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.
WARNING
SAFETY PRECAUTIONS AND WARNINGS
WARNING:
•
DO NOT ALLOW JUMPER CABLE CLAMPS TO
TOUCH EACH OTHER WHEN CONNECTED TO A
BOOSTER SOURCE.
•
DO NOT USE OPEN FLAME NEAR BATTERY.
•
REMOVE
METALLIC
JEWELRY
WORN
ON
HANDS OR WRISTS TO AVOID INJURY BY ACCI-
DENTAL ARCING OF BATTERY CURRENT.
•
WHEN USING A HIGH OUTPUT BOOSTING
DEVICE, DO NOT ALLOW THE DISABLED VEHI-
CLE’S BATTERY TO EXCEED 16 VOLTS. PER-
SONAL INJURY OR DAMAGE TO ELECTRICAL
SYSTEM CAN RESULT.
•
TO PROTECT THE HANDS FROM BATTERY
ACID, A SUITABLE PAIR OF HEAVY DUTY RUBBER
GLOVES, NOT THE HOUSEHOLD TYPE, SHOULD
BE WORN WHEN REMOVING OR SERVICING A
BATTERY. SAFETY GLASSES ALSO SHOULD BE
WORN.
DIAGNOSIS AND TESTING - BATTERY SYSTEM
The battery, starting, and charging systems in the
vehicle operate with one another and must be tested
as 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.
MICRO 420 BATTERY TESTER
The
Micro
420
automotive
battery
tester
is
designed to help the dealership technicians diagnose
the cause of a defective battery. Follow the instruc-
tion manual supplied with the tester to properly
diagnose a vehicle. If the instruction manual is not
available refer to the standard procedure in this sec-
tion, which includes the directions for using the
Micro 420 battery tester.
8F - 2
BATTERY SYSTEM
ZB
BATTERY SYSTEM (Continued)