAUTION: Exercise care when inserting the tip of
the hydrometer into a battery cell to avoid damag-
ing the plate separators. Damaged plate separators
can cause early battery failure.
Hydrometer floats are generally calibrated to indi-
cate the specific gravity correctly only at 26.7É C.
When testing the specific gravity at any other tem-
perature, a correction factor is required. The correc-
tion factor is approximately a specific gravity value
of 0.004, which may also be identified as four points
of specific gravity. For each 5.5É C above 26.7É C, add
four points. For each 5.5É C below 26.7É C, subtract
four points. Always correct the specific gravity for
temperature variation.
EXAMPLE:A battery is tested at -12.2É C and has
a specific gravity of 1.240. Determine the actual spe-
cific gravity as follows:
(1) Determine the number of degrees above or
below 26.7É C:26.7É C + -12.2É C = 14.5É C below
the 26.7É C specification
(2) Divide the result from Step 1 by 5.5É C:14.5É
C ÷ 5.5É C = 2.64
(3) Multiply the result from Step 2 by the temper-
ature correction factor (0.004):2.64 X 0.004 = 0.01
(4) The temperature at testing was below 26.7É C;
therefore, the temperature correction factor is sub-
tracted:1.240 - 0.01 = 1.23
(5) The corrected specific gravity of the battery cell
in this example is 1.23.
Fig. 8 Built-In Indicator Sight Glass Chart
KJBATTERY SYSTEM 8F - 11
BATTERY (Continued)