Lamp DAEWOO LACETTI 2004 Service Workshop Manual

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

1F – 134IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0123
THROTTLE POSITION SENSOR HIGH VOLTAGE
Circuit Description
The aim of the MTIA (Main Throttle Idle Actuator) is to con-
trol the idle speed with the throttle body itself. The throttle
is motorized for low opening angle (05, 195). The charac-
teristics of the airflow are not the same for low and high
opening angles. As a matter of fact, the gradient of the
mass air flow function of TPS is lower for small angles that
permits to be more precise during the idle speed control.
Out of idle speed the throttle is actuated mechanically by
a classical bowdencable.
The throttle position sensor (TPS) provides a voltage sig-
nal that changes in relation to the throttle plate angle. The
signal voltage will vary from about nearly 5.0 V at idles to
about 0.2V to 0.4 V at wide–open throttle. The TPS is one
of the most important inputs used by the ECM for fuel con-
trol and other functions such as idle, wide open throttle,
deceleration enleanment, and acceleration enrichment.
Conditions for Setting the DTC
S TPS voltage is greater than 4.8V.
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 The coolant fan turns ON.
S The ECM will default to 20°C (68°F) for the first 60
seconds of the engine run time, and then 92 °C
(198 °F).
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
If the DTC P0123 cannot be duplicated, the information in-
cluded in the Freeze Frame data can be useful. Use the
scan tool DTC information data to determine the status of
the DTC. If the DTC occurs intermittently, using the DTC
P0121 diagnostic table may help isolate the problem.
With the ignition ON and the throttle at closed position the
voltage should read between 0.20 V and 0.90V and in-
crease steadily to over 4.5V at WOT.
DTCs P0123 and P0113 stored at the same time could be
the result of an open sensor ground circuit.

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 – 137
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0131
FRONT HEATED OXYGEN SENSOR LOW VOLTAGE
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 44 and 13.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
(Case A)
S The engine controls system is in closed loop.
S Engine speed is less than 6,000rpm.
S The oxygen sensor voltage is below 0.07V for at
least 40seconds.
S DTCs P0107, P0108, P0117, P0118, P0122,
P0123, P0335, P0336, P0341, P0342, P0400,
P0404, P0405, P0406 are NOT SET.
(Case B)
S The engine controls system is in closed loop.
S Engine speed is less than 6,000rpm.
S The oxygen sensor voltage is between 0.352 and
0.499 at least 10 seconds.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 The coolant fan turns ON.
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
Normal scan tool voltage varies between 0.1volts and 0.9
volts while in closed loop.
Inspect the oxygen (O2) sensor wire. The O2 sensor may
be positioned incorrectly and contacting the exhaust man-
ifold.

1F – 140IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0132
FRONT HEATED OXYGEN SENSOR HIGH VOLTAGE
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 44 and 13.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
S The oxygen sensor voltage is more than 1.2V.
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 The coolant fan turns ON.
Conditions for Clearing the MIL/DTCS 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 10 sec-
onds.
Diagnostic Aids
Normal scan tool voltage varies between 0.1volts and 0.9
volts while in closed loop.
Inspect the oxygen (O2) sensor wire. The O2 sensor may
be positioned incorrectly and contacting the exhaust man-
ifold.
Check for an intermittent ground in the wire between the
O2 sensor and the engine control module.
Perform an injector 2alance test to determine if a restricted
fuel injector may be causing the lean condition.
Vacuum of crankcase leaks will cause a lean running con-
dition.
An exhaust manifold gasket leak of a cracked exhaust
manifold may cause outside air to be pulled into the ex-
haust and past the sensor.

1F – 142IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0133
FRONT HEATED OXYGEN SENSOR NO ACTIVITY
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 44 and 13.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
S The engine controls system is in closed loop.
S Engine Coolant Temperature is higher than
70°C(158°F). (1.4L DOHC)
S Engine Coolant Temperature is higher than
60°C(140°F). (1.6L DOHC)
S The mass air flow (MAF) is between 100mg/tdc and
250mg/tdc. (1.4L DOHC)
S The mass air flow (MAF) is between 60mg/tdc and
160mg/tdc. (1.6L DOHC)
S The engine speed is between 1,700 rpm and 2,200
rpm. (1.4L DOHC)
S The engine speed is between 1,800 rpm and 2,900
rpm. (1.6L DOHC)S The vehicle speed is between 40 km/h (24.9 mph)
and 60 km/h (37.3 mph). (1.4L DOHC)
S The vehicle speed is between 45 km/h (28.0 mph)
and 55 km/h (34.2 mph). (1.6L DOHC)
S The manifold air pressure is higher than 700hPa.
S The ignition is at 10 volts.
S The upstream O2 sensor periods higher than 1.6
seconds.
S A number of glitches higher than 5 during the test.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0132, P0137,
P0138, P1671, P0300, P0335, P0336, P0341,
P0400, P0404, P0405, P0444, P0445 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.
S The coolant fan turns ON.
S The vehicle will operate in Open Loop.

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 – 148IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0137
REAR HEATED OXYGEN SENSOR LOW VOLTAGE
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 14 and 16.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
(Case A)
S The engine controls system is in closed loop.
S Engine speed is less than 6,000rpm.
S The heated oxygen sensor voltage is below 0.07V
for at least 40 seconds.
S DTCs P0107, P0108, P0117, P0118, P0122,
P0123, P0335, P0336, P0341, P0342, P0400,
P0404, P0405, P0406 are NOT SET.
(Case B)
S The engine controls system is in full fuel cut off.
S Engine speed is less than 6,000rpm.
S The heated oxygen sensor voltage is between
0.352 and 0.499 at least 10 seconds.S DTCs P0107, P0108 and P0141 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 Records
buffers.
S A history DTC is stored.
S The coolant fan turns ON.
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 10 sec-
onds.
Diagnostic Aids
S Normal scan tool voltage varies between 0.1 volts
and 0.9 volts while in closed loop.
S Inspect the oxygen (O2) sensor wire. The O2 sen-
sor may be positioned incorrectly and contacting
the exhaust manifold.

ENGINE CONTROLS 1F – 151
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0138
REAR HEATED OXYGEN SENSOR HIGH VOLTAGE
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 64 and 16.
The Heated oxygen (O2) sensor varies the voltage within
a range of about 1volt if the exhaust is rich, down to about
100mm volts if the exhaust is lean. The Heated O2 sensor
is like an open circuit and produces no voltage when it is
below 360°C(600°F). An open O2 sensor circuit or a cold
O2 sensor causes ”open loop” operation.
Conditions for Setting the DTC
S The Heated oxygen sensor voltage is more than
1.2V.
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/DTCS 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 10 sec-
onds.
Diagnostic Aids
S Normal scan tool voltage varies between 0.1volts
and 0.9volts while in closed loop.
S Inspect the oxygen (O2) sensor wire. The O2 sen-
sor may be positioned incorrectly and contacting
the exhaust manifold.
S Check for an intermittent ground in the wire be-
tween the O2 sensor and the engine control mod-
ule.
S Perform an injector balance test to determine if a
restricted fuel injector may be causing the lean con-
dition.
S Vacuum of crankcase leaks will cause a lean run-
ning condition.
S An exhaust manifold gasket leak of a cracked ex-
haust manifold may cause outside air to be pulled
into the exhaust and past the sensor.

ENGINE CONTROLS 1F – 153
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0140
REAR HEATED OXYGEN SENSOR NO ACTIVITY
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 64 and 16.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
S The engine controls system is in closed loop.
S Engine Coolant Temperature is higher than 75°C
(167°F). (1.4L DOHC)
S Engine Coolant Temperature is higher than 70°C
(158°F). (1.6L DOHC)
S The engine speed is between 1,760 rpm and 2,368
rpm. (1.4L DOHC)
S The engine speed is between 1,300 rpm and 3,000
rpm. (1.6L DOHC)
S The vehicle speed is between 47 km/h (29.2 mph)
and 80 km/h (49.7 mph). (1.4L DOHC)
S The vehicle speed is between 26 km/h (16.2 mph)
and 54 km/h (33.6 mph). (1.6L DOHC)
S The manifold air pressure is higher than 700hPa.S No transition from rich side to lean side or lean side
to rich side during 7.8 seconds even with a forcing
of O2 sensor controller.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0137, P0138, P1671,
P0300, P0335, P0336, P0341, P0400, P0404,
P0405, P0644, P0645 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.
S The coolant fan turns ON.
S The vehicle will operate in Open Loop.
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 10 sec-
onds.