2003 DAEWOO MATIZ engine overheat

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.

1D–8 ENGINE COOLING
DAEWOO M-150 BL2
COOLING SYSTEM DIAGNOSIS
Condition Probable Cause Correction
Engine OverheatsA loss of the coolant.Add the coolant.
A weak coolant solution.Confirm that the coolant solution is a
50/50 mixture of ethylene glycol and
water.
Any dirt, any leaves, or any insects
on the front of the radiator.Clean the front of the radiator.
The leakage from the hoses, the
coolant pump, the heater, the
thermostat housing, the radiator, the
heater core, or the head gasket.Replace any damaged components.
A faulty thermostat.Replace a damaged thermostat.
Retarded ignition timing.Perform an ECM code diagnosis.
Confirm the integrity of the timing
belt.
An improperly operating electric
cooling fan.Replace the electric cooling fan.
Plugged or rotted radiator hoses.Replace any damaged radiator
hoses.
A faulty water pump.Replace a faulty water pump.
A faulty surge tank cap.Replace a faulty surge tank cap.
A cracked or plugged cylinder head
or engine block.Repair the damaged cylinder head or
the damaged engine block.
A faulty radiator.Replace a faulty radiator.
Loss of CoolantA leak in the radiator.Replace a damaged radiator.
A leak in the surge tank or the hose.Replace the surge tank or the hose.
Looseness or damage of radiator
hoses, heater hoses, or connections.Reseat the hoses.
Replace the hoses or the clamps.
Leaks in the coolant pump seal.Replace the coolant pump seal.
Leaks in the coolant pump gasket.Replace the coolant pump gasket.
An improper cylinder head torque.Tighten the cylinder head bolts to
specifications.
Replace the cylinder head gasket, if
needed.
Leaks in the intake manifold, cylinder
head gasket, heater core.Repair or replace any components,
as needed to correct the leak.
Engine Fails to Reach
Normal OperatingThermostat to be stuck open or to be
wrong type.Install a new thermostat of the
correct type and heat range.
Temperature or Cool Air
from the HeaterThe coolant level below the MIN
mark on the surge tank.Add sufficient coolant to raise the
fluid to the specified mark on the
surge tank.

ENGINE ELECTRICAL 1E – 19
DAEWOO M-150 BL2
REPAIR INSTRUCTIONS
UNIT REPAIR
D102E701
STARTER MOTOR
Inspection / Measurement
(Before the Overhaul)
1. Remove the starter. Refer to “Starter” in this section.
2. Pinion clearance inspection.

Disconnect the starter motor terminal M (1).

Connect the 12-volt battery lead to the starter mo-
tor terminals M and S.
Notice: Complete the testing in a minimum amount of
time to prevent overheating and damaging the solenoid.
(in 10 seconds)
D102E702

Switch on to move the pinion gear (2).

Now check the clearance between the pinion and
the stopper with the filler gauge (3).

If the clearance does not fall within the limits,
check for improper installation and replace all worn
parts.
D102E703
3. Magnetic switch pull-in test.

Disconnect the starter motor terminal M (1).

Connect the 12-volt battery lead to the starter mo-
tor terminals M and S.
Notice: Complete the testing in a minimum amount of
time to prevent overheating and damaging the solenoid.
(in 10 seconds)

1E–20 ENGINE ELECTRICAL
DAEWOO M-150 BL2
D102E704

Inspect the pinion gear’s moving to the outside (2).

If the pinion gear does not move outside, replace
the magnetic switch.
D102E705
4. Solenoid hold-in test.

Disconnect the starter motor terminal M (1).

Connect the 12-volt battery lead to the starter mo-
tor terminal S and body.
Notice: Complete the testing in a minimum amount of
time to prevent overheating and damaging the solenoid.
D102E706

Check the pinion gear’s moving to the outside (2).

If the pinion gear move to the inside, the circuit is
open. Replace the magnetic switch.
D102E707
5. Solenoid return test.

Disconnect the starter motor terminal M (1).

Connect the 12-volt battery lead to the starter mo-
tor terminal S and body.
Notice: Complete the testing in a minimum amount of
time to prevent overheating and damaging the solenoid.

1E–26 ENGINE ELECTRICAL
DAEWOO M-150 BL2
D102E728
8. Remove the rectifier / brush holder / regulator from
the stator.

Remove the rectifier / brush holder / regulator con-
nections (1).

Remove the stator and rectifier connections (2).
Notice: If the stator connections are welded, melt the
lead. Avoid overheating as it can damage the diodes.
D102E729
Inspection / Measurement
1. Inspect the rotor assembly.

Test the rotor for an open circuit by using the ohm-
meter (1). Replace the rotor if necessary.
D102E730

Test the rotor for open or short circuit (2).
DesciptionLimit
The measured
resistance2.9Ω

Replace the rotor if necessary.

Test the rotor for open or ground circuit by using
the ohmmeter (3). Replace the rotor if necessary.
D102E731
2. Inspect the stator.

Test the stator for an open circuit by using the ohm-
meter (1). Replace the stator if necessary.

ENGINE CONTROLS 1F–7
DAEWOO M-150 BL2
manifold to decrease combustion temperature. The
amount of exhaust gas recirculated is controlled by vari-
ations in vacuum and exhaust back pressure. If too
much exhaust gas enters, combustion will not take
place. For this reason, very little exhaust gas is allowed
to pass through the valve, especially at idle.
The EEGR valve is usually open under the following
conditions:

Warm engine operation.

Above idle speed.
Results of Incorrect Operation
Too much EEGR flow tends to weaken combustion,
causing the engine to run roughly or to stop. With too
much EEGR flow at idle, cruise, or cold operation, any of
the following conditions may occur:

The engine stops after a cold start.

The engine stops at idle after deceleration.

The vehicle surges during cruise.

Rough idle.
If the EEGR valve stays open all the time, the engine
may not idle. Too little or no EEGR flow allows combus-
tion temperatures to get too high during acceleration
and load conditions. This could cause the following con-
ditions:

Spark knock (detonation)

Engine overheating

Emission test failure
INTAKE AIR TEMPERATURE
SENSOR
The Intake Air Temperature (IAT) sensor is a thermistor,
a resistor which changes value based on the tempera-
ture of the air entering the engine. Low temperature pro-
duces a high resistance (100 kohms at –40C [–40F]),
while high temperature causes a low resistance (70
ohms at 130C [266F]).
The Engine Control Module (ECM) provides 5 volts to
the IAT sensor through a resistor in the ECM and mea-
sures the change in voltage to determine the IAT. The
voltage will be high when the manifold air is cold and low
when the air is hot. The ECM knows the intake IAT by
measuring the voltage.
The IAT sensor is also used to control spark timing when
the manifold air is cold.
A failure in the IAT sensor circuit sets a diagnostic
trouble code P0112 or P0113.
IDLE AIR CONTROL VALVE
Notice: Do not attempt to remove the protective cap
and readjust the stop screw. Misadjustment may result
in damage to the Idle Air Control (IAC) valve or to the
throttle body.The IAC valve is mounted on the throttle body where it
controls the engine idle speed under the command of
the Engine Control Module (ECM). The ECM sends volt-
age pulses to the IAC valve motor windings, causing the
IAC valve pintle to move in or out a given distance (a
step or count) for each pulse. The pintle movement con-
trols the airflow around the throttle valves which, in turn,
control the engine idle speed.
The desired idle speeds for all engine operating condi-
tions are programmed into the calibration of the ECM.
These programmed engine speeds are based on the
coolant temperature, the park/neutral position switch
status, the vehicle speed, the battery voltage, and the
A/C system pressure, if equipped.
The ECM “learns” the proper IAC valve positions to
achieve warm, stabilized idle speeds (rpm) desired for
the various conditions (park/neutral or drive, A/C on or
off, if equipped). This information is stored in ECM ”keep
alive” memories (information is retained after the ignition
is turned off). All other IAC valve positioning is calcu-
lated based on these memory values. As a result, en-
gine variations due to wear and variations in the
minimum throttle valve position (within limits) do not af-
fect engine idle speeds. This system provides correct
idle control under all conditions. This also means that
disconnecting power to the ECM can result in incorrect
idle control or the necessity to partially press the accel-
erator when starting until the ECM relearns idle control.
Engine idle speed is a function of total airflow into the
engine based on the IAC valve pintle position, the
throttle valve opening, and the calibrated vacuum loss
through accessories. The minimum throttle valve posi-
tion is set at the factory with a stop screw. This setting
allows enough airflow by the throttle valve to cause the
IAC valve pintle to be positioned a calibrated number of
steps (counts) from the seat during “controlled” idle op-
eration. The minimum throttle valve position setting on
this engine should not be considered the “minimum idle
speed,” as on other fuel injected engines. The throttle
stop screw is covered with a plug at the factory following
adjustment.
If the IAC valve is suspected as being the cause of im-
proper idle speed, refer to “Idle Air Control System
Check” in this section.
MANIFOLD ABSOLUTE PRESSURE
SENSOR
The Manifold Absolute Pressure (MAP) sensor mea-
sures the changes in the intake manifold pressure which
result from engine load and speed changes and con-
verts these to a voltage output.
A closed throttle on engine coast down produces a rela-
tively low MAP output. MAP is the opposite of vacuum.
When manifold pressure is high, vacuum is low. The
MAP sensor is also used to measure barometric pres-
sure. This is performed as part of MAP sensor calcula-

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).