2004 DAEWOO LACETTI vehicle speed sensor

5A2 – 60IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0722 Output Shaft Speed (OSS) sensor Circuit No Signal
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Install the Scan tool.
3. With the engine OFF, turn the ignition switch to
the ON position.
4. Select Store Freeze Frame/Failure Records
from the Diagnostic Trouble Codes Information
menu.
5. Store Freeze Frame/Failure Records.
6. Select Clear DTC Information from the Diag-
nostic Trouble Codes Information menu.
7. Clear DTC Information.
8. Perform one vehicle drive cycle.
Is the Malfunction Indicator Lamp (MIL) ON?–Go to Step 2Repair the tem-
porary connec-
tion failure of
connector (Re-
fer to ”Wiring
Harness and
Connector In-
spection” in this
section.)
21. Select Request DTC by Status from the Diag-
nostic Trouble Codes Information menu.
2. Request DTC by Status.
Is DTC P0722 displayed?–Go to Step 3Repair the tem-
porary connec-
tion failure of
connector (Re-
fer to ”Wiring
Harness and
Connector In-
spection” in this
section.)
31. Turn the ignition OFF.
2. Inspect the voltage between vehicle harness
and the Output Shaft Speed (OSS) sensor.
3. Disconnect the connector (X–1) of the vehicle
harness.
4. Connect the voltmeter to monitor the voltage
between terminal B25 and ground.
5. Turn ignition ON and lift up the vehicle.
6. Check the voltage change from approximately
0 v to 12 v when the wheel is turned slowly.
Does the measurement change within the specified
value?0–12 vGo to Step 4Go to Step 5
41. Estimate the failure of between the vehicle wir-
ing harness connector and TCM.
2. Inspect the connector. Refer to ”Wiring Har-
ness and Connector Inspection” in this section.
3. Inspect the connection condition between the
connectors (C–1).
Is the connection condition OK?–Go to Step 6Repair the wir-
ing harness
connectors.
51. Estimate the failure of T/M wire or between the
connectors of OSS sensor.
2. Inspect the OSS sensor. Refer to ”Unit Inspec-
tion” in this section
Is the condition of OSS sensor OK?–Go to Step 7Replace the
OSS sensor

5A2 – 218IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
TRANSAXLE DESCRIPTION
The new automatic transmission is an electronically con-
trolled 4–speed automatic transmission with Lock–up
mechanism.
The transmission is mainly composed of the torque con-
verter with lock up clutch, newly developed 4–speed plan-
etary gear unit, the hydraulic control system and the elec-
tric control system.
ELECTRONICAL COMPONENTS
Transmission Control Module (TCM)
The TCM primarily controls shift points and lockup en-
gagement. It is located on the driver side under the instru-
ment panel.
The transmission is controlled by an electronic shift sys-
tem. The Transmission Control Module (TCM) processes
input signals. From the information received, the TCM
controls the transmission hydraulic system.
The electronic shift system consists of the following :
S Transmission control module (TCM)
S Shift solenoids (SS1 and SS2)
S Pressure control solenoid (PCS)
S Lockup solenoid
S Input shaft speed (ISS) sensor
S Output shaft speed (OSS) sensor
S Transmission Fluid Temperature (TFT) sensor
S Transmission Range (TR) Switch
Transmission Range (TR) Switch
Transmission Range (TR) Switch transmits the informa-
tion which range includes shift lever of A/T to Starter and
TCM.
S It is possible for TR switch to start an engine in only
”P” and ”N”. (Prevention of reckless driving)
S TR switch makes backup lamp turn on when re-
versing.
S It is used for TR switch to shift control.
TR switch transmits the information by combination of
starter and reverse circuit to vehicle side directly without
TCM.
Shift Solenoid No 1,2 (SS1, SS2)
2 shift solenoids are installed directly in the valve body.
The solenoids operate of ON and OFF by the control sig-
nal from TCM. Combinations of 2 solenoids, SS1 and SS2
changes gear ranges.

5A2 – 220IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Output Shaft Speed (ISS) Sensor
OSS sensor is located on the upper position of the trans-
axle and detects the vehicle speed from the rotation num-
ber of the differential gear.
Shift Control
When the ATF is below specification (15°C), 4th up–shift
is prevented.

POWER STEERING GEAR 6C – 33
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
POWER RACK AND PINION
The power rack and pinion steering system has a rotary
control valve that directs hydraulic fluid coming from the
hydraulic pump to one side or the other side of the rack pis-
ton. The integral rack piston is attached to the rack. The
rack piston converts hydraulic pressure to a linear force
that moves the rack left or right. That force is then trans-
mitted through the tie rods to the steering knuckles, which
turn the wheels.
If power rack and pinion steering is not available, manual
rack and pinion control is used; however, with this system,
more steering effort is required. The movement of the
steering wheel is transferred to the pinion. The rotary
movement of the pinion is then transferred through the pin-
ion threads, which mesh with teeth on the rack, thereby
causing the rack to move in a linear direction.
A vane–type of hydraulic pump provides hydraulic pres-
sure for both steering systems.
SPEED SENSITIVE POWER
STEERING SYSTEM
The speed sensitive power steering (SSPS) system varies
the driver effort required to steer as the vehicle speed
changes. At low speeds, the system provides maximum
power assist for easy turning and parking maneuvers. At
higher speeds, the steering power is reduced to provide
the driver with firmer steering and directional stability. The
SSPS system accomplishes this by reducing the amount
of power steering fluid flow from the power steering pump
to the power steering gear as the vehicle speed increases.
When the vehicle is stationary, the SSPS system provides
maximum fluid flow to the steering gear. As the vehicle
speed increases, the fluid flow to the steering gear is de-
creased.
Control Module
The SSPS control module processes the vehicle speed in-
formation from the engine control module (ECM) and uses
the steering wheel rotation sensor to provide a control sig-
nal to the electronic variable orifice (EVO) actuator located
on the power steering pump.
Electronic Variable Orifice (EVO) Actuator
The electronic variable orifice (EVO) actuator is located on
the power steering pump and contains a solenoid– oper-
ated pintle valve. Fluid leaving the pump passes through
an orifice in the actuator tip. When the EVO actuator is
powered by the SSPS control module, the pintle moves
into the orifice and reduces the power steering fluid flow.As the vehicle speed increases, current from the SSPS
control module increases, and the pintle blocks more and
more of the orifice.
Steering Wheel Rotation Sensor
The steering wheel rotation sensor is located at the end of
the steering column housing and is used to send a signal
to the controller when abrupt or evasive steering maneu-
vers are needed.
Power Steering Pressure Hose
SSPS vehicles have a specific pressure hose assembly
which includes an in–line check valve in the rack and pin-
ion assembly. This reduces the amount of steering wheel
”kick” when driving over irregular road surfaces while oper-
ating at speeds with reduced flow rate and pressure.
Power Rack and Pinion
Except for differences in valve machining, the design of
the SSPS power rack and pinion assembly is the same as
for the a non–SSPS system. The steering wheel move-
ment is transferred to the pinion via the intermediate shaft.
The pinion moves the rack left or right through meshing the
pinion and the rack teeth. The force is then transmitted
through the tie rods and steering knuckle to steer the
wheels.
The power rack and pinion steering system has a rotary
control valve which directs the hydraulic fluid from the
power steering pump to one side or the other side of the
rack piston. The piston is attached to the rack and uses hy-
draulic pressure to move the rack left or right. The rotary
control valve regulates the degree of assist by responding
to the driver’s torque input.
If hydraulic assist is not available, manual control is main-
tained. However, under this condition, more steering effort
is required.
Power Steering Pump
The standard vane–type pump, which provides hydraulic
pressure for the system, incorporates a special discharge
fitting to hold the EVO actuator.
System Operation
System operation originates with input from the vehicle
speed sensor via the engine control module to the SSPS
control module. The SSPS control module sends a signal
to the SSPS actuator to vary the rate of fluid flow output
by the power steering pump.
Circuit Operation
The SSPS system uses inputs from the speed sensor and
steering wheel rotation sensor to the SSPS controller to
determine the desired amount of power steering assist.
The SSPS control module constantly compares the
amount of current flowing through the EVO actuator to the
desired current it has calculated. The EVO actuator has a
pintle that moves in and out of an orifice, regulating power

6C – 34IPOWER STEERING GEAR
DAEWOO V–121 BL4
steering fluid flow. The SSPS control module can change
the amount of current flowing through the EVO actuator by
varying the output duty cycle. If the EVO actuator is dis-
connected, the pintle will be pulled out of the orifice for
maximum power steering assist.
The SSPS control module has the ability to detect faults
in the steering wheel rotation sensor, the EVO actuator, or
the circuitry to those components. Any default detected
will cause the power steering assist to remain at maximum
with the pintle in its normally retracted position for all
speeds.
When the system is operating normally, increasing the ve-
hicle speed will decrease power steering assist, allowing
the driver to have improved road feel and directional stabil-
ity. When sudden steering wheel turns are made, as in
evasive maneuvers, they are detected by the SSPS con-trol module through the steering wheel rotation sensor.
When detected, the SSPS control module reduces current
to the EVO actuator, allowing greater power steering as-
sist.
SSPS (Speed Sensitive Power Steering) is to control pow-
er steering effort properly according to varying conditions
for both convenience and safety.
At low speed or standstill, power steering effort becomes
light to provide easy steering. On the contrary, at high
speed, power steering effort becomes heavy to provide
stable steering.
SSPS offered to LACETTI is EVO (Electric Variable Ori-
fice) type, which controls steering effort by modulating
pressurized fluid supply to the steering unit from the power
steering pump.
Steering wheel rotation sensor is installed at the bottom of
the steering column.
This sensor detects steering wheel rotation which is used
to calculate the angle speed of the steering wheel by
SSPS module.
If the angle speed was big enough for intervention into nor-mal steering force control during high vehicle speed, which
means a driver made an evasive steering maneuver to
avoid an accident, SSPS module would supply enough
steering support.
The sensor consists of a variable resistor.

POWER STEERING GEAR 6C – 37
DAEWOO V–121 BL4
[Vehicle Speed – Actuator Current Relation]
SOLENOID RESISTANCE
13 W
The control module is installed on the right side of the au-
dio and can be accessible after the glove box is removed.
It receives signals from the vehicle speed sensor and the
steering wheel rotation sensor and processes them to de-
cide proper fluid flow through the actuator.
It also has a self–diagnosis. If it detects any malfunction,
it starts default mode, which is basically actuator full open
for light steering effort.
TERMINALCOLORFUNCTION
1SBActuator Low
2VActuator High
3BWSteering Wheel Sensor Ground
4–Not used
5GrSteering Wheel Sensor 5V ref.
6GWVSS
7–Not Used
8PIGN ON
9BrWarning Lamp
10BWGround
11–Not Used
12–Not Used
13LDiagnosis
14SBSteering Wheel Sensor Signal

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

9E – 10IINSTRUMENTATION/DRIVER INFORMATION
DAEWOO V–121 BL4
SPEEDOMETER
Speedometer Inoperative, Other Gauges and Warning Lamps Are
OK
StepActionValue(s)YesNo
11. Connect a scan tool.
2. Check for engine control diagnostic trouble
codes (DTCs).
Is the vehicle speed sensor DTC set?–Go to
Section 1F, En-
gine ControlsGo to Step 2
21. Turn the ignition OFF.
2. Disconnect the engine control module (ECM)
connector.
3. Remove the instrument cluster.
4. Check continuity between ECM terminal K6
(B23 ; HV–240, 51 ; SIRIUS D4) and the in-
strument cluster connector terminal B5.
Does the ohmmeter indicate the specified value?0 WGo to Step 4Go to Step 3
3Repair the open circuit between the instrument clus-
ter connector terminal B5 and the ECM.
Is the repair complete?–System OK–
4Replace the speedometer.
Is the repair complete?–System OK–
FUEL GAUGE
Fuel Gauge Inoperative, Other Gauges and Warning Lamps are OK
StepActionValue(s)YesNo
11. Connect a scan tool.
2. Check for engine control diagnostic trouble
codes (DTCs).
Is the vehicle speed sensor DTC set?–Go to
Section 1F, En-
gine ControlsGo to Step 2
21. Turn the ignition OFF.
2. Disconnect engine control module (ECM) con-
nector.
3. Remove the instrument cluster.
4. Check continuity between ECM terminal K30
(B31 ; HV–240, 40 ; SIRIUS D4) and the in-
strument cluster terminal B3.
Does the ohmmeter indicate the specified value?0 WGo to Step 4Go to Step 3
3Repair the open circuit between the instrument clus-
ter connector terminal B3 and the ECM terminal K30
(B31; HV–240, 40 ; SIRIUS D4).
Is the repair complete?–System OK–
4Replace the fuel gauge.
Is the repair complete?–System OK–