Page 190 of 1184
1F–92 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0133 – Oxygen Sensor No Activity (Cont’d)
StepActionValue(s)YesNo
11Replace the O2 sensor.
Is the repair complete?–Go to Step 12–
12
1. Clear any DTCs from the ECM
2. Perform the diagnostic system check
Is the repair complete
–
Go to Step 13
–
13
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–Go to applicable
DTC table
System OK
Page 192 of 1184

1F–94 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F140
DIAGNOSTIC TROUBLE CODE (DTC) – P0137 HEATED OXYGEN SENSOR LOW
V O LTA G E
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 44 and
13. The oxygen (O
2) 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 O
2 sensor is like
an open circuit and produces no voltage when it is below
360°C(600°F). An open O
2 sensor circuit or a cold O2
sensor causes “open loop” operation.
Conditions for Setting the DTC
(Case A)
The engine controls system is in closed loop.
Engine speed is less than 6,000rpm.
The heated oxygen sensor voltage is below 0.07V for
at least 40 seconds.
DTCs P0107, P0108, P0117, P0118, P0122, P0123,
P0335, P0336, P0341, P0342, P0400, P0404,
P0405, P0406 are NOT SET.
(Case B)
The engine controls system is in closed loop.
Engine speed is less than 6,000rpm.
The heated oxygen sensor voltage is between 0.352
and 0.499 at least 60 seconds.
Action Taken when the DTC Sets
Emission related.
“Armed” after two trip with a fail.
“Disarmed” after one trip with a pass.MIL on if failure is detected in three consecutive trips.
Stores a History DTC on the third consecutive with a
fail (The DTC will be armed after the second fail).
Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).
Conditions for Clearing the MIL/DTC
The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Normal scan tool voltage varies between 0.1 volts
and 0.9 volts while in closed loop.
Inspect the oxygen (O
2) sensor wire. The O2 sensor
may be positioned incorrectly and contacting the ex-
haust manifold.
Check for an intermittent ground in the wire between
the O
2 sensor and the engine control module.
Perform an injector balance test to determine if a re-
stricted fuel injector may be causing the lean condi-
tion.
Vacuum of crankcase leaks will cause a lean running
condition.
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.
Page 193 of 1184

ENGINE CONTROLS 1F–95
DAEWOO M-150 BL2
DTC P0137 – Heated Oxygen Sensor Low Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. 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 downstream oxygen (O2)
sensor1 voltage within the value specified?
0.07–0.352VGo to Step 4Go to Step 3
3
Does the scan tool the heated oxygen (O2) sensor1
voltage within the value specified?
0.1VGo to Step 9
Go to
“Diagnostic
Aids”
4
1. Turn the ignition switch to LOCK.
2. Disconnect the Heated O2 sensor connector and
engine control module (ECM) connector.
3. Check the Heated O2 sensor wire between the
Heated O2 sensor connector terminal 4 and ECM
connector terminal 35 for short to ground.
Is the problem found?
–
Go to Step 5Go to Step 6
5
1. 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
–
6
1. Turn the ignition switch to LOCK.
2. Disconnect the Heated O2 sensor connector and
engine control module (ECM) connector.
3. Check the O2 sensor wire between the O2 sensor
connector terminal 3 and ECM connector terminal
76 for short to ground.
Is the problem found?
–
Go to Step 7Go to Step 8
7
1. 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
–
8
1. Turn the ignition switch to LOCK.
2. Replace the Heated O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?
–
Go to Step 10
–
9
1. 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 10
–
Page 194 of 1184
1F–96 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0137 – Heated Oxygen Sensor Low Voltage (Cont’d)
StepActionValue(s)YesNo
10
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK
Page 196 of 1184

1F–98 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F140
DIAGNOSTIC TROUBLE CODE (DTC) – P0138 HEATED OXYGEN SENSOR HIGH
V O LTA G E
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 64 and
13. The Heated oxygen (O
2) 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
O
2 sensor is like an open circuit and produces no volt-
age when it is below 360°C(600°F). An open O
2 sensor
circuit or a cold O
2 sensor causes “open loop” operation.
Conditions for Setting the DTC
The Heated oxygen sensor voltage is more than 4.8V
for at least 0.2 seconds.
A high voltage condition exists.
Action Taken when the DTC Sets
Emission related.
“Armed” after two trip with a fail.
“Disarmed” after one trip with a pass.
MIL on if failure is detected in three consecutive trips.
Stores a History DTC on the third consecutive with a
fail (The DTC will be armed after the second fail).
Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).Conditions for Clearing the MIL/DTC
The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Normal scan tool voltage varies between 0.1volts and
0.9volts while in closed loop.
Inspect the oxygen (O
2) sensor wire. The O2 sensor
may be positioned incorrectly and contacting the ex-
haust manifold.
Check for an intermittent ground in the wire between
the O
2 sensor and the engine control module.
Perform an injector 2alance test to determine if a re-
stricted fuel injector may be causing the lean condi-
tion.
Vacuum of crankcase leaks will cause a lean running
condition.
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.
Page 197 of 1184

ENGINE CONTROLS 1F–99
DAEWOO M-150 BL2
DTC P0138 – Heated Oxygen Sensor High Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. 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 Heated oxygen(O2) sensor
voltage within the value specified?
More than
1.2V
Go to Step 3Go to Step 6
3
1. Turn the ignition switch to LOCK.
2. Disconnect the Heated O2 sensor connector and
engine control module (ECM) connector.
3. Check the Heated O2 sensor wire between the
Heated O2 sensor connector terminal 4 and ECM
connector terminal 35 for an open or short to
battery voltage.
Is the problem found?
–
Go to Step 4Go to Step 5
4
1. 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
–
5
1. Turn the ignition switch to LOCK.
2. Replace the Heated O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?
–
Go to Step 7
–
6
1. 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
–
7
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK
Page 199 of 1184

ENGINE CONTROLS 1F–101
DAEWOO M-150 BL2
DTC P0140 – Heated Oxygen Sensor No Activity
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Run the engine to above the specified operating
temperature.
2. Install a scan tool.
3. Operate the engine above the specified rpm for
2minuets.
Does the scan tool the indicate Closed Loop?
80°C(176°F)
1,200 rpm
Go to Step 3Go to Step 4
3
1. Turn the Turn the ignition switch to ON.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the freeze frame
conditions and Conditions for Setting the DTC as
noted?
Does the scan tool the indicate Closed Loop?
–
Go to Step 12Go to Step 4
4
Disconnect the Heated O2 sensor connector and
jumper the Heated O2 sensor low circuit, terminal 4
to ground.
Is the HO2 voltage below the specified value and
does the scan tool indicate the heated oxygen
sensor heater voltage within the specified value?
0.5VGo to Step 5Go to Step 6
5
Check the Heated O2 sensor connector for
malfunction terminals or poor connection and repair
as necessary.
Is repair necessary?
–
Go to Step 12Go to Step 9
6
1. Turn the ignition switch to On.
2. Remove the jumper wire.
3. Using a digital voltmeter(DVM), measure the
voltage between the Heated O2 sensor signal
circuit, terminal 3 to ground.
Does the Heated O2 sensor voltage measure above
the specified value?
0.6VGo to Step 10Go to Step 9
7Does the Heated O2 sensor voltage measure below
the specified value?
0.3VGo to Step 11Go to Step 8
8
Check the Heated O2 sensor ground circuit, terminal
4 for an open or poor connection and repair as
necessary.
Is repair necessary?
–
Go to Step 12Go to Step 8
11
Check the Heated O2 sensor signal circuit, terminal
3 for an open or poor connection and repair as
necessary.
Is repair necessary?
–
Go to Step 12Go to Step 8
10
1. If disconnected, reconnect Heated O2 sensor
connector.
2. Using the scan tool, clear the DTCs.
3. Start the engine and idle at normal operating
temperature.
4. Operate the vehicle within the conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicated that this diagnostic has
run and passed?
–
Go to Step 13Go to Step 2
Page 200 of 1184
1F–102 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0140 – Heated Oxygen Sensor No Activity (Cont’d)
StepActionValue(s)YesNo
11
1. Turn the ignition switch to LOCK.
2. Replace the Heated O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?
–
Go to Step 15
–
12
1. 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 15
–
13
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK