2004 DAEWOO LACETTI speed

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.

1F – 158IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0171
FUEL TRIM SYSTEM TOO LEAN
System Description
If the adaptation value threshold is permanently exceed-
ed, the deviation of the adaptive terms enables to detect
a slow default coming out. Two time counters (one for the
rich side and another one for the lean side) are increased
while the lambda controller exceeds the adaptation
thresholds. As soon as one of the time counters reaches
its maximum value, the error is detected.
The aim of this test is to simulate a failure that would result
in exceeding the adaptive terms. Two kinds of failure must
be created.
S A lean side deviation: P0171
S A rich side deviation : P0172
It is thus necessary to determine, for each kind of failure,
the limit good and the limit bad. For a given failure, mea-
sure the emission threshold until the legal emission
thresholds are exceeded.
Note that the problem is due to the emission thresholds re-
quired, it is not simple to disturb the system so that the
emission thresholds will be exceeded. The tuning has
been made thanks to a dedicated calibration but, as such
a procedure is not permitted by the regulation, it is neces-
sary to create some material malfunction (fuel pressure
regulator, fuel injector, air leakage...).
Conditions for Setting the DTC
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0132, P0337,
P0338, P0341, P0342, P0400, P1319, P1402,
P1404, P1405, P1671 and P1672 are not set.
S Coolant temperature is greater than 20°C (68°F).
(1.4L DOHC)
S Coolant temperature is greater than 80°C (176°F).
(1.6L DOHC)
S Manifold Absolute Pressure (MAP) is greater than
70 kPa (10.2 psi).
S System is in closed loop.
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/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
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 O2S 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 O2S display on the scan tool
while moving the connectors and the wiring harness re-
lated 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.

1F – 160IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
8Lean condition is not present.
Does a driveability problem exist?–Go to
”Symptom
Diagnosis”Go to Step 16
91. Visually/physically inspect the following items
for vacuum leaks:
S Intake manifold.
S Throttle body.
S Injector O–rings.
2. Repair any leaks found as necessary.
Is the repair complete?–Go to Step 16Go to Step 16
10Allow the engine to idle.
Are the Idle Air Control (IAC) counts above the spe-
cified value?5Go to Step 11Go to Step 12
11Check the fuel for excessive water, alcohol, or other
contaminants and correct the contaminated fuel
condition if present.
Is the repair complete?–Go to Step 16Go to Step 13
12Check the IAC valve performance. Refer to ”DTC
P0506 Idle Speed RPM Lower Than Desired Idle
Speed” or ”DTC P0507 Idle Speed RPM Higher
Than Desired Idle Speed” in this section and repair
as necessary.
Is the repair complete?–Go to Step 16Go to Step 13
131. Connect a fuel pressure gauge to the fuel sys-
tem.
2. Turn the ignition OFF for at least 10 seconds.
3. Turn the ignition ON, with the engine OFF. The
fuel pump will run for approximately 2–3 sec-
onds. It may be necessary to cycle the ignition
switch ON more than once to obtain maximum
fuel pressure.
4. Note the fuel pressure with the fuel pump run-
ning. The pressure should be within the speci-
fied value. When the fuel pump stops, the pres-
sure may vary slightly then hold steady.
Is the fuel pressure steady and does the fuel pres-
sure hold?241–276 kPa
(35–40 psi)Go to Step 14Go to
”Fuel System
Diagnosis”
141. Start and idle the engine at normal operating
temperature.
2. The fuel pressure noted in the above step
should drop by the indicated value.
Does the fuel pressure drop by the indicated value?21–69 kPa
(3–10 psi)Go to
”Fuel Injector
Balance Test”Go to
”Fuel System
Diagnosis”
15Replace the MAP sensor.
Is the action complete?–Go to Step 16–

ENGINE CONTROLS 1F – 163
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
3With the engine running, operate the vehicle until the
LOOP STATUS indicates closed.
Is the Long Term Fuel Trim value above the specified
value?–30%Go to Step 4Go to Step 5
41. Turn the ignition switch ON, with the engine
OFF.
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 Long Term Fuel Trim value above the spe-
cified value while operating under the specified con-
ditions?–30%Go to Step 21Go to Step 5
5Visually/physically check the air cleaner filter for ex-
cessive dirt or being plugged and repair as needed.
Is the repair complete?–Go to Step 21Go to Step 6
6Visually/physically check the air intake system for
collapsed or restricted and repair as needed.
Is the repair complete?–Go to Step 21Go to Step 7
7Inspect the throttle body inlet for damaged or foreign
objects which may partially block the airflow and re-
pair as needed.
Is the repair complete?–Go to Step 21Go to Step 8
81. Turn the ignition OFF.
2. Inspect the throttle bore, throttle plate and Idle
Air Control (IAC) passages for clocking and
foreign objects and repair as needed.
Is the repair complete?–Go to Step 21Go to Step 9
9Start the engine with the vehicle in park or neutral
and A/C off and note the idle quality.
Is a low or unsteady idle being experienced?–Go to Step 10Go to Step 12
10Idle the engine.
Are the IAC counts below the specified value?100Go to Step 12Go to Step 11
111. Turn the ignition OFF.
2. Disconnect the Manifold Absolute Pressure
(MAP) sensor electrical connector.
3. Start the engine.
4. Operate the vehicle in Closed Loop while moni-
toring the Long Term Fuel Trim value.
Does the Long Term Fuel Trim value increase above
the specified value?–30%Go to Step 20Go to Step 12
12Check the IAC valve performance. Refer to ”DTC
P0506 Idle Speed RPM Lower Than Desired Idle
Speed” or ”DTC P0507 Idle Speed RPM Higher
Than Desired Idle Speed” in this section and repair
as necessary.
Is the repair complete?–Go to Step 21Go to Step 13

ENGINE CONTROLS 1F – 165
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0222
MAIN THROTTLE IDLE ACTUATOR (MTIA) LOW 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, 22.55). The char-
acteristics of the air flow 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 idle to
about 0.2 V 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 MTIA voltage is less than 0.275V.
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 Records buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after 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
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

1F – 168IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0223
MAIN THROTTLE IDLE ACTUATOR (MTIA) 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, 22.55). The char-
acteristics of the air flow 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 idle to
about 0.2 V 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 MTIA voltage is higher than 4.9V.
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 Records buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after 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
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

1F – 188IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0300
MULTIPLE CYLINDER MISFIRE (CATALYST DAMAGE)
System Description
The Engine Control Module (ECM) monitors the crank-
shaft and camshaft positions to detect if the engine is mis-
firing. The ECM looks for a quick drop in crankshaft speed.
This test is executed in blocks of 200 engine revolution
tests. It may take between one to several tests to store a
Diagnostic Trouble Code (DTC), the Malfunction Indicator
Lamp (MIL). Severe misfire will flash the MIL, indicating
that catalyst damage is possible.
Conditions for Setting the DTC
S The engine speed is less than 4,500 rpm.
S The fuel tank level is greater than 20%.
S No anti–jerk correction.
S No rough road detection.
S No crankshaft oscillation detection.
S DTCs P0107, P0108, P0122, P0123, P0341,
P0342, P0336 and P0337 are not set.
Action Taken When the DTC SetsS The malfunction Indicator Lamp (MIL) will blinking.
S The ECM will record operating conditions at the
time the diagnostic fails. The 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 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
An intermittent can also be the result of a defective reluctor
wheel. Remove the CKP sensor and inspect the reluctor
wheel through the sensor mount hole. Check for porosity
and the condition of wheel. If the DTC is intermittent refer
to ”Symptoms Diagnosis” in this section.
DTC P0300 – Multiple Cylinder Misfire(Catalyst Damage)
StepActionValue(s)YesNo
1Perform an Euro 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, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs).
Are DTCs P0261, P0262, P0264, P0265, P0267,
P0268, P0270, P0271 set?–Go to
Applicable DTC
tableGo to Step 3
3Perform a visual/physical inspection.
Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”

1F – 192IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0300
MULTIPLE CYLINDER MISFIRE (INCREASE EMISSION)
System Description
The Engine Control Module (ECM) monitors the crank-
shaft and camshaft positions to detect if the engine is mis-
firing. The ECM looks for a quick drop in crankshaft speed.
This test is executed in blocks of 1,000 engine revolution
tests. It may take between one to several tests to store a
Diagnostic Trouble Code (DTC) and illuminate the Mal-
function Indicator Lamp (MIL).
Conditions for Setting the DTC
S The engine speed is less than 4,500 rpm.
S The fuel tank level is greater than 20%.
S No anti–jerk correction.
S No rough road detection.
S No crankshaft oscillation detection.
S DTCs P0107, P0108, P0122, P0123, P0341,
P0342, P0336 and P0337 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 fails. The 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 DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
An intermittent can also be the result of a defective reluctor
wheel. Remove the CKP sensor and inspect the reluctor
wheel through the sensor mount hole. Check for porosity
and the condition of wheel. If the DTC is intermittent refer
to ”Symptoms Diagnosis” in this section.
DTC P0300 – Multiple Cylinder Misfire(Increase Emission)
StepActionValue(s)YesNo
1Perform an Euro 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, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs).
Are DTCs P0261, P0262, P0264, P0265, P0267,
P0268, P0270, P0271 set?–Go to
Applicable DTC
tableGo to Step 3
3Perform a visual/physical inspection.
Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”