2004 DAEWOO NUBIRA check engine

ENGINE CONTROLS 1F – 479
DAEWOO V–121 BL4
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic 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 malfunction occurred. The information is then
stored on the scan tool for later reference.
2. Commanding the EGR valve open determines
whether the EGR system can control the EGR
valve accurately and if the fault is present.
3. If the EGR valve 5 volt reference is shorted to
ground, the digital voltmeter (DVM) will read no
voltage and additional DTCs may be set and the
engine performance will be poor. When this circuit
is open, only a DTC P0405 will be set.
4. Jumpering the 5 volt reference circuit to the signal
circuit checks the signal circuit and the ECM. The
scan tool should display the Actual EGR Position
as 100% if the signal circuit and ECM are OK.
6. Although the ECM and circuitry acted correctly in
the previous step, a problem may still lie within the
terminals which would not show up in probe typetesting. Be sure to check the terminals for being
backed out, improperly formed or damaged, and for
poor tension.
10. All circuits to the EGR valve are OK at this point.
The fault lies internally in the EGR valve and there-
fore must be replaced. Be sure all gasket material
is removed from the EGR mounting surface. Even
a small amount of material may cause a DTC
P0401 to set.
13. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
14. Check the terminals for being backed out, improp-
erly formed or damaged, and for poor tension.
15. Clearing DTCs is a very important step for this
diagnostic. The clearing function allows the EGR
valve to relearn a new pintle position as the old
pintle position was inaccurate due to the failure that
caused the DTC. The DTC must be cleared with
the ignition ON, engine OFF or when the engine is
idling. If the ECM sees an EGR command, the new
pintle will not be learned.
16. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation.
DTC P0405 – Exhaust Gas Recirculation Pintle Position Low
Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON.
3. Command the Exhaust Gas Recirculation
(EGR) valve to the specific values.
Does the Actual EGR Position follow the Desired
EGR Position?25%, 50%,
75%, 100%Go to Step 15Go to Step 3
31. Turn the ignition OFF.
2. Disconnect the EGR valve.
3. Turn the ignition ON.
4. With a voltmeter connected to the ground,
probe the 5 volt reference circuit at terminal 4
of the EGR valve wiring harness connector.
Is the voltage near the specified value?5 VGo to Step 4Go to Step 5
4Jumper the 5 volt reference circuit to the signal cir-
cuit at terminal 4 and C at the EGR valve wiring har-
ness connector.
Does the Actual EGR Position display the specific
value?100%Go to Step 6Go to Step 7

1F – 480IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
5With a test light connected to B+, probe the 5 volt ref-
erence circuit at the EGR valve wiring harness con-
nector terminal 4.
Dose the test light illuminate?–Go to Step 8Go to Step 9
6Check the 5 volt reference and signal circuit for a
poor connection or proper terminal tension and re-
pair as needed.
Is the repair complete?–Go to Step 15Go to Step 10
7With a test light connected to B+, probe the signal
circuit at terminal 3 of the EGR valve wiring harness
connector.
Dose the test light illuminate?–Go to Step 11Go to Step 12
8Check for a short to ground in EGR valve 5 volt refer-
ence circuit and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 13
9Check for an open in EGR valve 5 volt reference cir-
cuit and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 14
101. Turn the ignition OFF.
2. Replace the EGR valve.
Is the repair complete?–Go to Step 15–
11Check for a short to ground in the EGR valve signal
circuit and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 13
12Check for an open in the EGR valve signal circuit
and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 14
131. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 15–
14Check the ECM connector for a poor connection and
repair as needed.
Is the repair complete?–Go to Step 15Go to Step 13
151. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 16Go to Step 2
16Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 481
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0406
EXHAUST GAS RECIRCULATION PINTLE POSITION HIGH
VOLTAGE
Circuit Description
An Exhaust Gas Recirculation (EGR) system is used to
lower Nitrogen Oxide (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced
A linear EGR valve is used on this system. The linear EGR
valve is designed to accurately supply exhaust gases to
the engine without the use of intake manifold vacuum. The
valve controls exhaust flow going into the intake manifold
from the exhaust manifold through an orifice with an En-
gine Control Module (ECM) controlled pintle. The ECM
controls the pintle position using inputs from the Throttle
Position (TP) and Manifold Absolute Pressure (MAP) sen-
sors. The ECM then commands the EGR valve to operate
when necessary by controlling an ignition signal through
the ECM. This can be monitored on a scan tool as the De-
sired EGR Position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-
back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The Actual EGR Position
should always be near the commanded or Desired EGR
Position. This diagnostic Trouble Code (DTC) will detect
short circuit.Conditions for Setting the DTC
S EGR position signal is greater than 98%.
S Ignition voltage is between 11.7 and 16 volts.
S Fail condition last more than 10 seconds.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive ignition cycle with a fail.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history Diagnostic Trouble Code (DTC) is stored.
S EGR is disabled.
Conditions for Clearing the MIL/DTC
S The MIL will turns off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EGR valve may freeze and stick in cold weather at times.
After the vehicle is brought into a warm shop for repairs,
the valve warms and the problem disappears. By watching
the Actual EGR and Desired EGR Positions on a cold ve-
hicle with a scan tool, the fault can be easily verified.
Check the freeze frame data to determine if the DTC set
when the vehicle was cold by viewing the Engine Coolant
Temperature (ECT).

1F – 482IENGINE CONTROLS
DAEWOO V–121 BL4
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic 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 malfunction occurred. The information is then
stored on the scan tool for later reference.
2. Commanding the EGR valve open determines
whether the EGR system can control the EGR
valve accurately and if the fault is present.
3. If the EGR valve 5 volt reference is shorted to
ground, the digital voltmeter (DVM) will read no
voltage and additional DTCs may be set and the
engine performance will be poor. When this circuit
is open, only a DTC P0405 will be set.
4. Jumpering the 5 volt reference circuit to the signal
circuit checks the signal circuit and the ECM. The
scan tool should display the Actual EGR Position
as 100% if the signal circuit and ECM are OK.
6. Although the ECM and circuitry acted correctly in
the previous step, a problem may still lie within the
terminals which would not show up in probe typetesting. Be sure to check the terminals for being
backed out, improperly formed or damaged, and for
poor tension.
10. All circuits to the EGR valve are OK at this point.
The fault lies internally in the EGR valve and, there-
fore, must be replaced. Be sure all gasket material
is removed from the EGR mounting surface. Even
a small amount of material may cause a DTC
P0401 to set.
12. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
13. Check the terminals for being backed out, improp-
erly formed or damaged, and for poor tension.
14. Clearing DTCs is a very important step for this
diagnostic. The clearing function allows the EGR
valve to relearn a new pintle position as the old
pintle position was inaccurate due to the failure that
caused the DTC. The DTC must be cleared with
the ignition ON, engine OFF or when the engine is
idling. If the ECM sees an EGR command, the new
pintle will not be learned.
15. no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation.
DTC P0406 – Exhaust Gas Recirculation Pintle Position High
Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Install a scan tool to the Data Link Connector
(DLC).
3. Command the Exhaust Gas Recirculation
(EGR) valve to the specific values.
Does the Actual EGR Position follow the Desired
EGR Position?25%, 50%,
75%, 100%Go to Step 14Go to Step 3
31. Turn the ignition OFF.
2. Disconnect the EGR valve.
3. Turn the ignition ON.
4. With a voltmeter connected to the ground,
probe the 5 volt reference circuit at terminal 4
of the EGR valve wiring harness connector.
Is the voltage near the specified value?5 VGo to Step 4Go to Step 5
4Jumper the 5 volt reference circuit to the signal cir-
cuit at terminal 4 and C at the EGR valve wiring har-
ness connector.
Does the Actual EGR Position display the specific
value?100%Go to Step 6Go to Step 7

ENGINE CONTROLS 1F – 483
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
5With a test light connected to B+, probe the 5 volt ref-
erence circuit at the EGR valve wiring harness con-
nector terminal 4.
Dose the test light illuminate?–Go to Step 8Go to Step 9
6Check the 5 volt reference and signal circuit for a
poor connection or proper terminal tension and re-
pair as needed.
Is the repair complete?–Go to Step 14Go to Step 10
7With a test light connected to B+, probe the signal
circuit at terminal 3 of the EGR valve wiring harness
connector.
Dose the test light illuminate?–Go to Step 11Go to Step 13
8Check for a short to ground in EGR valve 5 volt refer-
ence circuit and repair as needed.
Is the repair complete?–Go to Step 14Go to Step 12
9Check for an open in EGR valve 5 volt reference cir-
cuit and repair as needed.
Is the repair complete?–Go to Step 14Go to Step 13
101. Turn the ignition OFF.
2. Replace the EGR valve.
Is the repair complete?–Go to Step 14–
11Check for a short to ground in the EGR valve signal
circuit and repair as needed.
Is the repair complete?–Go to Step 14Go to Step 12
121. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 14–
13Check the ECM connector for a poor connection and
repair as needed.
Is the repair complete?–Go to Step 14Go to Step 12
141. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 15Go to Step 2
15Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 484IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST OXYGEN SENSOR LOW EFFICIENCY
Circuit Description
In order to control exhaust emissions of Hydrocarbons
(HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx),
a Three–Way Catalytic Converter (TWC) is used. The cat-
alyst within the converter promotes a chemical reaction
which oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide, it also reduces NOx, converting it into nitrogen.
The catalytic converter also has the ability to store oxygen.
The Engine Control Module (ECM) has the capability to
monitor this process using a Heated
Rear Heated Oxygen Sensor (HO2S2) located in the ex-
haust stream past the TWC. The HO2S2 produces an out-
put signal which indicates the oxygen storage capacity of
the catalyst; this in turn indicates the catalyst’s ability to
convert exhaust emissions effectively. The ECM monitors
the catalyst efficiency by first allowing the catalyst to heat
up, waiting for a stabilization period while the engine is id-
ling, and then adding and removing fuel while monitoring
the reaction of the HO2S2. When the catalyst is function-
ing properly, the HO2S2 response to the extra fuel is slow
compared to the Front Heated Oxygen Sensor (HO2S1).
When the HO2S2 response is close to that of the HO2S1,
the Oxygen storage capability or efficiency of the catalyst
is considered to be bad, and the Malfunction Indicator
Lamp (MIL) will illuminate.
Conditions for Setting the DTC
S Oxygen storage capacity index time is less than 0.3
seconds.
S Before idle test, the vehicle needs to be driven for
at least:
S 15 seconds at airflow is greater than 9.2 g/sec.
for manual transaxle.
S 11 seconds at airflow is greater than 12 g/sec
for automatic transaxle.
S Oxygen Sensor Capacity test condition:
S Closed loop stoichiometry.
S Purge concentration learned.
S Engine is running more than 330 seconds.
S Airflow is between 2.5 and 7.25 g/sec.
S Throttle Position (TP) sensor is less than 1.5%.
S Intake Air Temperature (IAT) is between –7°C
(19.4°F) and 105°C (221°F).
S Barometric pressure (BARO) is greater than 72 kPa
(10.4 psi).
S Catalyst temperature is between 500°C (932°F)
and 850°C (1562°F) for automatic transaxle.
S Catalyst temperature is between 450°C (842°F)
and 850°C (1562°F) for automatic transaxle.
S Closed Loop integrator change is less than 0.03.
S Idle time is less than 1 minute.
S Vehicle speed is less than 3 km/h (1.9 mph).S Block Learn Mode is learned.
S Above condition is stabilized for 5 seconds.
Note : Test is aborted for this idle if:
S Change in engine speed is greater than 80 rpm.
S A/C status changed.
S Cooling fan status changed.
S Insufficient air/fuel shift.
S DTC(s) P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0133, P1133,
P0134, P0135, P0137, P0138, P0140, P0141,
P1167, P1171, P0171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0341,
P0342, P0351, P0352, P0402, P0404, P1404,
P0405, P0406, P0443, P0502, P0506, P0507, and
P0562 are not set.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
The catalyst test may abort due to a change in the engine
load. Do not change the engine load (i.e. A/C, coolant fan,
heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the intermittent
complaint, should be thoroughly checked for the following
conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.

ENGINE CONTROLS 1F – 485
DAEWOO V–121 BL4
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 malfunction occurred. The information is then
stored on the scan tool for later reference.
2. If any component DTCs are set, diagnose those
DTCs first. A fault in a component can cause the
converter to appear degraded or may have caused
its failure.
3. This step includes checks for conditions that can
cause the three–way catalytic converter to appear
degraded. Repair any problems found before pro-
ceeding with this table.
5. If the three–way catalytic converter needs to be
replaced, make sure that another condition is not
present which would cause the converter to be-
come damaged. These conditions may include thefollowing: misfire, high engine oil or coolant con-
sumption, and/or retarded spark timing or weak
spark. To avoid damaging the replacement convert-
er, correct any possible causes of converter dam-
age before replacing the catalytic converter.
6. Clearing DTCs allows the catalyst test to be run up
to 6 times this ignition cycle. Once the ignition is
cycled, the test will run only once. Driving the ve-
hicle heats the catalyst to a test temperature. The
ECM must see predetermined amount of time at
above idle before allowing the catalyst test to run at
idle. Once at idle, the ECM will allow the system to
stabilize and then test the catalyst in 2 stages.
7. If no faults have been found at this point and no
additional DTCs were set, refer to ”Diagnostic Aids”
in this section for additional checks and informa-
tion.
DTC P0420 – Catalyst Oxygen Sensor Low Efficiency
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2S Install a scan tool to the Data Link Connector
(DLC).
S Turn the ignition ON.
Are any component Diagnostic Trouble Codes
(DTCs) set?–Go to
applicable DTC
tablesGo to Step 3
3Visually/physically check the following:
S Exhaust system for a leak.
S Rear Heated Oxygen Sensor (HO2S2)
Is a problem found?–Go to Step 4Go to Step 5
4Repair the exhaust system as needed.
Is the repair complete?–Go to Step 6–
5Replace the Three Way Catalytic Converter (TWC).
Is the repair complete?–Go to Step 6–
61. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 7Go to Step 2
7Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 487
DAEWOO V–121 BL4
DTC P0443 – Evaporative Emission System Purge Solenoid
Control Circuit
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON.
3. Command the Evaporative Emission (EVAP)
Purge Solenoid ON and OFF.
Does the solenoid turn ON and OFF with each com-
mand.ON–99%
OFF–0%Go to Step 3Go to Step 5
31. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition ON.
4. Using a ammeter on a 10 ampere scale, mea-
sure the current between the solenoid control
circuit, terminal M4 at the ECM connect and
ground for 2 minutes.
Does the current draw measure less than the speci-
fied value?0.75 AGo to
”Diagnostic
Aids”Go to Step 4
41. Disconnect the solenoid.
2. Using ohmmeter measure the resistance be-
tween the solenoid control circuit, terminal M4
of the ECM connector and ground.
Does the ohmmeter display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition OFF.
2. Disconnect the solenoid.
3. Connect a test light between the terminal 1 and
2 of the solenoid.
4. Turn the ignition ON.
5. Using the scan tool, command the solenoid ON
and OFF.
Does the test light turn ON and OFF with each com-
mand?–Go to Step 8Go to Step 6
6With a test light connected to ground, probe the igni-
tion feed circuit, terminal 1 in the solenoid harness
connector.–Go to Step 7Go to Step 11
71. Turn the ignition OFF.
2. Reconnect the solenoid.
3. Disconnect the ECM connector.
4. Turn the ignition ON.
5. With a fused jumper wire connected to ground,
probe the solenoid control circuit terminal M4 in
the ECM connector.
Does the solenoid operate?–Go to Step 9Go to Step 10
8Check the connections at the solenoid.
Is a problem found and corrected?–Go to Step 14Go to Step 12