2004 DAEWOO LACETTI Intake air temperature

1F – 48IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
11Compare the Engine Coolant Temperature (ECT)
with the Intake Air Temperature (IAT).
Is the ECT relatively close to the IAT?–Go to Step 12Go to ”DTC
P0118 Engine
Coolant Tem-
perature High
Voltage
121. Check if the Manifold Absolute Pressure (MAP)
sensor reading is over the specified reading.
2. Crank the engine while watching the MAP sen-
sor reading.
Does the MAP sensor read above the specified val-
ue and then change while cranking the engine?4 vGo to Step 13Go to Step 14
13Crank the engine.
Does the Crankshaft Position (CKP) Active Counter
increment while cranking?–Go to Step 16Go to Step 18
14Check the scan data for serial data.
Was serial data lost while cranking the engine?–Go to Step 15Go to ”MAP
Sensor Output
Check”
15Repair voltage loss to the engine control module
(ECM) from the ignition switch.
Is the repair complete?–System OK–
16Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
Is spark present from all of the ignition wires?–Go to Step 41Go to Step 17
171. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a resist-
ance above the value specified.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?30,000 WGo to Step 3Go to Step 18
181. Turn the ignition OFF.
2. Disconnect the Crankshaft Position (CKP) sen-
sor connector.
3. Measure the voltage between the CKP connec-
tor terminals 1 and 3.
4. Repair the wiring as needed.
Does the voltage measure near the value specified?1.4 v (2.5 v)*Go to Step 19Go to Step 20
19Measure the voltage between the CKP connector
terminals 2 and 3.
Does the voltage measure near the value specified1.4 v (2.5 v)*Go to Step 26Go to Step 21
20Measure the voltage between the CKP connector
terminals 1 and ground.
Does the voltage measure near the value specified?1.4 v (2.5 v)*Go to Step 22Go to Step 23
21Measure the voltage between the CKP connector
terminals 2 and ground.
Does the voltage measure near the value specified?1.4 v (2.5 v)*Go to Step 22Go to Step 24
22Check for an open or short in the wire between the
CKP connector terminal 3 and ground.
Is the problem found?–Go to Step 25Go to Step 40
23Check for an open or short in the wire between the
CKP connector terminal 1 and the ECM connector
terminal M21
Is the problem found?–Go to Step 25Go to Step 40

ENGINE CONTROLS 1F – 111
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS
(1.4L/1.6L DOHC)
CLEARING TROUBLE CODES
Notice : To prevent Engine Control Module (ECM) dam-
age, the key must be OFF when disconnecting or recon-
necting the power to the ECM (for example battery cable,
ECM pigtail connector, ECM fuse, jumper cables,
etc.).When the ECM sets a Diagnostic Trouble Code
(DTC), the Malfunction Indicator Lamp (MIL) lamp will be
turned on only for type A, B and E but a DTC will be stored
in the ECM’s memory for all types of DTC. If the problemis intermittent, the MIL will go out after 10 seconds if the
fault is no longer present. The DTC will stay in the ECM’s
memory until cleared by scan tool. Removing battery volt-
age for 10 seconds will clear some stored DTCs.
DTCs should be cleared after repairs have been com-
pleted. Some diagnostic tables will tell you to clear the
codes before using the chart. This allows the ECM to set
the DTC while going through the chart, which will help to
find the cause of the problem more quickly.
DIAGNOSTIC TROUBLE CODES (1.4L/1.6L DOHC)
DTCFunctionError
TypeIlluminate MIL
P0107Manifold Absolute Pressure Sensor Low VoltageAYES
P0108Manifold Absolute Pressure Sensor High VoltageAYES
P0112Intake Air Temperature Sensor Low VoltageEYES
P0113Intake Air Temperature Sensor High VoltageEYES
P0117Engine Coolant Temperature Sensor Low VoltageAYES
P0118Engine Coolant Temperature Sensor High VoltageAYES
P0122Throttle Position Sensor Low VoltageAYES
P0123Throttle Position Sensor High VoltageAYES
P0131Front Heated Oxygen Sensor Low VoltageAYES
P0132Front Heated Oxygen Sensor High VoltageAYES
P0133Front Heated Oxygen Sensor No ActivityEYES
P0135Front Heated Oxygen Sensor Heater Circuit Not FunctioningEYES
P0137Rear Heated Oxygen Sensor Low VoltageEYES
P0138Rear Heated Oxygen Sensor High VoltageEYES
P0140Rear Heated Oxygen Sensor No ActivityEYES
P0141Rear Heated Oxygen Sensor Heater MalfuctionEYES
P0171Fuel Trim System Too LeanEYES
P0172Fuel Trim System Too RichEYES
P0222Main Throttle Idle Actuactor (MTIA) Low VoltageAYES
P0223Main Throttle Idle Actuactor (MTIA) High VoltageAYES
P0261Injector 1 Low VoltageAYES
P0262Injector 1 High VoltageAYES
P0264Injector 2 Low VoltageAYES
P0265Injector 2 High VoltageAYES
P0267Injector 3 Low VoltageAYES
P0268Injector 3 High VoltageAYES
P0270Injector 4 Low VoltageAYES
P0271Injector 4 High VoltageAYES
P0300Multiple Cylinder Misfire (Catalyst Damage)ABLINKING

1F – 120IENGINE CONTROLS
DAEWOO V–121 BL4
J3B11F51
BRNORN
/BLK
DIAGNOSTIC TROUBLE CODE (DTC) P0112
INTAKE AIR TEMPERATURE SENSOR LOW VOLTAGE
Circuit Description
The Intake Air Temperature (IAT) Sensor uses a thermis-
tor to control the signal voltage to the engine control mod-
ule (ECM). The ECM supplies a 5 volt reference voltage
and a ground to the sensor. When the air is cold, the resist-
ance is high ; therefore IAT sensor signal voltage will be
high. If the intake air is warm, resistance is low ; therefore
the IAT sensor signal voltage will be low.
Conditions for Setting the DTC
S IAT voltage is less than 0.01V.
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 ECM will default to 605C(1405F) for intake air
temperature. The scan tool will not show the de-
faulted 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 10 sec-
onds.
Diagnostic Aids
If the vehicle is at ambient temperature, compare the IAT
sensor to the engine coolant temperature(ECT) sensor.
The IAT sensor and the ECT sensor should be relatively
close to each other. Use the temperature vs. Resistance
Values table to evaluate the possibility of a skewed sensor.
Refer to ”Temperature vs. Resistance” in this section.

ENGINE CONTROLS 1F – 121
DAEWOO V–121 BL4
DTC P0112 – Intake Air Temperature 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.
Does the scan tool show the IAT sensor reading
within the value specified?15~80°CGo to
”Diagnostic
Aids”Go to Step 3
31. Turn the ignition switch to LOCK.
2. Disconnect the IAT sensor connector.
3. Turn the ignition switch to ON.
Does the scan tool show the IAT sensor reading
within the value specified? –30°CGo to Step 4Go to Step 5
4Check for a faulty connector or terminals at the IAT
sensor connector.
Is the problem found?–Go to Step 7Go to Step 6
5Check for wire for a short to ground between the IAT
connector terminal 1 and the ECM connector termi-
nal 78.
Is the problem found?–Go to Step 7Go to Step 6
6Check for wire for a short to ECM reference voltage
between the IAT sensor connector terminal 2 and
the ECM connector terminal 13.
Is the problem found?4.5 – 5.5VGo to Step 7Go to Step 9
71. Turn the ignition switch to LOCK.
2. Repair the wire or the connector terminal as
needed.
3. Clear any DTCs from the ECM.
4. Run the engine until it reaches operating tem-
perature.
5. Perform the diagnostic system check.
Is the repair complete?–System OK–
81. Turn the ignition switch to LOCK.
2. Replace the IAT sensor.
3. Clear any DTCs from the ECM.
4. Run the engine until it reaches operating tem-
perature.
5. Perform the diagnostic system check.
Is the repair complete?–System OK–
91. Turn the ignition switch to LOCK.
2. Replace the engine control module(ECM).
3. Run the engine until it reaches operating tem-
perature.
4. Perform the diagnostic system check.
Is the repair complete?–Go to Step 10–
10Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to the appli-
cable DTC
tableSystem OK

1F – 122IENGINE CONTROLS
DAEWOO V–121 BL4
J3B11F51
BRNORN
/BLK
DIAGNOSTIC TROUBLE CODE (DTC) P0113
INTAKE AIR TEMPERATURE SENSOR HIGH VOLTAGE
Circuit Description
The Intake Air Temperature (IAT) Sensor uses a thermis-
tor to control the signal voltage to the engine control mod-
ule (ECM). The ECM supplies a 5 volt reference voltage
and a ground to the sensor . when the air is cold, the resist-
ance is high ; therefore IAT sensor signal voltage will be
high. If the intake air is warm, resistance is low ; therefore
the IAT sensor signal voltage will be low.
Conditions for Setting the DTC
S IAT voltage is less than 4.99V.
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 ECM will default to 605C(1405F) for intake air
temperature. The scan tool will not show the de-
faulted 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 10 sec-
onds.
Diagnostic Aids
S If the vehicle is at ambient temperature, compare
the IAT sensor to the engine coolant temperature
(ECT) sensor. The IAT sensor and the ECT sensor
should be relatively close to each other.
S Use the temperature vs. Resistance Values table to
evaluate the possibility of a skewed sensor. Refer
to ”Temperature vs. Resistance” in this section.

ENGINE CONTROLS 1F – 123
DAEWOO V–121 BL4
DTC P0113 – Intake Air Temperature 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. Connect the scan tool to the data link connec-
tor (DLC).
2. Run the engine unit it reaches operating tem-
perature.
Does the scan tool show the intake air temperature
(IAT) sensor reading within the value specified?15~80°C
(10~176°F)Go to
”Diagnostic
Aids”Go to Step 3
31. Turn the ignition switch to LOCK.
2. Disconnect the IAT sensor connector.
3. Jumper to IAT sensor connector terminals.
4. Turn the ignition switch to ON.
Does the scan tool show the IAT sensor reading the
value specified?180°C
(356°F)Go to Step 4Go to Step 5
4Check for a faulty connector or terminals 1 and 2 of
the IAT sensor connector.
Is the problem found?–Go to Step 10Go to Step 9
5Measure the voltage between terminals 1 and 2 of
IAT sensor connector.
Does the voltage measure within the value speci-
fied?4.5~5.5VGo to Step 11Go to Step 6
6Measure the voltage between the IAT sensor con-
nector terminal 2 and the battery ground(negative)
post.
Does the voltage measure within the value speci-
fied?4.5~5.5VGo to Step 7Go to Step 8
71. Turn the ignition switch to LOCK.
2. Check for an open or short to battery voltage in
the wire between the IAT sensor connector ter-
minal 2 and the engine control module(ECM)
connector terminal 13.
Is the problem found?–Go to Step 10Go to Step 11
81. Turn the ignition switch to LOCK.
2. Check for an open or short to battery voltage in
the wire between the IAT sensor connector ter-
minal 1 and the ECM connector terminal 78.
Is the problem found?–Go to Step 10Go to Step 11
91. Turn the ignition switch to LOCK.
2. Replace the IAT sensor.
3. Clear any DTCs from the ECM.
4. Perform the diagnostic system check.
Is the repair complete?–System OK–
101. Turn the ignition switch to LOCK.
2. Repair the wire of the connector terminals as
needed.
3. Clear any DTCs from the ECM.
4. Perform the diagnostic system check.
Is the repair complete?–System OK–

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–

1F – 218IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0400
EXHAUST GAS RECIRCULATION OUT OF LIMIT
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced.
A linear EGR valve is used on this system. The linear EGR
valve is designed to accurately supply exhaust gases to
the engine without the use of intake manifold vacuum. The
valve controls exhaust flow going into the intake manifold
from the exhaust manifold through an orifice with a engine
control module(ECM) controlled pintle. The ECM controls
the pintle position using inputs from the Throttle Position
(TP) and the Manifold Absolute Pressure (MAP) sensor.
The ECM then commands the EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a scan tool as the Desired
EGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The actual EGR position
should always be near the commanded or Desired EGR
position.
This Diagnostic Trouble Code(DTC) will detect an open or
short circuit.
Conditions for Setting the DTC
S The vehicle is part load.
S The engine controls system is in closed loop.
S Engine Coolant Temperature (ECT) is higher than
70°C (158°F). (1.4L DOHC)
S Engine Coolant Temperature (ECT) is higher than
60°C (140°F). (1.6L DOHC)
S Mass Air Flow is between 120~230mg/tdc.
(1.4L DOHC)
S Mass Air Flow is between 71~174mg/tdc.
(1.6L DOHC)
S Engine Speed is Between 1,800~2,400rpm.
(1.4L DOHC)
S Engine Speed is Between 1,950~2,600rpm.
(1.6L DOHC)
S Intake Air Temperature(IAT) is higher than
15°C(59°F).
S Manifold Absolute Pressure is greater than 75kPA.
S The EGR is higher than 10%.