speed DAEWOO LACETTI 2004 Service Repair Manual

7B – 52IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
SYSTEM COMPONENTS–CONTROL
Controller
The operation of the A/C system is controlled by the
switches and the lever on the control head. The compres-
sor clutch and the blower are connected electrically to the
control head by a wiring harness. The blower circuit is
open in the OFF mode. Airflow is provided by the four
blower speeds available in the remaining modes. Cooled
and dehumidified air is available in the MAX, NORMAL,
BI–LEVEL, and DEFROST modes.
The temperature is controlled by the position of the tem-
perature knob on the control head. A cable connects this
knob to the temperature door, which controls the airflow
through the heater core. As the temperature knob is
moved through its range of travel, a sliding clip on the
cable at the temperature valve connection should assume
a position ensuring that the temperature door will seat in
both extreme positions. The temperature door position is
independent of the mode control switch. The temperature
door on some models is controlled electrically, eliminating
the need for the temperature cable.
The electric engine cooling fan on some vehicles is not
part of the A/C control system; however, the fan is opera-
tional any time the A/C control is in the MAX, NORMAL,
or BI–LEVEL modes. Some models provide for engine
cooling fan operation when the controller is in the DE-
FROST mode. This added feature is part of the A/C con-
troller function and is aimed at preventing excessive com-
pressor head temperatures. It also allows the A/C system
to function more efficiently. On some models, the engine
cooling fan will be turned off during road speed conditions
above 56 km/h (35 mph), when the airflow though the con-
denser coil is adequate for efficient cooling. The operation
of the cooling fan is controlled by the powertrain control
module (PCM), or the engine control module (ECM),
through the cooling fan relay.
Pressure Transducer
The pressure transducer incorporates the functions of the
high–pressure and the low–pressure cutout switches
along with the fan cycling switch. The pressure transducer
is located in the high–side liquid refrigerant line near the
right front strut tower and the air filter assembly.
Wide–Open Throttle (WOT) Compressor
Cutoff
During full throttle acceleration on vehicles equipped with
multi–port injection (MPI), the throttle position sensor
(TPS) sends a signal to the PCM or the ECM, which then
controls the compressor clutch.
A/C Time Delay Relay
This relay on some vehicles controls the current to the en-
tire A/C system and provides a short delay of A/C opera-
tion upon start–up.
V5 COMPRESSOR–GENERAL
DESCRIPTION
Different vehicles with V5 compressors may exhibit differ-
ences in mounting and installation, but overhaul proce-
dures are similar.
Before removing the compressor or performing on–ve-
hicle repairs, clean the compressor connections and the
outside of the compressor.
Important : After removing a compressor from the vehicle
for servicing, drain the oil by removing the oil drain plug.
Also drain the oil from the suction and the discharge ports
to insure complete draining. Measure the amount of oil
drained, and record that amount. Discard the used oil and
add the same amount of new polyalkaline glycol (PAG) re-
frigerant oil to the compressor.
The compressor has been removed from the vehicle un-
less otherwise indicated.
Clean tools and a clean work area are important for proper
servicing. Keep dirt and foreign material from getting on or
into the compressor parts. Parts that are to be reassem-
bled should be cleaned with trichloroethane, naphtha,
stoddard solvent, kerosene, or equivalent solvents. Dry
the cleaned parts with clean dry air. Use only lint–free
cloths to wipe the parts.
V5 COMPRESSOR–DESCRIPTION OF
OPERATION
The V5 is a variable displacement compressor that can
match the automotive air conditioning (A/C) demand un-
der all conditions without cycling. The basic compressor
mechanism is a variable angle wobble–plate with five ax-
ially oriented cylinders. The center of control of the com-
pressor displacement is a bellows–actuated control valve
located in the rear head of the compressor. The control
valve senses compressor suction pressure.
The wobble–plate angle and the compressor displace-
ment are controlled by the crankcase suction pressure dif-
ferential. When the A/C capacity demand is high, the suc-
tion pressure will be above the control point. The valve will
maintain a bleed from crankcase to suction. With no
crankcase suction pressure differential, the compressor
will have maximum displacement.
When the A/C capacity demand is lower and the suction
pressure reaches the control point, the valve will bleed dis-
charge gas into the crankcase and close off a passage
from the crankcase to the suction plenum. The angle of the
wobble–plate is controlled by a force balance on the five
pistons. A slight elevation of the crankcase suction pres-
sure differential creates total force on the pistons resulting
in a movement about the wobbleplate pivot pin that re-
duces the plate angle.
The compressor has a unique lubrication system. The
crankcase suction bleed is routed through the rotating
wobble–plate for lubrication of the wobble–plate bearing.
The rotation acts as an oil separator which removes some

7D – 8IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
NO HOT AIR FROM BLOWER
StepActionValue(s)YesNo
1Check the coolant level.
Is the coolant level correct?–Go to Step 3Go to Step 2
2Add coolant as needed.
Is the heater operating?–System OKGo to Step 3
31. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit flash on and off?–Go to Step 4Go to Step 5
4Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashesGo to Step 7
5Observe the blower motor operation.
Is the blower motor functioning at all?–Go to Step 6Go to ”Blower
Motor Does
Not Run at All”
6Use the blower push switch to cycle the blower
through its different speeds.
Does the motor function at different speeds?–Go to Step 7Go to ”Code 6
– Power Tran-
sistor Error”
71. Run the blower and operate the MODE push
switch manually.
2. Check for airflow out the various outlets.
Does the air flow from the different outlets as it
should?–Go to Step 9Go to Step 8
81. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions found.
Is the heater operating?–System OKGo to Step 9
9Observe the air mix door (AMD) motor while chang-
ing the temperature setting from 18 to 32°C (64 to
90°F) and then from 32 to 18°C (90 to 64°F).
Is the AMD motor functioning properly?–Go to Step 10Go to”Code 4 –
Air Mix Door
Error”
10Check the coolant hoses for leaks or kinks.
Are the coolant hoses in good condition?–Go to Step 12Go to Step 11
11Repair any problem with the coolant hoses.
Is the heater operating?–System OKGo to Step 12
12Check the surge tank cap.
Is the surge tank cap in good condition?–Go to Step 14Go to Step 13
13Repair or replace the surge tank cap as needed.
Is the heater operating?–System OKGo to Step 14
141. Set the A/C switch to OFF.
2. Set the temperature control to 32°C (90°F).
3. Set the blower motor speed to full high (all seg-
ments illuminated on the display).
4. Remove the surge tank cap.
5. Start the vehicle and run the engine at idle.
6. Watch for the flow of the coolant when the ther-
mostat opens.
Does the coolant flow?–Go to Step 16Go to Step 15

7D – 10IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
NO COOL AIR FROM BLOWER
StepActionValue(s)YesNo
11. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit flash on and off?–Go to Step 2Go to Step 3
2Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashes.Go to Step 7
3Observe the blower motor operation.
Is the blower motor functioning at all?–Go to Step 4Go to ”Blower
Motor Does
Not Run at All”
4Use the blower push switch to cycle the blower
through its different speeds.
Does the motor function at different speeds?–Go to Step 5Go to”Code 6 –
Power Transis-
tor Error”
51. Run the blower and operate the MODE push
switch manually.
2. Check for airflow out the various outlets.
Does the air flow from the different outlets as it
should?–Go to Step 7Go to Step 6
61. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions found.
Is the heater operating?–System OKGo to Step 9
7Observe the air mix door motor (AMD) while chang-
ing the temperature setting from 18 to 32°C (64 to
90°F) and then from 32 to 18°C (90 to 64°F).
Is the AMD motor functioning properly?–Go to Step 8Go to”Code 3 –
Air Mix Door
Error”
8Perform the checks found in ”Insufficient Cooling
Diagnosis.”
Is the system operating normally now?–System OKGo to Step 9
9Place the controller in the AUTO mode.
Is smoke taken into the intake port of the in–car sen-
sor?–Go to Step 12Go to Step 10
10Check the intake hose for the in–car sensor.
Is the hose in good condition?–Go to Step 12Go to Step 11
11Repair or replace the intake hose.
Is the repair complete?–System OK–
12Check the in–car sensor using the tests in ”Code 1
– In–Car Sensor Error.”
Is there a problem indicated in the sensor, the sensor
wiring, or the controller?–Go to Step 13Go to Step 14
13Repair or replace the sensor, the wiring, or the con-
troller as required.
Is the repair complete?–System OK–
14Check the ambient air temperature sensor using the
tests in ”Code 2 – Ambient Air Temperature Sensor
Error.”
Is there a problem indicated in the sensor, the sensor
wiring, or the controller?–Go to Step 15Go to Step 16

AUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7D – 29
DAEWOO V–121 BL4
CODE 6 – POWER TRANSISTOR ERROR
StepActionValue(s)YesNo
11. Disconnect the ATC controller connectors A
and B.
2. Disconnect the connectors from the power
transistor.
3. Measure the resistance circuit GRY/BLK from
terminal 4 of the power transistor to terminal
B1 of the ATC controller.
Does the resistance equal the specified value?
0 WGo to Step 2Go to Step 6
2Measure the resistance in the circuit from terminal
1 of the power transistor to terminal B12 of the ATC
controller.
Does the resistance equal the specified value?
0 ΩGo to Step 3Go to Step 6
31. Reconnect the wiring harness to the ATC con-
troller and to the power transistor.
2. Turn the ignition switch to ON.
3. Measure the voltage from ground to terminal
B12 of the ATC controller.
4. Cycle the fan speed controller manually from
the lowest (speed 1) to the highest speed (8).
Do the voltages measured match approximately the
specified values within ±0.5 v?1: 4.0 v
2: 5.0 v
3: 6.0 v
4: 7.0 v
5: 8.0 v
6: 9.0 v
7: 10.0 v
8: Max Hi:Go to Step 4Go to Step 5
4Replace the ATC controller.
Is the repair complete?–System OK–

AUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7D – 31
DAEWOO V–121 BL4
CODE 7 – MAX–HI RELAY ERROR
StepActionValue(s)YesNo
11. Turn the ignition switch ON.
2. Set the blower speed manually for maximum
speed.
3. Measure voltage between the ATC controller
terminal A10 and ground.
Is the voltage approximately equal to the specified
value?
0 ΩGo to Step 3Go to Step 2
2Replace the ATC controller.
Is the repair complete?–System OK–
31. Check the wiring harness associated with the
MAX–HI relay for defects or high terminal re-
sistance.
2. Repair any defects found.
Is the repair complete?–System OKGo to Step 4
4Replace the MAX–HI relay.
Is the repair complete?–System OK–

7D – 40IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
GENERAL INFORMATION
THE V5 SYSTEM
Refer to Section 7B, Manual Control Heating, Ventilation,
and Air Conditioning System,for general information de-
tails for the following:
S System Components – Functional.
S The V5 A/C System.
S V5 Compressor – Description of Operation.
S V5 Compressor – General Description.
SYSTEM COMPONENTS–CONTROL
Controller
The operation of the A/C system is controlled by the
switches on the control head. This console–mounted
heating and ventilation system contains the following
knobs and display:
Temperature Control Push Knobs
1. Raise the temperature of the air entering the ve-
hicle by pressing the top switch, with the red arrow
pointing upward.
2. Lower the temperature by pressing the bottom
switch, with the blue arrow pointing downward.
3. Actuate the air mix door by an electric motor.
4. Vary the mix of the air passing through the heater
core with the air bypassing the core.
Each press of a switch changes the set temperature by in-
crements of 0.5°C (1°F). This is shown in the temperature
window on the function display.
The Function Display
This is an LCD display indicating the status of the control
settings selected. Starting from the left end of the display,
the sections are as follows:
1. Temperature setting – Indicates the temperature set
with the temperature control knob.
2. Auto status – Indicates whether the system is oper-
ating in the full auto mode or the manual mode.
3. Defroster icon – Indicates manual selection of full
defrost mode.
4. Mode – Indicated by icon, the mode chosen by the
system in auto (or by the operator in manual) is
shown by an illumination arrow indicating the air
path.
5. A/C – A snowflake icon indicating whether the A/C
is ON or OFF.
6. Fan speed – Indicates the fan speed by illuminating
a bar based on the segment at the front, for low
speed, and adding additional segments in order up
to the fifth, for high speed.Eight Additional Push Knobs
1. Full defrost – Causes the mode motors to direct all
air to the windshield and aide window outlets for
maximum defrosting.
2. Air intake – Switches between fresh air intake, the
default, and recirculating air. Airflow arrows on the
display indicate the mode in effect.
3. Full Auto Switch – Maintains the set temperature
automatically. In this mode, the fully automatic tem-
perature control (FATC) system controls the follow-
ing:
S The air mix door motor.
S The mode door motor.
S The blower motor speed.
S The inlet air door motor.
S A/C ON/OFF.
4. OFF Switch – Turns the automatic air conditioning
and fan control off.
5. Mode Switch – Allows manual selection of the air-
flow direction.
S Selection is shown on the function display.
S Each time the mode switch is pressed, the next
function is displayed.
6. A/C Switch – Allows manual selection and control
of the air conditioning function.
7. Fan Control Switch – Allows manual selection
among five fan speeds.
8. Defogger Switch – Turns on the electric defogging
heater in the rear window and the outside rearview
mirrors, if the vehicle is equipped with heated mir-
rors.
Pressure Transducer
Pressure transducer switching incorporates the functions
of the high–pressure and the low–pressure cutout
switches along with the fan cycling switch. The pressure
transducer is located in the high–side liquid refrigerant line
behind the right strut tower, between the right strut tower
and the fire wall. The output from this pressure transducer
goes to the electronic control module (ECM), which con-
trols the compressor function based on the pressure sig-
nal.
Wide–Open Throttle (WOT) Compressor
Cutoff
During full–throttle acceleration, the throttle position sen-
sor (TPS) sends a signal to the ECM, which then controls
the compressor clutch.
High RPM Cutoff
As engine rpm approaches the maximum limit, the ECM
will disengage the compressor clutch until the engine
slows to a lower rpm.

9D – 6IWIPERS/WASHER SYSTEMS
DAEWOO V–121 BL4
DIAGNOSIS
WINDSHIELD WIPERS
Windshield Wipers Do Not Work At Any Speed
StepActionValue(s)YesNo
1Check fuse F9.
Is fuse F9 blown?–Go to Step 2Go to Step 3
21. Check for a short circuit and repair it, if neces-
sary.
2. Replace the fuse.
Is the repair complete?–System OK–
3Check the voltage at fuse F9.
Is the voltage equal to the specified value?11–14 vGo to Step 5Go to Step 4
4Repair the open power supply circuit to fuse F9.
Is the repair complete?–System OK–
51. Disconnect the wiper motor connector.
2. Turn the ignition ON.
3. Turn the wiper switch to HI.
4. Check the voltage at the wiper motor connector
terminal 5.
Is the voltage equal to the specified value?11–14 vGo to Step 6Go to Step 7
6Replace the wiper motor.
Is the repair complete?–System OK–
71. The wiper switch is still disconnected.
2. Turn the ignition ON.
3. Check for battery voltage at the wiper switch
connector terminal A8.
Is the voltage equal to the specified value?11–14 vGo to Step 9Go to Step 8
8Repair the open circuit between the wiper switch
connector terminal A8 and fuse F9.
Is the repair complete?–System OK–
91. The wiper switch is still disconnected.
2. Turn the wiper switch to HI.
3. Use an ohmmeter to check for continuity be-
tween wiper switch terminal A8 and A9.
Does the ohmmeter indicate the specified value?
0 WGo to Step 11Go to Step 10
10Replace the wiper switch.
Is the repair complete?–System OK–
11Repair the open circuit between the wiper switch and
the wiper motor.
Is the repair complete?–System OK–

WIPERS/WASHER SYSTEMS 9D – 7
DAEWOO V–121 BL4
Wipers Do Not Work On HI Speed, LO Speed OK
StepActionValue(s)YesNo
11. Turn the ignition ON.
2. Turn the wiper switch to HI.
3. Check voltage at the wiper motor connector
terminal 5.
Is voltage equal to the specified value?11–14 vGo to Step 2Go to Step 3
2Replace the wiper motor.
Is the repair complete?–System OK–
31. Disconnect the wiper switch.
2. Turn the wiper switch to HI.
3. Use an ohmmeter to check for continuity be-
tween wiper switch terminal A8 and A9.
Does the ohmmeter indicate the specified value?
0 WGo to Step 5Go to Step 4
4Replace the wiper switch.
Is the repair complete?–System OK–
5Repair the open circuit between wiper switch con-
nector terminal A9 and wiper motor connector termi-
nal 5.
Is the repair complete?–System OK–
Wipers Do Not Work On LO Speed, HI Speed OK
StepActionValue(s)YesNo
11. Turn the ignition ON.
2. Turn the wiper switch to LO.
3. Check the voltage at the wiper motor connec-
tor, terminal 6.
Is the voltage equal to the specified value?11–14 vGo to Step 2Go to Step 3
2Replace the wiper motor.
Is the repair complete?–System OK–
31. Disconnect the wiper switch.
2. Turn wiper switch to LO.
3. Use an ohmmeter to check for continuity be-
tween wiper switch terminal A8 and A5.
Does the ohmmeter indicate the specified value?
0 WGo to Step 5Go to Step 4
4Replace the wiper switch.
Is the repair complete?–System OK–
5Repair the open circuit between wiper switch con-
nector terminal A5 and wiper motor connector termi-
nal 5.
Is the repair complete?–System OK–

9D – 8IWIPERS/WASHER SYSTEMS
DAEWOO V–121 BL4
Wipers Do Not Work On Intermittent (INT), Other Speeds OK
StepActionValue(s)YesNo
11. Turn the ignition ON.
2. Turn the wiper switch to INT.
3. Check the voltage at wiper motor connector
terminal 2.
Does the voltmeter indicate a voltage equal to the
specified value?11–14 vGo to Step 5Go to Step 2
2Check for an open circuit between wiper switch con-
nector terminal B2 and wiper motor connector termi-
nal 2.
Is there an open circuit?–Go to Step 4Go to Step 3
3Replace the wiper switch.
Is the repair complete?–System OK–
4Repair the open circuit between wiper switch con-
nector terminal B2 and wiper motor connector termi-
nal 2.
Is the repair complete?–System OK–
51. Turn the ignition ON.
2. Turn the wiper switch to INT.
3. Check for pulsing voltage at wiper motor con-
nector terminal 6.
Does the voltmeter indicate a pulsating voltage
equal to the specified value?11–14 vGo to Step 7Go to Step 6
6Replace the wiper motor.
Is the repair complete?–System OK–
71. Ignition ON.
2. Check the voltage at the wiper switch connec-
tor terminal A6.
Is voltage pulsating at the specified value?11–14 vGo to Step 8Go to Step 9
8Replace the wiper switch.
Is the repair complete?–System OK–
9Repair the open circuit between the wiper switch and
the wiper motor.
Is the relay complete?–System OK–

9D – 22IWIPERS/WASHER SYSTEMS
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
WINDSHIELD WIPER SYSTEM
The windshield wiper system consists of a wiper motor, a
linkage, a wiper arm and a blade, and a wiper/washer
switch. The windshield wiper circuit incorporates a self–
parking device which consists of a worm gear and a cam
plate in order to keep the circuit engaged temporarily when
the switch is turned off. The wiper system is driven by a
permanent magnet–type motor. The windshield wiper mo-
tor is mounted on the dash panel and is directly connected
to the windshield wiper linkage.
The windshield wiper motor has two speeds, LO and HI,
and also has intermittent wiper capability. The wiper
switch is an integral part of the wiper/washer switch. Wind-
shield wiper operation is actuated through the lever on the
right side of the steering column.
WINDSHIELD WASHER SYSTEM
The windshield washer system is equipped with a washerfluid reservoir, a washer fluid pump, hoses, nozzles, and
a wiper/washer switch. The windshield washer reservoir
is mounted behind the front left wheel well splash shield.
Attached to the reservoir is a washer pump, which pumps
fluid through the hoses to the two nozzles mounted on the
hood. The washer switch is an integral part of the wiper/
washer switch. Windshield washer operation is actuated
through the lever on the right side of the steering column.
REAR WINDOW WIPER/WASHER
SYSTEM
The rear window wiper system consists of a wiper motor,
a wiper arm, and a blade. The rear window wiper motor is
located inside the hatchback/tailgate door and is directly
connected to the rear window wiper. The rear window
washer system is equipped with a separate washer fluid
pump and hose. The hatchback has a hatch–mounted
rear window washer nozzle and on the wagon, the washer
nozzle is incorporated into the rear wiper motor. The rear
window washer reservoir is mounted behind the front left
wheel well splash shield. Attached to the reservoir is a
washer pump, which pumps fluid through a hose to the
rear washer nozzle.