
1F – 104IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
341. Turn the ignition OFF.
2. Connect a test light between the cooling fan
relay Hi connector terminal 30 and ground.
Is the test light on?–Go to Step 35Go to Step 45
351. Disconnect the cooling fan control relay.
2. Connect a test light between the cooling fan
control relay connector terminal 85 and ground.
3. Turn the ignition ON.
Is the test light on?–Go to Step 36Go to Step 46
361. Turn the ignition OFF.
2. Connect a test light between the cooling fan
control relay connector terminal 87 and battery
positive.
Is the test light on?–Go to Step 37Go to Step 47
371. Connect the main cooling fan connector.
2. Connect the cooling fan relay Hi.
3. Connect the cooling fan control relay.
4. Disconnect the ECM connector.
5. Connect a fused jumper between the ECM
connector terminal K28 and ground.
6. Connect a fused jumper between the ECM
connector terminal K12 and ground.
7. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 30Go to Step 38
381. Turn the ignition OFF.
2. Check for an open wire between the cooling
fan relay Hi connector terminal 85 and the
ECM connector terminal K12.
Is the problem found?–Go to Step 22Go to Step 39
391. Disconnect the cooling fan relay Hi.
2. Connect a test light between the cooling fan
relay Hi connector terminal 87 and battery posi-
tive.
Is the test light on?–Go to Step 40Go to Step 48
401. Disconnect the ECM connector.
2. Connect a fused jumper between the ECM
connector terminal K12 and ground.
3. Disconnect the cooling fan relay Hi.
4. Connect a test light between the cooling fan
control relay connector terminal 86 and battery
positive.
Is the test light on?–Go to Step 41Go to Step 49

ENGINE CONTROLS 1F – 105
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
411. Connect the cooling fan control relay.
2. Connect a fused jumper between the ECM
connector terminal K12 and ground.
3. Disconnect the cooling fan relay Hi.
4. Connect a fused jumper between the cooling
fan relay Hi connector terminals 30 and 87.
5. Disconnect the low speed cooling fan relay.
6. Connect a fused jumper between the low
speed cooling fan relay connector terminals 30
and 87.
7. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 43Go to Step 42
421. Turn the ignition OFF.
2. Connect a fused jumper between the ECM
connector terminal K12 and ground.
3. Disconnect the cooling fan control relay.
4. Connect a fused jumper between the cooling
fan control relay connector terminals 30 and
87.
5. Connect a fused jumper between the low
speed cooling fan relay connector terminals 30
and 87.
6. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 27–
43Replace the cooling fan relay Hi.
Is the repair complete?–System OK–
44Repair the open wire between the cooling fan relay
Hi connector terminal 86 and the ignition switch.
Is the repair complete?–System OK–
45Repair the open wire between the cooling fan relay
Hi connector terminal 30 and the battery.
Is the repair complete?–System OK–
46Repair the open wire between the cooling fan control
relay connector terminal 85 and the ignition switch
Is the repair complete?–System OK–
47Repair the open wire between the cooling fan control
relay connector terminal 87 and ground.
Is the repair complete?–System OK–
48Repair the open wire between the cooling fan relay
Hi connector terminal 87 and the auxiliary cooling
fan connector terminal 2.
Is the repair complete?–System OK–
49Repair the open wire between the cooling fan control
relay connector terminal 85 and the ECM connector
terminal K12.
Is the repair complete?–System OK–

1F – 106IENGINE CONTROLS
DAEWOO V–121 BL4
DATA LINK CONNECTOR DIAGNOSIS (1.4L/1.6L DOHC)
Circuit Description
The provision for communicating with the Engine Control
Module (ECM) is the Data Link Connector (DLC). It is lo-
cated under the instrument panel. The DLC is used to con-
nect the scan tool. Battery power and ground is supplied
for the scan tool through the DLC. The Keyword 2000 seri-
al data circuit to the DLC allows the ECM to communicate
with the scan tool. A Universal Asynchronous Receiver
Transmitter (UART) serial data line is used to communi-
cate with the other modules such as the Electronic Brake
Control Module (EBCM), the Supplemental Inflatable Re-
straint (SIR) system. and the Instrument Panel Cluster.
Diagnostic Aids
Ensure that the correct application (model line, car year,
etc.) has been selected on the scan tool. If communication
still cannot be established, try the scan tool on another ve-
hicle to ensure that the scan tool or cables are not the
cause of the condition.
An intermittent may be caused by a poor connection,
rubbed through wire insulation, or a broken wire inside the
insulation.
Any circuitry that is suspected of causing an intermittent
complaint should be thoroughly checked for the following
conditions:
S Backed–out terminals.S Improper mating of terminals.
S Broken locks.
S Improperly formed or damaged terminals.
S Poor terminal–to–wiring connection.
S Physical damage to the wiring harness.
S Corrosion.
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.
2. Unlike the UART serial data circuit, the only time a
Class II serial data circuit has any voltage on it is
when a scan tool asks the ECM for information and
sends the information out.
5. Locate and repair any shorts that may have caused
the fuse to open before replacement, if the no volt-
age condition was due to an open fuse.
10. The scan tool or associated cables could be mal-
functioning. Refer to the scan tool’s manual for re-
pair information.

1F – 108IENGINE CONTROLS
DAEWOO V–121 BL4
DATA LINK CONNECTOR DIAGNOSIS (1.8L DOHC)
Circuit Description
The provision for communicating with the Engine Control
Module (ECM) is the Data Link Connector (DLC). It is lo-
cated under the instrument panel. The DLC is used to con-
nect the scan tool. Battery power and ground is supplied
for the scan tool through the DLC. The Keyword 2000 seri-
al data circuit to the DLC allows the ECM to communicate
with the scan tool. A Universal Asynchronous Receiver
Transmitter (UART) serial data line is used to communi-
cate with the other modules such as the Electronic Brake
Control Module (EBCM), the Supplemental Inflatable Re-
straint (SIR) system. and the Instrument Panel Cluster.
Diagnostic Aids
Ensure that the correct application (model line, car year,
etc.) has been selected on the scan tool. If communication
still cannot be established, try the scan tool on another ve-
hicle to ensure that the scan tool or cables are not the
cause of the condition.
An intermittent may be caused by a poor connection,
rubbed through wire insulation, or a broken wire inside the
insulation.
Any circuitry that is suspected of causing an intermittent
complaint should be thoroughly checked for the following
conditions:
S Backed–out terminals.S Improper mating of terminals.
S Broken locks.
S Improperly formed or damaged terminals.
S Poor terminal–to–wiring connection.
S Physical damage to the wiring harness.
S Corrosion.
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.
2. Unlike the UART serial data circuit, the only time a
Class II serial data circuit has any voltage on it is
when a scan tool asks the ECM for information and
sends the information out.
5. Locate and repair any shorts that may have caused
the fuse to open before replacement, if the no volt-
age condition was due to an open fuse.
10. The scan tool or associated cables could be mal-
functioning. Refer to the scan tool’s manual for re-
pair information.

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

ENGINE CONTROLS 1F – 115
DAEWOO V–121 BL4
The ECM as an indication of vehicle altitude uses this in-
formation. Comparison of this reading with a known good
vehicle with the same sensor is a good way to check the
accuracy of a suspect sensor. Readings should be the
same ± 0.4volt.
If a DTC P0107 is intermittent, refer to ”Manifold AbsolutePressure Check” in this section for further diagnosis.
If the connections are OK monitor the manifold absolute
pressure (MAP) sensor signal voltage while moving re-
lated connectors and the wiring harness. If the failure is in-
duced, the display on the scan tool will change. This may
help to isolate the location of an intermittent malfunction.
DTC P0107 – Manifold Absolute Pressure 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. Turn the ignition switch to ON.
Does the scan tool show the manifold absolute pres-
sure (MAP) sensor voltage above the value speci-
fied?4VGo to Step 3Go to Step 4
31. Disconnect the vacuum line from the MAP sen-
sor.
2. Apply 88kPA (20in.of Hg) of vacuum to the
MAP sensor.
Does the scan tool show the MAP sensor voltage
within the value specified?1.0–1.5VGo to
”Diagnostic
Aids”Go to Step 4
41. Turn the ignition switch to LOCK.
2. Disconnect the MAP sensor connector.
3. Turn the ignition switch to ON.
4. Measure the voltage between the MAP sensor
connector terminals A and C.
Does the voltage measure within the value speci-
fied?4.5–5.5VGo to Step 5Go to Step 6
5Connect a fused jumper between the MAP sensor
connector terminals B and C.
Does the scan tool show the MAP sensor voltage
above the value specified?4VGo to Step 11Go to Step 9
6Measure the voltage between the MAP sensor con-
nector terminal A 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. Check for open wires between the MAP sensor
connector terminal A and the ECM connector
terminal 13.
Is the problem found?–Go to Step 10Go to Step 12
81. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the
wire between the MAP sensor connector termi-
nal C and the ECM connector terminal 50.
Is the problem found ?–Go to Step 10Go to Step 12

1F – 118IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0108 – Manifold Absolute Pressure 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. Turn the ignition switch to ON.
Does the scan tool show the manifold absolute pres-
sure (MAP) sensor voltage above the value speci-
fied?4VGo to Step 3Go to Step 4
31. Disconnect the vacuum line from the MAP sen-
sor.
2. Apply 66kPA (20in.of Hg) of vacuum to the
MAP sensor.
Does the scan tool show the MAP sensor voltage
within the value specified?1.0–1.5VGo to
”Diagnostic
Aids”Go to Step 4
41. Turn the ignition switch to LOCK.
2. Disconnect the MAP sensor connector.
3. Turn the ignition switch to ON.
4. Measure the voltage between the MAP sensor
connector terminals A and C.
Does the voltage measure within the value speci-
fied?4.5–5.5VGo to Step 5Go to Step 6
5Connect a fused jumper between the MAP sensor
connector terminals B and C.
Does the scan tool show the MAP sensor voltage
above the value specified?4VGo to Step 11Go to Step 9
6Measure the voltage between the MAP sensor con-
nector terminal A 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. Check for open wires between the MAP sensor
connector terminal A and the ECM connector
terminal 13.
Is the problem found?–Go to Step 10Go to Step 12
81. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the
wire between the MAP sensor connector termi-
nal C and the ECM connector terminal 50.
Is the problem found ?–Go to Step 10Go to Step 12
91. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the
wire between the MAP sensor connector termi-
nal B and the ECM connector terminal 75.
Is the problem found ?–Go to Step 10Go to Step 12

1F – 132IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0122 – Throttle Position 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”
2Turn the ignition switch to ON.
Is the Malfunction Indicator Lamp (MIL) on steady?–Go to Step 4Go to Step 3
31. Turn the ignition switch to LOCK.
2. Connect the scan tool to the DLC.
3. Turn the Turn the ignition switch to ON.
Are any diagnostic trouble codes (DTCs) displayed?–Go to Step 4Try with anoth-
er scan tool
4Refer to the applicable DTC table.
Is only one DTC identified as valid trouble code
P0122?–Go to Step 5Go to applica-
ble DTC table
and Go to ”Mul-
tiple DTC”
51. Connect the scan tool to the DLC.
2. Turn the ignition switch to ON.
3. Press the accelerator pedal while watching
TPS for smooth changes in the voltage.
Does the scan tool show the TPS voltage change
smoothly within the value specified?0.3V–4.8VGo to
”Diagnostic
Aids”Go to Step 6
61. Turn the ignition switch to lock.
2. Disconnect the MTIA connector.
3. Measure the voltage between terminal 2 and 8.
Does the voltage measure within the value speci-
fied?4.8V–5.0VGo to Step 7Go to Step 8
7Connect a fused jumper between the MTIA connec-
tor terminal 2 and terminal 7.
Does the scan tool show the TPS voltage above val-
ue specified?4.8V–5.0VGo to Step 13Go to Step 11
8Measure the voltage between the MTIA connector
2 and ground.
Does the voltage measure within the value speci-
fied?5.0VGo to Step 9Go to Step 10
91. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 8 and ECM
connector 19.
Is the problem found?–Go to Step 12Go to Step 14
101. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 2 and ECM
connector 79.
Is the problem found?–Go to Step 12Go to Step 14
111. Turn the ignition switch to lock.
2. Check for an open or short to ground in the
wire between the MTIA connector 7 and ECM
connector 74.
Is the problem found?–Go to Step 12Go to Step 14