Page 370 of 2643
1F – 124IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Replace the ECM.
2. Perform the diagnostic system check.
Is the repair complete?–Go to Step 12–
12Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to
applicable
DTC tableSystem OK
Page 371 of 2643

ENGINE CONTROLS 1F – 125
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0117
ENGINE COOLANT TEMPERATURE SENSOR LOW
VOLTAGE
Circuit Description
The Engine Coolant Temperature sensor (ECT) uses a
thermistor to control the signal voltage to the engine con-
trol module (ECM).
The ECM supplies a voltage on the signal circuit to the
sensor. When the engine coolant is cold, the resistance is
high; therefore the ECT signal voltage will be high.
As the engine warms, the sensor resistance becomes
less, and the voltage drops. At normal engine operating
temperature, the voltage will be between 1.5 and 2.0 volts
at the ECT signal terminal.
The ECT sensor is used to the following items:
S Fuel delivery.
S Lock Up Clutch (LUC).
S Ignition.
S Evaporative Emission (EVAP) Canister Purge
Valve.
S Electric cooling fan.
Conditions for Setting the DTC
S ECT voltage is less than 0.03V.
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 ECM will default to 20°C (68°F) for the first 60
seconds of the engine run time, and then 92 °C
(198 °F).
S The scan tool will not show the 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
After the engine has started, the ECT should rise steadily
to about 90°C (194°F) then stabilize when the thermostat
opens.
Use the temperature vs. Resistance values table to evalu-
ate the possibility of a skewed sensor. Refer to ”Tempera-
ture vs. Resistance” in this section.
Page 372 of 2643

1F – 126IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0117 – Engine Coolant 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 ECT sensor reading
within the value specified?80~110°C
(176~260°F)Go to
”Diagnostic
Aids”Go to Step 3
31. Turn the ignition switch to LOCK.
2. Disconnect the ECT sensor connector.
3. Turn the ignition switch to ON.
Does the scan tool show the IAT sensor reading
within the value specified?–30°C
(–22°F)Go to Step 4Go to Step 6
41. Jumper the ECT sensor signal circuits at termi-
nal 1 and 2.
2. Turn the ignition switch to ON.
Does the scan tool show the ECT sensor reading
within the value specified?120°CGo to Step 5Go to Step 6
51. Replace the ECT sensor.
2. Clear any DTCs from the ECM.
3. Perform the diagnostic system check.
Is the replacement complete?–System OK–
6Measure the voltage between ECT terminal 2 and
ground.
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. Disconnect the ECM wiring connector.
3. Check for a faulty connector or terminals at the
ECT sensor connectors and ECM connectors
for short to ECM reference voltage.
Is the problem found?–Go to Step 9Go to Step 8
81. Turn the ignition switch to LOCK.
2. Repair the wire of the connector terminals 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–
Page 373 of 2643
ENGINE CONTROLS 1F – 127
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Replace the ECM.
2. Run the engine until it reaches operating tem-
perature.
3. 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 applica-
ble DTC tableSystem OK
Page 374 of 2643

1F – 128IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0118
ENGINE COOLANT TEMPERATURE SENSOR HIGH
VOLTAGE
Circuit Description
The coolant temperature sensor (ECT) uses a thermistor
to control the signal voltage to the engine control module
(ECM).
he ECM supplies a voltage on the signal circuit to the sen-
sor. When the air is cold, the resistance is high; therefore
the ECT sensor signal voltage will be high.
As the engine warms, the sensor resistance becomes
less, and the voltage drops. At normal engine operating
temperature, the voltage will be between 1.5 and 2.0 volts
at the ECT sensor signal terminal.
The ECT sensor is used to the following items:
S Fuel delivery.
S Lock Up Clutch (LUC).
S Ignition.
S Evaporative Emission (EVAP) Canister Purge
Valve.
S Electric cooling fan.
Conditions for Setting the DTC
S ECT voltage is greater than 4.98V.
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 ECM will substitutes a fixed MAP value and
use TP to control the fuel delivery (the scan tool will
not show defaulted)
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
After the engine has started, the ECT should rise steadily
to about 90°C (194°F) then stabilize when the thermostat
opens.
Use the temperature vs. Resistance values table to evalu-
ate the possibility of a skewed sensor. Refer to ”Tempera-
ture vs. Resistance” in this section.
Page 375 of 2643

ENGINE CONTROLS 1F – 129
DAEWOO V–121 BL4
DTC P0118 – Engine Coolant 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 until it reaches operating tem-
perature.
Does the scan tool show the ECT sensor reading
within the value specified?80~110°C
(176~260°F)Go to
”Diagnostic
Aids”Go to Step 3
31. Turn the ignition switch to LOCK.
2. Disconnect the ECT sensor connector.
3. Turn the ignition switch to ON.
Does the scan tool show the ECT sensor reading
within the value specified?–30°CGo to Step 4Go to Step 6
41. Jumper the ECT sensor signal circuits at termi-
nal 1 and 2.
2. Turn the ignition switch to ON.
Does the scan tool show the ECT sensor reading
within the value specified?180°C
(356°F)Go to Step 5Go to Step 6
51. Replace the ECT sensor.
2. Clear any DTCs from the ECM.
3. Perform the diagnostic system check.
Is the replacement complete?–System OK–
6Measure the voltage between ECT terminal 1 and
ground.
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. Disconnect the ECM wiring connector.
3. Check for a faulty connector or terminals at the
ECT sensor connector terminal 2 and the ECM
connector terminal 19 for an open or short to
battery voltage.
Is the problem found?–Go to Step 8Go to Step 9
81. Turn the ignition switch to LOCK.
2. Repair the wire of the connector terminals 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–
Page 376 of 2643
1F – 130IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Replace the ECM.
2. Run the engine until it reaches operating tem-
perature.
3. 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 applica-
ble DTC tableSystem OK
Page 377 of 2643

ENGINE CONTROLS 1F – 131
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0122
THROTTLE POSITION SENSOR 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, 195). The charac-
teristics of the airflow 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 idles to
about 0.2V 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 TPS voltage is less than 0.3V.
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 ECM will default to 20°C (68°F) for the first 60
seconds of the engine run time, and then 92 °C
(198 °F).
S The scan tool will not show the 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
If the DTC P0122 cannot be duplicated, the information in-
cluded in the Freeze Frame data can be useful. Use the
scan tool DTC information data to determine the status of
the DTC. If the DTC occurs intermittently, using the DTC
P0121 diagnostic table may help isolate the problem.