
1F – 80IENGINE CONTROLS
DAEWOO V–121 BL4
Idle Air Control System Check (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Turn the ignition switch to ON.
Is the Malfunction Indicator Lamp (MIL) on steady?–Go to Step 4Go to Step 3
3Turn the ignition switch to LOCK.
Connect the scan tool to the DLC.
Turn the Turn the ignition switch to ON.
Are any diagnostic trouble codes (DTCs) displayed?–Go to Step 4Try with
another scan
tool
4Refer to the applicable DTC table.
Is only one DTC identified as valid trouble code
P0122?–Go to Step 5Go to
applicable DTC
table And go to
”Multiple DTC”
51. Connect the scan tool to the DLC.
2. Turn the ignition switch to ON.
3. Press the accelerator pedal while watching
TPS for smooth changes in the voltage.
Does the scan tool show the TPS voltage change
smoothly within the value specified?0.3V–4.8VGo to
”Diagnostic
Aids”Go to Step 6
61. Turn the ignition switch to lock.
2. Disconnect the MTIA connector.
3. Measure the voltage between terminal 2 and 8.
Does the voltage measure within the value speci-
fied?4.8V–5.0VGo to Step 7Go to Step 8
7Connect a fused jumper between the MTIA connec-
tor terminal 2 and terminal 7.
Does the scan tool show the TPS voltage above val-
ue specified?4.8V–5.0VGo to Step 13Go to Step 11
8Measure the voltage between the MTIA connector
2 and ground.
Does the voltage measure within the value speci-
fied?>5.0VGo to Step 9Go to Step 10
91. Turn the ignition switch to lock.
2. Check for an open or low voltage in the wire
between the MTIA connector 8 and ECM con-
nector 19.
Is the problem found?–Go to Step 12Go to Step 14
101. Turn the ignition switch to LOCK.
2. Check for an open or low voltage in the wire
between the MTIA connector 2 and ECM con-
nector 79.
Is the problem found?–Go to Step 12Go to Step 14
111. Turn the ignition switch to LOCK.
2. Check for an open or low voltage in the wire
between the MTIA connector 7 and ECM con-
nector 74.
Is the problem found?–Go to Step 12Go to Step 14

ENGINE CONTROLS 1F – 111
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS
(1.4L/1.6L 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 problemis intermittent, 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 volt-
age 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 (1.4L/1.6L DOHC)
DTCFunctionError
TypeIlluminate MIL
P0107Manifold Absolute Pressure Sensor Low VoltageAYES
P0108Manifold Absolute Pressure Sensor High VoltageAYES
P0112Intake Air Temperature Sensor Low VoltageEYES
P0113Intake Air Temperature Sensor High VoltageEYES
P0117Engine Coolant Temperature Sensor Low VoltageAYES
P0118Engine Coolant Temperature Sensor High VoltageAYES
P0122Throttle Position Sensor Low VoltageAYES
P0123Throttle Position Sensor High VoltageAYES
P0131Front Heated Oxygen Sensor Low VoltageAYES
P0132Front Heated Oxygen Sensor High VoltageAYES
P0133Front Heated Oxygen Sensor No ActivityEYES
P0135Front Heated Oxygen Sensor Heater Circuit Not FunctioningEYES
P0137Rear Heated Oxygen Sensor Low VoltageEYES
P0138Rear Heated Oxygen Sensor High VoltageEYES
P0140Rear Heated Oxygen Sensor No ActivityEYES
P0141Rear Heated Oxygen Sensor Heater MalfuctionEYES
P0171Fuel Trim System Too LeanEYES
P0172Fuel Trim System Too RichEYES
P0222Main Throttle Idle Actuactor (MTIA) Low VoltageAYES
P0223Main Throttle Idle Actuactor (MTIA) High VoltageAYES
P0261Injector 1 Low VoltageAYES
P0262Injector 1 High VoltageAYES
P0264Injector 2 Low VoltageAYES
P0265Injector 2 High VoltageAYES
P0267Injector 3 Low VoltageAYES
P0268Injector 3 High VoltageAYES
P0270Injector 4 Low VoltageAYES
P0271Injector 4 High VoltageAYES
P0300Multiple Cylinder Misfire (Catalyst Damage)ABLINKING

1F – 132IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0122 – Throttle Position Sensor Low Voltage
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”
2Turn the ignition switch to ON.
Is the Malfunction Indicator Lamp (MIL) on steady?–Go to Step 4Go to Step 3
31. Turn the ignition switch to LOCK.
2. Connect the scan tool to the DLC.
3. Turn the Turn the ignition switch to ON.
Are any diagnostic trouble codes (DTCs) displayed?–Go to Step 4Try with anoth-
er scan tool
4Refer to the applicable DTC table.
Is only one DTC identified as valid trouble code
P0122?–Go to Step 5Go to applica-
ble DTC table
and Go to ”Mul-
tiple DTC”
51. Connect the scan tool to the DLC.
2. Turn the ignition switch to ON.
3. Press the accelerator pedal while watching
TPS for smooth changes in the voltage.
Does the scan tool show the TPS voltage change
smoothly within the value specified?0.3V–4.8VGo to
”Diagnostic
Aids”Go to Step 6
61. Turn the ignition switch to lock.
2. Disconnect the MTIA connector.
3. Measure the voltage between terminal 2 and 8.
Does the voltage measure within the value speci-
fied?4.8V–5.0VGo to Step 7Go to Step 8
7Connect a fused jumper between the MTIA connec-
tor terminal 2 and terminal 7.
Does the scan tool show the TPS voltage above val-
ue specified?4.8V–5.0VGo to Step 13Go to Step 11
8Measure the voltage between the MTIA connector
2 and ground.
Does the voltage measure within the value speci-
fied?5.0VGo to Step 9Go to Step 10
91. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 8 and ECM
connector 19.
Is the problem found?–Go to Step 12Go to Step 14
101. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 2 and ECM
connector 79.
Is the problem found?–Go to Step 12Go to Step 14
111. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 7 and ECM
connector 74.
Is the problem found?–Go to Step 12Go to Step 14

ENGINE CONTROLS 1F – 135
DAEWOO V–121 BL4
DTC P0123 – Throttle Position Sensor High Voltage
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”
2Turn the ignition switch to ON.
Is the Malfunction Indicator Lamp (MIL) on steady?–Go to Step 4Go to Step 3
31. Turn the ignition switch to LOCK.
2. Connect the scan tool to the DLC.
3. Turn the Turn the ignition switch to ON.
Are any diagnostic trouble codes (DTCs) displayed?–Go to Step 4Try with anoth-
er scan tool
4Refer to the applicable DTC table.
Is only one DTC identified as valid trouble code
P0122?–Go to Step 5Go to applica-
ble DTC table
and Go to ”Mul-
tiple DTC”
51. Connect the scan tool to the DLC.
2. Turn the ignition switch to ON.
3. Press the accelerator pedal while watching
TPS for smooth changes in the voltage.
Does the scan tool show the TPS voltage change
smoothly within the value specified?0.3V–4.8VGo to
”Diagnostic
Aids”Go to Step 6
61. Turn the ignition switch to lock.
2. Disconnect the MTIA connector.
3. Measure the voltage between terminal 2 and 8.
Does the voltage measure within the value speci-
fied?4.8V–5.0VGo to Step 7Go to Step 8
7Connect a fused jumper between the MTIA connec-
tor terminal 2 and terminal 7.
Does the scan tool show the TPS voltage above val-
ue specified?4.8V–5.0VGo to Step 13Go to Step 11
8Measure the voltage between the MTIA connector
2 and ground.
Does the voltage measure within the value speci-
fied?< 5.0VGo to Step 9Go to Step 10
91. Turn the ignition switch to lock.
2. Check for short to battery voltage in the wire
between the MTIA connector 8 and ECM con-
nector 19.
Is the problem found?–Go to Step 12Go to Step 14
101. Turn the ignition switch to lock.
2. Check for short to battery voltage in the wire
between the MTIA connector 2 and ECM con-
nector 79.
Is the problem found?–Go to Step 12Go to Step 14
111. Turn the ignition switch to lock.
2. Check for short to battery voltage in the wire
between the MTIA connector 7 and ECM con-
nector 74.
Is the problem found?–Go to Step 12Go to Step 14

ENGINE CONTROLS 1F – 145
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0135
FRONT HEATED OXYGEN SENSOR HEATER CIRCUIT
NOT FUNCTIONING
Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control
and post catalyst monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen con-
tent in the exhaust stream. The HO2S must reach operat-
ing temperature to provide an accurate voltage signal. A
heating element inside the HO2S minmizes the time re-
quired for the sensor to reach operating temperature. Volt-
age is provided to the heater by the ignition 1 voltage cir-
cuit through a fuse. With the engine running, ground is
provided to the heater by the HO2S heater low control cir-
cuit, through a low side driver within the engine control
module (ECM). The ECM monitors the current flow
through the heater for diagnosis.
If the ECM detects that the HO2S heater current is above
or blelow a specified range, DTC P0135 seats.
Conditions for Setting the DTC
S DTCs P0106, P0117, P0118, P1017 are not set.
S Engine run time is greater than 30 seconds.
S Filtered O2 heater current is less than 0.1 amps.
Action Taken When the DTC SetsS 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 fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history Diagnostic Trouble Code (DTC) is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after three 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.
Diagnostic Aids
An intermittent may be caused by rubbed through wire in-
sulation or a wire contacting the exhaust.
Check for poor connection or damaged harness – inspect
harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection

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 – 385
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0135
FRONT HEATED OXYGEN SENSOR (HO2S1) HEATER
CIRCUIT NOT FUNCTIONING
Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control
and post catalyst monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen con-
tent in the exhaust stream. The HO2S must reach operat-
ing temperature to provide an accurate voltage signal. A
heating element inside the HO2S minmizes the time re-
quired for the sensor to reach operating temperature. Volt-
age is provided to the heater by the ignition 1 voltage cir-
cuit through a fuse. With the engine running, ground is
provided to the heater by the HO2S heater low control cir-
cuit, through a low side driver within the engine control
module (ECM). The ECM monitors the current flow
through the heater for diagnosis.
If the ECM detects that the HO2S heater current is above
or blelow a specified range, DTC P0135 seats.
Conditions for Setting the DTC
S DTCs P0106, P0117, P0118, P1017 are not set.
S Engine run time is greater than 200 seconds.
S Filtered O2 heater current is less than 0.025 amps.
Action Taken When the DTC SetsS 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.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after three 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.
Diagnostic Aids
An intermittent may be caused by rubbed through wire in-
sulation or a wire contacting the exhaust.
Check for poor connection or damaged harness – inspect
harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection

1F – 594IENGINE CONTROLS
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
FUEL SYSTEM PRESSURE RELIEF
Procedure
CAUTION : The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pressure
before disconnecting the fuel lines.
1. Remove the fuel cap.
2. Remove the fuel pump fuse Ef18 from the engine
fuse block.
3. Start the engine and allow the engine to stall.
4. Crank the engine for an additional 10 seconds.
FUEL TANK
Removal Procedure
CAUTION : The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pressure
before disconnecting the fuel lines.
1. Relieve the fuel pressure. Refer to ” Fuel System
Pressure Relief ” in this section.
2. Disconnect the negative battery cable.
3. Drain the fuel tank.
4. Remove the front muffler. Refer to Section 1G, Ex-
haust System
5. Remove the fuel tank filler tube clamp at the fuel
tank.
6. Disconnect the fuel tank filler tube.
7. Disconnect the fuel vapor line near the fuel tank
filler tube.
8. Disconnect the fuel pump harness connector.