POWER STEERING SYSTEM 6A – 3
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
BLEEDING THE POWER STEERING
SYSTEM
If the power steering hydraulic system has been serviced,
an accurate fluid level reading cannot be obtained until the
air is bled from the system. Follow these steps to bleed the
air from the system.
1. Turn the wheels all the way to the left and add the
power steering fluid to the MIN mark on the fluid
level indicator.
Notice : When adding fluid or making a complete fluid
change, always use DEXRON®–II or III power steering
fluid. Failure to use the proper fluid will cause hose and
seal damage and fluid leaks.
2. Start the engine. With the engine running at fast
idle, recheck the fluid level. If necessary, add fluid
to bring the level up to the MIN mark.
3. Bleed the system by turning the wheels from side to
side without reaching the stop at either end. Keep
the fluid level at the MIN mark. The air must be
eliminated from the fluid before normal steering ac-
tion can be obtained.
4. Return the wheels to the center position. Continue
running the engine for 2 to 3 minutes.
5. Road test the car to be sure the steering functions
normally and is free from noise.
6. Recheck the fluid level as described in steps 1 and
2. Make sure the fluid level is at the MAX mark af-
ter the system has stabilized at its normal operating
temperature. Add fluid as needed.
CHECKING AND ADDING FLUID
Notice : When adding fluid or making a complete fluid
change, always use DEXRON®–II or III power steering
fluid. Failure to use the proper fluid will cause hose and
seal damage and fluid leaks.
1. The power steering fluid level is indicated either by
marks on a see–through fluid reservoir or by marks
on a fluid level indicator on the fluid reservoir cap.
2. If the fluid is warmed up to 66°C (150°F), the fluid
level should be between the MAX and MIN marks.
Add fluid as needed.
3. If the fluid is cool, 21°C (70°F), the fluid level
should be at the MIN mark. Add fluid as needed.
6C – 4IPOWER STEERING GEAR
DAEWOO V–121 BL4
Steering Surges or Jerks When Turning with Engine Running
ChecksAction
Check the power steering pump for insufficient pressure.Replace the power steering pump.
Check the power steering pump flow control valve for
sticking and improper operation.Replace the power steering pump.
Check the power steering pump serpentine belt for slip-
page.Tighten the power steering serpentine belt.
Check for air contamination in the power steering system.Bleed the power steering system.
Steering Vibrates During Low Speed or Static Steering
ChecksAction
Check for air contamination in the power steering system.Bleed the power steering system.
Check the power steering pump serpentine belt for loose-
ness.Tighten the power steering serpentine belt.
Excessive Wheel Kickback or Loose Steering
ChecksAction
Check for air contamination in the power steering system.Bleed the power steering system.
Check the wheel bearings for wear or damage.Replace the wheel bearings.
Check the steering gear mounting for improper installa-
tion.Tighten the steering gear mounting bracket nuts and bolts.
Check the intermediate shaft joints for improper installa-
tion.Adjust the intermediate shaft between the steering gear
and the steering column.
Replace the intermediate shaft.
Check the outer tie rods and ball joints for looseness.Tighten the tie rods and the ball joints. Replace the tie rods
and the ball joints.
Hard Steering or Lack of Assist (Especially During Parking)
ChecksAction
Adjust the intermediate shaft between the steering gear
and the steering column. Replace the coupling flange.Adjust the steering coupling flange on the steering gear
and the steering column. Replace the coupling flange as
needed.
Check the power steering pump flow control valve for
sticking and improper installation.Replace the power steering pump.
Check the power steering pump for insufficient pressure.Replace the power steering pump.
Check the power steering pump for internal leaks.Replace the power steering pump.
Check for a loose or a worn intermediate shaft.Tighten the intermediate shaft. Replace the intermediate
shaft as needed.
Check the power steering pump serpentine belt tension.Tighten the power steering serpentine belt.
POWER STEERING GEAR 6C – 5
DAEWOO V–121 BL4
POWER RACK AND PINION
STEERING GEAR BENCH TESTING
Removal, Setup and Testing Procedure
Notice : Pressure checks or pressure and flow checks
may also be conducted using this set–up.
1. Disconnect and remove the power steering gear.
Refer to ”Rack and Pinion Assembly” in this sec-
tion.
2. Place the power steering gear on a bench next to
the vehicle.
3. Disconnect the pressure line at the point where the
hose connects to the pipe. Extend this line in order
to reach the power steering gear on the bench.
4. Disconnect the return line from the the power steer-
ing fluid reservoir. Extend this line in order to reach
the power steering gear on the bench.
5. Connect the power steering pipes to the power
steering gear.6. Start the engine and allow it to idle for 10 seconds.
7. Check the power steering fluid level. Refer to Sec-
tion 6A, Power Steering System.
8. Start the engine and turn the rack and pinion stub
shaft to a full turn in each direction. Hold the shaft
against each stop for 5 seconds.
9. Inspect for possible leak points. Refer to Section
6A, Power Steering System.
Installation Procedure
1. Stop the engine.
2. Disconnect the power steering pipes from the pow-
er steering gear.
3. Remove the extensions and reconnect the pressure
and return lines.
4. Install and connect the power steering gear. Refer
to ”Rack and Pinion Assembly” in this section.
5. Start the engine and stay idle for 10 seconds.
6. Check the power steering fluid level. Refer to Sec-
tion 6A, Power Steering System.
POWER STEERING GEAR 6C – 7
DAEWOO V–121 BL4
SPEED SENSITIVE POWER STEERING SYSTEM
OPERATING WITH FULL ASSIST AT ALL TIMES
StepActionValue(s)YesNo
1Perform an initial inspection of the power steering
system.
Is the system operational?–Go to Step 2Go to
Section 6A,
Power Steering
System
2Check the speedometer.
Is the speedometer inoperative?–Go to
Section5,
TransaxleGo to Step 3
3Check the diagnostic trouble codes at the engine
control module (ECM).
Is the ECM code 24 set?–Go to
Section1F,
Engine
ControlsGo to Step 4
41. Turn the ignition ON.
2. Disconnect the electronic variable orifice (EVO)
solenoid actuator electrical connector at the
power steering pump.
3. Probe terminal 1 of the EVO actuator connec-
tor with a voltmeter.
Does the voltmeter display the specified value?–Go to Step 6Go to Step 5
5Repair the open or short in the circuit between termi-
nal 1 of the EVO solenoid actuator electrical connec-
tor and terminal 2 on the speed sensitive power
steering (SSPS) control module connector.
Is the repair complete?–System OK–
61. Remove the EVO solenoid actuator from the
power steering pump.
2. Turn the actuator upside down to position the
pintle.
3. Stimulate the actuator by connecting it to the
battery.
Does the actuator click?–Go to Step 8Go to Step 7
7Replace the EVO solenoid actuator.
Is the repair complete?–System OK–
81. Turn the ignition OFF.
2. Remove the SSPS control module from the
control module bracket.
3. Disconnect the SSPS control module connec-
tor.
4. Connect a test light from terminal 8 on the
SSPS control module connector to the ground.
5. Turn the ignition ON.
Is the test light on?–Go to Step 14Go to Step 9
9Check the ignition fuse.
Is the ignition fuse open?–Go to Step 10Go to Step 11
10Replace the ignition fuse.
Is the repair complete?–System OK–
11Check for an open or short in the circuit between ter-
minal 8 of the control module connector and the I/P
fuse block.
Is the connection faulty?–Go to Step 12Go to Step 13
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
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
HEATING AND VENTILATION SYSTEM 7A – 7
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
131. Check for the following problems:
S Restriction in the cooling system.
S Failed water pump impeller.
S Faulty thermostat.
2. Make repairs to the cooling system, as needed.
Are the repairs complete?–System OKGo to Step 14
141. Install the surge tank cap.
2. With the ignition ON, allow the engine to warm
up for about 20 minutes. Drive the vehicle at 48
km/h (30 mph).
3. Use a thermometer to measure the ambient air
temperature and the discharge air temperature
at the heater outlet.
Does the heater output meet the minimum values
given?Go to ”Heater
Temperature
Specifications”Go to Step 15Go to Step 16
151. Check the vehicle for cold air leaks at the fol-
lowing locations:
S Dash.
S Heater cases.
S Vents.
2. Check under the seat for obstructions.
3. Repair any leaks or obstructions.
Are the repairs complete?–System OK–
161. Turn the ignition OFF.
2. Turn the temperature control knob to full cold,
then rapidly to full hot.
3. Listen for the sound of the temperature door
slam just before it reaches the end of the travel
range of the control knob.
Does the door slam?–Go to Step 18Go to Step 17
171. Check the following aspects of the temperature
door:
S Travel.
S Cables.
S Linkage.
2. Verify the accuracy of the temperature controls
at full hot.
3. Verify the accuracy of the temperature controls
at full cold.
Is the repair complete?–System OK–
181. Set the temperature control knob to full hot.
2. Start the vehicle.
3. Check the temperature of the heater inlet hose
and the heater outlet hose by feel. The air tem-
perature around the hoses should be at least
29°C (84°F).
Is the heater inlet hose hot and the heater outlet
hose warm?–Go to Step 19Go to Step 22
19Check the thermostat. Refer to 2D, Engine Cooling.
Is the thermostat installed and seated properly?–Go to Step 20Go to Step 21
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–