
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.

ENGINE ELECTRICAL 1E – 11
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
GENERATOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the manifold air temperature (MAT)
sensor electrical connector the air intake tube.
3. Remove all the clamps from the air cleaner outlet
hose, and set aside the tube.
4. Raise and suitably support the vehicle.
5. Disconnect the harness connector from the back of
the generator, and the generator lead to the battery.
6. Remove the serpentine accessory drive belt by low-
ering the vehicle and turning the automatic tension-
er roller bolt clockwise to relieve tension on the belt.
Refer to Section 6B, Power Steering Pump.
7. Push up the power steering reservoir and set it
aside.
8. Remove the bolt of the generator upper engine con-
necting bracket to the 1.4L/1.6L engine.

ENGINE ELECTRICAL 1E – 25
DAEWOO V–121 BL4
GENERATOR
Disassembly Procedure
1. Remove the generator. Refer to ”Generator”in the
On–Vehicle Service section.
2. Mark a match line that cannot easily be removed on
the end frame to make assembly easier.
3. Pry off the plastic cover to expose the stator con-
nections.
Notice : If the stator connections are not welded, melt the
lead. Avoid excessive heating, as it can damage the
diodes in the rectifier bridge.
4. Remove the stator connections from the rectifier
bridge terminals by cutting the wires.
5. Pry off the baffle.
6. Remove the rectifier/regulator/brush holder assem-
bly screws.
7. Remove the brush holder assembly and the regula-
tor.
Important : If the brush can be reused, reassmble the
brush to the holder with the retaining pin, after cleaning the
brush with a soft, clean cloth.
8. Test the rectifier bridge by connecting the ohmme-
ter terminals to the brdge and the heat sink.

ENGINE ELECTRICAL 1E – 29
DAEWOO V–121 BL4
3. Position the rotor assembly shaft with the drive end
frame in the slip ring end assembly until the gap
between the outer lace and the end frame casting
is 1.9 mm (0.075 inch).
4. Install the generator through–bolts.
Tighten
Tighten the generator through–bolts to 10 NSm (89 lb–
in).
5. Position the fan, the collars, and the pulley on the
rotor shaft and secure with the nut.
Tighten
Tighten the generator drive end bearing nut to 81 NSm
(60 lb–ft).
6. Install the generator. Refer to ”Generator”in the
On–Vehicle Service section.
7. Weld the brush holder terminal to the regulator ter-
minal, if removed.
8. Fix the brush holder with the retainer pin, and weld
the regulator/brush holder assembled terminal to
the rectifier terminal.
9. Apply silicone grease between the bridge and the
end frame for radiation purposes.
10. Fasten the screws holding the rectifier regulator/
brush holder assembly to the end frame.
11. Punch the new baffle with the pin into the brush.
Notice : Take care to prevent damage to the vehicle by
protecting the diode in the rectifier bridge from excessive
heat while welding.
12. Weld the connectors of the rectifier bridge.

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-

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 – 5
DAEWOO V–121 BL4
SYMPTOM DIAGNOSIS1F–574 . . . . . . . . . . . . . . . . . . .
Important Preliminary Checks 1F–574. . . . . . . . . . . . .
Intermittents 1F–574. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hard Start 1F–576. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surges or Chuggles 1F–579. . . . . . . . . . . . . . . . . . . . . .
Lack of Power, Sluggishness, or Sponginess 1F–581
Hesitation, Sag, Stumble 1F–583. . . . . . . . . . . . . . . . .
Cuts Out, Misses 1F–584. . . . . . . . . . . . . . . . . . . . . . . .
Poor Fuel Economy 1F–587. . . . . . . . . . . . . . . . . . . . . .
Rough, Unstable, or Incorrect Idle, Stalling 1F–588. .
Excessive Exhaust Emissions or Odors 1F–591. . . . .
Dieseling, Run–On 1F–592. . . . . . . . . . . . . . . . . . . . . . .
Backfire 1F–593. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR1F–594 . . . . . . . . . . . . .
ON–VEHICLE SERVICE 1F–594. . . . . . . . . . . . . . . . . . .
Fuel System Pressure Relief 1F–594. . . . . . . . . . . . . .
Fuel Tank 1F–594. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump 1F–596. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 1F–597. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail and Injectors (1.4L/1.6L DOHC) 1F–598. . .
Fuel Rail and Injectors (1.8L DOHC) 1F–600. . . . . . .
Engine Coolant Temperature Sensor
(1.4L/1.6L DOHC) 1F–602. . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature Sensor
(1.8L DOHC) 1F–602. . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Position Sensor (1.8L DOHC) 1F–603. . . . . .
Throttle Body (1.4L/1.6L DOHC) 1F–603. . . . . . . . . . .
Throttle Body (1.8L DOHC) 1F–604. . . . . . . . . . . . . . .
Front Heated Oxygen Sensor (HO2S 1)
(1.4L/1.6L DOHC) 1F–606. . . . . . . . . . . . . . . . . . . . . .
Front Heated Oxygen Sensor (HO2S 1)
(1.8L DOHC) 1F–607. . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Heated Oxygen Sensor (HO2S 2) 1F–607. . . . .
Intake Air Temperature Sensor
(1.4L/1.6L DOHC) 1F–608. . . . . . . . . . . . . . . . . . . . . .
Intake Air Temperature Sensor (1.8L DOHC) 1F–609
Idle Air Control Valve (1.8L DOHC) 1F–609. . . . . . . . .
Manifold Absolute Pressure Sensor
(1.4L/1.6L DOHC) 1F–610. . . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Sensor
(1.8L DOHC) 1F–611. . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation Valve
(1.4L/1.6L DOHC) 1F–611. . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation Valve (1.8L DOHC) 1F–612
Knock Sensor (1.4L/1.6L DOHC) 1F–612. . . . . . . . . .
Knock Sensor (1.8L DOHC) 1F–613. . . . . . . . . . . . . . .
Evaporative Emission Canister 1F–614. . . . . . . . . . . . Evaporative Emission Canister Purge Solenoid Valve 1
F–615
Crankshaft Position (CKP) Sensor
(1.4L/1.6L DOHC) 1F–615. . . . . . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor
(1.8L DOHC) 1F–616. . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft Position Sensor (1.4L/1.6L DOHC) 1F–618
Camshaft Position Sensor (1.8L DOHC) 1F–619. . . .
Engine Control Module (1.4L/1.6L DOHC) 1F–620. . .
Engine Control Module (1.8L DOHC) 1F–621. . . . . . .
Electronic Ignition System Ignition Coil
(1.4L/1.6L DOHC) 1F–621. . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition System Ignition Coil
(1.8L DOHC) 1F–622. . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION1F–623 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition System Operation 1F–623. . . . . . . . . . . . . . . .
Electronic Ignition System Ignition Coil 1F–623. . . . . .
Crankshaft Position Sensor 1F–623. . . . . . . . . . . . . . .
Camshaft Position Sensor 1F–623. . . . . . . . . . . . . . . .
Idle Air System Operation 1F–623. . . . . . . . . . . . . . . . .
Fuel Control System Operation 1F–623. . . . . . . . . . . .
Evaporative Emission Control System
Operation 1F–624. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Evaporative Emission Canister 1F–625. . . . . . . . . . . .
Positive Crankcase Ventilation System
Operation 1F–625. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature Sensor 1F–625. . . . . . .
Throttle Position Sensor 1F–625. . . . . . . . . . . . . . . . . .
Catalyst Monitor Oxygen Sensors 1F–625. . . . . . . . . .
Exhaust Gas Recirculation Valve 1F–626. . . . . . . . . . .
Intake Air Temperature Sensor 1F–626. . . . . . . . . . . .
Idle Air Control Valve 1F–626. . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Sensor 1F–626. . . . . . . .
Engine Control Module 1F–627. . . . . . . . . . . . . . . . . . .
Fuel Injector 1F–627. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Knock Sensor 1F–627. . . . . . . . . . . . . . . . . . . . . . . . . . .
Rough Road Sensor 1F–627. . . . . . . . . . . . . . . . . . . . .
Strategy–Based Diagnostics 1F–628. . . . . . . . . . . . . .
EOBD Serviceability Issues 1F–628. . . . . . . . . . . . . . .
Serial Data Communications 1F–629. . . . . . . . . . . . . .
On–Board Diagnostic (EOBD) 1F–629. . . . . . . . . . . . .
Comprehensive Component Monitor Diagnostic
Operation 1F–630. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common EOBD Terms 1F–630. . . . . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes 1F–632. . . . . . . . .
Primary System–Based Diagnostics 1F–633. . . . . . . .

1F – 232IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0444
EVAP PURGE CONTROL CIRCUIT NO SIGNAL
Circuit Description
The evaporative emission (EVAP) system includes the fol-
lowing components :
S Fuel tank.
S EVAP vent solenoid.
S Fuel tank pressure sensor.
S Fuel pipes and hoses.
S Fuel vapor lines.
S Fuel cap.
S EVAP canister.
S Purge lines.
S EVAP canister purge valve.
S EVAP service port.
The evaporative emission system is checked by applying
vacuum to the EVAP system and monitoring for a vacuum
decay. The engine control module(ECM) monitors the
vacuum level through the fuel tank pressure sensor signal.
At the appropriate time, the EVAP canister purge valve
and the EVAP vent solenoid are turned on, allowing the en-
gine to draw a small vacuum on the entire EVAP system.
After the desired vacuum level has been achieved, the
EVAP canister purge valve is turned OFF, sealing the sys-tem. If a sufficient vacuum level cannot be achieved, a
large leak is indicated. This can be caused by the following
conditions :
Missing or faulty fuel cap.
Disconnected or faulty fuel tank pressure sensor.
Disconnected, damaged, pinched, or blocked EVAP
purge line.
Disconnected or faulty EVAP canister purge valve.
Disconnected or faulty EVAP vent solenoid.
Open ignition feed circuit to the EVAP vent or purge sole-
noid.
Damaged EVAP canister.
Leaking fuel sensor assembly O–ring.
Leaking fuel tank or fuel filler beck.
Any of the above conditions can set DTC P0444.
The test is failed if the tank vacuum is less than 10 in H20
for 15 seconds and the manifold vacuum integral is greater
than 49512 (proportional to purge mass from the tank).
Conditions for Setting the DTC
S The canister purge solenoid circuit is an open con-
dition exist.