
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

1.4L/1.6L DOHC ENGINE MECHANICAL 1C1 – 49
DAEWOO V–121 BL4
17. Disconnect the oxygen (O2) sensor connector, if
equipped.
18. Disconnect the fuel injector harness connectors.
19. Disconnect the MAT, MAP sensor connectors.
20. Disconnect the throttle position sensor (TPS) con-
nector.
21. Disconnect the generator voltage regulator connec-
tor and power lead.
22. Remove the electrical harness clamp bolt.
23. Disconnect all of the necessary vacuum lines, in-
cluding the brake booster vacuum hose.
24. Disconnect the fuel feed line at the fuel rail.
25. Disconnect the throttle cable from the throttle body
and the intake manifold bracket.
26. Disconnect the surge tank coolant hose at the
throttle body.
27. Disconnect the heater outlet hose at the coolant
pipe.
28. Disconnect the heater inlet hose from the cylinder
head.
29. Disconnect the surge tank coolant hose from the
coolant pipe.
30. Disconnect the lower radiator hose from the coolant
pipe. Disconnect the starter solenoid ”S” terminal
wire. Remove the A/C compressor, if equipped. Re-
fer to Section 7B, Manual Control Heating, Ventila-
tion, and Air Conditioning Systems.
31. Remove the catalytic converter retaining nuts from
the exhaust pipe.
32. Remove the exhaust pipe.

1D – 4IENGINE COOLING
DAEWOO V–121 BL4
COOLING SYSTEM DIAGNOSIS
Engine Overheats
ChecksAction
Check for a loss of the coolant.Add the coolant.
Check for a weak coolant solution.Confirm that the coolant solution is a 50/50 mixture of eth-
ylene glycol and water.
Check the front of the radiator for any dirt, any leaves, or
any insects.Clean the front of the radiator.
Check for leakage from the hoses, the coolant pump, the
heater, the thermostat housing, the radiator, the core
plugs, or the head gasket.Replace any damaged components.
Check for a faulty thermostat.Replace a damaged thermostat.
Check for retarded ignition timing.Perform an ECM code diagnosis. Confirm the integrity of
the timing belt.
Check for an improperly operating electric cooling fan.Replace the electric cooling fan.
Check for radiator hoses that are plugged or rotted.Replace any damaged radiator hoses.
Check for a faulty water pump.Replace a faulty water pump.
Check for a faulty surge tank cap.Replace a faulty surge tank cap.
Check for a cylinder head or an engine block that is
cracked or plugged.Repair the damaged cylinder head or the damaged engine
block.
Loss of Coolant
ChecksAction
Check for a leak in the radiator.Replace a damaged radiator.
Check for a leak in the following locations:
S Surge tank.
S Hose.Replace the following parts, as needed:
S Surge tank.
S Hose.
Check for loose or damaged radiator hoses, heater hoses,
and connections.Reseat the hoses.
Replace the hoses or the clamps.
Check for leaks in the coolant pump seal.Replace the coolant pump seal.
Check for leaks in the coolant pump gasket.Replace the coolant pump gasket.
Check for an improper cylinder head torque.Tighten the cylinder head bolts to specifications.
Replace the cylinder head gasket, if needed.
Check for leaks in the following locations:
S Intake manifold.
S Cylinder head gasket.
S Cylinder block plug.
S Heater core.
S Radiator drain plug.Repair or replace any components, as needed, to correct
the leak.
Engine Fails to Reach Normal Operating Temperature or Cool Air
from the Heater
ChecksAction
Check to determine if the thermostat is stuck open or is the
wrong type of thermostat.Install a new thermostat of the correct type and heat range.
Check the coolant level to determine if it is below the MIN
mark on the surge tank.Add sufficient coolant to raise the fluid to the specified
mark on the surge tank.

ENGINE COOLING 1D – 9
DAEWOO V–121 BL4
THERMOSTAT (1.4L/1.6L DOHC)
Removal Procedure
CAUTION : To prevent personal injury, do not remove
the surge tank cap while the engine and the radiator
are hot because the heat causes the system to remain
under pressure. Scalding fluid and steam may be
blown out under pressure.
1. Drain the coolant. Refer to ”Draining and Refilling
the Cooling System” in this section.
2. Loosen the hose clamp on the upper radiator hose
at the thermostat housing.
3. Disconnect the upper radiator hose from the ther-
mostat housing.
4. Loosen the clamp on the bypass hose.
5. Disconnect the bypass hose from the thermostat
housing.
6. Remove the mounting bolts that hold the thermo-
stat housing to the cylinder head.
7. Remove the thermostat housing from the head.
8. Remove the O–ring seal from the head.
9. Check the valve seat for foreign matter that could
prevent the valve from seating properly.
10. Check the thermostat for proper operation. Refer to
”Thermostat Test” in this section.
11. Clean the thermostat housing and the cylinder head
mating surfaces.
Installation Procedure
1. Coat the sealing surface of a new O–ring seal with
Lubriplater®.
2. Install a new O–ring seal into the recess in the cyl-
inder head.
3. Secure the thermostat housing to the cylinder head
with the mounting bolts.
Tighten
Tighten the thermostat housing mounting bolts to 20
NSm (15 lb–ft).

1D – 10IENGINE COOLING
DAEWOO V–121 BL4
4. Connect the upper radiator hose to the thermostat
housing.
5. Secure the upper radiator hose to the thermostat
housing with a hose clamp.
6. Connect the bypass hose to the thermostat hous-
ing.
7. Secure the bypass hose with a hose clamp.
8. Refill the engine cooling system. Refer to ”Draining
and Refilling the Cooling System” in this section.
THERMOSTAT (1.8L DOHC)
Removal Procedure
CAUTION : To prevent personal injury, do not remove
the surge tank cap while the engine and the radiator
are hot because the heat causes the system to remain
under pressure. Scalding fluid and steam may be
blown out under pressure.
1. Drain the coolant. Refer to ”Draining and Refilling
the Cooling System” in this section.
2. Loosen the hose clamp on the upper radiator hose
at the thermostat housing.
3. Disconnect the upper radiator hose from the ther-
mostat housing.
4. Remove the mounting bolts that hold the thermo-
stat housing to the cylinder head.
5. Remove the thermostat housing from the cylinder
head.
6. Remove the seal ring from the thermostat housing.
7. Remove the thermostat from the thermostat hous-
ing by pressing the thermostat mounting flange
downward and then rotating the flange clockwise.
8. Inspect the valve seat for foreign matter that could
prevent the valve from sealing properly.
9. Inspect the thermostat for proper operation. Refer
to ”Thermostat Test” in this section.
10. Clean the thermostat housing and the cylinder head
mating surfaces.

ENGINE COOLING 1D – 11
DAEWOO V–121 BL4
Installation Procedure
1. Install the thermostat into the thermostat housing
by pressing the thermostat mounting flange down-
ward and then rotating the flange counterclockwise.
Rotate the thermostat mounting flange until it is
seated in the thermostat housing recesses.
2. Coat the sealing surface of a new seal ring with
Lubriplater®.
3. Install a new seal ring into the recess in the thermo-
stat housing.
4. Install the thermostat housing to the cylinder head.
5. Secure the thermostat housing to the cylinder head
with the mounting bolts.
Tighten
Tighten the thermostat housing mounting bolts to 15
NSm (11 lb–ft).
6. Connect the upper radiator hose to the thermostat
housing.
7. Secure the upper radiator hose to the thermostat
housing with a hose clamp.
8. Refill the engine cooling system. Refer to ”Draining
and Refilling the Cooling System” in this section.
WATER PUMP
Removal Procedure
1. Drain the engine cooling system to a level below
the thermostat housing. Refer to ”Draining and Re-
filling the Cooling System” in this section.
2. Remove the timing belt. Refer to Section 1C DOHC
Engine Mechanical.
3. Remove the timing belt tension roller retaining bolt.
4. Remove the timing belt tension roller.

ENGINE ELECTRICAL 1E – 3
DAEWOO V–121 BL4
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Battery Cable Nuts5–44
Battery Carrier Tray Lower, Side and Upper Bolts2015–
Battery Retainer Clamp–to–Battery Rod Nuts5–44
Generator Drive End Bearing Nut8160–
Generator Lower Bracket–to–Engine Block Bolts (1.8L Engine)3727–
Generator Lower Bracket–to–Generator Nut (1.4L/1.6L Engine)2518–
Generator Through–Bolts10–89
Generator–to–Intake Manifold and Cylinder Head Support
Bracket Bolts (1.8L Engine)3727–
Generator–to–Intake Manifold Strap Bracket Bolt (1.8L Engine)2216–
Generator Upper Support Bracket Bolt (1.4L/1.6L Engine)2015–
Intake Manifold–to–Cylinder Body Strap Bracket Bolts (Over
Starter)2216–
Starter Field Connector Nut12–106
Starter Lower Mounting Stud Ground Wire Nut12–106
Starter Mounting Studs/Nuts (1.4L/1.6L Engine)2518–
Starter Solenoid Assembly Screws8–71
Starter Solenoid Terminal–to–Battery Cable Terminal Nut5.5–49
Starter Solenoid Terminal–to–Ignition Solenoid Terminal Nut5.5–49
Starter Through–Bolts6–53
Starter–to–Engine Block Mounting Bolt (1.8L Engine)4533–
Starter–to–Engine Transaxle Mounting Bolt (1.8L Engine)5037–

1E – 6IENGINE ELECTRICAL
DAEWOO V–121 BL4
DIAGNOSIS
NO CRANK
StepActionValue(s)YesNo
11. Turn the headlamps ON.
2. Turn the dome lamps ON.
3. Turn the ignition to START.
Did the lights dim or go out?–Go to Step 2Go to Step 8
2Check the battery state of charge.
Is the green eye showing from the built–in hydrome-
ter?–Go to Step 3Go to
”Charging Pro-
cedure”
31. Connect the voltmeter positive lead to the posi-
tive battery terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?< 9.6 vGo to
”Charging Pro-
cedure”Go to Step 4
41. Connect the voltmeter negative lead to the
negative battery terminal.
2. Connect the positive voltmeter lead to the en-
gine block.
Does the voltmeter indicate the value specified?> 0.5 vGo to Step 5Go to Step 6
5Clean, tighten, or replace the negative battery cable.
Is the repair complete?–System OK–
61. Connect the voltmeter positive lead to the start-
er ”B+” terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
Does the voltmeter indicate the value specified?< 9 vGo to Step 7Go to Step 13
7Clean, tighten, or replace the positive battery cable.
Is the repair complete?–System OK–
8Inspect the engine fuse block fuse Ef5.
Is the fuse OK?–Go to Step 10Go to Step 9
9Inspect the engine fuse block fuse Ef4.
Is the fuse OK?–System OK–
10Check the connection at the starter ”ST” terminal.
Is the connection OK?–Go to Step 12Go to Step 11
11Clean or tighten the connection as needed.
Is the repair complete?–System OK–
121. Connect the voltmeter positive lead to the start-
er ”ST” terminal.
2. Connect the voltmeter negative lead to the
negative battery terminal.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?< 7 vGo to Step 13Go to Step 14
13Repair or replace the starter as needed.
Is the repair complete?–System OK–
14Determine the type of transaxle on the vehicle.
Is the vehicle equipped with an automatic transaxle?–Go to Step 15Go to Step 32