heating system DAEWOO MATIZ 2003 Service Repair Manual

HVAC (HEATING, VENTILATION,
AND AIR CONDITIONING)
CONTENTS
SECTION 7A HEATING AND VENTILATION SYSTEM
SECTION 7B MANUAL CONTROL HEATING,
VENTILATION, AND AIR CONDITIONING
SYSTEM

1D – 2 ENGINE COOLING
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
GENERAL DESCRIPTION
The cooling system maintains the engine temperature at
an efficient level during all engine operating conditions.
When the engine is cold the cooling system cools the
engine slowly or not at all. This slow cooling of the en-
gine allows the engine to warm up quickly.
The cooling system includes a radiator(a) and cooling
fan(b), a thermostat and housing(c), a coolant pump(d),
a coolant pump drive belt and coolant hose. The timing
belt drives the coolant pump.
All components must function properly in order for the
cooling system to operate. The coolant pump draws the
coolant from the radiator. The coolant then circulates
through water jackets in the engine block and the cylin-
der head, distributor case(e), throttle body(f). When the
coolant reaches the operating temperature of the ther-
mostat, the thermostat opens. The coolant then goes
back to the radiator where it cools.
This system directs some coolant through the hoses to
the heater core(g). This provides for heating and de-
frosting. The surge tank(h) is connected to the radiator
and throttle body to recover the coolant displaced by ex-
pansion from the high temperatures. The surge tank
maintains the correct coolant level.
The cooling system for this vehicle has no radiator cap
and drain cock. The coolant is added to the cooling sys-tem through the surge tank. To drain the cooling system,
disconnect the lower radiator hose and drain the cool-
ant.
RADIATOR
This vehicle has a lightweight tube-and-fin aluminum ra-
diator.
SURGE TANK
The surge tank is a transparent plastic reservoir, similar
to the windshield washer reservoir.
The surge tank is connected to the radiator and throttle
body by a hose. As the vehicle is driven, the engine cool-
ant heats and expands. The portion of the engine cool-
ant displaced by this expansion flows from the radiator
into the surge tank. The air trapped in the radiator is de-
gassed into the surge tank.
When the engine is stops, the engine coolant cools and
contracts. The displaced engine coolant is then drawn
back into the radiator. This keeps the radiator filled with
the coolant to the desired level at all times and increases
the cooling efficiency.
Maintain the coolant level between the MIN and the
MAX marks on the surge tank when the system is cold.
D102D001

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.

1G – 2 ENGINE EXHAUST
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
EXHAUST SYSTEM
Notice: When you are inspecting or replacing exhaust
system components, make sure there is adequate clear-
ance from all points on the underbody to avoid possible
overheating of the floor pan and possible damage to the
passenger compartment insulation and trim materials.
Check the complete exhaust system and the nearby
body areas and tailgate for broken, damaged, missing or
mispositioned parts, open seams, holes, loose connec-
tions or other deterioration which could permit exhaust
fumes to seep into the luggage or passenger compart-
ment. Dust or water in the luggage may be an indication
of a problem in one of these areas. Any defects should
be corrected immediately.
MUFFLER
The muffler reduces the temperature, pressure, and
noise of the exhaust gas.
Aside from the exhaust manifold connection, the ex-
haust system uses a flange and seal joint design op-
posed to a slip joint coupling design with clamp. If holes,
open seams or any deterioration is discovered upon in-
spection of the front muffler and pipe assembly, thecomplete assembly should be replaced. The same pro-
cedure is applicable to the rear muffler assembly.
Heat shields in the front and rear muffler assembly posi-
tions, as well as for the catalytic converter and front ex-
haust pipe, protect the vehicle and the environment from
high temperatures the exhaust system develops.
CATALYTIC CONVERTER
Notice: When jacking or lifting the vehicle from the body
side rails, be certain that the lift pads do not contact the
catalytic converter as this could damage the catalytic
converter.
Notice: The catalytic converter requires the use of un-
leaded fuel only, or damage to the catalyst will result.
The catalytic converter is an emission control device
added to the exhaust system to reduce pollutants from
the exhaust pipes.
The oxidation catalyst is coated with a catalytic material
containing platinum and palladium, which reduces levels
of hydrocarbon (HC) and carbon monoxide (CO) from
the exhaust gas. The three-way catalyst has coatings
which contain platinum and rhodium, which additionally
lower the levels of oxides of nitrogen (NOx).

4C –6 POWER BOOSTER
DAEWOO M-150 BL2
D24C001
POWER BOOSTER ASSEMBLY
(RIGHT–HAND DRIVE)
Removal Procedure
1. Remove the master cylinder assembly. Refer to Sec-
tion 4B, Master Cylinder.
2. Disconnect the vacuum hose from the power booster.
3. Remove the instrument panel assembly. Refer to
Section 9E, Instrument/Driver Information.
4. Remove the evaporator unit mounting screws and
take off the evaporator unit a little. Refer to Section
7B, Manual Control Heating, Ventilation, and Air Con-
ditioning System.
5. Remove the power booster.

Straighten the cotter pin and remove it (1).

Remove the clevis pin (2).
D24C002

Remove the nuts (3).
D107A521

Remove the power booster (4).

POWER BOOSTER 4C–7
DAEWOO M-150 BL2
D24C003
Installation Procedure
1. Install the power booster with the new cotter pin, cle-
vis pin and nuts.
Tighten
Tighten the nuts to 16 Nm (12 lb-ft).
Important: Make sure the distance from the booster
to the center of the clevis bore should be 100mm
(3.94 in.).
2. Install the evaporator unit with the screws. Refer to
Section 7B, Manual Control Heating, Ventilation, and
Air Conditioning System.
3. Install the instrument panel assembly. Refer to Sec-
tion 9E, Instrument/Driver Information.
4. Connect the vacuum hose to the power booster.
5. Install the master cylinder assembly. Refer to Section
4B, Master Cylinder.

DAEWOO M-150 BL2
SECTION 7A
HEATING AND VENTILATION SYSTEM
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in B unless otherwise
noted.
TABLE OF CONTENTS
Description and Operation 7A-2. . . . . . . . . . . . . . . . . .
Heating and Ventilation Systems 7A-2. . . . . . . . . . . .
Component Locator 7A-3. . . . . . . . . . . . . . . . . . . . . . . .
Control Assembly 7A-3. . . . . . . . . . . . . . . . . . . . . . . . .
Blower Module Assembly 7A-4. . . . . . . . . . . . . . . . . . .
Air Distributor and Heater Module
Assembly 7A-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Informatin and Procedures 7A-6. . . . . . .
Heater System 7A-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insufficient Heating or Defrosting 7A-6. . . . . . . . . . . .
Blower Electrical 7A-10. . . . . . . . . . . . . . . . . . . . . . . . .
Improper Air Delivery or No Mode Shift 7A-11. . . . . .
Too Much Heat 7A-13. . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls 7A-15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Noise 7A-16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repair Instructions 7A-18. . . . . . . . . . . . . . . . . . . . . . . .
On-Vehicle Service 7A-18. . . . . . . . . . . . . . . . . . . . . . . . .
Control Assembly and Control Cables 7A-18. . . . . . . Blower Motor and Cooling Hose 7A-20. . . . . . . . . . . .
Blower Resistor 7A-20. . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Motor Switch 7A-21. . . . . . . . . . . . . . . . . . . . . .
Heater Hoses 7A-22. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Module 7A-24. . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Module 7A-25. . . . . . . . . . . . . . . . . . . . . . . . . . .
Defroster Duct and Hoses 7A-26. . . . . . . . . . . . . . . . .
Ventilation Duct 7A-27. . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Repair 7A-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Core 7A-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 7A-29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 7A-29. . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 7A-29. . . . . . . . . .
Special Tools and Equipment 7A-30. . . . . . . . . . . . . .
Special Tools Table 7A-30. . . . . . . . . . . . . . . . . . . . . . .
Schematic and Routing Diagrams 7A-31. . . . . . . . . .
Non-A/C Diagrams 7A-31. . . . . . . . . . . . . . . . . . . . . . .
Air Flow Through Ducts (Non–A/C) 7A-32. . . . . . . . .

7A–2 HEATING AND VENTILATION SYSTEM
DAEWOO M-150 BL2
DESCRIPTION AND SYSTEM OPERATION
HEATING AND VENTILATION
SYSTEMS
The base heater system is designed to provide heating,
ventilation, windshield defrosting, and side window de-
fogging.
The heater and fan assembly blower regulates the air-
flow from the air inlet for further processing and distribu-
tion.
The heater core transfers the heat from the engine cool-
ant to the inlet air.
The temperature door regulates the amount of the air
that passes through the heater core. The temperature
door also controls the temperature of the air by control-
ling the mix of the heated air and the ambient air.
The mode door regulates the flow and the distribution
of the processed air to the heater ducts and to the de-
froster ducts.
This console-mounted heating and ventilation panel
contains the following:
Three Rotary Control Knobs
1. The Rotary Temperature Control Knob

Actuates by cable.

Raises the temperature of the air entering the ve-
hicle by rotation toward the right, or the red portion
of the knob.
2. The Rotary Blower Control Knob

Turns on to operate the blower motor at four speeds.

Turns
to stop the blower.

Operates completely independently both from the
mode control that regulates the defroster door and
from the temperature control knob.
Changes the fan speed in any mode and at any
temperature setting.
3. The Rotary Mode Control Knob:

Actuates by cable.

Regulates the air distribution between the wind-
shield, the instrument panel, and the floor vents.
Push Knobs
1. The Rear Window Defogger Push Knob

Controls the rear window defogger.

Turns ON the rear window defogger when the push
knob is pressed and the indicator lamp is illumi-
nated.
2. The A/C Push Knob (if the vehicle is equipped with air
conditioning)

Controls the A/C.

Turns the A/C ON when the push knob is down.
However, if the blower control knob is OFF, the A/C
system is OFF, regardless of the position of the
A/C knob.
One Lever
1. The Fresh Air Control Lever

Operates by cable.

Switches between recirculating passenger compart-
ment air and bringing outside air into the passenger
compartment.

Draws in outside air when the lever is moved to the
left.

Recirculates inside air when the lever is moved to
the right.

HEATING AND VENTILATION SYSTEM 7A–3
DAEWOO M-150 BL2
COMPONENT LOCATOR
CONTROL ASSEMBLY
(Left–Hand Drive Shown, Right–Hand Drive Similar)
D108A401
1. HVAC Control Assembly
2. Temperature Control Cable
3. Mode Select Cable
4. Rack
5. Bracket
6. Cable Clamp
7. Bulb Socket Assembly
8. Pinion Assembly
9. A/C Switch
10. Housing
11. Detent Cap12. Detent Spring
13. Blower Switch
14. Rear Defogger Switch
15. Recirculating/Fresh Air Door Cable
16. Panel
17. A/C Push Knob
18. Rotary Knob
19. Recirculating Knob
20. Rear Defogger Push Knob
21. Recirculation