
ENGINE CONTROLS 1F – 219
DAEWOO V–121 BL4
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Recordsbuffers.
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.
DTC P0400 – Exhaust Gas Recirculation Out of Limit
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to with the engine OFF.
2. Install the scan tool.
3. Command the exhaust gas recirculation (EGR)
valve to the specified values.
Does the Actual EGR Position follow the desired
EGR position?25%, 50%
75%, 100%Go to Step 19Go to Step 3
31. Turn the ignition switch to ON.
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the
ground circuit to the EGR valve.
Does the test light illuminate?–Go to Step 4Go to Step 5
41. Connect the test light to ground.
2. Probe the EGR control circuit at terminal 3 to
the EGR valve.
3. Command the EGR valve to the specified val-
ues using a scan tool.
After the command is raised, does the test light glow
brighter, flash or maintain a steady glow?25%, 50%
75%, 100%Go to Step 6Go to Step 7
5Repair the open or poor connection in the EGR
ground circuit.
Is the repair complete?–Go to Step 19–
6With a test light still connected to ground, probe the
signal circuit at terminal 3.
Does the test light illuminate?–Go to Step 8Go to Step 9
7With a test light still connected to ground, again
probe the signal circuit without commanding the
EGR valve with the scan tool.
Does the test light illuminate?–Go to Step 10Go to Step 11
8Check the signal circuit for a short to voltage and re-
pair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
9With a digital voltmeter (DVM) connected to ground,
probe the 5V reference circuit at terminal 1.
Is the voltage measured near the specified value?5VGo to Step 13Go to Step 14

1F – 230IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST 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 Oxygen Sensor
(HO2S) located in the exhaust stream past the TWC. The
HO2S produces an output signal which indicates the oxy-
gen storage capacity of the catalyst; this in turn indicates
the catalyst’s ability to convert exhaust emissions effec-
tively. The ECM monitors the catalyst efficiency by first al-
lowing the catalyst to heat up, waiting for a stabilization pe-
riod while the engine is idling, and then adding and
removing fuel while monitoring the reaction of the HO2S.
When the catalyst is functioning properly, the HO2S re-
sponse to the extra fuel is slow compared to the Oxygen
Sensor (O2S). When the HO2S response is close to that
of the O2S, 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 Closed loop stoichiometry.
S Engine Coolant Temperature (ECT) is more than
75°C (167°F) . (1.4L DOHC)
S Engine Coolant Temperature (ECT) is more than
70°C (158°F) . (1.6L DOHC)
S Engine speed between 1,766rpm and 2,368rpm.
(1.4L DOHC)
S Engine speed between 1,760rpm and 2,530rpm.
(1.6L DOHC)
S Vehicle speed is between 47km/h (29.2mph) and
80km/h (49.7mph). (1.4L DOHC)
S Vehicle speed is between 60km/h (37.3mph) and
76km/h (47.2mph). (1.6L DOHC)
S The manifold absolute pressure is greater than 70
kpa. (1.4L DOHC)S The manifold absolute pressure is greater than 76
kpa. (1.6L DOHC)
S Activity of the heated oxygen sensor excited by
lambda controller stimuli higher than a threshold.
S DTC(s) P0107, P0108, P0117, P0118, P0122,
P0123, P0131, P0132, P0133, P0137, P0138,
P0140, P0141, P0171, P0172, P0300, P0336,
P0337, P0341, P0342, P0351, P0352, P0404,
P0405, P0405 and P0562 are not sets.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. 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.

1F – 308IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1402
EXHAUST GAS RECIRCULATION BLOCKED
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (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 a engine
control module(ECM) controlled pintle. The ECM controls
the pintle position using inputs from the Throttle Position
(TP) and the Manifold Absolute Pressure (MAP) sensor.
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 Desired
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 an open or
short circuit.
Conditions for Setting the DTC
S The vehicle is part load.
S The engine controls system is in closed loop.
S Engine Coolant Temperature(ECT) is greater than
60°C(140°F).
S Intake Air Temperature(IAT) is greater than
15°C(59°F).
S Manifold Absolute Pressure is greater than 75kPA.
S The EGR is greater than 10%.
S Mass Air Flow is between 71~174mg/tdc.
S Engine Speed Is Between 1,950~2,600rpm.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.
S EGR is disabled.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.

1F – 310IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1403
EXHAUST GAS RECIRCULATION VALVE FAILURE
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (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 a engine
control module(ECM) controlled pintle. The ECM controls
the pintle position using inputs from the Throttle Position
(TP) and the Manifold Absolute Pressure (MAP) sensor.
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 Desired
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 an open or
short circuit.
Conditions for Setting the DTC
S The vehicle is part load.
S The engine controls system is in closed loop.
S Engine Coolant Temperature(ECT) is greater than
60°C(140°F).
S Intake Air Temperature(IAT) is greater than
15°C(59°F).
S Manifold Absolute Pressure is greater than 75kPA.
S The open EGR value is higher than 10%.
S Mass Air Flow is between 71~174mg/tdc.
S Engine Speed Is Between 1,950~2,600rpm.
S EGR potentiometer voltage is less than 0.4V.
S EGR potentiometer voltage is higher than 1.75V or
integral term of EGR controller blocked in high or
low limit.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.

1F – 344IENGINE CONTROLS
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS (1.8L DOHC)
CLEARING TROUBLE CODES
Notice : To prevent Engine Control Module (ECM) dam-
age, the key must be OFF when disconnecting or recon-
necting the power to the ECM (for example battery cable,
ECM pigtail connector, ECM fuse, jumper cables, etc.).
When the ECM sets a Diagnostic Trouble Code (DTC), the
Malfunction Indicator Lamp (MIL) lamp will be turned on
only for type A, B and E but a DTC will be stored in the
ECM’s memory for all types of DTC. If the problem is inter-mittent, the MIL will go out after 10 seconds if the fault is
no longer present. The DTC will stay in the ECM’s memory
until cleared by scan tool. Removing battery voltage for 10
seconds will clear some stored DTCs.
DTCs should be cleared after repairs have been com-
pleted. Some diagnostic tables will tell you to clear the
codes before using the chart. This allows the ECM to set
the DTC while going through the chart, which will help to
find the cause of the problem more quickly.
DIAGNOSTIC TROUBLE CODES (1.8L DOHC)
DTCDescriptionTypeIlluminate MIL
P0106Manifold Absolute Pressure RationalityEYe s
P0107Manifold Absolute Pressure Low VoltageAYe s
P0108Manifold Absolute Pressure High VoltageAYe s
P0112Intake Air Temperature Low VoltageEYe s
P0113Intake Air Temperature High VoltageEYe s
P0117Engine Coolant Temperature Low VoltageAYe s
P0118Engine Coolant Temperature High VoltageAYe s
P0122Throttle Position Sensor Low VoltageAYe s
P0123Throttle Position Sensor High VoltageAYe s
P0131Front Heated Oxygen Sensor (HO2S1) Low VoltageAYe s
P0132Front Heated Oxygen Sensor (HO2S1) High VoltageAYe s
P0133Front Heated Oxygen Sensor (HO2S1) Slow ResponseEYe s
P0134Front Heated Oxygen Sensor (HO2S1) No Activity or OpenAYe s
P0135Front Heated Oxygen Sensor (HO2S1) Heater Circuit Not FunctioningEYe s
P0137Rear Heated Oxygen Sensor (HO2S2) Low VoltageEYe s
P0138Rear Heated Oxygen Sensor (HO2S2) High VoltageEYe s
P0140Rear Heated Oxygen Sensor (HO2S2) No Activity or OpenEYe s
P0141Rear Heated Oxygen Sensor (HO2S2) Heater Circuit Not FunctioningEYe s
P0171Fuel Trim System Too LeanBYe s
P0172Fuel Trim System Too RichBYe s
P0201Injector 1 Circuit FaultAYe s
P0202Injector 2 Circuit FaultAYe s
P0203Injector 3 Circuit FaultAYe s
P0204Injector 4 Circuit FaultAYe s
P0300Multiple Cylinder Misfire DetectedBYe s
P0301Cylinder 1 MisfireAYe s
P0302Cylinder 2 MisfireAYe s
P0303Cylinder 3 MisfireAYe s
P0304Cylinder 4 MisfireAYe s
P0317Rough Road Sensor Source Not DetectedCnlNo
P0325Knock Sensor Internal MalfunctionCnlNo

ENGINE CONTROLS 1F – 347
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0106
MANIFOLD ABSOLUTE PRESSURE RATIONALITY
Circuit Description
The Engine Control Module (ECM) uses the Manifold Ab-
solute Pressure (MAP) sensor to control the fuel delivery
and the ignition timing. The MAP sensor measures the
changes in the intake manifold pressure which results
from engine load (intake manifold vacuum) and the rpm
changes, and it converts these into voltage outputs. The
ECM can detect if the MAP sensor is not responding to the
Throttle Position (TP) changes by comparing the actual
MAP change to a predicted MAP change based on the
amount of TP change that occurs. If the ECM does not see
the expected MAP change or more, DTC P0106 will set.
Conditions for Setting the DTC
S Altitude compensated MAP reading is higher than
high threshold or lower than low threshold table
based on rpm and TP signal.
S DTCs P0107, P0108, P0117, P0118, P0122,
P0123, P0201, P0202, P0203, P0204, P0300,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406, P0506, P0507 are not set.
S Engine running.
S Valid Barometric Pressure (BARO) update.
S Torque Converter Clutch (TCC) steady (A/T).
S A/C steady state.
S No TP sensor fail conditions present.
S No MAP fail conditions present.
S Change in Idle Air Control (IAC) is less than 5%.
S Coolant temperature is greater than –10°C (14°F).
S Change in rpm is less than 200.
S Change in TP sensor is less than 3%.
S Change in Exhaust Gas Recirculation (EGR) value
is less than 6%.
S The rpm is between 1300 and 4500.
S All of the above are stabilized for 1.5 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 DTC is stored.
S The ECM will substitute a fixed MAP value and use
TP sensor to control the fuel delivery. (The scan
tool will not show defaulted value.)
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
With the ignition ON and the engine stopped, the manifold
pressure is equal to atmospheric pressure and the signal
voltage will be high. This information is used by the ECM
as an indication of vehicle altitude. Comparison of this
reading with a known good vehicle with the same sensor
is a good way to check the accuracy of a suspect sensor.
Readings should be the same +0.4 volt.
The MAP sensor vacuum source should be thoroughly
checked for restrictions at the intake manifold.
Test Description
Numbers below refer to the step numbers on the Diagnos-
tic 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. A sensor that displays an ignition ON, engine OFF
BARO value that does not appear normal for the
altitude the vehicle is in should be considered to be
malfunctioning.
3. While starting the engine, the MAP sensor should
detect any changes in the manifold pressure. This
test is to determine if the sensor is stuck at a value.
4. A normal MAP sensor will react as quickly to the
throttle changes as they can be made. A sensor
should not appear to be lazy or catch up with the
throttle movements.
5. This step checks if the reason for no MAP change
was due to a faulty sensor or vacuum source to the
sensor.
6. The MAP sensor vacuum source should be thor-
oughly checked for restrictions. A drill bit can be
used to clean out any casting flash that may exist in
the vacuum port.
7. The MAP sensor vacuum source should be thor-
oughly checked for restrictions. A drill bit can be
used to clean out any casting flash that may exist in
the vacuum port.
9. The MAP Sensor System Performance diagnostic
may have to complete several tests before deter-
mining if the diagnostic has passed or failed the last
test. Operate the vehicle in the Conditions for Set-
ting the DTC several times to ensure that the diag-
nostic runs enough tests to pass or fail.
10. 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 infor-
mation.

1F – 358IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0113
INTAKE AIR TEMPERATURE HIGH VOLTAGE
Circuit Description
The Intake Air Temperature (IAT) sensor uses a thermistor
to control the signal voltage to the Engine Control Module
(ECM). The ECM supplies a 5 volt reference and a ground
to the sensor. When the air is cold, the resistance is high;
therefore the IAT signal voltage will be high. If the intake
air is warm, resistance is low; therefore the IAT signal volt-
age will be low.
Conditions for Setting the DTC
S IAT is less than –38°C (–36°F).
S Vehicles speed is less than 25 km/h (16 mph).
S Engine run time is greater than 120 seconds.
S Engine Coolant Temperature (ECT) is above 70 °C
158 °F).
S Calculated air are flow is less than 15 g/second.
S DTC P0502, P0117, P0118 not set.
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 DTC is stored.
S The ECM will substitute a default value for intake
air temperature. The scan tool will not show the
defaulted value.
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
S If the vehicle is at ambient temperature, compare
the IAT sensor to the Engine Coolant Temperature
(ECT) sensor. The IAT sensor and the ECT sensor
should be relatively close to each other.
S Use the Temperature vs. Resistance Values table
to evaluate the possibility of a skewed sensor. Re-
fer to ”Temperature vs. Resistance” in this section.
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.
4. This step simulates a DTC P0112. If the ECM
senses the change, the ECM and wiring are OK.
5. This step will determine if the reason the ECM did
not sense the change was due to a open ground or
signal circuit or malfunctioning ECM.
11. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.

ENGINE CONTROLS 1F – 361
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0117
ENGINE COOLANT TEMPERATURE LOW VOLTAGE
Circuit Description
The Engine Coolant Temperature (ECT) sensor uses a
thermistor to control the signal voltage to the Engine Con-
trol Module (ECM). The ECM supplies a 5 volt reference
and a ground to the sensor. When the engine coolant is
cold, the resistance is high; therefore the ECT signal volt-
age will be high. If the engine coolant is warm, sensor re-
sistance becomes less; therefore the IAT signal voltage
drops. At normal engine operating temperature, the volt-
age will be between 1.5 to 2.0 volts at the ECT signal termi-
nal.
The ECT sensor is used to control following items:
S Fuel delivery.
S Ignition.
S Evaporative (EVAP) Emission canister purge valve.
S Idle Air Control (IAC) valve.
S Electric cooling fan.
Conditions for Setting the DTC
S Engine run time is greater than 60 seconds.
S ECT is less tan 149°C (300°F)
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.
S Both cooling fans turns on.
S The ECM will default to 20°C (68°F) for engine
coolant temperature for the first 60 seconds of en-
gine run time and then 92°C (198°F). The scan tool
will not show the defaulted value.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
After engine start the ECT should rise steadily to 90°C
(194°F) then stabilize when the thermostat opens.
Use the Temperature vs. Resistance Values table to eval-
uate the possibility of a skewed sensor. Refer to”Tempera-
ture vs. Resistance” in this section.
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.
4. This step simulates a DTC P0118 condition. If the
ECM senses the change, then the ECM and the
ECT wiring are OK.
7. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.