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
1F – 354IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
7With a ohmmeter connected to the ground, probe
the 5 volt reference circuit terminal M16.
Is the resistance within near the specified value.5 vGo to Step 8Go to Step 9
8Check the MAP sensor vacuum source for being
plugged or leaking.
Is a problem found?–Go to Step 10Go to Step 13
9Check the 5 volt reference circuit at terminal M16 for
a short to voltage and repair as needed.
Is the repair complete?–Go to Step 14Go to Step 12
10Repair the vacuum source as needed.
Is the action complete?–Go to Step 14–
11Check for an open in the MAP sensor ground circuit
at terminal 1 and repair as needed.
Is the repair complete?–Go to Step 14Go to Step 12
121. Turn the ignition switch OFF.
2. Replace the Engine Control Module (ECM).
Is the action complete?–Go to Step 14–
13Replace the MAP sensor.
Is the action complete?–Go to Step 14–
141. 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 15Go to Step 2
15Check 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 – 355
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0112
INTAKE AIR TEMPERATURE LOW VOLTAGE
Circuit Description
The Intake Air Temperature (IAT) sensor uses a thermistor
to control the signal voltage to the Engine Control Module
(ECM). The ECM supplies a 5 volt reference and a ground
to the sensor. When the air is cold, the resistance is high;
therefore the IAT signal voltage will be high. If the intake
air is warm, resistance is low; therefore the IAT signal volt-
age will be low.
Conditions for Setting the DTC
S IAT is less than 149°C (300°F).
S Engine run time is greater than 120 seconds.
S Vehicles speed is greater than or equal to 50 km/h
(31 mph).
S DTC P0502 is not set.
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 default value for intake
air temperature. 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 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 eval-
uate the possibility of a skewed sensor. Refer to ”Temper-
ature vs. Resistance” in this section.
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.
4. This step simulates a DTC P0113 condition. If the
scan tool displays the specified value, the IAT sig-
nal circuit, the ECM are OK.
8. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
1F – 356IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0112 – Intake Air Temperature 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 the Intake Air Temperature (IAT) value greater
than the specified value?128°C
(262 °F)Go to Step 4Go to Step 3
31. Turn the ignition switch ON with the engine
OFF, review Freeze Frame data, and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions and Conditions for Setting The DTC
as noted.
Is the IAT sensor value greater than the specified
value?128°C
(262 °F)Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition switch OFF.
2. Disconnect the IAT sensor electrical connector.
3. Turn the ignition switch ON.
Is the IAT sensor value below the specified value?–30 °C
(–22 °F)Go to Step 5Go to Step 6
5Replace IAT sensor.
Is the repair complete?–Go to Step 10–
6With a test light connected to battery +, probe the
IAT sensor signal circuit, terminal 2 at the IAT sensor
connector.
Does the test light illuminate?–Go to Step 7Go to Step 9
71. Turn the ignition switch OFF.
2. Disconnect the Engine Control Module (ECM)
connector.
3. With a test light connected to B+, probe the
IAT sensor signal circuit, terminal 2 at the IAT
sensor electrical connector.
Does the test light illuminate?–Go to Step 8Go to Step 9
8Repair the short to ground circuit in the IAT sensor
signal circuit as needed.
Is the repair complete?–Go to Step 10–
91. Turn the ignition OFF.
2. Replace the ECM.
Is the action complete?–Go to Step 10–
ENGINE CONTROLS 1F – 357
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
101. 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 11Go to Step 2
11Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to the appli-
cable DTC
tableSystem OK
1F – 358IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0113
INTAKE AIR TEMPERATURE HIGH VOLTAGE
Circuit Description
The Intake Air Temperature (IAT) sensor uses a thermistor
to control the signal voltage to the Engine Control Module
(ECM). The ECM supplies a 5 volt reference and a ground
to the sensor. When the air is cold, the resistance is high;
therefore the IAT signal voltage will be high. If the intake
air is warm, resistance is low; therefore the IAT signal volt-
age will be low.
Conditions for Setting the DTC
S IAT is less than –38°C (–36°F).
S Vehicles speed is less than 25 km/h (16 mph).
S Engine run time is greater than 120 seconds.
S Engine Coolant Temperature (ECT) is above 70 °C
158 °F).
S Calculated air are flow is less than 15 g/second.
S DTC P0502, P0117, P0118 not set.
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 default value for intake
air temperature. 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
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. Re-
fer to ”Temperature vs. Resistance” in this section.
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.
4. This step simulates a DTC P0112. If the ECM
senses the change, the ECM and wiring are OK.
5. This step will determine if the reason the ECM did
not sense the change was due to a open ground or
signal circuit or malfunctioning ECM.
11. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
ENGINE CONTROLS 1F – 359
DAEWOO V–121 BL4
DTC P0113 Intake Air Temperature 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 the Intake Air Temperature (IAT) value less than
the specified value?–30 °C
(–22 °F)Go to Step 4Go to Step 3
31. Turn the ignition switch ON with the engine
OFF, review Freeze Frame data, and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions and Conditions for Setting The DTC
as noted.
Is the IAT sensor value less than the specified val-
ue?–30 °C
(–22 °F)Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition switch OFF.
2. Disconnect the IAT sensor electrical connector.
3. Turn the ignition switch ON.
4. Jumper the IAT sensor signal circuit terminal 2
and ground circuit terminal 1.
Is the IAT sensor value greater than the specified
value?130 °C
(266 °F)Go to Step 6Go to Step 5
5Jumper the IAT sensor signal circuit at terminal 1 to
ground.
Is the IAT sensor value greater than the specified
value?130 °C
(266 °F)Go to Step 7Go to Step 8
6Check for a poor connection at the IAT sensor con-
nector and repair or replace any malfunctioning ter-
minal as needed.
Is the repair necessary?–Go to Step 12Go to Step 10
7Check the IAT sensor ground circuit for an open and
repair as needed.
Is the repair complete?–Go to Step 12Go to Step 9
8Check the IAT sensor signal circuit for an open and
repair as needed.
Is the repair complete?–Go to Step 12Go to Step 9
9Check for a poor IAT sensor ground circuit at termi-
nal M64 or a poor IAT sensor signal circuit terminal
M7 connection at Engine Control Module (ECM) and
repair as needed.
Is the repair necessary?–Go to Step 12Go to Step 11
10Replace the IAT sensor.
Is the action complete?–Go to Step 12
111. Turn the ignition OFF.
2. Replace the ECM.
Is the action complete?–Go to Step 12–
1F – 360IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
121. 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 13Go to Step 2
13Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK