Файл: 92FWD_8A.pdf

Fig. 1 Starting System Components

All front wheel drive vehicles are equipped with OBD and all OBD sensing systems are monitored by the Engine Control computer. The Engine Control computer will store in electronic memory, any detectable failure within the monitored circuits. It will retain this information for a period of 50 engine starts, then erase the memory if the failure does not reoccur during that period. This also will translate a moni-

Fig. 2 Charging System Components

tored failure as a FAULT CODE when a readout command is given. A readout command can be made by turning the ignition switch to ON-OFF-ON- OFF-ON without starting the engine. The CHECK ENGINE LAMP on the instrument cluster will flash in preset sequences to show Fault Codes. However, the Check Engine Lamp cannot express fault codes for all failures. Fault codes are easier to obtain and more complete with the use of Diagnostic Tool (DRB II). This tool is plugged into the diagnostic connector

located in the engine compartment (Fig. 2). Refer to the instructions provided with the (DRB II) tool being used.

For numbered Fault Codes pertaining to components within this Group, refer to Failure CodesÐOn

Board Diagnostics in Group 8A. For other Fault Codes which, do not pertaining to this Group 8A, refer to Group 14, Fuel System, On Board Diagnostics.

GENERAL INFORMATION

The battery stores, stabilizes, and produces electrical current to operate various electrical systems in the vehicle. The determination of whether a battery is good or bad is made by the battery's ability to accept a charge. It also must produce high amperage current output over an extended period to be able to start the vehicle. The capability of the battery to store electrical current comes from a chemical reaction. This reaction takes place between the sulfuric acid solution electrolyte and the lead +/- plates in each cell of the battery. As the battery discharges, the plates react with the acid from the electrolyte. When the charging system charges the battery, the water is converted to sulfuric acid in the battery. The amount of acid, specific gravity in the electrolyte can be measured with a hydrometer. The factory installed battery is equipped with a built in hydrometer as a test indicator (Figs. 3, 4 and 5) to help in determining the battery's state of charge. The factory installed battery also is sealed. Water cannot and should not be added.

Fig. 3 Battery Construction and Test Indicator

Fig. 4 Built in Test Indicator

Fig. 5 Test Indicator Sight Glass

The battery is vented to release gases that is created when the battery is being charged and discharged. The battery top, posts, and terminals should be cleaned when other under hood maintenance is performed (Fig. 3).

WARNING: DO NOT ASSIST BOOST, CHARGE, ADD WATER, OR LOAD TEST BATTERY WHEN ELECTROLYTE LEVEL IS BELOW THE TOP OF THE PLATES. PERSONAL INJURY MAY OCCUR.

When the electrolyte level is below the top of the plates a yellow or bright color indicator in sight glass

(Figs. 4 and 5), the battery must be replaced. Refer to Test Indicator. The battery must be completely charged with a green color in sight glass. The top, posts, and terminals should be properly cleaned before diagnostic procedures are performed. Also refer to Group 8B, Battery/Starter/Alternator Service.

TEST INDICATOR

The test indicator a hydrometer is viewed through a sight glass, it is built into the top of battery case (Figs. 3, 4 and 5). This provides visual information for battery testing. The test indicator sight glass is to be used with diagnostic procedures described in this Group.

It is important when using the Test Indicator that the battery be level and have a clean top to see the correct indications. A light may be required to view the Indicator.

WARNING: DO NOT USE OPEN FLAME NEAR BATTERY BECAUSE OF EXPLOSIVE GASES AT FORM ABOVE BATTERY.

STATE OF CHARGE TESTS

USING TEST INDICATOR

The built in test hydrometer (Figs. 3, 4 and 5) measures the specific gravity of the electrolyte. Specific Gravity (SG) of the electrolyte will show state of charge voltage. The test indicator WILL NOT show cranking capacity of the battery. Refer to Battery Load. Look into the sight glass (Figs. 4 and 5) and note the color of the indicator (Fig. 5). Refer to the following description of colors:

² GREEN = 75 to 100 degree state of charge

The battery is adequately charged for further testing and may be returned to use. If the vehicle will not crank for a maximum 15 seconds, refer to Battery Load Test in this Group for more information.

² BLACK OR DARK = 0 to 75 degree state of charge The battery is INADEQUATELY charged and must be charged until green dot is visible, (12.4 volts or greater) before the battery is tested or returned to

use. Refer to Causes of Battery Discharging.

² YELLOW OR BRIGHT COLOR = Battery must be replace

WARNING: DO NOT CHARGE, ASSIST BOOST, LOAD TEST, OR ADD WATER TO THE BATTERY WHEN YELLOW OR BRIGHT COLOR DOT IS VISIBLE. PERSONAL INJURY MAY OCCUR.

A yellow or bright color dot shows electrolyte level in battery is below the test indicator (Fig. 5). Water cannot be added to a maintenance free battery. The battery must be replaced. A low electrolyte level may be caused by an over charging condition. Refer to Alternator Test Procedures on Vehicle.

CAUSES OF BATTERY DISCHARGING

It is normal to have a small 5 to 30 milliamperes continuous electrical draw from the battery. This draw will take place with the ignition in the OFF position, and the courtesy, dome, storage compartments, and engine compartment lights OFF. The continuous draw is due to various electronic features or accessories that require electrical current with the ignition OFF to function properly. When a vehicle is not used over an extended period approximately 20 days the Main Fusible Link Connector (Fig. 6) should be disconnected. This is located near the battery on the engine wiring harness. Disconnection of this connector will help prevent battery discharging.

Fig. 6 Main Fusible Link Connector

ABNORMAL BATTERY DISCHARGING

(1)Corroded battery posts, cables or terminals.

(2)Loose or worn alternator drive belt.

(3)Electrical loads that exceed the output of the charging system due to equipment or accessories installed after delivery.

(4)Slow driving speeds in heavy traffic conditions or prolonged idling with high-amperage electrical systems in use.

(5)Defective electrical circuit or component causing excess Ignition Off Draw (IOD). Refer to Ignition OFF Draw (IOD).

(6)Defective charging system.

(7)Defective battery.