2004 DAEWOO LACETTI OBD port

1F – 530IENGINE CONTROLS
DAEWOO V–121 BL4
2. Verifies the fault is present.
3. If DTC P1112 can be repeated only by duplicating
the Fail Records conditions, refer to the Tempera-
ture Vs. Resistance Value Chart. The chart may be
used to test the IAT sensor at various temperaturesto evaluate the possibility of a ”shifted” sensor that
may be shorted above or below a certain tempera-
ture. If this is the case, replace the IAT sensor.
DTC P1112 – Intake Air Temperature Intermittent 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. Turn the ignition ON.
3. Request engine Diagnostic Trouble Code
(DTC).
Is DTC P0112 also set?–Go to
applicable DTC
tableGo to Step 3
3Check the Intake Air Temperature (IAT) signal circuit
between terminal 2 of the IAT sensor and terminal
M7 of the ECM for an intermittent short to ground
and repair as needed.
Is the repair complete?–Go to Step 4Go to
”Diagnostic
Aids”
41. 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 5Go to Step 2
5Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
table System OK

1F – 532IENGINE CONTROLS
DAEWOO V–121 BL4
Engine Coolant Temperature Sensor (Temperature Vs. Resistance
Value)
°C°FOHMS°C°FOHMS
10021217715594450
801763325417280
60140667–52312300
4511 31188–15521450
35951802–30–2252700
25772796–40–40100700
Above resistance is approximate value
DTC P1114 – Engine Coolant Temperature Intermittent 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. Turn the ignition ON.
3. Request engine Diagnostic Trouble Code
(DTC).
Is Diagnostic Trouble Code (DTC) P0117 also set?–Go to
applicable DTC
tableGo to Step 3
3Check the Engine Coolant Temperature (ECT) sig-
nal circuit between terminal 1 of the ECT sensor and
terminal M28 of the ECM for an intermittent short to
ground and repair as needed.
Is the repair complete?–Go to Step 4Go to
”Diagnostic
Aids”
41. 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 5Go to Step 2
5Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 534IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1115 – Engine Coolant Temperature Intermittent 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. Turn the ignition ON.
3. Request engine Diagnostic Trouble Code
(DTC).
Is Diagnostic Trouble Code (DTC) P0118 set?–Go to
applicable DTC
tableGo to Step 3
3Is DTC P1111 also set?–Go to Step 7Go to Step 4
4Check for a poor sensor ground circuit terminal 2 at
the Engine Coolant Temperature (ECT) sensor and
repair as needed.
Is the repair complete?–Go to Step 9Go to Step 5
5Check for a poor sensor signal circuit between termi-
nal 1 of the ECT sensor and terminal M28 of the En-
gine Control Module (ECM) for an intermittent open
and repair as needed.
Is the repair complete?–Go to Step 9Go to Step 6
6Check for sensor signal circuit between terminal 1 of
the ECT sensor and terminal M28 of the ECM for an
intermittent short to voltage and repair as needed.
Is the repair complete?–Go to Step 9Go to Step 7
7Check for poor sensor ground circuit terminal M64
at the ECM and repair as needed.
Is the repair complete?–Go to Step 9Go to Step 8
8Check for an intermittent open or a faulty splice in the
sensor ground circuit and repair as needed.
Is the repair complete?–Go to Step 9Go to
”Diagnostic
Aids”
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 – 535
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1121
THROTTLE POSITION SENSOR INTERMITTENT HIGH
VOLTAGE
Circuit Description
The Throttle Position (TP) sensor circuit provides a volt-
age signal that changes relative to throttle blade angle.
The TP sensor sends a voltage signal back to the Engine
Control Module (ECM) relative to the throttle plate open-
ing. The voltage signal will vary from approximately 0.33
volts at closed throttle, to over 4.3 volts at Wide Open
Throttle (WOT).
The TP signal is used by the ECM for fuel control and for
most of the ECM controlled outputs. The TP signal is one
of the most important inputs used by the ECM for fuel con-
trol and most of the ECM controlled outputs. If the ECM
detects a TP signal that is intermittently above the range
of the TP sensor, Diagnostic Trouble Code (DTC) P1121
will be set.
Conditions for Setting the DTC
S TP sensor voltage indicates a throttle voltage inter-
mittently greater than 4.9 volts.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC set as Failure Records data only.
This information will not be stored as Freeze Frame
data.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S A history will clear after 40 consecutive warm–up
cycles in which the diagnostic runs 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
Check for the following conditions:
S Poor connection at the ECM. Inspect harness con-
nectors for backed–out terminals, improper mating,
broken locks, improperly formed or damaged termi-
nals, and poor terminal–to–wire connection.
S Damaged harness. Inspect the wiring harness for
damage. If the harness appears OK, observe the
throttle position display on the scan tool while mov-
ing connectors and wiring harnesses related to the
TP sensor. A change in the display will indicate the
location of the fault.
If DTC P1121 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to be set occurs. This may assist in diagnosing
the condition.
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.

1F – 536IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1121 – Throttle Position Sensor Intermittent 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. Turn the ignition ON.
Is Diagnostic Trouble Code (DTC) P0123 also set?–Go to
applicable DTC
tableGo to Step 3
3Check for poor sensor ground circuit terminal 1 con-
nection at the Throttle Position (TP) sensor.
Is a problem found?–Go to Step 7Go to Step 4
4Check the TP signal circuit between TP sensor con-
nector and the Engine Control Module (ECM) for an
intermittent short to voltage.
Is a problem found?–Go to Step 8Go to Step 5
5Check for a poor sensor ground terminal M64 at the
ECM.
Is a problem found?–Go to Step 7Go to Step 6
6Check for an intermittent open or faulty spice in the
sensor ground circuit.
Is a problem found?–Go to Step 8Go to
”Diagnostic
Aids”
7Repair or replace the faulty harness connector ter-
minal for sensor ground circuit.
Is the repair complete?–Go to Step 9
8Repair the intermittent open/short circuit in wiring
harness as needed.
Is the repair 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 – 537
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1122
THROTTLE POSITION SENSOR INTERMITTENT LOW
VOLTAGE
Circuit Description
The Throttle Position (TP) sensor circuit provides a volt-
age signal that changes relative to throttle blade angle.
The TP sensor sends a voltage signal back to the Engine
Control Module (ECM) relative to the throttle plate open-
ing. The voltage signal will vary from approximately 0.33
volts at closed throttle, to over 4.3 volts at Wide Open
Throttle (WOT).
The TP signal is used by the ECM for fuel control and for
most of the ECM controlled outputs. The TP signal is one
of the most important inputs used by the ECM for fuel con-
trol and most of the ECM controlled outputs. If the ECM
detects a TP signal that is intermittently above the range
of the TP sensor, Diagnostic Trouble Code (DTC) P1122
will be set.
Conditions for Setting the DTC
S TP sensor voltage indicates a throttle voltage inter-
mittently less than 0.14 volts.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC set as Failure Records data only.
This information will not be stored as Freeze Frame
data.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S A history will clear after 40 consecutive warm–up
cycles in which the diagnostic runs 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
Check for the following conditions:
S Poor connection at the ECM. Inspect harness con-
nectors for backed–out terminals, improper mating,
broken locks, improperly formed or damaged termi-
nals, and poor terminal–to–wire connection.
S Damaged harness. Inspect the wiring harness for
damage. If the harness appears OK, observe the
throttle position display on the scan tool while mov-
ing connectors and wiring harnesses related to the
TP sensor. A change in the display will indicate the
location of the fault.
If DTC P1122 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to be set occurs. This may assist in diagnosing
the condition.
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.

1F – 538IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1122 – Throttle Position Sensor Intermittent 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. Turn the ignition ON.
Is Diagnostic Trouble Code (DTC) P0123 also set?–Go to
applicable DTC
tableGo to Step 3
3Check for poor 5 volt reference circuit terminal 2 con-
nection at the Throttle Position (TP) sensor.
Is a problem found?–Step 7Step 4
4Check the TP signal circuit between TP sensor con-
nector and the Engine Control Module (ECM) for an
intermittent open or short to ground.
Is a problem found?–Go to Step 8Go to Step 5
5Check for a poor 5 volt reference circuit terminal M32
at the ECM.
Is a problem found?–Go to Step 7Go toStep 6
6Check for an intermittent open in the 5 volt reference
circuit.
Is a problem found?–Go to Step 8Go to Step 4
7Repair or replace the faulty harness connector ter-
minal for 5 volt reference circuit and/or the TP signal
circuit as needed.
Is the repair complete?–Go to Step 9–
8Repair the intermittent open/short circuit in wiring
harness as needed.
Is the repair 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

1F – 544IENGINE CONTROLS
DAEWOO V–121 BL4
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
A malfunction in the HO2S1 ignition feed or ground circuit
may cause a DTC P1134 to set. Check HO2S1 circuitry for
intermittent faults or poor connections. If connections and
wiring are OK and DTC P1134 continues to set, replace
the HO2S1.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how open
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Chart.
3. A condition that affects pre–converter and post–
converter oxygen sensors indicates probable con-
tamination. To avoid damaging replacement sen-
sors, correct the condition which caused the
contamination before replacing the affected sen-
sors.
5. This step checks for conditions which may cause
the oxygen sensor to appear faulty. Correct any of
the described conditions if present.
8. To avoid damaging replacement sensors, correct
the condition which caused the contamination be-
fore replacing the affected sensors
DTC P1134 – Front Heated Oxygen Sensor (HO2S1) Transition
Ratio
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”
2Important : If any Diagnostic Trouble Codes (DTCs)
are set, refer to those DTCs before processing with
this diagnostic chart.
1. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine and idle at normal operating
temperature.
3. Operate the engine within parameters specified
under Conditions for Setting the DTC.
4. Using a scan tool, monitor specific DTC info for
DTC P1134 until the DTC P1134 test runs.
5. Note the test result.
Does the scan tool indicate DTC P1134 failed this
ignition?–Go to Step 3Go to
”Diagnostic
Aids”
3Perform an exhaust system leak test.
If an exhaust leak is found, repair as needed.
The exhaust leak isolated?–Go to Step 14Go to Step 4
4Visually/physically inspect for the following items:
S Front Heated Oxygen Sensor (HO2S1) is se-
curely installed.
S Corrosion on the terminals.
S Terminal tension.
S HO2S1 wiring harness for poor terminal con-
nection or damaged wiring.
Is a problem found in any of the above areas?–Go to Step 7Go to Step 5