fuel DAEWOO LACETTI 2004 Service Workshop Manual

ENGINE CONTROLS 1F – 29
DAEWOO V–121 BL4
COMPONENT LOCATOR (1.8L DOHC)
Components on ECM Harness
11. Engine Control Module (ECM)
12. Data Link Connector (DLC)
13. Malfunction Indicator Lamp (MIL)
14. ECM/ABS Harness Ground
15. Fuse Panel (2)
ECM Controlled Devices
20. Exhaust Gas Recirculation (EGR) Valve
21. Fuel Injector (4)
22. Idle Air Control (IAC) Valve
23. Fuel Pump Relay
24. Cooling Fan Relays (High)
25. Cooling Fan Control Relay (A/C Only)
26. Electronic Ignition System Ignition Coil
27. Evaporative Emission (EVAP) Control Purge Sole-
noid
28. Main Relay
29. A/C Compressor Relay30. Cooling Fan Relays (Low)
Information Sensors
31. Manifold Absolute Pressure (MAP) Sensor
32. Front Heated Oxygen Sensor (HO2S1)
33. Throttle Position (TP) Sensor
34. Engine Coolant Temperature (ECT) Sensor
35. Intake Air Temperature (IAT) Sensor
36. Vehicle Speed Sensor (VSS)
38. Crankshaft Position (CKP) Sensor
39. Knock Sensor
40. Rear Heated Oxygen Sensor (HO2S2)
41. Camshaft Position (CMP) Sensor
Not PCM/ECM Connected
42. Evaporative Emission Canister (under vehicle, be-
hind right rear wheel)
43. Engine Oil Pressure Switch
44. Air Cleaner

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
DAEWOO V–121 BL4
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 – 36IENGINE CONTROLS
DAEWOO V–121 BL4
MULTIPLE ECM INFORMATION SENSOR DTCS SET
Circuit Description
The Engine Control Module (ECM) monitors various sen-
sors to determine engine operating conditions. The ECM
controls fuel delivery, spark advance, transaxle operation,
and emission control device operation based on the sen-
sor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull–up resistor and
monitors the voltage present between the sensor and the
resistor to determine the status of the Engine Coolant
Temperature (ECT) sensor, the Intake Air Temperature
(IAT) sensor. The ECM provides the Exhaust Gas Recir-
culation (EGR) Pintle Position Sensor, the Throttle Posi-
tion (TP) sensor, the Manifold Absolute Pressure (MAP)
sensor, and the Fuel Tank Pressure Sensor with a 5 volt
reference and a sensor ground signal. The ECM monitors
the separate feedback signals from these sensors to de-
termine their operating status.
Diagnostic Aids
Be sure to inspect the ECM and the engine grounds for be-
ing secure and clean.
A short to voltage in one of the sensor circuits can cause
one or more of the following DTCs to be set: P0108,
P0113, P0118, P0123, P1106, P1111, P1115, P1121,
P0463, P0533.
If a sensor input circuit has been shorted to voltage, en-
sure that the sensor is not damaged. A damaged sensor
will continue to indicate a high or low voltage after the af-
fected circuit has been repaired. If the sensor has been
damaged, replace it.
An open in the sensor ground circuit between the ECM and
the splice will cause one or more of the following DTCs to
be set: P0107, P0108, P0113, P0118, P0122, P0123,
P1106, P1111, P1115, P1121, P0462, P0532.
A short to ground in the 5 volt reference circuit or an open
in the 5 volt reference circuit between the ECM and the
splice will cause one or more of the following DTCs to be
set: P0107, P0112, P0117, P0122, P1107, P1112, P1114,
P1122, P0462, P0532.Check for the following conditions:
S Inspect for a poor connection at the ECM. Inspect
harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire con-
nection.
S Inspect the wiring harness for damage. If the har-
ness appears to be OK, observe an affected sen-
sor ’s displayed value on the scan tool with the igni-
tion ON and the engine OFF while moving
connectors and wiring harnesses related to the af-
fected sensors. A change in the affected sensor’s
displayed value will indicate the location of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The Powertrain On–Board Diagnostic (EOBD) Sys-
tem Check prompts the technician to complete
some basic checks and store the freeze frame and
failure records data on the scan tool if applicable.
This creates an electronic copy of the data taken
when the malfunction occurred. The information is
then stored on the scan tool for later reference.
9. A faulty EGR valve can leak a small amount of cur-
rent from the ignition feed circuit to the 5 volt refer-
ence circuit. If the problem does not exist with the
EGR valve disconnected, replace the EGR valve.
0. If a sensor input circuit has been shorted to voltage,
ensure that the sensor has not been damaged. A
damaged IAT or ECT sensor will continue to indi-
cate a high voltage or low temperature after the
affected circuit has been repaired. A damaged ACT,
TP, MAP, Fuel Tank Pressure, or EGR Pintle Posi-
tion sensor will indicate a high or low voltage or
may be stuck at a fixed value after the affected cir-
cuit has been repaired. If the sensor has been dam-
aged, replace it.
21. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.

1F – 38IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
10Replace the EGR valve.
Is the replacement complete?–Go to Step 19–
11Locate and repair the short to voltage in the MAP
sensor signal circuit.
Is the repair complete?–Go to Step 19–
12Locate and repair the short to voltage in the TP sen-
sor signal circuit.
Is the repair complete?–Go to Step 19–
13Locate and repair the short to voltage in the IAT sen-
sor signal circuit.
Is the repair complete?–Go to Step 19–
14Locate and repair the short to voltage in the ECT
sensor signal circuit.
Is the repair complete?–Go to Step 19–
15Locate and repair the short to voltage in the EGR
Pintle Position sensor circuit.
Is the repair complete?–Go to Step 19–
16Measure the voltage of the fuel tank pressure sensor
signal circuit between the ECM harness connector
and ground.
Does the voltage near the specified value?0 VGo to Step 18Go to Step 17
17Locate and repair the short to voltage in the fuel tank
pressure sensor signal circuit.
Is the replacement complete?–Go to Step 19–
18Replace the ECM.
Is the repair complete?–Go to Step 19
191. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTCs as specified in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 20Go to Step 2
22Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

1F – 40IENGINE CONTROLS
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN (1.4L/1.6L DOHC)
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the occurred. The information is then stored on the
scan tool for later reference.
2. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
3. It is important to check for the presence of sparkfrom all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the Crank-
shaft Position (CKP) sensor is OK.
19. In checking the engine control module (ECM) out-
puts for the electronic spark timing signal, it recom-
mended to use an oscilloscope to view the varying
voltage signals. In measuring these outputs with a
voltmeter, intermittent errors may occur that cannot
be seen by a voltmeter.
35. This step checks for proper operation of the ECM’s
control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the ECM to operate the fuel injectors. If there is
no ground present during the cranking of the en-
gine, and the fuel injector wiring is OK, the ECM is
at fault.
Engine Cranks But Will Not Run (1.4L/1.6L DOHC)
CAUTION : Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines.Damage to the lines could cause a fuel leak, resulting
in possible fire or personal injury.
Step
ActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the check complete.–Go to Step 2Go to
”Euro On–
Board Diagnos-
tic System
Check”
2Crank the engine.
Does the engine start and continue to run?–System OKGo to Step 3
3Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?689 kPa
(100 psi)Go to Step 7Go to Step 4
4Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 6Go to Step 5
5Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 2–
6Repair internal engine damage as needed.
Is the repair complete?–Go to Step 2–
7Inspect the fuel pump fuse.
Is the problem found?–Go to Step 8Go to Step 9
8Replace the fuse.
Is the repair complete?–Go to Step 2–
9Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
Is spark present from all of the ignition wires?–Go to Step 23Go to Step 10
101. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a resist-
ance above the value specified.
3. Check for the presence of spark from all of the
ignition wire.
Is spark present from all of the ignition wires?30000 WGo to Step 2Go to Step 11

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

1F – 44IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
39Repair the open or short circuit the following termi-
nals.
S Terminal 6 of ECM and terminal 86 of fuel
pump relay.
S Terminal 87 of fuel pump relay and terminal
3 of fuel pump.
Is the repair complete?–Go to Step 2–
40Replace the fuel pump relay.
Is the repair complete?–Go to Step 2–
411. Turn the ignition OFF.
2. Disconnect the fuel inject harness connectors
from all of the fuel injectors.
3. Turn the ignition ON.
4. Connect test light between fuel injector harness
connector 2 and ground.
5. Repeat step 4 for each of the remaining fuel
injectors.
Does the test light on at all of the fuel injectors?–Go to Step 42Go to Step 45
421. Turn the ignition OFF.
2. Connect test light between fuel injector harness
connector 1 and battery positive.
3. Crank the engine.
4. Repeat step 2 and 3 for each of the remaining
fuel injectors.
Does the test light flash for all of the fuel injectors?–Go to Step 43Go to Step 46
43Measure the resistance of each fuel injectors.
Is the resistance within the value specified.
Notice : the resistance will increase slightly at higher
temperature.11.6–12.4WSystem OKGo to Step 44
44Replace any of the fuel injectors with a resistance
out of specification.
Is the repair complete?–Go to Step 2–
451. Inspect the fuse EF22 in engine fuse block.
2. Check for an open between the circuit from
terminal 2 of the four fuel injectors and terminal
87 of main relay.
Is the problem found?–Go to Step 48Go to
”Main Relay
Circuit Check”
46Measure the resistance between following termi-
nals.
S Terminal 2 of injector 1 connector and terminal
59 of ECM connector.
S Terminal 2 of injector 2 connector and terminal
90 of ECM connector.
S Terminal 2 of injector 3 connector and terminal
60 of ECM connector.
S Terminal 2 of injector 4 connector and terminal
89 of ECM connector.
Does the resistance within the specified value?0 WGo to Step 49Go to Step 47
47Repair the open fuel injector harness wire(s).
Is the repair complete?–Go to Step 2–

ENGINE CONTROLS 1F – 47
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN (1.8L DOHC)
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the occurred. The information is then stored on the
scan tool for later reference.
2. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
3. It is important to check for the presence of sparkfrom all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the Crank-
shaft Position (CKP) sensor is OK.
19. In checking the engine control module (ECM) out-
puts for the electronic spark timing signal, it recom-
mended to use an oscilloscope to view the varying
voltage signals. In measuring these outputs with a
voltmeter, intermittent errors may occur that cannot
be seen by a voltmeter.
35. This step checks for proper operation of the ECM’s
control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the ECM to operate the fuel injectors. If there is
no ground present during the cranking of the en-
gine, and the fuel injector wiring is OK, the ECM is
at fault.
Engine Cranks But Will Not Run (1.8L DOHC)
CAUTION : Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines.Damage to the lines could cause a fuel leak, resulting
in possible fire or personal injury.
Step
ActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic
(EOBD) Sys-
tem Check”
2Check for set Diagnostic Trouble Code (DTC)
P0601.
Is the DTC set?–Go to applica-
ble DTC tableGo to Step 4
3Crank the engine.
Does the engine start and continue to run?–System OKGo to Step 5
4Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?689 kPa
(100 psi)Go to Step 8Go to Step 5
5Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 7Go to Step 6
6Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 3–
7Repair the internal engine damage as needed.
Is the repair complete?–Go to Step 3–
8Inspect the fuel pump fuse.
Is the problem found?–Go to Step 9Go to Step 10
9Replace the fuse.
Is the repair complete?–Go to Step 3–
101. Install a scan tool.
2. Turn the ignition ON, the engine OFF and close
the throttle.
Does the Throttle Position (TP) sensor read less
than the specified value.1.0 vGo to Step 11Go to ”DTC
P0123 Throttle
Position Sensor
High Voltage”