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the proper voltage depending on battery tempera-
ture.

All vehicles are equipped with On-Board Diagnos-

tics (OBD). All OBD-sensed systems, including the
EVR (field control) circuitry, are monitored by the
PCM. Each monitored circuit is assigned a Diagnos-
tic Trouble Code (DTC). The PCM will store a DTC in
electronic memory for any failure it detects. See On-
Board Diagnostic System Test in this group for more
information.

GENERATOR

The generator is belt-driven by the engine. It is

serviced only as a complete assembly. If the genera-
tor fails for any reason, the entire assembly must be
replaced.

As the energized rotor begins to rotate within the

generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.

The Y type stator winding connections deliver the

induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicle electrical system
through the generator, battery, and ground terminals.

Noise emitting from the generator may be caused

by:

Worn, loose or defective bearings

Loose or defective drive pulley

Incorrect, worn, damaged or misadjusted drive

belt

Loose mounting bolts

Misaligned drive pulley

Defective stator or diode

BATTERY TEMPERATURE SENSOR

The battery temperature sensor is used to deter-

mine the battery temperature. This temperature
data, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
System voltage will be higher at colder temperatures
and is gradually reduced at warmer temperatures.

The sensor is located forward of the vehicle battery,

and is attached to the battery tray (Fig. 1).

ELECTRONIC VOLTAGE REGULATOR

The Electronic Voltage Regulator (EVR) is not a

separate component. It is actually a voltage regulat-
ing circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.

Operation: The amount of DC current produced

by the generator is controlled by EVR circuitry con-
tained within the PCM. This circuitry is connected in

series with the generators second rotor field terminal
and its ground.

Voltage is regulated by cycling the ground path to

control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage and bat-
tery temperature (refer to Battery Temperature Sen-
sor for more information). It then compensates and
regulates generator current output accordingly. Also
see Charging System Operation for additional infor-
mation.

DIAGNOSIS AND TESTING

CHARGING SYSTEM

When the ignition switch is turned to the ON posi-

tion, battery potential will register on the voltmeter.
During engine cranking a lower voltage will appear
on the meter. With the engine running, a voltage
reading higher than the first reading (ignition in ON)
should register.

The following are possible symptoms of a charging

system fault:

The voltmeter does not operate properly

An undercharged or overcharged battery condi-

tion occurs.

Remember that an undercharged battery is often

caused by:

Accessories being left on with the engine not

running

A faulty or improperly adjusted switch that

allows a lamp to stay on. See Ignition-Off Draw Test
in Group 8A, Battery for more information.

Fig. 1 Battery Temperature Sensor

BATTERY TRAY

BATTERY

TEMPERATURE

SENSOR

AIR

INLET

TUBE

8C - 2

CHARGING SYSTEM

PL

DESCRIPTION AND OPERATION (Continued)

Содержание Neon PL 1997

Страница 1: ...ed All OBD sensed systems are monitored by the PCM Each monitored circuit is assigned a Diagnos tic Trouble Code DTC The PCM will store a DTC in electronic memory for any failure it detects See the On Board Diagnostics Test in Group 8C Charging System for more information DESCRIPTION AND OPERATION CHARGING SYSTEM OPERATION The charging system consists of Generator Electronic Voltage Regulator EVR ...

Страница 2: ...warmer temperatures The sensor is located forward of the vehicle battery and is attached to the battery tray Fig 1 ELECTRONIC VOLTAGE REGULATOR The Electronic Voltage Regulator EVR is not a separate component It is actually a voltage regulat ing circuit located within the Powertrain Control Module PCM The EVR is not serviced separately If replacement is necessary the PCM must be replaced Operation...

Страница 3: ...y Replace battery if electrolyte level is low 4 Inspect generator mounting bolts for tightness Replace or tighten bolts if required Refer to the Gen erator Removal Installation section of this group for torque specifications 5 Inspect generator drive belt condition and ten sion Tighten or replace belt as required Refer to Belt Tension Specifications in Group 7 Cooling Sys tem 6 Inspect automatic b...

Страница 4: ...Charging System Schematic Typical 8C 4 CHARGING SYSTEM PL DIAGNOSIS AND TESTING Continued ...

Страница 5: ...OLTS YES CLEAN MOUNTING SUR FACES TIGHTEN FASTENERS TO SPECIFIED TORQUE NO CHECK ON BOARD DIAG NOSTIC TROUBLE CODES DTC PERFORM OUTPUT VOLT AGE TEST YES LOW OR NO CHARGING VOLTAGE OR DTC 41 OR 47 NO REFER TO VOLTAGE DROP TEST NO CHARGING SYSTEM AND GENERATOR IS OK CHARGING VOLTAGE ABOVE MAXIMUM OR DTC 41 OR 46 REFER TO LOAD TEST VOLTAGE YES REFER TO OVERCHARGE TEST PL CHARGING SYSTEM 8C 5 DIAGNOSI...

Страница 6: ...UT VOLTAGE TEST DISCONNECT FIELD TERMINAL MEASURE RESISTANCE FROM K20 CIRCUIT ON WIRING HAR NESS TO ENGINE GROUND YES IS RESISTANCE LESS THAN 1000 OHMS NO REPAIR SHORT TO GROUND MEASURE RESISTANCE FROM K20 TERMINAL ON GENERATOR TO ENGINE GROUND REPLACE GENERATOR YES IS RESISTANCE LESS THAN 1000 OHMS NO REPEAT OUTPUT VOLTAGE TEST 8C 6 CHARGING SYSTEM PL DIAGNOSIS AND TESTING Continued ...

Страница 7: ...erature 4 Shut engine off 5 Connect an engine tachometer 6 Fully engage the parking brake TEST 1 Start engine 2 Place heater blower in high position 3 Turn on headlamps and place in high beam position 4 Turn vehicle interior lamps on 5 Start engine Bring engine speed up to 2400 rpm and hold 6 Testing ground circuitry a Touch the negative lead of voltmeter directly to battery positive POST Fig 4 b ...

Страница 8: ...ating instructions supplied with tester When using a tester equipped with an inductive type clamp removal of wiring at the gener ator will not be necessary 7 Start the engine and allow it to reach operating temperature 8 Shut engine off 9 Turn off all electrical accessories and all vehicle lighting 10 Connect the volt amp tester leads to the bat tery Be sure the carbon pile rheostat control is in ...

Страница 9: ...EN NO CHECK FOR BLOWN FUSE LINK NO IF LESS THAN 5 OHMS IF GREATER THAN 5 OHMS MEASURE VOLTAGE AT K 20 TERMI NAL ON THE GENERATOR YES YES REPAIR WIRE DISCONNECT FIELD CONNECTOR REPLACE PCM REPLACE GENERATOR YES VOLTAGE AT K 20 LESS THAN 10 VOLTS REPEAT OUTPUT VOLTAGE TEST CHECK SHORT CIRCUIT IN WIRE REPAIR FUSE LINK AND WIRE SHORT REFER TO GROUP 8W WIRING DIA GRAMS YES SHORT CIRCUIT IN FEED WIRE NO...

Страница 10: ...ure they are operational A Diagnostic Trouble Code DTC is assigned to each input and output circuit monitored by the OBD system Some circuits are checked continuously and some are checked only under certain conditions If the OBD system senses that a monitored circuit is bad it will put a DTC into electronic memory The DTC will stay in electronic memory as long as the circuit continues to be bad Th...

Страница 11: ...llows 1 Lamp on for 2 seconds then turns off 2 Lamp flashes 4 times pauses and then flashes 1 time 3 Lamp pauses for 4 seconds flashes 4 times pauses then flashes 7 times 4 The two DTC s are 41 and 47 Any number of DTC s can be displayed as long as they are in mem ory The lamp will flash until all stored DTC s are displayed then it will flash a DTC 55 to indicate the test is complete ERASING DIAGN...

Страница 12: ...EMPERATURE SENSOR REMOVAL 1 Make sure ignition switch is in OFF position and all accessories are OFF 2 Remove battery negative cable first then the positive cable Fig 12 3 Remove battery thermoguard Fig 13 WARNING TO PROTECT THE HANDS FROM BAT TERY ACID A SUITABLE PAIR OF HEAVY DUTY RUBBER GLOVES NOT THE HOUSEHOLD TYPE SHOULD BE WORN WHEN REMOVING OR SERVIC ING A BATTERY SAFETY GLASSES ALSO SHOULD...

Страница 13: ... m 75 in lbs Battery Hold Down Clamp Bolt 9 N m 75 in lbs Generator Mounting Bolt 54 N m 40 ft lbs Generator Pivot Bolt 54 N m 40 ft lbs Fig 15 Battery Temperature Sensor Connector BATTERY TRAY BATTERY TEMPERATURE SENSOR AIR INLET TUBE TYPE PART NUMBER RATED SAE AMPS ENGINES MINIMUM TEST AMPS MELCO 4793190 83 AMPS 2 0L SOHC DOHC 75 AMPS PL CHARGING SYSTEM 8C 13 REMOVAL AND INSTALLATION Continued ...

Страница 14: ......

Страница 15: ...CHARGING SYSTEM CONTENTS page DIAGNOSIS AND TESTING CHARGING SYSTEM 2 PL CHARGING SYSTEM 8C 1 ...

Страница 16: ...DIAGNOSIS AND TESTING CHARGING SYSTEM INSPECTION Charging System Test 8C 2 CHARGING SYSTEM PL ...

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