DAEWOO NUBIRA 2004 Service Repair Manual

ENGINE CONTROLS 1F – 575
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
5Replace the sensor in the affected circuit, if a Diag-
nostic Trouble Code (DTC) was stored for this circuit
(except for the DTCs P0171 and P0172.
Is the repair complete?–System OK–
6Does an intermittent Malfunction Indicator Lamp
(MIL) or DTC occur?–Go toStep 7Go toStep 8
71. Check for a faulty relay, electronic control mod-
ule (ECM) driven solenoid, or switch.
2. Check for improper installation of electrical de-
vices, such as lights, two–way radios, electric
motors, etc.
3. Inspect the ignition control wires for proper
routing (away from ignition wires, ignition sys-
tem components, and the generator).
4. Check for a short–to–ground in the MIL circuit
or the DLC ”test” terminal.
5. Inspect the ECM ground connections.
6. Correct or repair the affected circuits as need-
ed.
Is the repair complete?–System OK–
81. Check for a loss of DTC memory.
2. 2. Disconnect the Throttle Position Sensor.
3. Run the engine at idle until the MIL comes on.
4. Turn the ignition OFF.
Is DTC P0122 stored in memory?–Go toStep 10Go toStep 9
9Replace the ECM.
Is the repair complete?–System OK–
10Does the vehicle stall while driving?–Go toStep 11Go toStep 12
11Monitor the Front Heated Oxygen Sensor (HO2S1)
and the injector base pulse width with the scan tool.
Does the scan tool display a steady low voltage
(about 0 mv) for the HO2S1 sensor with the control
module commanding an injector base pulse width of
the value specified?8 msGo toStep 9Go toStep 12
121. Check for an open diode across the A/C clutch
and for other open diodes.
2. Repair or replace any components as needed.
Is the repair complete?–System OK–

1F – 576IENGINE CONTROLS
DAEWOO V–121 BL4
HARD START
Definition : The engine cranks OK, but does not start for
a long time. The engine eventually runs or may start and
immediately die.Important : Ensure that the driver is using the correct
starting procedure. Before diagnosing, check service bul-
letins for updates.
Step
ActionValue(s)YesNo
1Were the Important Preliminary Checks performed?–Go toStep 2Go to
”Important Pre-
liminary
Checks”
21. Connect the scan tool to the Data Link Con-
nector (DLC).
2. Check the Engine Coolant Temperature (ECT)
sensor and the Intake Air Temperature (IAT)
sensor using the scan tool.
3. Compare the coolant temperature and the IAT
with the ambient temperature when the engine
is cold.
Do the ECT and the IAT readings differ from the am-
bient temperature by more than the value specified?5°F (3°C)Go toStep 3Go toStep 4
31. Measure the resistance of the ECT and the IAT
sensor.
2. Compare the resistance value to specifications
using the Temperature Vs. Resistance tables
for diagnostic trouble codes (DTCs) P0118 and
P0113.
3. If the resistance is not the same, replace the
faulty sensor.
Is the repair complete?–System OK–
41. Check for a sticking throttle shaft or a binding
linkage that may cause a high Throttle Position
(TP) sensor voltage. Repair or replace as
needed.
2. Check the TP sensor voltage reading with the
throttle closed.
Does the voltage measure within the value speci-
fied?0.4–0.8 vGo toStep 5Go toStep 26
51. Check the Manifold Absolute Pressure (MAP)
sensor response and accuracy.
2. Replace the MAP sensor as needed.
Is the repair complete?–System OKGo toStep 6
6Check the fuel pump operation.
Does the fuel pump operate for the specified time
when the ignition switch is turned ON?2 secGo toStep 7Go to
”Fuel Pump
Relay Circuit
Check”
7Check the fuel system pressure.
Is the fuel pressure within the specifications?41–47 psi
(284–325 kPa)Go toStep 8Go toStep 29
8Check for water contamination in the fuel.
Is fuel contaminated?–Go toStep 9Go toStep 10
9Replace the contaminated fuel.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 577
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
101. Check the fuel injector driver circuit.
2. Disconnect all of the fuel injector harness con-
nectors at the fuel injectors.
3. Connect an injector test light between the har-
ness terminals of each fuel injector connector.
4. Note the test light while cranking the engine.
Does the test light blink at all connectors?–Go toStep 13Go toStep 11
11Check the fuel injector driver wiring harness, the
connectors, and the connector terminals for the
proper connections.
Is the problem found?–Go toStep 12Go toStep 30
12Repair the wiring harness, the connector, or the con-
nector terminal as needed.
Is the repair complete?–System OK
13Measure the resistance of each fuel injector at 68°F
(20°C). The resistance will increase slightly at high-
er temperatures.
Is the fuel injector resistance within the value speci-
fied?11.6–12.4 ΩGo toStep 15Go toStep 14
14Replace any fuel injector with a resistance that is out
of specifications.
Is the repair complete?–System OK–
15Perform an injector balance test.
Is the problem found?–Go toStep 16Go toStep 17
16Replace any restricted or leaking fuel injectors as
needed.
Is the repair complete?–System OK–
171. Check for the proper ignition voltage output for
each cylinder with a spark tester.
2. Inspect the spark plugs for cracks, wear, im-
proper gap, burned electrodes, or heavy de-
posits.
3. Inspect the ignition wires for short conditions.
4. Inspect all of the ignition grounds for loose con-
nections.
5. Inspect the powertrain control module
(PCM)/engine control module (ECM) for the
proper operation.
Is the problem found?–Go toStep 18Go toStep 19
18Correct or replace any faulty ignition components.
Is the repair complete?–System OK–
19Does the engine misfire or cut out under load or at
idle?Go to
”Ignition Sys-
tem Check”Go toStep 20
20Does the engine start, but then immediately stall?–Go toStep 21Go toStep 23
211. Remove the Crankshaft Position (CKP) sensor.
2. Inspect for faulty connections and repair as
needed.
Is the problem found?–Go toStep 22Go toStep 25
22Repair the faulty connections as needed.
Is the repair complete?–System OK–

1F – 578IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
231. Check for the proper valve timing.
2. Check the cylinder compression.
3. Inspect the pushrods, the rocker arms, the
valve springs, and the camshaft lobes for ex-
cessive wear.
4. Inspect the intake manifold and the exhaust
manifold passages for casting flash.
Is the problem found?–Go toStep 24Go toStep 25
24Repair or replace any components as needed.
Is the repair complete?–System OK–
25Check the Idle Air Control (IAC) valve operation. Re-
pair or replace components as needed.
Is the repair complete?–System OK–
26Check the base idle setting of the throttle body.
Is the repair complete?–Go toStep 27Go toStep 28
27Check the Throttle Position (TP) sensor circuit for
proper operation. Repair or replace components as
needed.
Is the repair complete?–System OK–
28Adjust the base idle setting to specifications.
Is the repair complete?–System OK–
29Repair the fuel system as needed.
Is the repair complete?–System OK–
30Replace the ECM.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 579
DAEWOO V–121 BL4
SURGES OR CHUGGLES
Definition : Engine power varies under steady throttle or
cruise, making it feel as if the vehicle speeds up and slows
down with no change in the accelerator pedal position.
Important : Make sure the driver understands Torque
Converter Clutch (TCC) and A/C compressor operation as
described in the owner’s manualThe speedometer reading and the speed reading on the
scan tool should be equal.
Before diagnosing the symptom, check service bulletins
for updates.
Step
ActionValue(s)YesNo
1Were the Important Preliminary Checks performed?–Go toStep 2Go to
”Important Pre-
liminary
Checks”
2Connect the scan tool to the Data Link Connector
(DLC).
Does the Front Heated Oxygen Sensor (HO2S1) re-
spond quickly to different throttle positions?–Go toStep 4Go toStep 3
31. Check the HO2S1 sensor for silicone or other
contaminants from fuel or use of improper
Room Temperature Vulcanizing (RTV) sealant.
2. Replace the contaminated HO2S1 sensor.
Is the repair complete?–System OK–
41. Drive the vehicle at the speed of the complaint.
2. Monitor the long term fuel trim reading using
the scan tool.
Is the long term fuel trim reading within the value
specified?–20–25%Go toStep 7Go toStep 5
5Is the long term fuel trim reading below the value
specified?–20%Go to
”Diagnostic
Aids for DTC
P0172”Go toStep 6
6Is the long term fuel trim reading above the value
specified?25%Go to
”Diagnostic
Aids for DTC
P0171”–
7Check the fuel system pressure while the condition
exists.
Is the fuel system pressure within specifications?41–47 psi
(284–325 kPa)Go toStep 8Go toStep 17
8Check the in–line fuel filter.
Is the filter dirty or plugged?–Go toStep 18Go toStep 9
9Perform an injector diagnosis.
Does the injector balance test pinpoint the problem?–Go toStep 19Go toStep 10
101. Check for proper ignition voltage output using a
spark tester.
2. Inspect the spark plugs for cracks, wear, im-
proper gap, burned electrodes, or heavy de-
posits.
Is the problem found?–Go toStep 11Go toStep 12
11Repair or replace any ignition system components
as needed.
Is the repair complete?–System OK–

1F – 580IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
121. Inspect the engine control module (ECM)
grounds to make sure they are clean, tight, and
in their proper locations.
2. Inspect the vacuum lines for kinks or leaks.
Is the problem found?–Go toStep 13Go toStep 14
13Repair the electrical connections or the vacuum
lines as needed.
Is the repair complete?–System OK–
14Check the generator output voltage.
Is the generator voltage within the value specified?12–16 vGo toStep 16Go toStep 15
15Repair the generator.
Is the repair complete?–System OK–
161. Check for intermittent Exhaust Gas Recircula-
tion (EGR) valve operation.
2. Check Torque Converter Clutch (TCC) opera-
tion.
3. Repair or replace any components as needed.
Is the repair complete?–System OK–
17Repair the fuel system as needed.
Is the repair complete?–System OK–
18Replace the fuel filter.
Is the repair complete?–System OK–
19Replace the leaking or restricted fuel injectors.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 581
DAEWOO V–121 BL4
LACK OF POWER, SLUGGISHNESS, OR SPONGINESS
Definition : The engine delivers less than expected power. There is little or no increase in speed when the accelerator pedal
is partially applied.
Step
ActionValue(s)YesNo
1Were the Important Preliminary Checks performed?–Go toStep 2Go to
”Important Pre-
liminary
Checks”
21. Verify the customer’s complaint.
2. Compare the performance of the customer’s
vehicle with a similar unit.
Does the problem exist?–Go toStep 3System OK
31. Inspect the air filter for excessive contamina-
tion.
2. Replace the air filter as needed.
3. Check the transaxle shift pattern and downshift
operation.
Does the transaxle operate properly?–Go toStep 4Go toStep 5
4Check the fuel system pressure.
Is the fuel system pressure within specifications?41–47 psi
(284–325 kPa)Go toStep 7Go toStep 6
5Repair the transaxle as needed.
Is the repair complete?–System OK–
6Repair the fuel system as needed.
Is the repair complete?–System OK–
7Check for a restricted fuel filter or contaminated fuel.
Is the problem found?–Go toStep 8Go toStep 9
8Repair or replace any components as needed.
Is the repair complete?–System OK–
91. Check the ignition system output for all of the
cylinders using a spark tester.
2. Check for proper ignition control operation.
Is the ignition system operating properly?–Go toStep 10Go toStep 11
101. With the engine at normal operating tempera-
ture, connect a vacuum gauge to a vacuum
port on the intake manifold.
2. Operate the engine at 1,000 rpm.
3. Record the vacuum reading.
4. Increase the engine speed to 2,500 rpm.
5. Note the vacuum reading at a steady 2,500
rpm.
Does the vacuum decrease more than the value
specified?10 kPa
(3 in. Hg)Go toStep 12Go toStep 15
11Repair or replace any ignition system components
as needed.
Is the repair complete?–System OK–
12Inspect the exhaust system for restrictions and dam-
aged or collapsed pipes.
Is the problem found?–Go toStep 13Go toStep 15
13Repair or replace any components as needed.
Is the repair complete?–System OK–

1F – 582IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
141. Check the cylinder compression and valve tim-
ing.
2. Inspect the camshaft for excessive wear.
Is the problem found?–Go toStep 15Go toStep 16
15Repair or replace any engine components as need-
ed.
Is the repair complete?–System OK–
161. Check the engine control module (ECM)
grounds for being clean, tight, and in their prop-
er location.
2. Check the Exhaust Gas Recirculation (EGR)
valve for being open or partially open all the
time.
3. Check the Torque Converter Clutch (TCC) op-
eration.
4. Check the A/C system operation.
5. Check the generator output.
6. Repair the generator if the output is not within
the specified range.
Are all checks and repairs complete?12–16 vSystem OK–

ENGINE CONTROLS 1F – 583
DAEWOO V–121 BL4
HESITATION, SAG, STUMBLE
Definition : Involves a momentary lack of response as the
accelerator is pushed down. This can occur at any vehicle
speed. It is usually the most severe when first trying to
make the vehicle move, as from a stop. Hesitation, sag,
or stumble may cause the engine to stall if severe enough.Important : Before diagnosing this condition, check ser-
vice bulletins for Programmable Read–Only Memory
(PROM) updates.
Step
ActionValue(s)YesNo
1Were the Important Preliminary Checks performed?–Go toStep 2Go to
”Important Pre-
liminary
Checks”
21. Check the fuel system pressure. If the pres-
sure is not within the value specified, service
the fuel system as needed.
2. Inspect the Throttle Position (TP) sensor for
binding or sticking. The TP sensor voltage
should increase at a steady rate as the throttle
is moved toward Wide Open Throttle (WOT).
Is the problem found?41–47 psi
(284–325 kPa)Go toStep 3Go toStep 4
3Repair or replace any components as needed.
Is the repair complete?–System OK–
41. Check the Manifold Absolute Pressure (MAP)
sensor response and accuracy.
2. Inspect the fuel for water contamination.
3. Check the Evaporative (EVAP) Emission canis-
ter purge system for proper operation.
Is the problem found?–Go toStep 5Go toStep 6
5Repair or replace any components as needed.
Is the repair complete?–System OK–
61. Disconnect all of the fuel injector harness con-
nectors.
2. Connect an injector test light between the har-
ness terminals of each fuel injector.
3. Note the test light while cranking the engine.
Does the test light blink on all connectors?–Go toStep 8Go toStep 7
71. Repair or replace the faulty fuel injector drive
harness, the connector, or the connector termi-
nal.
2. If the connections and the harnesses are good,
replace the engine control module (ECM) for
an internal open in the fuel injector driver cir-
cuit.
Is the repair complete?–System OK–
8Measure the resistance of each fuel injector. The re-
sistance will increase slightly at higher tempera-
tures.
Is the fuel injector resistance within the value speci-
fied?11.6–12.4 ΩGo toStep 10Go toStep 9
9Replace any of the fuel injectors with a resistance
that is out of specifications.
Is the repair complete?–System OK–
10Perform an injector balance test.
Is the problem found?–Go toStep 11Go toStep 12

1F – 584IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
11Replace any restricted or leaking fuel injectors.
Is the repair complete?–System OK–
12Check the fuel system pressure after a cold start or
during moderate or full throttle acceleration.
Is the fuel pressure within specifications?41–47 psi
(284–325 kPa)Go toStep 14Go toStep 13
13Repair the restriction in the fuel system or replace
the faulty fuel pump.
Is the repair complete?–System OK–
141. Check for faulty ignition wires.
2. Inspect for fouled spark plugs.
3. Check the ignition system output on each cylin-
der with a spark tester.
Is the problem found?–Go toStep 15Go toStep 16
15Repair or replace any ignition components as need-
ed.
Is the repair complete?–System OK–
161. Check the generator output voltage.
2. Repair or replace the generator if the generator
output is less than the value specified.
3. Check the Exhaust Gas Recirculation (EGR)
valve operation.
Are all checks and needed repairs complete?12–16 vSystem OK–
CUTS OUT, MISSES
Definition : This Involves a steady pulsation or jerking that follows engine speed, usually more pronounced as engine load
increases. The exhaust has a steady spitting sound at idle or low speed.
Step
ActionValue(s)YesNo
1Were the Important Preliminary Checks performed?–Go toStep 2Go to
”Important Pre-
liminary
Checks”
2Check the ignition system output voltage for all of the
cylinders using a spark tester.
Is spark present on all of the cylinders?–Go toStep 3Go to
”Ignition Sys-
tem Check”
31. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy de-
posits.
2. Check the resistance of the ignition wires. Re-
place any ignition wires that have a resistance
greater than the value specified.
Is the problem found?3,000 ΩGo toStep 4Go toStep 5
4Repair or replace any components as needed.
Is the repair complete?–System OK–
5With the engine running, spray the ignition wires with
a fine water mist to check for arcing and shorting to
ground.
Is the problem found?–Go toStep 6Go toStep 7
6Replace the ignition wires.
Is the repair complete?–System OK–