ABS DAEWOO NUBIRA 2004 Service Workshop Manual

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 – 348IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0106 – Manifold Absolute Pressure Rationality
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition switch to ON, with the engine
not running.
3. Compare the Barometric Pressure (BARO)
reading with a known good vehicle.
Is the BARO reading similar?–Go to Step 3Go to Step 8
3Start the engine while watching the Manifold Abso-
lute Pressure (MAP) sensor value.
Does the MAP sensor value change while starting
the engine?–Go to Step 4Go to Step 5
4With the engine still running, snap the throttle while
watching the MAP sensor display on the scan tool.
Does the MAP sensor value change rapidly with the
throttle position changes?–Go to Step 9Go to Step 6
51. Turn the ignition switch OFF.
2. Remove the MAP sensor and install a vacuum
pump to the MAP sensor.
3. Turn the ignition switch ON, with the engine
OFF.
4. Apply 380 mm Hg (15 in Hg) to the MAP sen-
sor.
Does the MAP sensor value on the scan tool
change?–Go to Step 7Go to Step 8
61. Remove the MAP sensor from the manifold
port.
2. Inspect the port and MAP sensor for restric-
tions and repair as necessary.
Is the repair complete?–Go to Step 9Go to Step 8
7Repair the restriction in the MAP sensor or vacuum
port as necessary.
Is the action complete?–Go to Step 9–
8Replace the MAP sensor.
Is the action complete?–Go to Step 9–
91. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 349
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0107
MANIFOLD ABSOLUTE PRESSURE LOW VOLTAGE
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 sends a 5 volt reference voltage to the MAP sensor.
As the manifold pressure changes, the output of MAP sen-
sor also changes. By monitoring the Map sensor output
voltage, the ECM knows the manifold pressure. A low
pressure (low voltage) output voltage will be about 1.0 to
1.5 volts while the higher pressure (high voltage) output
voltage will be about 4.5 to 4.8 volts at Wide Open
Throttle(WOT). The MAP sensor is also used, under cer-
tain conditions to measure Barometric Pressure (BARO),
allowing the ECM to make adjustments for different alti-
tude.
Conditions for Setting the DTC
S MAP is less than 12 kPa (1.7 psi)
S No TP sensor fail conditions present.
S TP sensor is greater than 0% if the rpm is less than
1000.
S TP sensor is greater than 5% if the rpm is greater
than 1000.
S System voltage is between 11.0 and 11.5 volts.
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 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 12 kPa.
If a DTC P0107 is intermittent, refer to ”Manifold Absolute
Pressure Check” in this section for further diagnosis.
Important : After repairs, use the scan tool FUEL TRIM
RESET function to reset long–term fuel trim to 128 (0%).
Test Description
Numbers below refer to the step numbers on the Diagnos-
tic Table.

1F – 350IENGINE CONTROLS
DAEWOO V–121 BL4
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.
2. This step will determine if DTC P0107 is the result
of a hard failure or an intermittent condition.
3. Jumpering harness terminals 2 to 1 (signal circuit to
5 volts) will determine if the sensor is malfunction-
ing or if there is a problem with the ECM or wiring.6. The scan tool may not display 5 volts. The Impor-
tant thing is that the ECM recognizes the voltage as
more than 4 volts, indicating that the ECM and the
signal circuit are OK. A test light that illuminates
indicates a short to ground in the signal circuit.
7. A short to ground in the 5 volt reference circuit
could also set additional DTCs.
11. The replacement ECM must be programmed. Refer
to the latest Techline procedure for the ECM repro-
gramming.
DTC P0107 Manifold Absolute Pressure Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine.
3. Read the Manifold Absolute Pressure (MAP).
Does the scan tool display a MAP below the speci-
fied value?12 kPaGo to Step 3Go to Step 4
31. Turn the ignition switch OFF.
2. Disconnect the MAP sensor electrical connec-
tor.
3. Jumper the MAP signal circuit at terminal 2 to
the 5 volt reference circuit at terminal 1.
4. Turn the ignition switch ON.
Does the MAP read more than the specified value?96 kPaGo to Step 5Go to Step 6
41. Turn the ignition switch ON with the engine
OFF, review the Freeze Frame data, and note
the parameters.
2. Operate the vehicle within the freeze frame
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display MAP below the specified
value?12 kPaGo to Step 3Go to
”Diagnostic
Aids”
5Inspect the MAP sensor harness electrical connec-
tor terminals for the following conditions:
S Poor connections.
S Proper contact tension.
S Poor terminal to wire connection.
Is a problem found?–Go to Step 8Go to Step 9
61. Turn the ignition switch OFF.
2. Remove the jumper wire.
3. Probe the MAP sensor signal circuit terminal 2
with a test light to B+.
4. Turn the ignition switch ON.
Does the scan tool read over the specified value?90 kPaGo to Step 7Go to Step 12
7Check the MAP sensor 5 volt reference circuit at ter-
minal 1 for an open or short to ground.
Is a problem found?–Go to Step 10Go to Step 11

1F – 352IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0108
MANIFOLD ABSOLUTE PRESSURE HIGH VOLTAGE
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 sends a 5 volt reference voltage to the MAP sensor.
As the manifold pressure changes, the output of MAP sen-
sor also changes. By monitoring the Map sensor output
voltage, the ECM knows the manifold pressure. A low
pressure (low voltage) output voltage will be about 1.0 to
1.5 volts while the higher pressure (high voltage) output
voltage will be about 4.5 to 4.8 volts at Wide Open
Throttle(WOT). The MAP sensor is also used, under cer-
tain conditions to measure Barometric Pressure (BARO),
allowing the ECM to make adjustments for different alti-
tude.
Conditions for Setting the DTC
S MAP is greater than 103 kPa (15 psi)
S No Throttle Position (TP) sensor fail conditions
present.
S Engine is running more than 10 seconds.
S TP sensor is less than 10% if the rpm is less than
2500.
S TP sensor is less than 35 % if the rpm is great than
2500.
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 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 12 kPa.
If a DTC P0108 is intermittent, refer to ”Manifold Absolute
Pressure Check” in this section for further diagnosis.
DTC P0108 may set as result of a misfire. If misfire is pres-
ent, repair the cause of misfire before using this table. The
misfire counters may be used to determine which cylin-
der(s) is misfiring.
Note : After repairs, use the scan tool FUEL TRIM RESET
function to reset long–term fuel trim to 128 (0%).

ENGINE CONTROLS 1F – 353
DAEWOO V–121 BL4
If DTC P0172 is also set, check 5 volt reference circuit for
short to voltage.
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 malfunction occurred. The information is then
stored on the scan tool for later reference.
2. This step will determine if DTC P0108 is the result
of a hard failure or an intermittent condition.
3. This step simulates conditions for a DTC P0107. If
the ECM recognizes the change, the ECM, the 5
volt reference and the sensor signal circuits are
OK.5. This step also looks for an open in the sensor
ground circuit. If the circuit was open, additional
DTCs will also be set. If no other DTCs are set and
the circuit is found to be open, then the open must
be between the MAP sensor and the electrical con-
nector ground splice.
6. When the sensor signal circuit is shorted to battery
voltage, the TP will be displayed above 0% at all
times and A/C High Side will be displayed high. The
vehicle will also remain in Open Loop.
8. The MAP sensor vacuum source should only sup-
ply vacuum to the MAP sensor. Check the vacuum
port for a restriction caused by casting flash.
9. Disconnect all sensors that use a 5 volt reference
one at a time while monitoring the short on the 5
volt reference circuit. Replace any sensor that may
have caused the short on the 5 volt reference cir-
cuit.
11. The replacement ECM must be programmed to the
latest Techline procedure for the ECM reprogram-
ming.
DTC P0108 – Manifold Absolute Pressure High Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine.
3. Read the Manifold Absolute Pressure (MAP).
Does the scan tool display a MAP of the specified
value or over?85 kPaGo to Step 3Go to Step 4
31. Turn the ignition switch OFF.
2. Disconnect the MAP sensor electrical connec-
tor.
3. Turn the ignition switch ON.
Does the MAP read less than the specified value?28 kPaGo to Step 5Go to Step 6
41. Turn the ignition switch ON with the engine
OFF, review the Freeze Frame data, and note
the parameters.
2. Operate the vehicle within the freeze frame
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display MAP equal to or greter
than the specified value?85 kPaGo to Step 3Go to
”Diagnostic
Aids”
5Probe the MAP sensor signal ground circuit at termi-
nal 3 with a test light connected to battery +.
Does the test light illuminate?–Go to Step 7Go to Step 11
6Check the MAP sensor signal circuit at terminal M8
of ECM for a short to voltage and repair as needed.
Is a repair necessary?–Go to Step 14Go to Step 12

ENGINE CONTROLS 1F – 373
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 The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
S Fuel pressure – The system will be lean if the fuel
pressure is too low. It may be necessary to monitor
the fuel pressure while driving the vehicle at various
road speeds and/or loads to confirm. Refer to ”Fuel
System Diagnosis” in this section.
S Manifold Absolute Pressure (MAP) sensor – An
output that causes the ECM to sense a lower than
normal manifold pressure (high vacuum) can cause
the system to go lean. Disconnecting the MAP sen-
sor will allow the ECM to substitute a fixed (default)
value for the MAP sensor. If the lean condition is
gone when the sensor is disconnected, substitute a
known good sensor and recheck.
S Fuel contamination – Water, in even small amounts
near the in–tank fuel pump inlet can be delivered to
the injector. The water causes a lean exhaust and
can set DTC P0131.
S Sensor harness – The HO2S1 sensor pigtail may
be mis–positioned and contacting the exhaust man-
ifold.
S Engine misfire – A misfiring cylinder will result in
unburned oxygen in the exhaust, which could cause
DTC P0131 to set. Refer to DTC P0300 Engine
Misfire in this section.S Cracked Front Heated Oxygen Sensor – A cracked
HO2S1 or poor ground at the sensor could cause
DTC P0131. Refer to”Symptoms Diagnosis” in this
section.
S Plugged fuel filter – A plugged fuel filter can cause
a lean condition and cause a DTC P0131 to set.
S Plugged Front Heated Oxygen Sensor – A plugged
reference port on the HO2S1 will indicate a lower–
than–normal voltage output from the HO2S1.
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.
2. This step determines if DTC P0131 is the result of
a hard failure or an intermittent condition. It may be
necessary to operate the vehicle within the Freeze
Frame conditions and Conditions for Setting the
DTC in order to duplicate the malfunction detected
by the ECM.
4. This step simulates DTC P0134. If the ECM senses
the change, the ECM and the wiring are OK.
6. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
8. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” for additional checks and information.
DTC P0131 – Front Heated Oxygen Sensor (HO2S1) Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine and idle at normal operating
temperature.
Does the Front Heated Oxygen Sensor (HO2S1)
voltage remain below the value specified?0.1 VGo to Step 4Go to Step 3
31. Review the Freeze Frame data and note the
parameters.
2. Operate the vehicle within the Freeze frame
conditions and Conditions For Setting the DTC
as noted.
Does the HO2S1 voltage stay below the specified
value?0.1 VGo to Step 4Go to Step 7

1F – 376IENGINE CONTROLS
DAEWOO V–121 BL4
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
The DTC P0132 or rich exhaust is most likely caused by
one of the following items:
S Fuel pressure – The system will go rich if the fuel
pressure is too high. The ECM can compensate for
some increase, but if it gets too high, a DTC P0132
will be set
S Leaking injector – A leaking or malfunctioning injec-
tor can cause the system to go rich causing a DTC
P0132.
S Manifold Absolute Pressure (MAP) sensor – An
output that causes the ECM to sense a higher than
normal manifold pressure (low vacuum) can cause
the system to go rich. Disconnecting the MAP sen-
sor will allow the ECM to substitute a fixed value for
the MAP sensor. Substitute a different a MAP sen-
sor, if the rich condition is gone while the sensor is
disconnected.
S Pressure regulator – Check for a leaking fuel pres-
sure regulator diaphragm by checking for the pres-
ence of liquid fuel in the vacuum line to the regula-
tor.
S TP sensor – An intermittent TP sensor output will
cause the system to go rich due to a false indica-
tion of the engine accelerating.
S HO2S1 contamination – Inspect the HO2S1 for sili-
cone contamination from fuel or the use of improper
Room Temperature Vulcanizing sealant. The sensormay have a white powdery coating which may re-
sult in a high but false voltage signal (rich exhaust
indication). The ECM will then reduce the amount
of fuel delivered to the engine, causing a severe
surge or driveability problem.
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.
2. This step determines if DTC P0132 is the result of
a hard failure or an intermittent condition. It may be
necessary to operate the vehicle within the Freeze
Frame conditions and Conditions for Setting the
DTC in order to duplicate the malfunction detected
by the ECM.
4. This step simulates a DTC P0131. If the ECM
senses the change, the ECM and the wiring are
OK.
6. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
8. If no malfunctions 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.
DTC P0132 – Front Heated Oxygen Sensor (HO2S1) High Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine and idle at normal operating
temperature.
Does the Front Heated Oxygen Sensor (HO2S1)
voltage remain below the value specified?952 mVGo to Step 4Go to Step 3
31. Review the Freeze Frame data and note the
parameters.
2. Operate the vehicle within the Freeze frame
conditions and Conditions For Setting the DTC
as noted.
Does the HO2S1 voltage stay below the specified
value?952 mVGo to Step 4Go to Step 7

ENGINE CONTROLS 1F – 379
DAEWOO V–121 BL4
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.
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 The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
DTC P0133 or slow response is most likely caused by one
of the following items:
S Fuel pressure – The system will go rich if fuel pres-
sure is too high. The ECM can compensate for
some increase, but if it gets too high, a DTC P0133
may set. Refer to”Fuel System Diagnosis” in this
section.
S Leaking injector – A leaking or malfunctioning injec-
tor can cause the system to go rich.
S Manifold Absolute Pressure (MAP) sensor – An
output that causes the ECM to sense a higher than
normal manifold pressure (low vacuum) can cause
the system to go rich. Disconnecting the MAP sen-
sor will allow the ECM to set a fixed value for the
MAP sensor. Substitute a different MAP sensor if
the rich condition is gone while the sensor is dis-
connected.S Pressure regulator – Check for a leaking fuel pres-
sure regulator diaphragm by checking for the pres-
ence of liquid fuel in the vacuum line to the pres-
sure regulator.
S Throttle Position (TP) sensor – An intermittent TP
sensor output can cause the system to go rich due
to a false indication of the engine accelerating.
S HO2S1 contamination – Inspect HO2S1 for silicone
contamination from fuel or use of improper room
temperature vulcanizing (RTV) sealant. The sensor
may have a white powdery coating, resulting in a
high but false voltage signal (rich exhaust indica-
tion). The ECM will then reduce the amount of fuel
delivered to the engine causing a severe surge or
driveability problem.
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.
14. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
17. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” for additional checks and information.
DTC P0133 – Front Heated Oxygen Sensor (HO2S1) Slow
Response
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
DLC).
2. Turn the ignition ON.
Are any additional Diagnostic Trouble Codes
(DTCs) set?–Go to
”Applicable
DTC table”Go to Step 3
31. Start the engine and idle at normal operating
temperature.
2. Operate the vehicle within the specified param-
eter under the Conditions For Setting the DTC.
3. Using the scan tool monitor the specific DTC
information for DTC P0133 until DTC P0133
test run.
Does the scan tool indicate DTC P0133 failed this
ignition cycle?–Go to Step 4Go to
”Diagnostic
Aids”

1F – 400IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0171
FUEL TRIM SYSTEM TOO LEAN
System Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a Closed Loop air/fuel
metering system is used. While in Closed Loop, the En-
gine Control Module (ECM) monitors the Front Heated
Oxygen Sensor (HO2S1) signal voltage and adjusts fuel
delivery based on signal voltage. A change made to fuel
delivery will be indicated by the long and short term fuel
trim values which can be monitored with the scan tool.
Ideal fuel trim values are around 128 (0%). If the HO2S1
signal is indicating a lean condition, the ECM will add fuel
resulting in fuel trim values above 128 (0% to 100%). If a
rich condition is detected, the fuel trim values will be below
128 (0% to –100%), indicating that the ECM is reducing
the amount of fuel delivered. If exhaust emissions reach
an excessive level due to a lean or rich condition, a fuel
trim Diagnostic Trouble Code (DTC) is set.
Conditions for Setting the DTC
S The average of adaptive index multiplier value is
greater than 1.28.
S No intrusive tests active.
S DTCs P0106, P0107, P0108, P0112, P0113,
P0117, P0118, P0122, P0123, P0131, P0132,
P0133, P0134, P0135, P1167, P1171, P0300,
P0336, P0337, P0341, P0342, P0402, P0404,
P1404, P0405, P0406, P0443, P0506, and P0507
are not set.
S Throttle Position (TP) is less than 95%.
S Engine speed is between 700 and 6000 rpm.
S Barometric Pressure (BARO) is greater than 72.0
kPa (10.4 psi).
S Coolant temperature is between 70°C (158°F) and
11 5°C (239°F).
S Manifold Absolute Pressure (MAP) is between 25
kPa (3.6 psi) and 99.7 kPa (14.5 psi).
S Intake Air Temperature (IAT) is between –40°C
(–40°F) and 120°C (248°F).
S Airflow is between 1.5 and 45 g/sec.
S Vehicle speed is less than 140 km/h (87 mph).
S System is in closed loop.
S Adaptive index is ready.
S System voltage is greater than 11 volts.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after two consecutive ignitions cycle in which the
diagnostic runs with the fault active.
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.Conditions for Clearing the MIL/DTC
S The MIL will turn off after two consecutive ignition
cycles in which the diagnostic runs without a fault
within the freeze frame conditions that the DTC
failed.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Important : After repairs, use the scan tool Fuel Trim Re-
set function to reset the long–term fuel trim to 128 (0%).
S Fuel pressure – The system will be lean if the pres-
sure is too low. It may be necessary to monitor fuel
pressure while driving the vehicle at various road
speeds and/or loads to confirm.
S Map sensor – An output that causes the ECM to
sense a lower than normal manifold pressure (high
vacuum) can cause the system to go lean. Discon-
necting the MAP sensor will allow the ECM to sub-
stitute a fixed (default) value for the MAP sensor. If
the lean condition is gone when the sensor is dis-
connected, substitute a known good sensor and
recheck.
S Fuel contamination – Water, in even small amounts,
near the in–tank fuel pump inlet can be delivered to
the injector. The water causes a lean exhaust and
can set DTC P0171.
Check for poor HO2S1 or MAP sensor connection at the
ECM. Inspect the harness connectors 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
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the HO2S1 display on the scan
tool while moving the connectors and the wiring harness
related to the engine harness. A change in the display will
indicate the location of the fault.
Check the brake power booster check valve for possible
leaks.
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-