
1F–48 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
ENGINE COOLING FAN CIRCUIT CHECK
Circuit Description
The engine cooling fan circuit operates the cooling fan.
The cooling fan is controlled by the engine control mod-
ule (ECM) based on input from the coolant temperature
sensor (CTS) and the A/C ON/OFF. The ECM controls
the low speed cooling fan operation by internally ground-
ing the ECM connector terminal 39. This energizes the
low speed cooling fan relay and operates the cooling fan
at low speed. The low speed cooling fan operation is
achieved by the cooling fan resistor causing a drop in
the voltage supplied to the cooling fan. The ECM con-
trols the high speed cooling fan operation by internally
grounding the ECM connector terminal 5. This ener-
gizes the high speed cooling fan relay, bypassing the ra-
diator fan resistor. This results in high speed cooling fan
operation.
Diagnostic Aids
If the owner complained of an overheating problem, it
must be determined if the complaint was due to anactual boil over, or the engine coolant temperature
gauge indicated overheating. If the engine is over-
heating and the cooling fans are on, the cooling sys-
tem should be checked.
If the engine fuse block fuse EF15 become open
(blown) immediately after installation, inspect for a
short to ground in the wiring of the appropriate circuit.
If the fuse become open (blown) when the cooling
fans are to be turned on by the Engine Control Mod-
ule (ECM), suspect a faulty cooling fan motor.
The ECM will turn the cooling fan on at low speed
when the coolant temperature is 93C (199F). The
ECM will turn the cooling fans off when the coolant
temperature is 90C (194F).
The ECM will turn the cooling fans on at high speed
when the coolant temperature is 100C (212F). The
ECM will change the cooling fans from high speed to
low speed when the coolant temperature is 97C
(207F).

ENGINE CONTROLS 1F–49
DAEWOO M-150 BL2
Engine Cooling Fan Circuit Check
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to “Euro
On-Board
Diagnostic
System Check.
2
1. Check the fuses EF3 and EF10 in engine fuse
block.
2. Replace the fuse(s) as needed.
Is the fuse(s) OK?
–
Go to Step 3
Go to
“Diagnostic
Aids”
3
1. Turn the ignition OFF.
2. Turn the A/C switch OFF. If equipped.
3. Connect a scan tool to the Data Link Connector
(DLC).
4. Start the engine.
5. The main cooling fan should run at low speed
when the coolant temperature reaches 96C
(205F).
Does the cooling fan run at low speed?
–
Go to Step 4Go to Step 8
4
The cooling fans should run at high speed when the
coolant temperature reaches 100C (212F).
Do the cooling fans run at high speed?
–
Go to Step 5Go to Step 19
5
1. Turn the ignition OFF.
2. Start the engine.
3. Turn the A/C switch ON.
Does the cooling fan runs at low speed?
–
Go to Step 7Go to Step 6
6
1. Diagnose the A/C compressor clutch circuit.
2. Repair the A/C compressor clutch circuit as
needed.
Is the repair complete?
–
System OK
–
7
1. Turn the ignition OFF.
2. Start the engine.
3. Turn the A/C switch ON and raise the rpm.
4. The cooling fan should run at high speed when
the high side A/C pressure reaches 2068 kPa
(300 psi).
Do the cooling fans run at high speed?
–
System OK
–
8
1. Turn the ignition OFF.
2. Disconnect the cooling fan connector.
3. Turn the ignition ON.
4. Connect a test light between terminal 1 of cooling
fan connector and ground.
Is the test light on?
–
Go to Step 9Go to Step 12
9
Connect a test light between terminal 2 of cooling
fan connector and battery positive.
Is the test light on?
–
Go to Step 11Go to Step 10
10
Repair open circuit between terminal 2 of cooling fan
connector and ground.
Is the repair complete?
–
System OK
–
11
Check for a damaged terminals in main cooling fan
connector and repair it or replace the main cooling
fan.
Is the repair complete?
–
System OK
–

1F–50 ENGINE CONTROLS
DAEWOO M-150 BL2
Engine Cooling Fan Circuit Check (Cont’d)
StepActionValue(s)YesNo
12
1. Turn the ignition ON.
2. Connect a test light between terminals 86 and 30
of low speed cooling fan relay and ground.
Does the test light on for both case?
–
Go to Step 14Go to Step 13
13
Repair power supply circuit.
Fuse EF15 and terminal 30 of low speed cooling
fan relay.
Is the repair complete?
–
System OKGo to Step 14
14
1. Turn the ignition OFF.
2. Disconnect Engine Control Module (ECM)
connectors.
3. Turn the ignition ON.
4. Connect a jump wire between terminal 5 and
ground.
Does the cooling fan run at low speed?
–
Go to Step 15Go to Step 16
15Replace the ECM.
Is the repair complete?–System OK–
16
1. Turn the ignition OFF.
2. Measure the resistance between following
terminals:
Terminal 85 of low speed cooling fan relay and
terminal 39 of ECM connector.
Are the resistance within the value specified?
0 ΩGo to Step 18Go to Step 17
17Repair open circuit.
Is the repair complete?–System OK–
18Replace the low speed cooling fan relay.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 55
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE DIAGNOSIS
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 theproblem is intermittent, the MIL will go out after 10 sec-
onds if the fault is no longer present. The DTC will stay
in the ECM’s memory until cleared by scan tool. Remov-
ing battery voltage 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
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 Hig voltageAYES
P0131Oxygen Sensor Low VoltageAYES
P0132Oxygen Sensor High VoltageAYES
P0133Oxygen Sensor No ActivityEYES
P0137Heated Oxygen Sensor Low VoltageEYES
P0138Heated Oxygen Sensor high voltageEYES
P0140Heated Oxygen Sensor No ActivityEYES
P0141Heated Oxygen Sensor Heater MalfuctionEYES
P0171Fuel Trim System Too LeanEYES
P0172Fuel Trim System Too RichEYES
P1230Fuel Pump Relay Low VoltageAYES
P1231Fuel Pump Relay 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
P0300Multifle Cylinder MisfireA/EBLINKING/ON
P1320Crankshatft Segment Period Segment Adaptation At LimitEYES
P1321Crankshatft Segment Period Tooth ErrorEYES
P0327Knock Sensor Circuit FaultEYES
P0335Magnetic Crankshaft Position Sensor Electrical ErrorEYES

ENGINE CONTROLS 1F–59
DAEWOO M-150 BL2
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 isinduced, the display on the scan tool will change. This
may help to isolate the location of an intermittent mal-
function.
DTC P0107 – Manifold Absolute Pressure Sensor Low Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Connect the scan tool to the data link connector
(DLC).
2. Turn the ignition switch to ON.
Does the scan tool show the manifold absolute
pressure (MAP) sensor voltage above the value
specified?
4VGo to Step 3Go to Step 4
3
1. Disconnect the vacuum line from the MAP
sensor.
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?
1.0–1.5V
Go to
“Diagnostic
Aids”
Go to Step 4
4
1. 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
specified?
4.5–5.0VGo to Step 5Go to Step 6
5
Connect 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
6
Measure the voltage between the MAP sensor
connector terminal A and ground.
Does the voltage measure within the value
specified?
4.5–5.0VGo to Step 7Go to Step 8
7
1. Turn the ignition switch to LOCK.
2. Check for open wires between the MAP sensor
connector terminal A and the ECM connector
terminal 78.
Is the problem found?
–
Go to Step 10Go to Step 12
8
1. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the wire
between the MAP sensor connector terminal C
and the ECM connector terminal 12.
Is the problem found ?
–
Go to Step 10Go to Step 12
9
1. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the wire
between the MAP sensor connector terminal B
and the ECM connector terminal 73.
Is the problem found ?
–
Go to Step 10Go to Step 12

ENGINE CONTROLS 1F–63
DAEWOO M-150 BL2
DTC P0108 – Manifold Absolute Pressure Sensor High Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Connect the scan tool to the data link connector
(DLC).
2. Turn the ignition switch to ON.
Does the scan tool show the manifold absolute
pressure (MAP) sensor voltage above the value
specified?
4VGo to Step 3Go to Step 4
3
1. Disconnect the vacuum line from the MAP
sensor.
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?
1.0–1.5V
Go to
“Diagnostic
Aids”
Go to Step 4
4
1. 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
specified?
4.5–5.0VGo to Step 5Go to Step 6
5
Connect 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
6
Measure the voltage between the MAP sensor
connector terminal A and ground.
Does the voltage measure within the value
specified?
4.5–5.0VGo to Step 7Go to Step 8
7
1. Turn the ignition switch to LOCK.
2. Check for open wires between the MAP sensor
connector terminal A and the ECM connector
terminal 78.
Is the problem found?
–
Go to Step 10Go to Step 12
8
1. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the wire
between the MAP sensor connector terminal C
and the ECM connector terminal 12.
Is the problem found ?
–
Go to Step 10Go to Step 12
9
1. Turn the ignition switch to LOCK.
2. Check for an open or short to ground in the wire
between the MAP sensor connector terminal B
and the ECM connector terminal 73.
Is the problem found ?
–
Go to Step 10Go to Step 12
10
1. Repair the wire or the connector terminal as
needed.
2. Clear any DTCs from the ECM.
3. Perform the diagnostic system check.
Is the repair complete?
–
System OK
–

ENGINE CONTROLS 1F–227
DAEWOO M-150 BL2
a Freeze Frame conditions (rpm, load, vehicle speed, temperature, etc.) that .are noted. This will isolate when
the DTC failed.
DTC P0480 – Low Speed Cooling Fan Relay Circuit Fault (WITHOUT A/C)
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Turn the ignition switch to ON with the engine
OFF.
2. Install a scan tool.
3. Command the relay ON and OFF.
Does the relay turn ON and OFF when
commanded?
–
Go to Step 3Go to Step 5
3
1. Turn the ignition switch to LOCK.
2. Disconnect the engine control module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Using a digital voltmeter(DVM), measure the
current in low speed relay control circuit, at
terminal 39 to ground for 2 minutes.
Does the amperage measure less than the specified
value?
0.75 amps
Go to
“Diagnostic
Aids”
Go to Step 4
4
1. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 87 and 39 in the relay control circuit in
the ECM harness connector to ground.
Does the DVM display infinite resistance?
–
Go to Step 12Go to Step 10
5
1. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil
terminals 30 and 87 in the relay harness
connector.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON and
OFF.
Does the test light turn ON and OFF with each
commanded?
–
Go to Step 8Go to Step 6
6
With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?
–
Go to Step 7Go to Step 11
7
1. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 39 in the
ECM harness connector.
Does the relay operate?
–
Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12

ENGINE CONTROLS 1F–231
DAEWOO M-150 BL2
a Freeze Frame conditions (rpm, load, vehicle speed, temperature, etc.) that .are noted. This will isolate when
the DTC failed.
DTC P0480 – Low Speed Cooling Fan Relay Circuit Fault (with A/C)
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Turn the ignition switch to ON with the engine
OFF.
2. Install a scan tool.
3. Command the relay ON and OFF.
Does the relay turn ON and OFF when
commanded?
–
Go to Step 3Go to Step 5
3
1. Turn the ignition switch to LOCK.
2. Disconnect the engine control module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Using a digital voltmeter(DVM), measure the
current in low speed relay control circuit, at
terminal 10 to ground for 2 minutes.
Does the amperage measure less than the specified
value?
0.75 amps
Go to
“Diagnostic
Aids”
Go to Step 4
4
1. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 5 in the relay control circuit in
the ECM harness connector to ground.
Does the DVM display infinite resistance?
–
Go to Step 12Go to Step 10
5
1. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil
terminals 86 and 85 in the relay harness
connector.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON and
OFF.
Does the test light turn ON and OFF with each
commanded?
–
Go to Step 8Go to Step 6
6
With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?
–
Go to Step 7Go to Step 11
7
1. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 5 in the
ECM harness connector.
Does the relay operate?
–
Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12