speed DAEWOO LACETTI 2004 Service Repair Manual

6C – 10IPOWER STEERING GEAR
DAEWOO V–121 BL4
Trouble Code
DTCTroubleDefault Action
01Actuator circuit open
02Actuator HI to LO short
03Actuator circuit short to B+
04Actuator HI short to GroundWarning lamp ON, Actuator Off
05Actuator LO short to Ground
06Steering Wheel Speed Sensor Open
07Steering Wheel Speed Sensor short to 5V
08Battey Voltage Out of Range (9~16 V)

POWER STEERING GEAR 6C – 21
DAEWOO V–121 BL4
6. Fill the fluid reservoir with power steering fluid.
7. Inspect for leaks. If there are leaks, correct the
cause of the leaks and bleed the system. Refer to
”Bleeding the Power Steering System” in this sec-
tion.
SPEED SENSITIVE POWER
STEERING CONTROL MODULE
Removal Procedure
1. Disconnect negative battery cable.
2. Remove the glove box. Refer to Section 9G, Interi-
or Trim.
3. Slide the speed sensitive power steering (SSPS)
control module off from the control module bracket.
4. Disconnect the electrical connector from the SSPS
control module.
Installation Procedure
1. Connect the electrical connector to the SSPS con-
trol module.
2. Slide the SSPS control module onto the SSPS con-
trol module bracket.
3. Install the ashtray. Refer to Section 9G, Interior
Trim.
4. Connect the negative battery cable.

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.

6C – 36IPOWER STEERING GEAR
DAEWOO V–121 BL4
The flow control actuator is installed on the outlet of the
conventional vein type of the power steering pump. The
actuator modulates fluid flow to the steering gear from the
pump by current control from the SSPS module.
At low speed, small current is supplied to the actuator.
Then the actuator modulates flow high and steering effort
becomes light.
At high speed, On the contrary, big current to the actuator.
Low fluid flow and heavy steering effort.
If there happens an actuator malfunction, by default its
pintle valve opens the orifice 100% to supply light steering
effort.
The maximum pumping pressure with SSPS option is
74.4~81.6 kg/cm2.
If you try to measure voltage at the actuator terminal with
the connector removed, you can measure 6.5V.
VEHICLE SPEED (KPH)CURRENT (mA)
00
6050
100400
140650
160700

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

6E – 16ISTEERING WHEEL AND COLUMN
DAEWOO V–121 BL4
7. Disconnect the ignition switch electrical connection.
8. Adjust the steering to the straight–ahead position.
9. Remove the pinch bolt from the intermediate shaft
universal joint.
10. Disconnect the speed sensitive steering electrical
connector.
11. Remove the bolts and nuts holding the front bracket
of the steering column jacket assembly.
12. Remove the nuts holding the rear bracket of the
steering column jacket assembly.
13. Guide the steering column assembly out of steering
shaft flange and carefully lay down the assembly.

STEERING WHEEL AND COLUMN 6E – 17
DAEWOO V–121 BL4
Installation Procedure
Important : For proper installation of the steering column,
be sure the steering wheel spokes are centered diagonally
and pointed downward and the front wheels are positioned
in the straight–ahead position.
1. Carefully guide the steering shaft into the intermedi-
ate shaft universal joint.
Important : Provide support for the steering column as-
sembly until the mounting nuts are fastened. Do not let the
steering column assembly hang unsupported.
2. Install the pinch bolt into the non–threaded hole of
the flange.
Tighten
Tighten the steering shaft universal joint pinch bolt to
25 NSm (18 lb–ft).
3. Install the bolts and nuts for the front bracket of the
steering column jacket assembly.
Tighten
Tighten the steering column jacket assembly front
bracket bolts to 22 NSm (16 lb–ft).
4. Install the nuts for the rear bracket of the steering
column jacket assembly.
Tighten
Tighten the steering column jacket assembly rear
bracket nuts to 22 NSm (16 lb–ft).
5. Connect the speed sensitive steering electrical con-
nector.

7A – 6IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
DIAGNOSIS
HEATER SYSTEM
INSUFFICIENT HEATING OR DEFROSTING
CAUTION : The cooling system is pressurized when hot. Injury can result from removing the surge tank cap be-
fore the engine is sufficiently cool.
Step
ActionValue(s)YesNo
1Verify the customer’s complaint.
Are the customer’s concerns verified?–Go to Step 2System OK
2Check the coolant level.
Is the coolant level correct?–Go to Step 4Go to Step 3
3Add coolant as needed.
Is the repair complete?–System OKGo to Step 4
4Check the timing belt for tension or damage.
Are the drive belts OK?–Go to Step 6Go to Step 5
5Correct any problem with the timing belt.
Is the repair complete?–System OKGo to Step 6
6Check the coolant hoses for leaks or kinks.
Are the coolant hoses OK?–Go to Step 8Go to Step 7
7Repair any problem with the coolant hoses.
Is the repair complete?–System OKGo to Step 8
8Check the surge tank cap. Refer to Section 2D, En-
gine Cooling.
Is the surge tank cap OK?–Go to Step 10Go to Step 9
9Repair or replace the surge tank cap as needed.
Is the repair complete?–System OKGo to Step 10
101. Turn the A/C switch OFF on vehicles equipped
with air conditioning (A/C).
2. Set the blower motor switch on maximum
speed.
3. Set the heater control to full hot.
4. Turn the ignition ON.
5. Check for airflow from the vent outlet.
Is there heavy airflow from the heater outlet?–Go to Step 11Go to Step 26
11Check for a change in the airflow at various blower
speeds.
Does the blower speed increase as the switch is
turned from 1 to 4.–Go to Step 12Go to ”Blower
Electrical
(Manual and
Non–A/C)”
121. Turn the A/C switch OFF.
2. Set the temperature lever to full hot.
3. Set the blower motor switch on maximum
speed.
4. With the engine sufficiently cool, remove the
surge tank cap.
5. Start the vehicle and idle the engine.
6. Watch for the flow of the coolant.
Is the coolant flow visible?–Go to Step 14Go to Step 13

7A – 8IHEATING AND VENTILATION SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
20Replace the thermostat. Refer to Section 2D, En-
gine Cooling.
Is the repair complete?–System OK–
21Reinstall the thermostat.
Is the repair complete?–System OK–
22Inspect the heater hoses for proper installation.
Are the heater hoses reversed?–Go to Step 23Go to Step 24
23Reinstall the heater hoses properly.
Is the repair complete?–System OK–
241. Back flush the heater core.
2. Drain the cooling system.
3. Replace the coolant.
4. Warm the engine to an average operating tem-
perature.
5. Feel the heater inlet hose and the heater outlet
hose.
Is the heater inlet hose hot and the heater outlet
hose warm?–System OKGo to Step 25
25Replace the heater core.
Is the repair complete?–System OK–
26Recheck the system using the ”Control Settings/
Correct Results” tests. Refer to ”Improper Air Deliv-
ery or No Mode Shift” in this section.
Is the repair complete?–System OKGo to Step 27
27Check for airflow from the defroster or the vent out-
lets.
Is there high airflow from the defroster or vent out-
lets?–Go to Step 28Go to Step 29
281. Check the heater door at the floor and the vent
door to get the proper airflow and to verify
proper operation.
2. Repair as required.
Is the repair complete?–System OK–
29Switch the mode knob to defrost.
Is the defroster airflow OK?–Go to Step 30Go to Step 31
301. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions in the heater outlet.
Is the repair complete?–System OK–
31Check for airflow change at various blower speeds.
Does the blower speed increase as the control is
turned from 1 to 4?–Go to Step 32Go to ”Blower
Electrical
(Manual and
Non–A/C)”
32Check for obstructions in the system at the blower
inlet and at the air filter, if the vehicle is equipped with
one.
Are there any obstructions?–Go to Step 33Go to Step 34
33Remove the obstructions in the system at the blower
inlet or replace a clogged filter.
Is the repair complete?–System OK–