2004 DAEWOO LACETTI oxygen sensor

1F – 138IENGINE CONTROLS
DAEWOO V–121 BL4
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.
DTC P0131 – Front Heated Oxygen 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”
21. Connect the scan tool to the data link connec-
tor (DLC).
2. Run the engine until it reaches operating tem-
perature.
3. Check for closed loop operation.
Does the engine control module(ECM) go into
closed loop?–Go to Step 3Go to Step 9
31. Run the until until it reaches operating temper-
ature?
2. Run the engine at 1,200rpm.
Does the scan tool read the upstream oxygen(O2 )
sensor signal voltage between the valve specified?0.25~0.65VGo to Step 5Go to Step 4
4Does the scan tool read the Oxygen sensor signal
voltage fixed below the valve specified?0.01VGo to Step 7Go to
”Diagnostic
Aids”
51. Disconnect the Oxygen sensor connector.
2. Run the warm engine at idle.
Does the scan tool read the Oxygen sensor signal
voltage between the valve specified?0.25~0.65VGo to
”Diagnostic
Aids”Go to Step 6
61. Turn the ignition switch to LOCK.
2. Check the Oxygen sensor wire between the
Oxygen sensor and the ECM connector termi-
nal 44 and 13 is open.
Is the problem found?–Go to Step 8Go to Step 11
71. Turn the ignition switch to LOCK.
2. Check the Oxygen sensor wire between the
Oxygen sensor and the ECM connector termi-
nal 44 for a short to ground.
Is the problem found?–Go to Step 8Go to Step 11
81. Repair the wire or the connector terminal as
needed.
2. Clear the any DTCs from the ECM.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the repair complete?–System OK–
91. Turn the ignition switch to LOCK.
2. Disconnect the Oxygen sensor connector.
3. Turn the ignition switch to ON.
Does the scan tool the Oxygen sensor signal voltage
between the valve specified?0.3~0.6VGo to Step 10Go to Step 11

ENGINE CONTROLS 1F – 139
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
101. Replace the Oxygen sensor.
2. Clear the DTCs from the ECM.
3. Perform the diagnostic system check.
Is the repair complete?–System OK–
111. Replace the ECM.
2. Perform the diagnostic system check.
Is the repair complete?–Go to Step 12–
12Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

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.

ENGINE CONTROLS 1F – 141
DAEWOO V–121 BL4
DTC P0132 – Front Heated Oxygen 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”
21. Turn the ignition switch to ON, with the engine
OFF.
2. Install a scan tool.
3. Engine at operating temperature.
4. Run the engine at 1,200rpm.
Does the scan tool the upstream oxygen(O2) sen-
sor1 voltage within the value specified?More than
1.2VGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. Disconnect the O2 sensor connector and en-
gine control module (ECM) connector.
3. Check the O2 sensor wire between the O2
sensor and ECM connector terminal 44 for
short to battery voltage.
Is the problem found?–Go to Step 4Go to Step 5
41. Repair the wire of the connector terminal as
needed.
2. Clear the DTCs from the ECM.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the repair complete?–System OK–
51. Turn the ignition switch to LOCK.
2. Replace the O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?–Go to Step 7–
61. Turn the ignition switch to LOCK.
2. Replace the ECM.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?–Go to Step 7–
7Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

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 – 143
DAEWOO V–121 BL4
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
Normal scan tool voltage varies between 0.15 to 8.5mV
while in Closed Loop. If DTC P0133 is intermittent, refer
to ”Intermittents” in this section.
DTC P0133 – Front Heated Oxygen Sensor No Activity
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. Connect the scan tool to the data link connec-
tor (DLC).
2. Run the engine until it reaches operating tem-
perature.
3. Check for the closed loop operation.
Does the scan tool indicate the closed loop?–Go to Step 3Go to Step 4
31. Turn the ignition switch to LOCK.
2. Review the freeze frame data and note the pa-
rameters.
3. Operate the vehicle within the freeze frame
conditions and Conditions for Setting the DTC.
Does the scan tool indicate the closed loop?–Go to Step 12Go to Step 4
41. Disconnect the upstream oxygen(O2) sensor
connector.
2. Jumper the oxygen sensor connector terminal
1 to ground.
3. Turn the ignition switch to ON.
Does the scan tool read the oxygen sensor signal
voltage the specified valve?0.4~0.5VGo to Step 5Go to Step 8
5Check the oxygen sensorconnector for malfunction
terminals or poor connection and repair as neces-
sary.
Is repair necessary?–Go to Step 12Go to Step 6
61. Run the engine at idle.
2. Remove the jumper wire.
3. Measure the voltage between the oxygen sen-
sor connector terminal 3 and ground.
Does the oxygen sensor voltage measure above the
specified value?0.6VGo to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Measure the voltage between the upstream O2
sensor connector terminal 3 and ground.
Does the oxygen sensor voltage measure above the
specified value?0.3VGo to Step 9Go to Step 11
8Repair the wire or the connector between the upstre
O2 sensor terminal 1 and the engine control module
(ECM) terminal 44 is open or a short to ground.
Is the repair complete?–Go to Step 11Go to Step 9

1F – 144IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
9Repair the wire and the connector terminal between
the oxygen sensor connector terminal 3 and the
ECM connector terminal 13 is open or a short to
ground.
Is the repair complete?–Go to Step 12Go to Step 10
101. Turn the ignition switch to LOCK.
2. Replace the ECM.
3. Perform the diagnostic system check.
Is the repair complete?–System OK–
11Replace the O2 sensor.
Is the repair complete?–Go to Step 12–
121. Clear any DTCs from the ECM.
2. Perform the diagnostic system check.
Is the repair complete.–Go to Step 13–
13Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

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