low oil pressure DAEWOO LACETTI 2004 Service Owner's Manual

ENGINE CONTROLS 1F – 501
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0506
IDLE SPEED RPM LOWER THAN DESIRED IDLE SPEED
Circuit Description
The Engine Control Module (ECM) controls the air enter-
ing into the engine with an Idle Air Control (IAC) Valve. To
increase the idle rpm, the ECM commands the pintle in-
side the IAC valve away from the throttle body seat. This
allows more air to bypass through the throttle blade. To de-
crease the rpm the ECM commands the pintle towards the
throttle body seat. This reduces the amount of air bypass-
ing the throttle blade. A scan tool will read the IAC valve
pintle position in counts. The higher the counts, the more
air that is allowed to bypass the throttle blade. This Diag-
nostic Trouble Code (DTC) determines if a low idle condi-
tion exists as defined as 100 rpm below the desired idle
rpm.
Conditions for Setting the DTC
S No intrusive tests are active.
S DTC(s) P0106, P0107, P0108, P0112, P0113,
P0117, P0118, P0122, P0123, P0131, P0132,
P0133, P0135, P0141, P1133, P1134, P0171,
P01167, P1171, P0172, P0201, P0202, P0203,
P0204, P0300, P0336, P0337, P0341, P0342,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406, P0443, and P0502 are not set.
S Engine is running more than 60 seconds.
S Barometric Pressure (BARO) is greater than 72
kPa (10.4 psi).
S Engine Coolant Temperature (ECT) is greater than
60°C (140°F).
S Ignition voltage is between 11 and 16 volts.
S Manifold Absolute Pressure is less than 60 kPa (8.7
psi).
S IAC valve is controlled fully opened.
S All of the above must be met for greater than 5 sec-
onds.Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive ignition cycle with a fail.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Inspect the IAC valve electrical connection for proper mat-
ing.
Inspect the wiring harness for damage.
Inspect the throttle stop screw for signs of tampering.
Inspect the throttle linkage for signs of binding or exces-
sive wear.
A slow or unstable idle may be caused by one of the follow-
ing conditions:
S Fuel system too rich or too lean.
S Foreign material in the throttle body bore or in the
air induction system.
S A leaking or restricted intake manifold.
S Excessive engine overloading. Check for seized
pulleys, pumps, or motors on the accessory drive.
S Overweight engine oil.

1F – 610IENGINE CONTROLS
DAEWOO V–121 BL4
Notice : Do not use methyl ethyl ketone because it can
damage the parts.
6. Clean the IAC valve O–ring seal area, the pintle
valve seat, and the air passage with a suitable fuel
system cleaner.
Installation Procedure
Important : If installing a new IAC valve, be sure to re-
place it with an identical part. The IAC valve pintle shape
and diameter are designed for the specific application.
Measure the distance between the tip of the IAC valve
pintle and the mounting flange. If the distance is greater
than 1.1 inches (28 mm), use finger pressure to slowly re-
tract the pintle. The force required to retract the pintle will
not damage the IAC valve. The purpose of the 1.1–inch
(28–mm) setting is to prevent the IAC pintle from bottom-
ing out on the pintle seat. This 1.1–inch (28–mm) setting
is also an adequate setting for controlled idle on a restart.
1. Lubricate a new O–ring with engine oil. Install the
new O–ring onto the valve.
2. Install the IAC valve into the throttle body.
3. Install the IAC valve retaining bolts.
Tighten
Tighten the idle air control valve retaining bolts to 3
NSm (27 lb–in).
4. Connect the IAC valve connector.
5. Install the air intake resonator.
6. Connect the negative battery cable.
7. Start the engine and check for the proper idle
speed.
MANIFOLD ABSOLUTE PRESSURE
SENSOR (1.4L/1.6L DOHC)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the manifold Absolute pressure (MAP)
sensor electrical connector.
3. Disconnect the MAP sensor vacuum hose.
4. Remove the MAP sensor bolt.
5. Remove the MAP sensor.

ENGINE CONTROLS 1F – 623
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
IGNITION SYSTEM OPERATION
This ignition system does not use a conventional distribu-
tor and coil. It uses a crankshaft position sensor input to
the engine control module (ECM). The ECM then deter-
mines Electronic Spark Timing (EST) and triggers the di-
rect ignition system ignition coil.
This type of distributorless ignition system uses a ”waste
spark” method of spark distribution. Each cylinder is
paired with the cylinder that is opposite it (1–4 or 2–3). The
spark occurs simultaneously in the cylinder coming up on
the compression stroke and in the cylinder coming up on
the exhaust stroke. The cylinder on the exhaust stroke re-
quires very little of the available energy to fire the spark
plug. The remaining energy is available to the spark plug
in the cylinder on the compression stroke.
These systems use the EST signal from the ECM to con-
trol the electronic spark timing. The ECM uses the follow-
ing information:
S Engine load (manifold pressure or vacuum).
S Atmospheric (barometric) pressure.
S Engine temperature.
S Intake air temperature.
S Crankshaft position.
S Engine speed (rpm).
ELECTRONIC IGNITION SYSTEM
IGNITION COIL
The Electronic Ignition (EI) system ignition coil provides
the spark for two spark plugs simultaneously. The EI sys-
tem ignition coil is not serviceable and must be replaced
as an assembly.
CRANKSHAFT POSITION SENSOR
This direct ignition system uses a magnetic crankshaft
position sensor. This sensor protrudes through its mount
to within approximately 0.05 inch (1.3 mm) of the crank-
shaft reluctor. The reluctor is a special wheel attached to
the crankshaft or crankshaft pulley with 58 slots machined
into it, 57 of which are equally spaced in 6 degree intervals.
The last slot is wider and serves to generate a ”sync
pulse.” As the crankshaft rotates, the slots in the reluctor
change the magnetic field of the sensor, creating an in-
duced voltage pulse. The longer pulse of the 58th slot
identifies a specific orientation of the crankshaft and al-
lows the engine control module (ECM) to determine the
crankshaft orientation at all times. The ECM uses this in-
formation to generate timed ignition and injection pulses
that it sends to the ignition coils and to the fuel injectors.
CAMAHAFT POSITION SENSOR
The Camshaft Position (CMP) sensor sends a CMP sen-
sor signal to the engine control module (ECM). The ECM
uses this signal as a ”sync pulse” to trigger the injectors in
the proper sequence. The ECM uses the CMP sensor sig-
nal to indicate the position of the #1 piston during its power
stroke. This allows the ECM to calculate true sequential
fuel injection mode of operation. If the ECM detects an in-
correct CMP sensor signal while the engine is running,
DTC P0341 will set. If the CMP sensor signal is lost while
the engine is running, the fuel injection system will shift to
a calculated sequential fuel injection mode based on the
last fuel injection pulse, and the engine will continue to run.
As long as the fault is present, the engine can be restarted.
It will run in the calculated sequential mode with a 1–in–6
chance of the injector sequence being correct.
IDLE AIR SYSTEM OPERATION
The idle air system operation is controlled by the base idle
setting of the throttle body and the Idle Air Control (IAC)
valve.
The engine control module (ECM) uses the IAC valve to
set the idle speed dependent on conditions. The ECM
uses information from various inputs, such as coolant tem-
perature, manifold vacuum, etc., for the effective control
of the idle speed.
FUEL CONTROL SYSTEM
OPERATION
The function of the fuel metering system is to deliver the
correct amount of fuel to the engine under all operating
conditions. The fuel is delivered to the engine by the indi-
vidual fuel injectors mounted into the intake manifold near
each cylinder.
The two main fuel control sensors are the Manifold Abso-
lute Pressure (MAP) sensor, the Front Heated Oxygen
Sensor (HO2S1) and the Rear Heated Oxygen Sensor
(HO2S2).
The MAP sensor measures or senses the intake manifold
vacuum. Under high fuel demands the MAP sensor reads
a low vacuum condition, such as wide open throttle. The
engine control module (ECM) uses this information to ri-
chen the mixture, thus increasing the fuel injector on–time,
to provide the correct amount of fuel. When decelerating,
the vacuum increases. This vacuum change is sensed by
the MAP sensor and read by the ECM, which then de-
creases the fuel injector on–time due to the low fuel de-
mand conditions.
HO2S Sensors
The HO2S sensor is located in the exhaust manifold. The
HO2S sensor indicates to the ECM the amount of oxygen
in the exhaust gas and the ECM changes the air/fuel ratio
to the engine by controlling the fuel injectors. The best air/
fuel ratio to minimize exhaust emissions is 14.7 to 1, which
allows the catalytic converter to operate most efficiently.

HYDRAULIC BRAKES 4A – 5
DAEWOO V–121 BL4
DIAGNOSIS
BRAKE SYSTEM TESTING
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake perfor-
mance cannot be made if the roadway is wet, greasy, or
covered with loose dirt whereby all tires do not grip the
road equally. Testing will also be adversely affected if the
roadway is crowned so as to throw the weight so roughly
that the wheels tend to bounce.
Test the brakes at different vehicle speeds with both light
and heavy pedal pressure; however, avoid locking the
brakes and sliding the tires. Locked brakes and sliding
tires do not indicate brake efficiency since heavily braked,
but turning, wheels will stop the vehicle in less distance
than locked brakes. More tire–to–road friction is present
with a heavily–braked, turning tire than with a sliding tire.
Because of the high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
There are three major external conditions that affect brake
performance:
S Tires having unequal contact and grip of the road
will cause unequal braking. Tires must be equally
inflated, and the tread pattern of the right and the
left tires must be approximately equal.
S Unequal loading of the vehicle can affect the brake
performance since the most heavily loaded wheels
require more braking power, and thus more braking
effort, than the others.
S Misalignment of the wheels, particularly conditions
of excessive camber and caster, will cause the
brakes to pull to one side.
To check for brake fluid leaks, hold constant foot pressure
on the pedal with the engine running at idle and the shift
lever in NEUTRAL. If the pedal gradually falls away with
the constant pressure, the hydraulic system may be leak-
ing. Perform a visual check to confirm any suspected
leaks.
Check the master cylinder fluid level. While a slight drop
in the reservoir level results from normal lining wear, an ab-
normally low level indicates a leak in the system. The hy-
draulic system may be leaking either internally or external-
ly. Refer to the procedure below to check the master
cylinder. Also, the system may appear to pass this test
while still having a slight leak. If the fluid level is normal,
check the vacuum booster pushrod length. If an incorrect
pushrod length is found, adjust or replace the rod.
Check the master cylinder using the following procedure:
S Check for a cracked master cylinder casting or
brake fluid leaking around the master cylinder.
Leaks are indicated only if there is at least one drop
of fluid. A damp condition is not abnormal.S Check for a binding pedal linkage and for an incor-
rect pushrod length. If both of these parts are in
satisfactory condition, disassemble the master cyl-
inder and check for an elongated or swollen primary
cylinder or piston seals. If swollen seals are found,
substandard or contaminated brake fluid should be
suspected. If contaminated brake fluid is found, all
the components should be disassembled and
cleaned, and all the rubber components should be
replaced. All of the pipes must also be flushed.
Improper brake fluid, or mineral oil or water in the fluid,
may cause the brake fluid to boil or cause deterioration of
the rubber components. If the primary piston cups in the
master cylinder are swollen, then the rubber parts have
deteriorated. This deterioration may also be evidenced by
swollen wheel cylinder piston seals on the drum brake
wheels.
If deterioration of rubber is evident, disassemble all the hy-
draulic parts and wash the parts with alcohol. Dry these
parts with compressed air before reassembly to keep alco-
hol out of the system. Replace all the rubber parts in the
system, including the hoses. Also, when working on the
brake mechanisms, check for fluid on the linings. If exces-
sive fluid is found, replace the linings.
If the master cylinder piston seals are in satisfactory condi-
tion, check for leaks or excessive heat conditions. If these
conditions are not found, drain the fluid, flush the master
cylinder with brake fluid, refill the master cylinder, and
bleed the system. Refer to ”Manual Bleeding the Brakes”
or”Pressure Bleeding the Brakes” in this section.
BRAKE HOSE INSPECTION
The hydraulic brake hoses should be inspected at least
twice a year. The brake hose assembly should be checked
for road hazard damage, cracks, chafing of the outer cov-
er, and for leaks or blisters. Inspect the hoses for proper
routing and mounting. A brake hose that rubs on a suspen-
sion component will wear and eventually fail. A light and
a mirror may be needed for an adequate inspection. If any
of the above conditions are observed on the brake hose,
adjust or replace the hose as necessary.
WARNING LAMP OPERATION
This brake system uses a BRAKE warning lamp located
in the instrument panel cluster. When the ignition switch
is in the START position, the BRAKE warning lamp should
glow and go OFF when the ignition switch returns to the
RUN position.
The following conditions will activate the BRAKE lamp:
S Parking brake applied. The light should be ON
whenever the parking brake is applied and the igni-
tion switch is ON.
S Low fluid level. A low fluid level in the master cylin-
der will turn the BRAKE lamp ON.
S EBD system is disabled. The light should be ON
when the EBD system is malfunctioning.

4A – 12IHYDRAULIC BRAKES
DAEWOO V–121 BL4
12. Slowly push and hold the brake pedal one time.
13. Remove the bleeder valve dust cover and loosen
the bleeder screw to purge the air from the cylinder.
14. Tighten the bleeder screw.
Tighten
Tighten the bleeder screw to 8 NSm (71 lb–in).
15. Slowly release the brake pedal. Wait 15 seconds
before proceeding with the next step.
Important : Rapid pumping of the brake pedal pushes the
master cylinder secondary piston down the bore in a man-
ner that makes it difficult to bleed the system.
16. Repeat the sequence, including the 15–second
wait, until all the air is removed. It may be neces-
sary to repeat the sequence 10 or more times to
remove all the air.
17. Locate the front bleeder caps.
18. Proceed to bleed the front brakes following the ap-
propriate sequence, beginning with step 12.
19. Check the brake pedal for sponginess. Repeat the
entire bleeding procedure to correct this condition.
20. Replace the bleeder valve dust cover.
PRESSURE BLEEDING THE BRAKES
Notice : Pressure bleeding equipment must be of the dia-
phragm type. It must have a rubber diaphragm between
the air supply and the brake fluid to prevent air, moisture,
oil, and other contaminants from entering the hydraulic
system. Contamination could lead to deterioration of the
braking components and loss of braking action.
1. Disconnect the master cylinder electrical connector.
2. Remove the master cylinder reservoir cap.
3. Connect the bleeder with the adapter to the master
cylinder reservoir.
4. For vehicles with the antilock braking system
(ABS), locate and remove the hydraulic modulator
bleeder valves. Refer to Section 4F, Antilock Brake
System.
5. Charge the bleeder ball to 140 to 172 kPa (20 to 25
psi).
6. Connect the line to the adapter. Open the line
valve.
7. Raise and suitably support the vehicle.
Important : The bleeding sequence is as follows: right
rear, left front, left rear and right front.

MASTER CYLINDER 4B – 9
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
MASTER CYLINDER
The master cylinder is designed for use in a diagonal–split
system. One front and one diagonally opposite rear brake
are served by the primary piston. The opposite front and
rear brakes are served by the secondary piston. The mas-
ter cylinder incorporates the functions of the standard dual
master cylinder, plus a low fluid level indicator and the pro-
portioning valves in the non–antilock braking system. The
proportioning valves limit the outlet pressure to the rear
brakes after a predetermined master cylinder pressure
has been reached.
Important :
S Replace all the components included in the repair
kits used to service this master cylinder.S Lubricate rubber parts with clean brake fluid to ease
assembly.
S Do not use lubricated shop air on brake parts, as
this may damage rubber components.
S If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of
the brake system.
S The torque values specified are for dry, unlubri-
cated fasteners.
S Perform all service operations on a clean bench,
free from all traces of mineral oil.
FLUID LEVEL SENSOR
The master cylinder is equipped with a fluid level sensor.
This sensor will activate the BRAKE light if a low fluid level
condition is detected. Once the fluid level is corrected, the
BRAKE light will go out.

5–164WELECTRICAL WIRING DIAGRAMS
4) WARNING (SSPS, AIR BAG, OIL PRESSURE & SEAT BELT) LAMP & HOLD MODE LAMP
CIRCUITa. CONNECTOR INFORMATION
CONNECTOR(NO.)
(PIN NO. COLOR)
CONNECTING, WIRING HARNESSCONNECTOR POSITION
C108 (24 Pin, Black)Body
EngineLeft Engine Fuse Block
C201 (76 Pin, Black)I.P
I.P Fuse BlockI.P Fuse Block
C202 (89 Pin, White)I.P
BodyLeft CO–Driver Leg Room
C206 (22 Pin, White)I.P
TCMUpper Driver Leg Room
C207 (6 Pin, White)Air Bag
I.PUpper Left Driver Leg Room
G301BodyBelow Driver Cross Member Floor Panel
b. CONNECTOR IDENTIFICATION SYMBOL & PIN NUMBER POSITION
J3B1P061

SECTION : 5A1
ZF 4 HP 16 AUTOMATIC TRANSAXLE
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 LOCK unless otherwise noted.
TABLE OF CONTENTS
INTRODUCTION5A1–3 . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZF 4HP 16 Automatic Transaxle 5A1–3. . . . . . . . . . . .
Transaxle Components 5A1–4. . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS5A1–5 . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 5A1–5. . . . . . . . . . . . . . . . . . . .
Transaxle Gear Ratio 5A1–5. . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 5A1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 5A1–5. . . . . . . . . .
Shift Speed Chart 5A1–7. . . . . . . . . . . . . . . . . . . . . . . . .
Line Pressure 5A1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS5A1–9 . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 5A1–9. . . . . . . . . . . . . . . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS5A1–11 . . .
Transaxle Control Module (1 of 2) 5A1–11. . . . . . . . . .
Transaxle Control Module (2 of 2) 5A1–12. . . . . . . . . .
Shift Mode Diagram 5A1–13. . . . . . . . . . . . . . . . . . . . . .
Power Flow Diagram 5A1–17. . . . . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR5A1–33 . . . . . . . . . . . . . . . . . .
Transaxle Identification Information 5A1–33. . . . . . . .
Torque Converter 5A1–34. . . . . . . . . . . . . . . . . . . . . . . .
Transaxle Housing 5A1–35. . . . . . . . . . . . . . . . . . . . . . .
Oil Pump 5A1–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Cover & Oil Pan Cover 5A1–37. . . . . . . . . . . . . .
Parking Lever 5A1–38. . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Shaft & Shift Gear 5A1–39. . . . . . . . . . . . . . . . . .
Valve Body 5A1–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear Shift Control 5A1–42. . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSTIC INFORMATION AND PROCEDURES
DIAGNOSIS5A1–43 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge Required 5A1–43. . . . . . . . . . . . . . . .
Functional Check Procedure 5A1–43. . . . . . . . . . . . . .
Line Pressure Check Procedure 5A1–43. . . . . . . . . . .
Clutch Plate Diagnosis 5A1–45. . . . . . . . . . . . . . . . . . .
Cooler Flushing and Flow Test 5A1–45. . . . . . . . . . . . . Transaxle Fluid Level Service Procedure 5A1–45. . . .
Electrical/Garage Shift Test 5A1–47. . . . . . . . . . . . . . .
Road Test Procedure 5A1–47. . . . . . . . . . . . . . . . . . . . .
Torque Converter Lock–Up Clutch(TCC)
Diagnosis 5A1–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TCM Initialization Procedure 5A1–50. . . . . . . . . . . . . .
Shift Speed Chart 5A1–51. . . . . . . . . . . . . . . . . . . . . . . .
Internal Wiring Harness Check 5A1–51. . . . . . . . . . . .
Transaxle Wiring Harness Connector 5A1–54. . . . . . .
Symptom Diagnosis 5A1–56. . . . . . . . . . . . . . . . . . . . . .
DIAGNOSTIC TROUBLE CODE DIAGNOSIS5A1–60
Diagnostic Trouble Code (DTC) Identification 5A1–60
DTC P0562 – System Voltage Low 5A1–68. . . . . . . . .
DTC P0563 – System Voltage High 5A1–71. . . . . . . .
DTC P0601 – Internal Control Module Memory
Checksum Error 5A1–74. . . . . . . . . . . . . . . . . . . . . . .
DTC P0603 – Internal Control Module Keep
Alive Memory(KAM) Error 5A1–76. . . . . . . . . . . . . . .
DTC P0604 – Internal Control Module Random
Access Memory(RAM) Error 5A1–78. . . . . . . . . . . . .
DTC P0606 – Transaxle Control Module
Processor Fault 5A1–80. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0703 – Brake Switch Circuit
Malfunction 5A1–83. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0705 – Transmission Range Sensor
Circuit Malfunction(PRNDL Input) 5A1–86. . . . . . . .
DTC P0710 – Transmission Fluid Temperature
Sensor Circuit Malfunction 5A1–89. . . . . . . . . . . . . .
DTC P0715 – Input Speed Sensor(ISS) Circuit
Malfunction 5A1–92. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0716 – Input Speed Sensor(ISS) Circuit
Range/Performance 5A1–95. . . . . . . . . . . . . . . . . . . .
DTC P0717 – Input Speed Sensor(ISS) Circuit
No Signal 5A1–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0720 – Output Speed Sensor(OSS)
Circuit Malfunction 5A1–101. . . . . . . . . . . . . . . . . . . .
DTC P0721 – Output Speed Sensor(OSS)
Circuit Range/Performance 5A1–104. . . . . . . . . . . . .

5A1 – 6IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Application Lb–InLb–Ft NSm
Fluid Level Plug4533–
Line Pleasure Plugs2015–
Valve Housing 1 Cover Attachment Bolts6–53
Solenoid Valve Attachment Bolts6–53
Pressure Control Regulator(EDS) Attachment Bolts6–53
Oil Cooler Inlet Pipe Bolts3526–
Oil Cooler Outlet Pipe Bolts3526–
Shift Control Cable Adjuster Pinch Nut8–71
Shift Control Cable Attachment Nut8–71
Upper Transaxle–to–Engine Bolts7555–
Selector Lever(On Transaxle Case)1511–
Torque Converter Attachment Bolts4533–
Shift Control Assembly Mounting Bolt, Nut8–71
Lower Engine–to–Transaxle Bolts(a)7555–
Lower Engine–to–Transaxle Bolt(b)2115–
Lower Engine–to–Transaxle Bolts(c)3123–
Rear Transaxle Mounting Bracket Bolts6245–
Damping Block Connection Bolt and Nut6850–
Left Transaxle Mount Bracket Cage Bolt(a)11 081–
Left Transaxle Mount Bracket Cage Bolt(b)6548–
Left Transaxle Mount Bracket Cage Nut(c)6548–
Left Transaxle Mounting Bolts4835–

5A1 – 18IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Park/Neutral
In Park or Neutral with the engine running there is no drive
to the planetary gear set. Line pressure (from the oil pump)
is supplied to the valve body. Only clutch B is supplied and
the torque converter is released.
Control
Line Pressure Control Valve
The line pressure control valve sets the general pressure
level in the valve body. When gearshifts are not taking
place, the line pressure varies between two levels, de-
pending on the turbine torque. Line pressure increase lin-
early by time. But it has a limit point. When pressure reach-
es that point, excess oil pressure drains back into the oil
sump.
Reduction Valve
The reduction valve reduces the line pressure with which
the downstream solenoid valves and pressure control so-
lenoid valves (EDS) are supplied. This makes it possible
to use smaller solenoid valves.
The line pressure comes from the oil pump and flows to the
reduction valve. The inlet port to the reduction valve will be
blocked and line pressure will be maintained at the ap-
propriate level.
Solenoid Valve 1, 2
Solenoid Valve 1 controls the line pressure (high and low)
to the clutch valves. Solenoid Valve 1 is either ON or OFF.
When the solenoid is turned ON the line pressure will be
low [87~116psi (6~8bar)].When the solenoid is turned
OFF the line pressure will be high [232~261psi
(16~18bar)].
Solenoid 2 controls the fluid flow to clutch valve E or the
TCC clutch valve. When solenoid 2 is ON fluid is directed
to the TCC pressure valve and if the solenoid is switched
OFF fluid will flow to the inlet at clutch valve E.The TCM monitors numerous inputs to determine the ap-
propriate solenoid state combination and transaxle gear
for the vehicle operating conditions.
In Park and Neutral solenoid valve 1 is ON. So line pres-
sure flows to the safety valve and the line pressure control
valve via the solenoid valve.
Clutch B Engaged
In Park and Neutral solenoid valves 1 and 2 are both ON.
Pressure control solenoids (EDS) 4 and 6 are also turned
ON.
When EDS 6 is ON, the fluid supplied from the reduction
valve flows to the safety valve, clutch valve B and holding
valve B. The oil that is supplied to the inlet port of the clutch
valve presses on the valve spool. Line pressure then flows
to the holding valve and check ball, engaging clutch B.
Lock–up Clutch (TCC)
Solenoid 2 is turned ON and the line pressure control
valves spool will be depressed. Fluid will now flow through
the torque converter pressure valve.
As a result, the oil pressure behind the converter lock–up
clutch piston and in the turbine zone is equal. The direction
of flow is through the turbine shaft and through the space
behind the piston, to the turbine chamber.
Lubrication/Cooling.
The lubricating valve ensures that the converter is sup-
plied with cooling oil first if the pump rate is low. The lubri-
cating pressure valve in addition guarantees that the nec-
essary amount of cooling and lubricating oil is available via
the bypass duct.
The fluid, which is supplied from the torque converter,
flows to the cooler via the lubrication valve.