oil change DAEWOO MATIZ 2003 Service Repair Manual

GENERAL ENGINE INFORMATION 1A–7
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 Condition Probable cause Correction
Rough Engine IdlingMalfunction of
Ignition System
Loosening or damage of the
distributor rotor or cap.
Replace the rotor or cap.

Poor ignition timing.
Adjust the ignition timing.

Malfunction of the ignition
coil.
Replace the ignition coil.
Others
Clogged or contaminated air
cleaner element.
Clean or replace the air
cleaner element.

Leak of the intake manifold
gasket.
Replace the gasket.

Malfunction of Positive
Crankcase Ventilation (PCV)
valve.
Check the valve or replace it
if needed.

Poor connection or damage
or leakage of the vacuum
hose.
Connect the hose correctly
or replace it.
Engine Hesitate (Upon
pressing accelerating
pedal, the engineDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
makes delayed
response. ThisMalfunction of
Poor ignition timing.
Adjust the ignition timing.response. This
situation is remarkable
when cruising orIgnition System
Poor spark plug or poor
adjustment of the plug gap.
Replace the plug or adjust
the gap.
starting.)
Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.
Others
Malfunction of the air cleaner
system.
Clean or replace the air
cleaner system.

Leak of the intake manifold
gasket.
Replace the gasket.
Engine Surging
(Engine power makes
fluctuation in a fixedDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
speed and speed
changes withoutMalfunction of
Clogged fuel pipe.
Clean the pipe.changes without
operating the
accelerating pedal.)Fuel System
Clogged or contaminated
fuel filter.
Replace the filter.

Malfunction of the fuel
pressure regulator.
Replace the fuel pressure
regulator.
Malfunction of
Ignition System
Malfunction of the spark
plug.
Adjust or replace the spark
plug.

Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.

Worn distributor cap terminal
or accumulated carbon in
the distributor cap.
Clean or replace the
distributor cap.

Loosening or damage of the
distributor rotor or the cap.
Replace the distributor rotor
or the cap.

Poor ignition timing.
Adjust the ignition timing.

1A–8 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 
 Condition
 
 Probable cause
 
 Correction
Engine Surging
(Engine power makes
fluctuation in a fixedOthers
Leak of the intake manifold
gasket.
Clean or replace the gasket.
speed and speed
changes without
operating the
accelerating pedal.)
Leakage of the vacuum hose.
Connect the hose correctly
or replace it.
Excessive Detonation
(According to theOverheated
Engine
Refer to “Overheat” in this
page.
Refer to “Overheat” in this
page.
opening range of
throttle valve,Malfunction of
Abnormal spark plug.
Replace the spark plug.
knocking sound of
metallic is made withIgnition System
Poor ignition timing.
Adjust the ignition timing.metallic is made with
abnormal explosion.)

Electric leakage or poor
connection of the high tension
cable.
Connect the cable correctly
or replace it.
Malfunction of
Fuel System
Clogged or contaminated fuel
filter and fuel pipe.
Clean or replace the fuel
filter and the fuel pipe.
Others
Leak of the intake manifold
gasket.
Replace the gasket.

Excessive carbon deposit due
to abnormal combustion.
Remove the carbon.
OverheatMalfunction of
Lack of coolant.
Refill coolant.
Cooling System
Malfunction of the thermostat.
Replace the thermostat.

Malfunction of the cooling fan.
Check or replace the cooling
fan.

Poor water pump
performance.
Replace the pump.

Clogged or leaky radiator.
Clean, repair or replace the
radiator.
Malfunction of
Lubrication
Poor engine oil.
Replace engine oil with the
specified one.
System
Blocking oil filter or strainer.
Clean or replace the oil filter
or the strainer.

Lack of engine oil.
Refill oil.

Poor oil pump performance.
Replace or repair the pump.

Leakage of oil.
Repair.
Other
Damaged cylinder head
gasket.
Replace the gasket.
Poor Fuel
ConsumptionDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
Malfunction of
Fuel System
Leakage of the fuel tank or
the fuel pipe.
Repair or replace the fuel
tank or the fuel pipe.

GENERAL ENGINE INFORMATION 1A–11
DAEWOO M-150 BL2
CHECKING ENGINE FLUID LEVEL
Check the engine fluid level or condition. If needed, refill
or replace the oil.
Check the engine oil level within engine normal operat-
ing temperature as follows ;
1. After stopping the engine, wait for a few minutes to
accumulate oil into the oil pan.
2. After pulling out the oil level gauge (a), check the oil
level.
3. Clean the oil level gauge and insert the gauge into
guide.
4. After pulling out the oil level gauge again, recheck the
oil level and insert the gauge into guide again.
Important: Oil level should be between “MIN” mark and
“MAX” mark.
5. If oil level is below the “MIN” mark, refill engine oil as
much as the demanded quantify.
Important: If checking oil level under the engine cold
condition, oil is not accumulated into oil pan quickly and
correct level checking can not be performed. Therefore,
wait until temperature reaches the normal operating
condition and check the engine oil level.
D102A301
CHANGING ENGINE OIL OR OIL
FILTER
Tools Required
09915–47341 Oil Filter Wrench.
When checking engine oil level or condition, if needed,
change engine oil (including the filter) as follows ;
1. After stopping the engine, wait for a few minutes to
accumulate oil into the oil pan.
2. Remove the oil filter cap (b).3. Remove the oil drain plug (c) and draw oil off.
D102A302
4. After drawing oil completely, tighten the oil drain plug
to 30–40 Nm (22–30 lb-ft).
5. Replace the oil filter using the oil filter wrench
09915–47341 (d).

Remove the air cleaner/resonator/snorkel as-
sembly.

After removing the bolts, remove the heat
shield.

Loosen the power steering pump cap screw and
pull the power steering hose into the front.

Remove the oil filter.
Important: Whenever changing engine oil, replace the
oil filter. When replacing new oil filter, apply engine oil on
oil filter sealing.
D102A303

1A–14 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
SPECIFICATIONS
GENERAL SPECIFICATIONS
 Application Description
  Maximum Speed 144 km/h (90 mph)
 Vehicle Capacity Gradeability 0.420 tan θ
 
Vehicle Capacity
 Minimum Turning Radius 4.5 m (14.8 ft)
  Bore × Stroke 68.5 × 72.0 mm (2.70 × 2.83 inch)
  Displacement 796 cm3 (48.6 in3)
  Compression Ratio 9.3 : 1
  Maximum Power 37.5 KW (6,000 rpm)
 
Engine Information
 Maximum Torque 68.6 Nm (50.59 lb-ft) (at 4,600 rpm)
Ignition Timing (Ignition Sequence)5 BTDC (1–3–2) / 10 BTDC (1–3–2)   
Air Conditioning System (ON)
 
1,000 ± 50 rpm  Idle Speed Air Conditioning System (OFF) 950 rpm  Engine Overhead Cam L–3 
 
 
 Ignition Type
 
 Direct Ignition System (DIS) /
High Energy Ignition (HEI)
  Distributor Optical Sensor Type
  Starter SD 80
   Unleaded BPR5EY–11, RN9YC4, WR8DCX
  Spark–Plug Leaded BPR5EY, RN9YC, WR8DC
  Fuel Injection Type MPI
  Fuel Pump Electric Motor Pump
Engine Part TypeFuel FilterCartridge Engine Part Type 
Lubricating Type
 
Forced Feed Type  Oil Pump Rotary Pump Type  Cooling Type Forced Water Circulation  Radiator Cross – Flow  Water Pump Centrifugal  Thermostat Pellet Type
  Air Cleaner Element Non Woven Fablic
  Muffler Catalytic Converter, Closed Circuit
  Battery MF
Engine PartEngine OilSJ Grade
SAE 5W30, SAE 10W30, SAE 15W40
CapacityRefrigerantFour Seasons   
Engine Disassembly
 
3.0 L (3.17 qt)   Oil Change (Including filter) 2.7 L (2.85 qt)  Engine Oil Oil Change (Not including filter) 2.5 L (2.64 qt)   Oil Level Gauge 1 L (1.06 qt) (MIN to MAX)  Coolant 3.8 L (4.02 qt) Engine Information Battery 12V–35 AH, 246 CCA
 Engine Information  

Generator

65 A
  Starter 0.8 kW
   Output Capacity 90 – 133 Lph
  Fuel Pump Output Pressure 380 kPa (55.1 Psi)
  Fuel Tank Capacity 35 L (9.2 gal), 38 L (10 gal)

ENGINE ELECTRICAL 1E–5
DAEWOO M-150 BL2
the sequence of ignition order. It also adjusts the ignition
timing according to the engine condition.
This vehicle uses the distributor (optical sensor type)
which controls the preminary current of the ignition coil
by the ECM.
The ignition timing change is controlled electronically by
the ECM.
When diagnosing the ignition system, refer to Section
1F, Engine Controls.
IGNITION COIL
Ignition coil is a sort of transformer to generate high volt-
age (15,000–25,000V) which can bring spark at the
spark plugs and has an iron cored closed magnetic type.The closed magnetic typed ignition coil is used for the
High Energy Ignition (H.E.I) system. Comparing with the
iron cored open magnetic type, the closed type almost
has no loss of magnetic flux, and smaller in size, so it
produces the high voltage of secondary voltage.
SPARK PLUG
It is a part of ignition secondary current, and it burns the
compressed mixture by sparking the high voltage in-
duced from the ignition coil.

1F–4 ENGINE CONTROLS
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
IGNITION SYSTEM OPERATION
This ignition system does not use a conventional distrib-
utor and coil. It uses a crankshaft position sensor input
to the Engine Control Module (ECM). The ECM then de-
termines Electronic Spark Timing (EST) and triggers the
electronic ignition system ignition coil.
This type of distributorless ignition system uses a “waste
spark’’ method of spark distribution. Each cylinder is in-
dividural with coil per cylinder.
These systems use the EST signal from the ECM to
control the EST. The ECM uses the following informa-
tion:

Engine load (manifold pressure or vacuum).

Atmospheric (barometric) pressure.

Engine temperature.

Intake air temperature.

Crankshaft position.

Engine speed (rpm).
ELECTRONIC IGNITION SYSTEM
IGNITION COIL
The Electronic Ignition (EI) system ignition coil is
mounted near on the cylinder head.
A terminals of the EI system ignition coil provides the
spark for each spark plug. The EI system ignition coil is
not serviceable and must be replaced as an assembly.
CRANKSHAFT POSITION SENSOR
This Electronic Ignition (EI) system uses a magnetic
crankshaft position sensor. This sensor protrudes
through its mount to within approximately 1.3 mm (0.05
inch) of the crankshaft reluctor. The reluctor is a special
wheel attached to the crankshaft with 58 slots machined
into it, 57 of which are equally spaced in 6-degree inter-
vals. The last slot is wider and serves to generate a
“sync pulse.” As the crankshaft rotates, the slots in the
reluctor change the magnetic field of the sensor, creat-
ing an induced voltage pulse. The longer pulse of the
58th slot identifies a specific orientation of the crank-
shaft and allows the Engine Control Module (ECM) to
determine the crankshaft orientation at all times. The
ECM uses this information to generate timed ignition
and injection pulses that it sends to the ignition coils and
to the fuel injectors.
CAMSHAFT POSITION SENSOR
The Camshaft Position (CMP) sensor sends a CMP sig-
nal to the Engine Control Module (ECM). The ECM uses
this signal as a “sync pulse” to trigger the injectors in the
proper sequence. The ECM uses the CMP signal to indi-
cate the position of the #1 piston during its power stroke.
This allows the ECM to calculate true sequential fuel in-jection mode of operation. If the ECM detects an incor-
rect CMP signal while the engine is running, Diagnostic
Trouble Code (DTC) P0341 will set. If the CMP signal is
lost while the engine is running, the fuel injection system
will shift to a calculated sequential fuel injection mode
based on the last fuel injection pulse, and the engine will
continue to run. As long as the fault is present, the en-
gine can be restarted. It will run in the calculated se-
quential mode with a 1-in-6 chance of the injector
sequence being correct.
IDLE AIR SYSTEM OPERATION
The idle air system operation is controlled by the base
idle setting of the throttle body and the Idle Air Control
(IAC) valve.
The Engine Control Module (ECM) uses the IAC valve to
set the idle speed dependent on conditions. The ECM
uses information from various inputs, such as coolant
temperature, manifold vacuum, etc., for the effective
control of the idle speed.
FUEL CONTROL SYSTEM
OPERATION
The function of the fuel metering system is to deliver the
correct amount of fuel to the engine under all operating
conditions. The fuel is delivered to the engine by the in-
dividual fuel injectors mounted into the intake manifold
near each cylinder.
The main fuel control sensors are the Manifold Absolute
Pressure (MAP) sensor, the oxygen sensor (O2S), and
the heated oxygen sensor (HO2S).
The MAP sensor measures or senses the intake man-
ifold vacuum. Under high fuel demands, the MAP sensor
reads a low vacuum condition, such as wide open
throttle. The Engine Control Module (ECM) uses this in-
formation to enrich the mixture, thus increasing the fuel
injector on-time, to provide the correct amount of fuel.
When decelerating, the vacuum increases. This vacuum
change is sensed by the MAP sensor and read by the
ECM, which then decreases the fuel injector on-time
due to the low fuel demand conditions.
The O2S is located in the exhaust manifold. The HO2S
is located in the exhaust pipe. The oxygen sensors indi-
cate to the ECM the amount of oxygen in the exhaust
gas, and the ECM changes the air/fuel ratio to the en-
gine by controlling the fuel injectors. The best air/fuel ra-
tio to minimize exhaust emissions is 14.7:1, which
allows the catalytic converter to operate most efficiently.
Because of the constant measuring and adjusting of the
air/fuel ratio, the fuel injection system is called a “closed
loop” system.
The ECM uses voltage inputs from several sensors to
determine how much fuel to provide to the engine. The

1F–6 ENGINE CONTROLS
DAEWOO M-150 BL2
pors. Fresh air from the air cleaner is supplied to the
crankcase. The fresh air is mixed with blowby gases
which then pass through a vacuum hose into the intake
manifold.
Periodically inspect the hoses and the clamps. Replace
any crankcase ventilation components as required.
A restricted or plugged PCV hose may cause the follow-
ing conditions:

Rough idle

Stalling or low idle speed

Oil leaks

Oil in the air cleaner

Sludge in the engine
A leaking PCV hose may cause the following conditions:

Rough idle

Stalling

High idle speed
ENGINE COOLANT TEMPERATURE
SENSOR
The Engine Coolant Temperature (ECT) sensor is a
thermistor (a resistor which changes value based on
temperature) mounted in the engine coolant stream.
Low coolant temperature produces a high resistance
(100,000 ohms at –40C [–40F]) while high tempera-
ture causes low resistance (70 ohms at 130C [266F]).
The Engine Control Module (ECM) supplies 5 volts to
the ECT sensor through a resistor in the ECM and mea-
sures the change in voltage. The voltage will be high
when the engine is cold and low when the engine is hot.
By measuring the change in voltage, the ECM can de-
termine the coolant temperature. The engine coolant
temperature affects most of the systems that the ECM
controls. A failure in the ECT sensor circuit should set a
Diagnostic Trouble Code (DTC) P0117 or P0118. Re-
member, these DTC indicate a failure in the ECT circuit,
so proper use of the chart will lead either to repairing a
wiring problem or to replacing the sensor to repair a
problem properly.
THROTTLE POSITION SENSOR
The Throttle Position (TP) sensor is a potentiometer
connected to the throttle shaft of the throttle body. The
TP sensor electrical circuit consists of a 5-volt supply
line and a ground line, both provided by the Engine Con-
trol Module (ECM). The ECM calculates the throttle
position by monitoring the voltage on this signal line. The
TP sensor output changes as the accelerator pedal is
moved, changing the throttle valve angle. At a closed
throttle position, the output of the TP sensor is low,
about 0.4–0.8 volt. As the throttle valve opens, the out-
put increases so that, at Wide Open Throttle (WOT), the
output voltage will be about 4.5–5 volts.The ECM can determine fuel delivery based on throttle
valve angle (driver demand). A broken or loose TP sen-
sor can cause intermittent bursts of fuel from the injector
and an unstable idle, because the ECM thinks the
throttle is moving. A problem in any of the TP sensor cir-
cuits should set a Diagnostic Trouble Code (DTC)
P0122 or P0123. Once the DTC is set, the ECM will sub-
stitute a default value for the TP sensor and some ve-
hicle performance will return.
CATALYST MONITOR OXYGEN
SENSORS
Three-way catalytic converters are used to control emis-
sions of hydrocarbons (HC), carbon monoxide (CO),
and oxides of nitrogen (NOx). The catalyst within the
converters promotes a chemical reaction. This reaction
oxidizes the HC and CO present in the exhaust gas and
converts them into harmless water vapor and carbon
dioxide. The catalyst also reduces NOx by converting it
to nitrogen. The ECM can monitor this process using the
oxygen sensor (O2S) and heated oxygen sensor
(HO2S). These sensors produce an output signal which
indicates the amount of oxygen present in the exhaust
gas entering and leaving the three-way converter. This
indicates the catalyst’s ability to efficiently convert ex-
haust gasses. If the catalyst is operating efficiently, the
O2S signals will be more active than the signals pro-
duced by the HO2S. The catalyst monitor sensors oper-
ate the same way as the fuel control sensors. The
sensors’ main function is catalyst monitoring, but they
also have a limited role in fuel control. If a sensor output
indicates a voltage either above or below the 450 mV
bias voltage for an extended period of time, the Engine
Control Module (ECM) will make a slight adjustment to
fuel trim to ensure that fuel delivery is correct for catalyst
monitoring.
A problem with the O2S circuit will set DTC P0131,
P0132, P0133 or P0134 depending on the special condi-
tion. A problem with the HO2S signal will set DTC
P0137, P0138, P0140 or P0141 depending on the spe-
cial condition.
A fault in the heated oxygen sensor (HO2S) heater ele-
ment or its ignition feed or ground will result in lower oxy-
gen sensor response. This may cause incorrect catalyst
monitor diagnostic results.
ELECTRIC EXHAUST GAS
RECIRCULATION VALVE
The Electric Exhaust Gas Recirculation (EEGR) system
is used on engines equipped with an automatic trans-
axle to lower oxides of nitrogen (NOx) emission levels
caused by high combustion temperature. The main ele-
ment of the system is the EEGR valve, controlled electri-
cally by the Engine Control Module (ECM). The EEGR
valve feeds small amounts of exhaust gas into the intake

1F–10 ENGINE CONTROLS
DAEWOO M-150 BL2
fuels use alcohol to increase the octane rating of the
fuel. Although alcohol-enhanced fuels may raise the oc-
tane rating, the fuel’s ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
The EOBD system has been calibrated to run with Origi-
nal Equipment Manufacturer (OEM) parts. Something
as simple as a high performance-exhaust system that
affects exhaust system back pressure could potentially
interfere with the operation of the Electric Exhaust Gas
Recirculation (EEGR) valve and thereby turn on the
MIL. Small leaks in the exhaust system near the heated
oxygen sensor (HO2S) can also cause the MIL to turn
on.
Aftermarket electronics, such as cellular phones, ster-
eos, and anti-theft devices, may radiate Electromagnet-
ic Interference (EMI) into the control system if they are
improperly installed. This may cause a false sensor
reading and turn on the MIL.
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition sys-
tem. If the ignition system is rain-soaked, it can tempo-
rarily cause engine misfire and turn on the MIL.
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of opera-
tion contributes to the fuel fouling of the spark plugs and
will turn on the MIL with a set DTC P0300.
Poor Vehicle Maintenance
The sensitivity of the EOBD will cause the MIL to turn on
if the vehicle is not maintained properly. Restricted air fil-
ters, fuel filters, and crankcase deposits due to lack of oil
changes or improper oil viscosity can trigger actual ve-
hicle faults that were not previously monitored prior to
EOBD. Poor vehicle maintenance can not be classified
as a “non-vehicle fault,” but with the sensitivity of the
EOBD, vehicle maintenance schedules must be more
closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline
vibrations in the vehicle, such as caused by an exces-
sive amount of mud on the wheels, can have the same
effect on crankshaft speed as misfire and, therefore,
may set DTC P0300.
Related System Faults
Many of the EOBD system diagnostics will not run if the
Engine Control Module (ECM) detects a fault on a re-
lated system or component. One example would be thatif the ECM detected a Misfire fault, the diagnostics on
the catalytic converter would be suspended until the
Misfire fault was repaired. If the Misfire fault is severe
enough, the catalytic converter can be damaged due to
overheating and will never set a Catalyst DTC until the
Misfire fault is repaired and the Catalyst diagnostic is al-
lowed to run to completion. If this happens, the custom-
er may have to make two trips to the dealership in order
to repair the vehicle.
SERIAL DATA COMMUNICATIONS
Keyword 2000 Serial Data
Communications
Government regulations require that all vehicle
manufacturers establish a common communication sys-
tem. This vehicle utilizes the “Keyword 2000” commu-
nication system. Each bit of information can have one of
two lengths: long or short. This allows vehicle wiring to
be reduced by transmitting and receiving multiple sig-
nals over a single wire. The messages carried on Key-
word 2000 data streams are also prioritized. If two
messages attempt to establish communications on the
data line at the same time, only the message with higher
priority will continue. The device with the lower priority
message must wait. The most significant result of this
regulation is that it provides scan tool manufacturers
with the capability to access data from any make or
model vehicle that is sold.
The data displayed on the other scan tool will appear the
same, with some exceptions. Some scan tools will only
be able to display certain vehicle parameters as values
that are a coded representation of the true or actual val-
ue. On this vehicle, the scan tool displays the actual val-
ues for vehicle parameters. It will not be necessary to
perform any conversions from coded values to actual
values.
EURO ON-BOARD DIAGNOSTIC
(EOBD)
Euro On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which
is a pass or fail reported to the diagnostic executive.
When a diagnostic test reports a pass result, the diag-
nostic executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not cur-
rently active.
When a diagnostic test reports a fail result, the diagnos-
tic executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

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).

1F–226 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
DIAGNOSTIC TROUBLE CODE (DTC) – P0480 LOW SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITHOUT A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC

Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.

Ignition ON.
Ignition voltage is greater than 10 volts.

Engine run time is greater than 5 seconds.
Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC

A history DTC will clear after 40 consecutive warm-up
cycles without a fault.

DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported