2004 DAEWOO LACETTI brake

1.8L DOHC ENGINE MECHANICAL 1C2 – 39
DAEWOO V–121 BL4
8. Disconnect the idle air control (IAC) valve connec-
tor.
9. Disconnect the throttle position sensor (TPS) con-
nector.
10. Disconnect the manifold absolute pressure (MAP)
sensor connector.
11. Disconnect the coolant hoses at the throttle body.
12. Disconnect all of the necessary vacuum hoses, in-
cluding the vacuum hose at the fuel pressure regu-
lator and the brake booster vacuum hose at the
intake manifold.
13. Disconnect the throttle cable from the throttle body
and the intake manifold.
14. Remove the throttle cable bracket bolts from the
intake manifold.
15. Remove the throttle cable bracket.
16. Remove the generator–to–intake manifold strap
bracket bolts and strap.
17. Remove the fuel rail as an assembly. Refer to Sec-
tion 1F, Engine Controls.
18. Remove the generator–to–intake manifold support
bracket bolts.
19. Remove the generator–to–intake manifold support
bracket.
20. Remove the intake manifold support bracket bolt at
the engine block and the intake manifold.
21. Remove the intake manifold support bracket.
22. Remove the intake manifold retaining bolt and nuts
in the sequence shown.
23. Remove the intake manifold.
24. Remove the intake manifold gasket.
25. Clean the sealing surfaces of the intake manifold
and the cylinder head.

1.8L DOHC ENGINE MECHANICAL 1C2 – 47
DAEWOO V–121 BL4
19. Disconnect the oxygen (O2) sensor connector, if
equipped.
20. Disconnect the idle air control (IAC) valve connec-
tor.
21. Disconnect the throttle position sensor (TPS) con-
nector.
22. Disconnect the engine coolant temperature sensor
(CTS) connector.
23. Disconnect the CTS connector.
24. Disconnect the generator voltage regulator connec-
tor and power lead.
25. Disconnect all of the necessary vacuum lines, in-
cluding the brake booster vacuum hose.
26. Disconnect the fuel return line at the fuel rail.
27. Disconnect the fuel feed line at the fuel rail.
28. Remove the fuel rail and injector channel cover as
an assembly. Refer to Section 1F, Engine Controls.
29. Disconnect the throttle cable from the throttle body
and the intake manifold bracket.
30. Disconnect the coolant hose at the throttle body.
31. Disconnect the heater outlet hose at the coolant
pipe.
32. Disconnect the coolant bypass hose from the cylin-
der head.
33. Disconnect the surge tank coolant hose from the
coolant pipe.
34. Disconnect the lower radiator hose from the coolant
pipe.
35. Disconnect the starter solenoid ”S” terminal wire
and power lead.
36. Remove the A/C compressor. Refer to Section 7B,
Manual Control Heating, Ventilation, and Air Condi-
tioning Systems.
37. Remove the exhaust flex pipe retaining nuts from
the exhaust manifold studs.
38. Remove the exhaust flex pipe retaining nuts from
the catalytic converter or the connecting pipe.
39. Remove the exhaust flex pipe.

1C2 – 50I1.8L DOHC ENGINE MECHANICAL
DAEWOO V–121 BL4
18. Install the exhaust flex pipe retaining nuts to the
catalytic converter or the connecting pipe.
Tighten
Tighten the exhaust flex pipe–to–catalytic converter
or connecting pipe retaining nuts to 35 NSm (26 lb–ft).
19. Connect the power steering pressure hose.
20. Connect the power steering return hose.
21. Install the A/C compressor, if equipped. Refer to
Section 7B, Manual Control Heating, Ventilation,
and Air Conditioning System.
22. Install the serpentine accessory drive belt. Refer to
Section 6B, Power Steering Pump.
23. Install the right front wheel well splash shield.
24. Install the right front wheel. Refer to Section 2E,
Tires and Wheels.
25. Connect the fuel feed line to the fuel rail.
26. Connect the fuel return line to fuel rail.
27. Install the fuel rail and injector channel cover as an
assembly. Refer to Section 1F, Engine Controls.
28. Connect all of the necessary vacuum lines including
the brake booster vacuum hose.
29. Connect the O2 sensor connector, if equipped.
30. Connect the starter solenoid ”S” terminal wire and
power lead.
31. Connect the generator voltage regulator connector.
32. Connect the CTS connector.
33. Connect the engine CTS connector.
34. Connect the TPS connector.
35. Connect the IAC valve connector.
36. Connect the MAP sensor connector.
37. Connect the knock sensor, if necessary
38. Connect the electrical connector at the DIS ignition
coil and the ECM ground terminal and at the starter
motor.
39. Install the air cleaner outlet hose between the
throttle body and the air cleaner housing.
40. Connect the breather tubes to the camshaft cover.
41. Connect the MAT sensor connector.
42. Install the cooling system radiator and the engine
cooling fans. Refer to Section 1D, Engine Cooling.

ENGINE ELECTRICAL 1E – 31
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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

ENGINE CONTROLS 1F – 9
DAEWOO V–121 BL4
Spark Advance
This is a display of the spark advance Ignition Coil (IC) cal-
culation which the ECM is programming in the ignition sys-
tem. It computes the desired spark advance using data
such as engine temperature, rpm, engine load, vehicle
speed and operating mode.
TCC Engaged
When the brake pedal is applied, the Torque Converter
Clutch (TCC) brake switch sends a signal to the ECM to
disengage the TCC and disable the cruise control.
Total Misfire Current Counter
Indicates the total number of misfires that have been de-tected in all the cylinders after 100 engine cycles. One
cycle equals one complete 4 stroke cycle. The total misfire
only increments during the steady state cruise conditions.
TP Sensor
The ECM uses the TP Sensor in order to determine the
amount of the throttle demanded by the vehicle’s operator.
The TP Sensor reads between 0.36–0.96 volts at idle to
above 4 volts at WOT.
Vehicle Speed
The vehicle speed sensor signal is converted into mph or
km/h for display. The vehicle speed output from the ECM
is 4000 pulses per mile. The scan tool uses the KWP 2000
serial data from the ECM to obtain vehicle speed, while the
Instrument Panel Cluster (IPC), cruise control module and
the chime alarm module use the 4000 ppm output.

1F – 30IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSIS
SYSTEM DIAGNOSIS
DIAGNOSTIC AIDS
If an intermittent problem is evident, follow the guidelines
below.
Preliminary Checks
Before using this section you should have already per-
formed the ”On–Board Diagnostic System Check.”
Perform a thorough visual inspection. This inspection can
often lead to correcting a problem without further checks
and can save valuable time. Inspect for the following con-
ditions:
S Engine control module (ECM) grounds for being
clean, tight, and in their proper location.
S Vacuum hoses for splits, kinks, collapsing and prop-
er connections as shown on the Vehicle Emission
Control Information label. Inspect thoroughly for
any type of leak or restriction.
S Air leaks at the throttle body mounting area and the
intake manifold sealing surfaces.
S Ignition wires for cracks, hardness, proper routing,
and carbon tracking.
S Wiring for proper connections.
S Wiring for pinches or cuts.
Diagnostic Trouble Code Tables
Do not use the Diagnostic Trouble Code (DTC) tables to
try to correct an intermittent fault. The fault must be pres-
ent to locate the problem.
Incorrect use of the DTC tables may result in the unneces-
sary replacement of parts.
Faulty Electrical Connections or Wiring
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful inspection of sus-
pect circuits for the following:
S Poor mating of the connector halves.
S Terminals not fully seated in the connector body.
S Improperly formed or damaged terminals. All con-
nector terminals in a problem circuit should be care-
fully inspected, reformed, or replaced to insure con-
tact tension.S Poor terminal–to–wire connection. This requires
removing the terminal from the connector body.
Road Test
If a visual inspection does not find the cause of the prob-
lem, the vehicle can be driven with a voltmeter or a scan
tool connected to a suspected circuit. An abnormal voltage
or scan tool reading will indicate that the problem is in that
circuit.
If there are no wiring or connector problems found and a
DTC was stored for a circuit having a sensor, except for
DTC P0171 and DTC P0172, replace the sensor.
Fuel System
Some intermittent driveability problems can be attributed
to poor fuel quality. If a vehicle is occasionally running
rough, stalling, or otherwise performing badly, ask the cus-
tomer about the following fuel buying habits:
S Do they always buy from the same source? If so,
fuel quality problems can usually be discounted.
S Do they buy their fuel from whichever fuel station
that is advertising the lowest price? If so, check the
fuel tank for signs of debris, water, or other contam-
ination.
IDLE LEARN PROCEDURE
Whenever the battery cables, the engine control module
(ECM), or the ECM fuse is disconnected or replaced, the
following idle learn procedure must be performed:
1. Turn the ignition ON for 5 seconds.
2. Turn the ignition OFF for 5 seconds.
3. Turn the ignition ON for 5 seconds.
4. Start the engine in park/neutral.
5. Allow the engine to run until the engine coolant is
above 185° F (85°C ).
6. Turn the A/C ON for 10 seconds, if equipped.
7. Turn the A/C OFF for 10 seconds, if equipped.
8. If the vehicle is equipped with an automatic trans-
axle, apply the parking brake. While pressing the
brake pedal, place the transaxle in D (drive).
9. Turn the A/C ON for 10 seconds, if equipped.
10. Turn the A/C OFF for 10 seconds, if equipped.
11. Turn the ignition OFF. The idle learn procedure is
complete.

ENGINE CONTROLS 1F – 31
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TEC (TOOTH ERROR CORRECTION)
LEARN PROCEDURE
When an ECM is reflashed, initialized or replaced, and dri-
veplate of fly wheel has been replaced, follow these proce-
dures to relearn the crankshaft position (CKP) system
variation :
CAUTION : To avoid personal injury when performing
the TEC learn procedure, always set the vehicle park-
ing brake and block the drive wheels. Release the
throttle immediately when the engine starts to decel-
erate. Once the learning procedure is completed, en-
gine control will be learned to the operator, and the
engine will respond to throttle position.1. Stay the gear parking or neutral.
2. Install the scan tool and select ”TEC (Toth Error
Correction) LEARN” menu.
3. Start the engine with A/C off.
4. Keep the engine coolant temperature above 65°C
(149° F)
5. Put the acceleration pedal above 4000 RPM until
the fuel cut–off occurs.
6. Wait 10–15 seconds.
7. Fulfill this procedure again if the scan tool does not
display ”OK” message.
8. Turn the ignition switch OFF.
9. Turn the ignition swtich ON and then clear the DTC
code.

1F – 82IENGINE CONTROLS
DAEWOO V–121 BL4
IDLE AIR CONTROL SYSTEM CHECK (1.8L DOHC)
Circuit Description
The Engine Control Module (ECM) controls the engine idle
speed with the Idle Air Control (IAC) valve. To increase the
idle speed, the ECM pulls the IAC pintle away from its seat,
allowing more air to pass by the throttle body. To decrease
the idle speed, it extends the IAC valve pintle toward its
seat, reducing bypass air flow. A scan tool will read the
ECM commands to the IAC valve in counts. The higher
counts indicate more air bypass (higher idle). The lower
counts indicate less air is allowed to bypass (lower idle).
Diagnostic Aids
If the idle is too high, stop the engine. Fully extend the Idle
Air Control (IAC) valve with a IAC driver. Start the engine.
If the idle speed is above 800 rpm, locate and repair the
vacuum leak. Also, check for a binding throttle plate or
throttle linkage or an incorrect base idle setting.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. The IAC valve is extended and retracted by the IAC
driver. IAC valve movement is verified by an engine
speed change. If no change in engine speed oc-
curs, the valve can be removed from the throttle
body and tested. Connect the IAC driver to the re-
moved IAC valve and turn the ignition ON. Do not
start the engine.5. This step checks the quality of the IAC valve move-
ment in Step 2. Fully extending the IAC valve may
cause an engine stall. This may be normal.
6. Steps 2 and 5 verify proper IAC valve operation.
This step checks the IAC circuit for a wiring or ECM
fault.
Idle Air Control Valve Reset Procedure
Whenever the battery cable or the Engine Control Module
(ECM) connector or the ECM fuse Ef11 is disconnected or
replaced, the following idle learn procedure must be per-
formed:
1. Turn the ignition ON for 5 seconds.
2. Turn the ignition OFF for 10 seconds.
3. Turn the ignition ON for 5 seconds.
4. Start the engine in park/neutral.
5. Allow the engine to run until the engine coolant is
above 185°F (85°C).
6. Turn the A/C ON for 10 seconds, if equipped.
7. Turn the A/C OFF for 10 seconds, if equipped.
8. If the vehicle is equipped with an automatic trans-
axle, apply the parking brake. While pressing the
brake pedal, place the transaxle in D (drive).
9. Turn the A/C ON for 10 seconds, if equipped.
10. Turn the A/C OFF for 10 seconds, if equipped.
11. Turn the ignition OFF. The idle learn procedure is
complete.