2004 DAEWOO LACETTI Ect

HOW TO USE ELECTRICAL WIRING DIAGRAMW1–3
2. CIRCUIT IDENTIFICATION SYMBOL
IDENTIFICATION
SYMBOLMEANING
CConnector
DDiode
EfFuse in engine room fuse box
FFuse in passenger room fuse box
GGround
SSplice pack(Junction connector)
3. FUNCTION OF POWER SUPPLY LINE (NUMBER)
Power supply NoPower supply condition
15Battery Voltage(B+) supply in Ignition Switch ”ON” and ”ST” (IGN 1)
15ABattery Voltage(B+) supply in Ignition Switch ”ON” (IGN 2)
15CBattery Voltage(B+) supply in Ignition Switch ”ON” and ”ACC”
30Battery Voltage(B+) supply directly regardless of Ignition Switch
31Ground connected to battery(
)
58Battery Voltage(B+) supply in Head Lamp Switch 1st and 2nd step (Illumination circuit)
4. WIRING HARNESS COLOR IDENTIFICATION
AbbreviationColorAbbreviationColor
BrBrownSbSky Blue
GGreenRRed
VVioletLBlue
PPinkYYellow
WWhiteGrGray
OrOrangeBBlack
LgLight Green
5. HOW TO CHECK TERMINAL NUMBER OF CONNECTOR
" Terminal number is given based on Female Terminal Connectorex) Terminal Number 4 of C901 connection

SECTION : 1A
GENERAL ENGINE INFORMATION
TABLE OF CONTENTS
DIAGNOSIS1A–1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression Test 1A–1. . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pressure Test 1A–2. . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Leak Diagnosis 1A–3. . . . . . . . . . . . . . . . . . . . . . . .
Knock Diagnosis 1A–4. . . . . . . . . . . . . . . . . . . . . . . . . . Noise Diagnosis 1A–8. . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL INFORMATION1A–11 . . . . . . . . . . . . . . . . . .
Cleanliness and Care 1A–11. . . . . . . . . . . . . . . . . . . . .
On–Engine Service 1A–11. . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS
COMPRESSION TEST
Important : Disconnect the Crankshaft Position (CKP)
Sensor connector to disable the fuel and the ignition sys-
tems.
Test the compression pressure for each cylinder. Low
compression pressure may be the fault of the valves or the
pistons. The following conditions should be considered
when you check the cylinder compression:
S The engine should be at normal operating tempera-
ture.
S The throttle must be wide open.
S All the spark plugs should be removed.
S The battery must be at or near full charge.
1. Place approximately three squirts of oil from a
plunger– type oiler into each spark plug port.
2. Insert the engine compression gauge into each
spark plug port.
3. Crank test each cylinder with four to five compres-
sion strokes using the starter motor.4. The lowest reading should not be less than 70% of
the highest reading. The compression gauge read-
ing should not be less than 689 kPa (100 psi) for
any of the cylinders.
5. Examine the gauge readings obtained after the four
”puffs” per cylinder are obtained from cranking the
starter motor. The readings are explained in the
following descriptions:
S Normal Condition – Compression builds up quickly
and evenly to the specified compression on each
cylinder.
S Piston Rings Faulty – Compression is low on the
first stroke and tends to build up on following
strokes, but the compression pressure does not
reach normal. The compression pressure improves
considerably with the addition of oil into the cylin-
der.
S Valves Faulty – Low compression pressure on the
first stroke. The compression pressure does not
tend to build up on the following strokes. The com-
pression pressure does not improve much with the
addition of oil into the cylinder.

1A – 2IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
OIL PRESSURE TEST
StepActionValue(s)YesNo
1Is the oil pressure warning lamp on?–Go to Step 2System OK
2Check the oil level in the crankcase.
Is the oil level low?–Go to Step 3Go to Step 4
3Add oil so that the oil level is up to the fullmark on the
indicator.
Is the repair complete?–Go to Step 1–
4Check the idle speed.
Is the idle speed below the specified value ?825 rpmGo to Step 5Go to Step 6
5Increase the idle speed.
Is the speed increased?–Go to Step 1–
6Inspect the oil pressure switch.
Is the oil pressure switch incorrect or malfunction-
ing?–Go to Step 7Go to Step 8
7Install a new oil pressure switch.
Is the repair complete?–Go to Step 1–
8Inspect the oil pressure gauge.
Is the oil pressure gauge incorrect or malfunction-
ing?–Go to Step 9Go to Step 10
9Install a new oil pressure gauge.
Is the repair complete?–Go to Step 1–
10Inspect the engine oil.
Is the engine oil in the crankcase diluted or of the im-
proper viscosity?–Go to Step 11Go to Step 12
11Install new engine oil of the proper viscosity for the
expected temperatures.
Is the repair complete?–Go to Step 1–
12Inspect the oil pump.
Is the pump worn or dirty?–Go to Step 13Go to Step 14
13Replace the oil pump.
Is the repair complete?–Go to Step 1–
14Inspect the oil filter.
Is the oil filter plugged?–Go to Step 15Go to Step 16
15Install a new oil filter.
Is the repair complete?–Go to Step 1–
16Inspect the oil pickup screen.
Is the oil pickup screen loose or plugged?–Go to Step 17Go to Step 18
17Tighten or replace the oil pickup screen, as neces-
sary.
Is the repair complete?–Go to Step 1–
18Inspect the oil pickup tube.
Are there any holes in the oil pickup tube?–Go to Step 19Go to Step 20
19Replace the oil pickup tube.
Is the repair complete?–Go to Step 1–

GENERAL ENGINE INFORMATION 1A – 3
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
20Inspect the bearing clearances.
Are the bearing clearances more than the specified
values?Crankshaft
0.026 ~0.046
mm
(0.0010~0.001
8 in.)
Connecting
Rod 0.019 ~
0.070 mm
(0.0007 ~
0.0027 in.)Go to Step 21Go to Step 22
21Replace the bearing, if necessary.
Is the repair complete?–Go to Step 1–
22Inspect the oil galleries.
Are the oil galleries cracked, porous, or plugged?–Go to Step 23Go to Step 24
23Repair or replace the engine block.
Is the repair complete?–Go to Step 1–
24Inspect the gallery plugs.
Are any of the gallery plugs missing or installed im-
properly?–Go to Step 25Go to Step 26
25Install the plugs or repair, as necessary.
Is the repair complete?–Go to Step 1–
26Inspect the camshaft.
Is the camshaft worn or is there evidence of poor
machining?–Go to Step 27System OK
27Replace the camshaft.
Is the repair complete?–Go to Step 1–
OIL LEAK DIAGNOSIS
Most fluid oil leaks are easily located and repaired by visu-
ally finding the leak and replacing or repairing the neces-
sary parts. On some occasions, a fluid leak may be difficult
to locate or repair. The following procedures may help you
in locating and repairing most leaks.
Finding the Leak:
1. Identify the fluid. Determine whether it is engine oil,
automatic transmission fluid, power steering fluid,
etc.
2. Identify where the fluid is leaking from.
1) After running the vehicle at normal operating
temperature, park the vehicle over a large sheet
of paper.
2) Wait a few minutes.
3) Find the approximate location of the leak by the
drippings on the paper.
3. Visually check around the suspected component.
Check around all the gasket mating surfaces for
leaks. A mirror is useful for finding leaks in areas
that are hard to reach.
4. If the leak still cannot be found, it may be neces-
sary to clean the suspected area with a degreaser,
steam, or spray solvent.
1) Thoroughly clean the area.2) Dry the area.
3) Operate the vehicle for several miles at normal
operating temperature and varying speeds.
4) After operating the vehicle, visually check the
suspected component.
5) If you still cannot locate the leak, try using the
powder or black light and dye method.
Powder Method:
1. Clean the suspected area.
2. Apply an aerosol–type powder, (such as foot pow-
der), to the suspected area.
3. Operate the vehicle under normal operating condi-
tions.
4. Visually inspect the suspected component. Trace
the leak path over the white powder surface to the
source.
Black Light and Dye Method:
A dye and light kit is available for finding leaks. Refer to the
manufacturer ’s directions when using the kit.
1. Pour the specified amount of dye into the engine oil
fill tube.
2. Operate the vehicle under normal operating condi-
tions as directed in the kit.
3. Direct the light toward the suspected area. The
dyed fluid will appear as a yellow path leading to
the source.

1A – 4IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
Repairing the Leak
Once the origin of the leak has been pinpointed and traced
back to its source, the cause of the leak must be deter-
mined in order for it to be repaired properly. If a gasket is
replaced, but the sealing flange is bent, the new gasket will
not repair the leak. The bent flange must be repaired also.
Before attempting to repair a leak, check for the following
conditions and correct them as they may cause a leak.
Gaskets:
S The fluid level/pressure is too high.
S The crankcase ventilation system is malfunctioning.
S The fasteners are improperly tightened or the
threads are dirty or damaged.
S The flanges or the sealing surface is warped.S There are scratches, burrs or other damage to the
sealing surface.
S The gasket is damaged or worn.
S There is cracking or porosity of the component.
S An improper seal was used, (where applicable).
Seals:
S The fluid level/pressure is too high.
S The crankcase ventilation system is malfunctioning.
S The seal bore is damaged, scratched, burred or
nicked.
S The seal is damaged or worn.
S Improper installation is evident.
S There are cracks in the component.
S The shaft surface is scratched, nicked or damaged.
S A loose or worn bearing is causing excess seal
wear.
KNOCK DIAGNOSIS
Definition for Knock
Engine knock refers to various types of engine noise.
Heavy knock is usually very loud and the result of broken
or excessively worn internal engine components. Lightknock is a noticeable noise, but not as loud. Light knock
can be caused by worn internal engine components.
Loose or broken external engine components can also
cause heavy or light knock.
Engine Knocks Cold and Continues for Two–Three Minutes and/or
Knock Increases with Engine Torque
StepActionValue(s)YesNo
1Does the engine knock when it is cold and continue
for two to three minutes or does the knock increase
with torque?–Go to Step 2System OK
2Inspect the flywheel.
Is the flywheel contacting the splash shield?–Go to Step 3Go to Step 4
3Reposition the splash shield.
Is the repair complete?–Go to Step 1–
4Inspect the balancer and the drive pulleys.
Is either the balancer or the drive pulleys loose or
broken?–Go to Step 5Go to Step 6
5Tighten or replace the balancer or the drive pulleys.
Is the repair complete?–Go to Step 1–
6Inspect the piston–to–bore clearance.
Is the clearance more than the specified value?0.030 mm
(0.001 in.)Go to Step 7Go to Step 8
71. Rebore the cylinder and hone to size.
2. Replace the piston.
Is the repair complete?*–Go to Step 1–
8Inspect the connecting rod.
Is the connecting rod bent?–Go to Step 9System OK
9Replace the connecting rod.
Is the repair complete?–Go to Step 1–
* Cold engine piston knock usually disappears when the cylinder is grounded out. Cold engine piston knock, which disap-
pears in about 1.5 minutes, is considered acceptable.

GENERAL ENGINE INFORMATION 1A – 5
DAEWOO V–121 BL4
Heavy Knock Hot with Torque Applied
StepActionValue(s)YesNo
1Is there a heavy knock when the engine is hot and
torque is applied?–Go to Step 2System OK
2Inspect the balancer and the pulley hub.
Is the balancer or the pulley hub broken?–Go to Step 3Go to Step 4
3Replace the broken balancer or the pulley hub.
Is the repair complete?–Go to Step 1–
4Inspect the torque converter bolts.
Are the bolts tightened to specified value?45 NSm
(33 lb–ft)Go to Step 5Go to Step 6
5Tighten the torque converter bolts.
Is the repair complete?–Go to Step 1–
6Inspect the accessory belts.
Are the belts too tight or nicked?–Go to Step 7Go to Step 8
7Replace and/or tension the belts to specifications,
as necessary.
Is the repair complete?–Go to Step 1–
8Inspect the exhaust system.
Is the system grounded?–Go to Step 9Go to Step 10
9Reposition the system, as necessary.
Is the repair complete?–Go to Step 1–
10Inspect the flywheel.
Is the flywheel cracked?–Go to Step 11Go to Step 12
11Replace the flywheel.
Is the repair complete?–Go to Step 1–
12Inspect the main bearing clearance.
Is the clearance more than the specified value?0.026~0.046
mm (0.0010~
0.0018 in.)Go to Step 13Go to Step 14
13Replace the main bearings, as necessary.
Is the repair complete?–Go to Step 1–
14Inspect the rod bearing clearance.
Is the clearance more than the specified value?0.019 ~
0.070 mm
(0.0007 ~
0.0028 in.)Go to Step 15System OK
15Replace the rod bearings, as necessary.
Is the repair complete?–Go to Step 1–

1A – 6IGENERAL ENGINE INFORMATION
DAEWOO V–121 BL4
Light Knock Hot
StepActionValue(s)YesNo
1Is there a light knock when the engine is hot?–Go to Step 2System OK
2Is detonation or spark knock evident?–Go to Step 3Go to Step 4
3Check the engine timing and the fuel quality.
Was the problem found?–Go to Step 1–
4Inspect the torque converter bolts.
Are the bolts tightened to the specified value?45 NSm
(33 lb–ft)Go to Step 5Go to Step 6
5Tighten the torque converter bolts.
Is the repair complete?–Go to Step 1–
6Inspect the manifold.
Is there an exhaust leak at the manifold?–Go to Step 7Go to Step 8
7Tighten the bolts or replace the gasket.
Is the repair complete?–Go to Step 1–
8Check the rod bearing clearance.
Is the clearance within the specified value?0.019 ~
0.070 mm
(0.0007 ~
0.0028 in.)Go to Step 9System OK
9Replace the rod bearings, as necessary.
Is the repair complete?–Go to Step 1–
Knocks During Initial Start–Up But Last Only a Few Seconds
StepActionValue(s)YesNo
1Does the engine knock during initial start–up but last
only a few seconds?–Go to Step 2System OK
2Check the engine oil.
Is the proper viscosity oil used in the crankcase?–Go to Step 4Go to Step 3
3Install oil of the proper viscosity for the expected
seasonal temperatures.
Is the repair complete?–Go to Step 1–
4Inspect the hydraulic lifters.
Is there evidence of hydraulic lifter bleed–down?–Go to Step 5Go to Step 6
5Clean, test and replace the lifters, as necessary.
Is the repair complete?*–Go to Step 1–
6Inspect the crankshaft end clearance.
Is the clearance more than specified value?0.1 mm
(0.0039 in.)Go to Step 7Go to Step 8
7Replace the crankshaft thrust bearing.
Is the repair complete?–Go to Step 1–
8Inspect the front main bearing clearance.
Is the clearance more than the specified value?0.026~0.046
mm (0.0010~
0.0018 in.)Go to Step 9System OK
9Replace the worn parts of the front main bearing.
Is the repair complete?–Go to Step 1–
* When the engine is stopped, some valves will be open. Spring pressure against the lifters will tend to bleed lifter down.
Attempts to repair this should be made only if the problem is consistent.
An engine that is only operated for short periods between start–ups may have lifter noise that lasts for a few minutes. This
is a normal condition.

GENERAL ENGINE INFORMATION 1A – 7
DAEWOO V–121 BL4
Knocks at Idle Hot
StepActionValue(s)YesNo
1Does the engine knock at idle when hot?–Go to Step 2System OK
2Inspect the drive belts.
Are the belts loose or worn?–Go to Step 3Go to Step 4
3Tension or replace the belts, as necessary.
Is the repair complete?–Go to Step 1–
4Inspect the A/C compressor and the generator.
Is either the compressor or the generator faulty?–Go to Step 5Go to Step 6
5Replace the faulty A/C compressor or the generator.
Is the repair complete?–Go to Step 1–
6Inspect the valve train.
Are valve train components faulty?–Go to Step 7Go to Step 8
7Replace the faulty valve train components.
Is the repair complete?–Go to Step 1–
8Check the engine oil.
Is the proper viscosity oil used in the crankcase?–Go to Step 10Go to Step 9
9Install oil of the proper viscosity for the expected
seasonal temperatures.
Is the repair complete?–Go to Step 1–
10Inspect the piston pin clearance.
Is the clearance more than the specified value?0.020 mm
(0.0008 in.)Go to Step 11Go to Step 12
11Replace the piston and the pin.
Is the repair complete?–Go to Step 1–
12Check the connecting rod alignment.
Is the alignment faulty?–Go to Step 13Go to Step 14
13Check and replace rods, as necessary.
Is the repair complete?–Go to Step 1–
14Inspect the piston–to–bore clearance.
Is the clearance within the specified value?0.030 mm
(0.0012 in.)Go to Step 16Go to Step 15
15Hone the bore and fit a new piston.
Is the repair complete?Go to Step 1–
16Inspect the crankshaft balancer.
Is the balancer loose?–Go to Step 17Go to Step 18
17Torque or replace worn parts.
Is the repair complete?–Go to Step 1–
18Check the piston pin offset.
Is the offset at the specified value?0.5 ± 0.1 mm
(0.020 ~ 0.003
in.)
Toward Thrust
SideGo to Step 19System OK
19Install the correct piston.
Is the repair complete?–Go to Step 1–