2004 DAEWOO LACETTI light

ENGINE ELECTRICAL 1E – 9
DAEWOO V–121 BL4
STARTER MOTOR NOISE
To correct starter motor noise during starting, use the following procedure:
Checks
Action
Check for a high–pitched whine during cranking, before
the engine fires. The engine cranks and fires properly.The distance is too great between the starter pinion and
the flywheel. Shimming the starter toward the flywheel is
required.
Check for a high–pitched whine after the engine fires, as
the key is being released. The engine cranks and fires
properly. This intermittent complaint is often diagnosed as
”starter hang–in” or ”solenoid weak.”The distance is too small between the starter pinion and
the flywheel. Shimming the starter away from the flywheel
is required.
Check for a loud ”whoop” after the engine fires but while
the starter is still held engaged. The sound is like a siren
if the engine is revved while the starter is engaged.The most probable cause is a defective clutch. A new
clutch will often correct this problem.
Check for a ”rumble,” a ”growl,” or, in severe cases, a
”knock” as the starter is coasting down to a stop after start-
ing the engine.The most probable cause is a bent or unbalanced starter
armature. A new armature will often correct this problem.
If the complaint is noise, correction can be achieved by
proper shimming as follows:
1. Check for a bent or a worn flywheel.
2. Start the engine and carefully touch the outside di-
ameter of the rotating flywheel ring gear with chalk
or a crayon to show the high point of the tooth run-
out. Turn the engine OFF and rotate the flywheel so
that the marked teeth are in the area of the starter
pinion gear.
3. Disconnect the negative battery cable to prevent
cranking the engine.
4. Check the pinion–to–flywheel clearance by using a
wire gauge of 0.5 mm (0.02 inch) minimum thick-
ness (or diameter). Center a pinion tooth between
two flywheel teeth and the gauge. Do not gauge in
the corners, where a misleading larger dimension
may be observed. If the clearance is under this
minimum, shimming the starter away from the fly-
wheel is required.
5. If the clearance approaches 1.5 mm (0.06 inch) or
more, shimming the starter toward the flywheel is
required. This condition is generally the cause of
broken flywheel teeth or the starter housing. Shim
the starter toward the flywheel by shimming only
the outboard starter mounting pad. A shim of 0.40
mm (0.016 inch) thickness at this location will de-
crease the clearance by approximately 0.30 mm
(0.012 inch). If normal starter shims are not avail-
able, plain washers or other suitable material may
be used as shims.BATTERY LOAD TEST
1. Check the battery for obvious damage, such as a
cracked or broken case or cover, which could per-
mit the loss of electrolyte. If obvious damage is
noted, replace the battery.
CAUTION : Do not charge the battery if the hydrome-
ter is clear or light yellow. Instead, replace the battery.
If the battery feels hot, or if violent gassing or spew-
ing of electrolyte through the vent hole occurs, dis-
continue charging or reduce the charging rate to
avoid personal injury.
2. Check the hydrometer. If the green dot is visible, go
to the load test procedure. If the indicator is dark
but green is not visible, charge the battery. For
charging a battery removed from the vehicle, refer
to ”Charging a Completely Discharged Battery” in
this section.
3. Connect a voltmeter and a battery load tester
across the battery terminals.
4. Apply a 300–ampere load for 15 seconds to remove
any surface charge from the battery.
5. Remove the load.
6. Wait 15 seconds to let the battery recover, and ap-
ply a 270–ampere load.
Important : The battery temperature must be estimated
by touch and by the temperature condition the battery has
been exposed for the preceding few hours.
7. If the voltage does not drop below the minimum
listed, the battery is good and should be reinstalled.
If the voltage is less than the minimum listed, re-
place the battery. Refer to ”Battery Specifications”
in this section.

1E – 10IENGINE ELECTRICAL
DAEWOO V–121 BL4
GENRATOR OUTPUT TEST
1. Perform the generator system test. Refer to ”Gen-
erator System Check”in this section.
2. Replace the generator if it fails that test. Refer to
”Generator” in the On–Vehicle Service portion of
this section. If it passes the test, perform the on–
vehicle output check which follows.
Important : Always check the generator for output before
assuming that a grounded ”L” terminal circuit has dam-
aged the regulator.
3. Attach a digital multimeter, an ammeter, and a car-
bon pile load to the vehicle.
Important : Be sure the vehicle battery is fully charged,
and the carbon pile load is turned off.
4. With the ignition switch in the OFF position, check
and record the battery voltage.
5. Remove the harness connector from the generator.
6. Turn the ignition to RUN with the engine not run-
ning. Use a digital multimeter to check for voltage in
the harness connector ”L” terminal.
7. The reading should be near the specified battery
voltage of 12 volts. If the voltage is too low, check
the indicator
L" terminal circuits for open and
grounded circuits causing voltage loss. Correct any
open wires, terminal connections, etc., as neces-
sary. Refer to”Charging System” in this section.
8. Attach the generator harness connector.
9. Run the engine at a moderate idle, and measure
the voltage across the battery terminals. The read-
ing should be above that recorded in step 14, but
less than 16 volts. If the reading is over 16 volts or
below the previous reading, replace the generator.
Refer to”Generator” in the On–Vehicle Service sec-
tion.
10. Run the engine at a moderate idle, and measure
the generator amperage output.
11. Turn on the carbon pile, and adjust it to obtain the
maximum amps while maintaining the battery volt-
age above 13 volts.
12. If the reading is within 15 amps of the generator’s
rating noted on the generator, the generator is
good. If not, replace the generator. Refer to”Gener-
ator” in the On–Vehicle Service section.
13. With the generator operating at the maximum out-
put, measure the voltage between the generator
housing and the battery negative terminal. The volt-
age drop should be 0.5 volt or less. If the voltage
drop is more than 0.5 volt, check the ground path
from the generator housing to the negative battery
cable.
14. Check, clean, tighten, and recheck all of the ground
connections.
GENERATOR SYSTEM CHECK
When operating normally, the generator indicator lamp will
come on when the ignition is in RUN position and go out
when the engine starts. If the lamp operates abnormally
or if an undercharged or overcharged battery condition oc-
curs, the following procedure may be used to diagnose the
charging system. Remember that an undercharged bat-
tery is often caused by accessories being left on overnight
or by a defective switch that allows a lamp, such as a trunk
or a glove box lamp, to stay on.
Diagnose the generator with the following procedure:
1. Visually check the belt and the wiring.
2. With the ignition in the ON position and the engine
stopped, the charge indicator lamp should be on. If
not, detach the harness at the generator and
ground the ”L” terminal in the harness with a 5–am-
pere jumper lead.
S If the lamp lights, replace the generator. Refer to
”Generator” in the On–Vehicle Service section.
S If the lamp does not light, locate the open circuit
between the ignition switch and the harness
connector. The indicator lamp bulb may be
burned out.
3. With the ignition switch in the ON position and the
engine running at moderate speed, the charge indi-
cator lamp should be off. If not, detach the wiring
harness at the generator.
S If the lamp goes off, replace the generator. Re-
fer to ”Generator” in the On–Vehicle Service
section.
S If the lamp stays on, check for a short to ground
in the harness between the connector and the
indicator lamp.
Important : Always check the generator for output before
assuming that a grounded ”L” terminal circuit has dam-
aged the regulator. Refer to”Generator” in the Unit Repair
section.

1E – 30IENGINE ELECTRICAL
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
BATTERY
The sealed battery is standard on all cars. There are no
vent plugs in the cover. The battery is completely sealed,
except for two small vent holes in the sides. These vent
holes allow the small amount of gas produced in the bat-
tery to escape. The battery has the following advantages
over conventional batteries:
S No water addition for the life of the battery.
S Overcharge protection. If too much voltage is ap-
plied to the battery, it will not accept as much cur-
rent as a conventional battery. In a conventional
battery, the excess voltage will still try to charge the
battery, leading to gassing, which causes liquid
loss.
S Not as liable to self–discharge as compared to a
conventional battery. This is particularly important
when a battery is left standing for long periods of
time.
S More power available in a lighter and smaller case.
The battery has three major functions in the electrical sys-
tem. First, the battery provides a source of energy for
cranking the engine. Second, the battery acts as a voltage
stabilizer for the electrical system. Finally, the battery can,
for a limited time, provide energy when the electrical de-
mand exceeds the output of the generator.
RATINGS
A battery has two ratings: (1) a reserve capacity rating
designated at 27°C (80°F), which is the time a fully
charged battery will provide 25 amperes current flow at or
above 10.5 volts; (2) a cold cranking amp rating deter-
mined under testing at –18°C (0°F), which indicates the
cranking load capacity.
RESERVE CAPACITY
The reserve capacity is the maximum length of time it is
possible to travel at night with the minimum electrical load
and no generator output. Expressed in minutes, Reserve
Capacity (or RC rating) is the time required for a fully
charged battery, at a temperature of 27°C (80°F) and be-
ing discharged at a current of 25 amperes, to reach a ter-
minal voltage of 10.5 volts.
COLD CRANKING AMPERAGE
The cold cranking amperage test is expressed at a battery
temperature of –18°C (0°F). The current rating is the mini-
mum amperage, which must be maintained by the battery
for 30 seconds at the specified temperature, while meeting
a minimum voltage requirement of 7.2 volts. This rating is
a measure of cold cranking capacity.The battery is not designed to last indefinitely. However,
with proper care, the battery will provide many years of
service.
If the battery tests well, but fails to perform satisfactorily
in service for no apparent reason, the following factors
may point to the cause of the trouble:
S Vehicle accessories are left on overnight.
S Slow average driving speeds are used for short pe-
riods.
S The vehicle’s electrical load is more than the gener-
ator output, particularly with the addition of after-
market equipment.
S Defects in the charging system, such as electrical
shorts, a slipping generator belt, a faulty generator,
or a faulty voltage regulator.
S Battery abuse, including failure to keep the battery
cable terminals clean and tight, or a loose battery
hold–down clamp.
S Mechanical problems in the electrical system, such
as shorted or pinched wires.
BUILT – IN HYDROMETER
The sealed battery has a built–in, temperature–compen-
sated hydrometer in the top of the battery. This hydrome-
ter is to be used with the following diagnostic procedure:
1. When observing the hydrometer, make sure that
the battery has a clean top.
2. Under normal operation, two indications can be ob-
served:
S GREEN DOT VISIBLE – Any green appearance
is interpreted as a ”green dot,” meaning the bat-
tery is ready for testing.
S DARK GREEN DOT IS NOT VISIBLE – If there
is a cranking complaint, the battery should be
tested. The charging and electrical systems
should also be checked at this time.
3. Occasionally, a third condition may appear:
S CLEAR OR BRIGHT YELLOW – This means
the fluid level is below the bottom of the hydrom-
eter. This may have been caused by excessive
or prolonged charging, a broken case, excessive
tipping, or normal battery wear. Finding a battery
in this condition may indicate high charging by a
faulty charging system. Therefore, the charging
and the electrical systems may need to be
checked if a cranking complaint exists. If the
cranking complaint is caused by the battery, re-
place the battery.
CHARGING PROCEDURE
1. Batteries with the green dot showing do not require
charging unless they have just been discharged
(such as in cranking a vehicle).
2. When charging sealed–terminal batteries out of the
vehicle, install the adapter kit. Make sure all the
charger connections are clean and tight. For best
results, batteries should be charged while the elec-

ENGINE ELECTRICAL 1E – 31
DAEWOO V–121 BL4
trolyte and the plates are at room temperature. A
battery that is extremely cold may not accept cur-
rent for several hours after starting the charger.
3. Charge the battery until the green dot appears. The
battery should be checked every half–hour while
charging. Tipping or shaking the battery may be
necessary to make the green dot appear.
4. After charging, the battery should be load tested.
Refer to ”Starter Motor” in this section.
CHARGING TIME REQUIRED
The time required to charge a battery will vary depending
upon the following factors:
S Size of Battery – A completely discharged large
heavy–duty battery requires more than twice the re-
charging time as a completely discharged small pas-
senger car battery.
S Temperature – A longer time will be needed to
charge any battery at –18°C (0°F) than at 27°C
(80°F). When a fast charger is connected to a cold
battery, the current accepted by the battery will be
very low at first. The battery will accept a higher cur-
rent rate as the battery warms.
S Charger Capacity – A charger which can supply only
5 amperes will require a much longer charging period
than a charger that can supply 30 amperes or more.
S State–of–Charge – A completely discharged battery
requires more than twice as much charge as a one–
half charged battery. Because the electrolyte is nearly
pure water and a poor conductor in a completely dis-
charged battery, the current accepted by the battery
is very low at first. Later, as the charging current
causes the electrolyte acid content to increase, the
charging current will likewise increase.
CHARGING A COMPLETELY
DISCHARGED BATTERY (OFF THE
VEHICLE)
Unless this procedure is properly followed, a perfectly
good battery may need to be replaced.
The following procedure should be used to recharge a
completely discharged battery:
1. Measure the voltage at the battery terminals with
an accurate voltmeter. If the reading is below 10
volts, the charge current will be very low, and it
could take some time before the battery accepts
the current in excess of a few milliamperes. Refer
to ””Charging Time Required” in this section, which
focuses on the factors affecting both the charging
time required and the rough estimates in the table
below. Such low current may not be detectable on
ammeters available in the field.
2. Set the battery charger on the high setting.Important : Some chargers feature polarity protection cir-
cuitry, which prevents charging unless the charger leads
are correctly connected to the battery terminals. A com-
pletely discharged battery may not have enough voltage
to activate this circuitry, even though the leads are con-
nected properly, making it appear that the battery will not
accept charging current. Therefore, follow the specific
charger manufacturer’s instruction for bypassing or over-
riding the circuitry so that the charger will turn on and
charge a low–voltage battery.
3. Continue to charge the battery until the charge cur-
rent is measurable. Battery chargers vary in the
amount of voltage and current provided. The time
required for the battery to accept a measurable
charge current at various voltages may be as fol-
lows:
Voltage
Hours
16.0 or moreUp to 4 hours
14.0–15.9Up to 8 hours
13.9 or lessUp to 16 hours
S If the charge current is not measurable at the
end of the above charging times, the battery
should be replaced.
S If the charge current is measurable during the
charging time, the battery is good, and charging
should be completed in the normal manner.
Important : It is important to remember that a completely
discharged battery must be recharged for a sufficient num-
ber of ampere hours (AH) to restore the battery to a usable
state. As a general rule, using the reserve capacity rating
(RC) as the number of ampere hours of charge usually
brings the green dot into view.
S If the charge current is still not measurable after
using the charging time calculated by the above
method, the battery should be replaced.
JUMP STARTING PROCEDURE
1. Position the vehicle with the good (charged) battery
so that the jumper cables will reach.
2. Turn off the ignition, all the lights, and all the electri-
cal loads in both vehicles. Leave the hazard flasher
on if jump starting where there may be other traffic
and any other lights needed for the work area.
3. In both vehicles, apply the parking brake firmly.
Notice : To avoid vehicle damage,Make sure the cables
are not on or near pulleys, fans, or other parts that will
move when the engine starts.
4. Shift an automatic transaxle to PARK, or a manual
transaxle to NEUTRAL.
CAUTION : In order to avoid injury, do not use cables
that have loose or missing insulation.
5. Clamp one end of the first jumper cable to the posi-
tive terminal on the battery. Make sure it does not
touch any other metal parts. Clamp the other end of

1E – 32IENGINE ELECTRICAL
DAEWOO V–121 BL4
the same cable to the positive terminal on the other
battery. Never connect the other end to the nega-
tive terminal of the discharged battery.
CAUTION : To avoid injury do not attach the cable di-
rectly to the negative terminal of the discharged bat-
tery. Doing so could cause sparks and a possible bat-
tery explosion.
6. Clamp one end of the second cable to the negative
terminal of the booster battery. Make the final con-
nection to a solid engine ground (such as the en-
gine lift bracket) at least 450 millimeters (18 inches)
from the discharged battery.
7. Start the engine of the vehicle with the good bat-
tery. Run the engine at a moderate speed for sever-
al minutes. Then start the engine of the vehicle
which has the discharged battery.
8. Remove the jumper cables by reversing the above
sequence exactly. Remove the negative cable from
the vehicle with the discharged battery first. While
removing each clamp, take care that it does not
touch any other metal while the other end remains
attached.
GENERATOR
The Delco–Remy CS charging system has several mod-
els available, including the CS. The number denotes the
outer diameter in millimeters of the stator lamination.
CS generators are equipped with internal regulators. A
Delta stator, a rectifier bridge, and a rotor with slip rings
and brushes are electrically similar to earlier generators.
A conventional pulley and fan are used. There is no test
hole.
Unlike three–wire generators, the CS may be used with
only two connections: battery positive and an ”L’’ terminal
to the charge indicator lamp.
As with other charging systems, the charge indicator lamp
lights when the ignition switch is turned to RUN, and goes
out when the engine is running. If the charge indicator is
on with the engine running, a charging system defect is in-
dicated. This indicator light will glow at full brilliance for
several kinds of defects as well as when the system volt-
age is too high or too low.The regulator voltage setting varies with temperature and
limits the system voltage by controlling rotor field current.
At high speeds, the on–time may be 10 percent and the
off–time 90 percent. At low speeds, with high electrical
loads, on–time may be 90 percent and the off–time 10 per-
cent.
CHARGING SYSTEM
CS generators use a new type of regulator that incorpo-
rates a diode trio. A Delta stator, a rectifier bridge, and a
rotor with slip rings and brushes are electrically similar to
earlier generators. A conventional pulley and fan are used.
There is no test hole.
STARTER
Wound field starter motors have pole pieces, arranged
around the armature, which are energized by wound field
coils.
Enclosed shift lever cranking motors have the shift lever
mechanism and the solenoid plunger enclosed in the drive
housing, protecting them from exposure to dirt, icy condi-
tions, and splashes.
In the basic circuit, solenoid windings are energized when
the switch is closed. The resulting plunger and shift lever
movement causes the pinion to engage the engine fly-
wheel ring gear. The solenoid main contacts close. Crank-
ing then takes place.
When the engine starts, pinion overrun protects the arma-
ture from excessive speed until the switch is opened, at
which time the return spring causes the pinion to disen-
gage. To prevent excessive overrun, the switch should be
released immediately after the engine starts.
STARTING SYSTEM
The engine electrical system includes the battery, the igni-
tion, the starter, the generator, and all the related wiring.
Diagnostic tables will aid in troubleshooting system faults.
When a fault is traced to a particular component, refer to
that component section of the service manual.
The starting system circuit consists of the battery, the
starter motor, the ignition switch, and all the related electri-
cal wiring. All of these components are connected electri-
cally.

ENGINE CONTROLS 1F – 41
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the ignition OFF.
2. Disconnect the crankshaft position (CKP) sen-
sor connector.
3. Turn the ignition ON.
4. Measure the voltage between following termi-
nals:
S Terminal 1 and 3 of the CKP sensor con-
nector.
S Terminal 2 and 3 of the CKP sensor con-
nector.
S Terminal 1 of the CKP sensor connector
and ground.
S Terminal 2 of the CKP sensor connector
and ground.
Are the voltage measure within the value specified?
1.4 VGo to Step 13Go to Step 12
12Check for an open or short in the wires between CKP
sensor connector and ECM connector and repair as
need.
Is the repair complete?–Go to Step 2–
131. Disconnect electronic Ignition (EI) system igni-
tion coil connector to prevent the vehicle from
starting.
2. Measure the voltage at ECM connector termi-
nal 85 and 54 by backprobing the ECM con-
nector.
Are the voltage readings near the value specified?1.4V with
ignition ON,
1.6V during
crankingGo to Step 15Go to Step 14
14Replace the CKP sensor.
Is the repair complete?–Go to Step 2–
151. Turn the ignition OFF.
2. Disconnect the electrical connector at EI sys-
tem ignition coil.
3. Connect a test light between terminal 2 of the
EI system ignition coil connector and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 17Go to Step 16
16Check for open in wire between the battery and EI
system ignition coil connector terminal 2 and repair
as needed.
Is the repair complete?–Go to Step 2–
171. Turn the ignition OFF.
2. Disconnect ECM connect and EI system igni-
tion coil connector.
3. Measure the resistance between following ter-
minals:
S Terminal 1 of ignition coil and terminal 31 of
ECM connector.
S Terminal 1 of ignition coil and terminal 32 of
ECM connector.
Are the resistance within the value specified?0 WGo to Step 19Go to Step 18
18Check for open circuit and repair as needed.
Is the repair complete?–Go to Step 2–

1F – 42IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
191. Measure the resistance between following ter-
minals:
S Terminal 1 and 2 of ignition coil.
S Terminal 2 and 1 of ignition coil.
Are the resistance within the value specified.
1. Remove the high tension cable.
2. Measure the resistance between second coil.
S Between 1 and 4
S Between 2 and 3
Are the resistance within the value specified.0.9 W
5.3 kWGo to Step 21Go to Step 20
20Replace the EI system ignition coil.
Is the repair complete?–Go to Step 2–
211. Check for any damages or poor connection in
ignition wires and repair as needed.
2. Connect the EI system ignition coil connector
and ECM connector.
3. Check for the presence of spark from all of the
ignition wires.
Is the spark present from all of the ignition wires?–Go to Step 2Go to Step 22
22Replace ECM.
Is the repair complete?–Go to Step 2–
231. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 26Go to Step 24
241. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump ter-
minals 2 and 3.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 sec.Go to Step 25Go to 34
25Replace the fuel pump.
Is the repair complete?–Go to Step 2–
26Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 27Go to Step 29
27Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 28Go to Step 41
281. Remove the contaminated fuel from the fuel
tank.
2. Clean the fuel tank as needed.
Is the repair complete?–Go to Step 2–
291. Check the fuel filter for restriction.
2. Inspect the fuel lines for kinks and restrictions.
3. Repair or replace as needed.
4. Measure the fuel pressure.
Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 2Go to Step 30

ENGINE CONTROLS 1F – 43
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
301. Disconnect vacuum line from the fuel pressure
regulator.
2. Inspect the vacuum line for the presence of
fuel.
3. Inspect the fuel pressure regulator vacuum port
for the presence of fuel.
Is any fuel present?–Go to Step 31Go to Step 32
31Replace the fuel pressure regulator.
Is the repair complete?–Go to Step 2–
321. Remove the fuel pump assembly from the fuel
tank.
2. Inspect the fuel pump sender and the fuel cou-
pling hoses for a restriction.
3. Inspect the in–tank fuel filter for restriction.
Is the problem found?–Go to Step 33Go to Step 25
33Replace the fuel pump sender, the in–tank fuel filter,
and/or the fuel coupling hoses as needed.
Is the repair complete?–Go to Step 2–
341. Turn the ignition OFF.
2. Disconnect the electric connector at the fuel
pump.
3. Connect a test light between fuel pump con-
nector terminal 3 and ground.
4. Turn the ignition ON.
5. With the ignition ON, the test light should illumi-
nate for the time specified.
Is the test light on?2 secGo to Step 35Go to Step 36
35Repair the open circuit between the fuel pump con-
nector terminal 2 and ground.
Is the repair complete?–Go to Step 2–
361. Turn the ignition OFF.
2. Disconnect the fuel pump relay.
3. Turn the ignition ON.
4. Measure the voltage at terminal 30 and 86 of
fuel pump relay.
Is the voltage within the value specified?11–14 VGo to Step 38Go to Step 37
37Repair open or short circuit for power supply.
Is the repair complete?–Go to Step 2–
381. Turn the ignition OFF.
2. Disconnect ECM connector.
3. Using an ohmmeter, measure the resistance
between following terminals.
S Terminal 6 of ECM and terminal 85 of fuel
pump relay.
S Terminal 87 of fuel pump relay and terminal
3 of fuel pump.
Does the resistance within the value specified?0 WGo to Step 40Go to Step 39