2004 DAEWOO LACETTI Gear

5A1 – 234IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Shift Elements: Multi–disc Clutches and
Brakes
The purpose of the shift elements is to perform shifts un-
der load without the tractive flow being interrupted.
The shift elements consist of the following.
1. Snap Ring
2. Steel Disc
3. Lined Disc
4. Cup Spring
5. Baffle Plate
6. Disc Carrier
7. Input Shaft
8. Oil Supply to Dynamic Pressure Equalizer
9. Oil Supply to Clutch
10. Cylinder
11. Piston
12. Spring Disc
The shift elements are engaged hydraulically. The pres-
surized oil reaches the space between the cylinder and
piston, as a result the discs are compressed. The clutch/
brake is engaged when the oil pressure drops, the cup
spring acting on the piston presses the piston back into its
initial position. The clutch/brake is now released again.
Depending on the gear, the multi–disc clutches B and E
supply the engine torque to the planetary gear train, with
multi–disc brakes C, D and F directing the torque into the
housing.The dynamic pressure at clutches B and E is equal : i.e.
the dynamic pressure in front of and behind the piston is
equal. This equalizing effect is achieved in the following
way.
The space between the baffle plate and piston is filled with
unpressurized oil. A dynamic pressure dependent on the
engine speed builds up. The space between pressure also
builds up. However, there is simultaneously a static pres-
sure, which causes the clutch to engage. If the static pres-
sure is relieved, the cup spring is able to force the piston
back into its original position.
The advantages of this dynamic pressure equalization
are:
S Reliable clutch opening in all speed ranges
S Smoother shifts.
Parking Lock
The parking lock is actuated via the selector lever when in
position P. It protects the vehicle mechanically against roll-
ing away.
The stop plate is actuated by the selector shaft, which is
permanently connected to the selector lever via a pull
cable. The parking lock pawl on the parking lock gear is
welded onto the lateral shaft of the transaxle and this pre-
vents the drive wheels from turning.
This blocks the driven wheels.
1. Pawl
2. Supporting Bolt
3. Leg Spring

5A1 – 236IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
ELECTRONICAL COMPONENTS
Selector Lever/Program Switch
The driver engages the travel position via the selector le-
ver:
P : Park Position
R : Reverse
N : Neutral
D : Forward Speeds
Park/Neutral Position Switch
The Park/Neutral Position Switch is located on the selec-
tor shaft and informs the TCM of the current selector lever
position P–R–N–D–3–2–1.
The selector lever position is transmitted to the TCM in en-
coded form along 4 lines. The encoding is such that mal-
functions in the connecting lead are identified.
The Park/Neutral Position Switch is located on the selec-
tor shaft, which is connected to the selector lever via a pull
cable. In addition, the Park/Neutral Position Switch con-
trols the starter interlock, the reversing light and the selec-
tor lever position indicator on the instrument panel.
Signal Combination
L1L2L3L4
P00120
R00012
N01200
D1212120
31212012
21201212
10121212
Automatic Transaxle Output Speed Sensor
(A/T OSS)
The vehicle A/T OSS is a magnetic inductive pickup that
relays information relative to vehicle speed to the TCM.
Vehicle speed information is used by the TCM to control
shift timing, line pressure, and TCC (lock–up clutch) apply
and release.
The output speed sensor mounts in the case at the speed
sensor rotor, which is pressed onto the spur gear. An air
gap of 0.1mm~1.3mm(0.004~0.05in) is maintained be-
tween the sensor and the teeth on the spur gear teeth. The
sensor consists of a permanent magnet surrounded by a
coil of wire.
As the differential rotates, an AC signal is generated by the
output speed sensor (OSS).
Automatic Transaxle Input Speed Sensor
(A/T ISS)
The A/T ISS is a magnetic inductive pickup that relays in-
formation relative to transaxle input speed to the TCM.
The TCM uses transaxle input speed information to con-
trol line pressure, TCC apply and release and transaxle
shift patterns. This information is also uses to calculate the
appropriate operating gear ratios and TCC slippage.
The input speed sensor mounts onto piston B that is inside
of valve body.
An air gap of 1.8~2.2mm(0.07~0.086inch) is maintained
between the sensor and the piston B.
The sensor consists of a permanent magnet surrounded
by a coil of wire. As the piston B is driven by the turbine
shaft, an AC signal induced in the input speed sensor.
Higher vehicle speeds induce a higher frequency and volt-
age measurement at the sensor.
Sensor resistance should measure between 825~835
ohms at 20°C (68°F). Sensor can measure from
1,000~8,000HZ.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 237
DAEWOO V–121 BL4
Shift Solenoid Valve: Solenoid 1,2
The shift solenoids are two identical, normally open elec-
tronic exhaust work that control upshifts and downshifts in
all forward gear ranges. These shift solenoids valves to-
gether in a combination of ON and OFF sequences to con-
trol the line pressure and shift mechanisms (clutches,
brakes).
Solenoid 1 controls the high or low of the line pressure
(flow to each clutch valve) by the operation type (ON/
OFF), i.e. solenoid 1is ON, line pressure will be low
(87~116 psi (6~8bar)), solenoid 1 is OFF, line pressure will
be high (232~261 psi (16~18bar)).
Solenoid 2 controls the oil flow to clutch valve E or lockup
clutch valve by the ON/OFF signal.
The TCM monitors numerous inputs to determine the ap-
propriate solenoid state combination and transaxle gear
for the vehicle operating conditions.
Gear
Solenoid 1Solenoid 2
Park, NeutralONON
FirstON/OFFON
SecondON/OFFOFF
ThirdON/OFFOFF
FourthON/OFFOFF
ReverseON/OFFON
Line PressureResistance
Solenoid
valve 1/Sole-
noid valve 2ON(low)
89.9~98.6 psi
(6.2~6.8 bar)
OFF(high)
S 221.9~253.24
psi
S (15.3~17.46
bar)26.5 ± 0.5ohm
Pressure Control Solenoid Valve (EDS
VALVE 3,4,5,6)
The pressure control valve (EDS valve 3,4,5,6) is a preci-
sion electronic pressure regulator that controls the opera-
tion of the clutches, brakes and the lock–up clutch.
The valve reduces the system pressure with which the
downstream solenoid valves and electrical pressure regu-
lating valves are supplied. It is possible to use smaller so-
lenoid valves as a result. The EDS require a constant input
pressure.

5A1 – 238IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Transaxle Fluid Temperature (TFT) Sensor
The TFT sensor is a positive temperature coefficient
thermistor (temperature sensitive resistor) that provides
information to the TCM regarding transaxle fluid tempera-
ture. The temperature sensor is located in valve body. Cal-
culated temperature is a factor used to determine the shift
time and shift delay time.
The internal electrical resistance of the sensor varies in
relation to the operating temperature of the transaxle fluid
(see chart).
The TCM sends a 5 volt–reference signal to the tempera-
ture sensor and measures the voltage rise in the electrical
circuit. A higher fluid temperature creates a higher resist-
ance in the temperature sensor, thereby measuring a low-
er voltage signal.
The TCM measures this voltage as another input to help
control line pressure, shift schedules and TCC apply.
When transaxle fluid temperature reaches 140°C (284°F)
the TCM enters ”hot mode.” Above this temperature the
TCM modifies transaxle shift schedules and TCC apply in
an attempt to reduce fluid temperature by reducing trans-
axle heat generation. During hot mode the TCM applies
the TCC at all times in fourth gear.
Also, the TCM commands the 2–3 and 3–4 shifts earlier
to help reduce fluid heat generation. Hot mode may not be
available on some applications.
Transaxle Sensor – Temperature To
Resistance To Voltage (approximate)
°C (°F)R high (ohms)R low (ohms)°C (°F)R high (ohms)R low (ohms)
–40 (–40)58655650 (122)1,2061,173
–30 (–22)64161160 (146)1,2951,256
–20 (–4)69967070 (158)1,3881,341
–10 (14)76073280 (176)1,4851,430
0 (32)82579990 (194)1,5851,522
10 (50)893868100 (212)1,6901,617
20 (68)963942110 (230)1,7981,715
25 (77)1,000980120 (248)1,9101,816
30 (86)1,0391,017130 (266)2,0251,920
140 (284)2,1452,027
Transaxle Electrical Connector
The transaxle electrical connector is a very important part
of the transaxle operating system. Any interference with
the electrical connection can cause the transaxle to set
Diagnostic Trouble Codes (DTCs) and/or affect proper op-
eration.
The following items can affect the electrical connections:S Bent pins in the connector from rough handling dur-
ing connection and disconnection.
S Wires backing away from the pins or coming un-
clamped (in either internal or external wiring har-
ness).
S Dirt contamination entering the connector when dis-
connected.
S Pins in the internal wiring connector backing out of
the connector or pushed out during reconnection.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 241
DAEWOO V–121 BL4
TCM INPUTS THAT AFFECT THE 4HP
16 TRANSAXLE
Throttle Position Sensor
S Provides throttle position data to the TCM for deter-
mining shift patterns and TCC apply/release.
S An incorrect throttle position sensor input could
causes erratic or shift pattern, poor shift quality or
TCC function
Automatic Transaxle Output (Shaft) Speed
Sensor
S Provides vehicle speed data to the TCM for deter-
mining shift patterns and TCC apply/release, and
gear ratio calculations.
S An incorrect throttle position sensor input could
causes erratic or shift pattern, poor shift quality or
TCC function
Automatic Transaxle Input (Shaft) Speed
Sensor
S Provides transaxle input speed data to the TCM for
determining shift patterns and TCC apply/release,
and gear ratio.
Engine Coolant Temperature Sensor
S Provides coolant temperature data to the TCM for
determining initial TCC engagement.
S An incorrect engine coolant temperature sensor
input could causes an incorrect initial TCC apply
Engine Speed
S The ignition module provides engine speed data the
TCM.
S The TCM uses engine speed information for con-
trolling wide open throttle shifts and the TCC PWM
solenoid duty cycle.
Stoplamp Switch
S Provides brake apply information to the TCM for
controlling TCC apply and release.
S An incorrect TCC stoplamp switch input could
causes an incorrect TCC apply or release.
Transaxle Fluid Temperature (TFT) Sensor
S Provides transaxle fluid temperature information to
the TCM for determining alternate shift patterns and
TCC apply during high temperature conditions (hot
mode operation).
S An incorrect transaxle temperature sensor input
could causes altered shift patterns, poor shift quali-
ty and incorrect TCC apply.

SECTION : 5A2
AISIN 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 erminals. 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
SPECIFICATIONS5A2–3 . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 5A2–3. . . . . . . . . . . . . . . . . . . .
Transaxle Gear Ratio 5A2–3. . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 5A2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Line Pressure Specification 5A2–3. . . . . . . . . . . . . . . .
Fastener Tightening Specifications 5A2–4. . . . . . . . . .
SPECIAL TOOLS5A2–5 . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 5A2–5. . . . . . . . . . . . . . . . . . . . . . .
SCHEMATIC DIAGRAMS5A2–8 . . . . . . . . . . . . . . . . . . .
Transmission Control Module (1 of 4) 5A2–8. . . . . . . .
Transmission Control Module (2 of 4) 5A2–9. . . . . . . .
Transmission Control Module (3 of 4) 5A2–10. . . . . . .
Transmission Control Module (4 of 4) 5A2–11. . . . . . .
Shift Mode Diagram 5A2–12. . . . . . . . . . . . . . . . . . . . . .
COMPONENT LOCATOR5A2–17 . . . . . . . . . . . . . . . . . .
Shift Select Control 5A2–17. . . . . . . . . . . . . . . . . . . . . .
Automatic Transaxle Components 5A2–18. . . . . . . . .
Bearing and Races Installation Position
Direction 5A2–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS5A2–25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Connector View 5A2–25. . . . . . . . . . . . . . . . .
Wiring Harness and Connector Inspection 5A2–27. . .
Road Test 5A2–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Function Check 5A2–28. . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Inspection 5A2–30. . . . . . . . . . . . . . . . . . . . . . . . . .
On–Vehicle Repair (Matrix Chart) 5A2–34. . . . . . . . . .
DIAGNOSIS TROUBLE CODE DIAGNOSIS5A2–36 .
Diagnosis Trouble Code Chart 5A2–36. . . . . . . . . . . . .
DTC P0562 System Voltage Low 5A2–37. . . . . . . . . .
DTC P0563 System Voltage High 5A2–40. . . . . . . . . .
DTC P0601 Internal Control Module Memory
Checksum Error 5A2–43. . . . . . . . . . . . . . . . . . . . . . .
DTC P0604 Internal Transmission Control Module
(TCM) Random Access Memory (RAM)
Error 5A2–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DTC P0705 Transmission Range (TR) Switch
Circuit Malfunction 5A2–47. . . . . . . . . . . . . . . . . . . . .
DTC P0712 Transmission Fluid Temperature
(TFT) Sensor Circuit Low Input 5A2–50. . . . . . . . . .
DTC P0713 Transmission Fluid Temperature
(TFT) Sensor Circuit High Input 5A2–53. . . . . . . . . .
DTC P0717 Input Shaft Speed (ISS) Sensor
Circuit No Signal 5A2–56. . . . . . . . . . . . . . . . . . . . . . .
DTC P0722 Ouput Shaft Speed (OSS) Sensor
Circuit No Signal 5A2–59. . . . . . . . . . . . . . . . . . . . . . .
DTC P0727 Engine Speed Input Circuit No
Signal 5A2–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0741 Torque Converter Clutch (TCC)
Circuit Stuck Off 5A2–65. . . . . . . . . . . . . . . . . . . . . . .
DTC P0742 Torque Converter Clutch (TCC)
Circuit Stuck On 5A2–67. . . . . . . . . . . . . . . . . . . . . . .
DTC P0743 Torque Converter Clutch (TCC)
Electrical 5A2–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0748 Pressure Control Solenoid (PCS)
Electrical 5A2–72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0751 Shift Solenoid 1 (SS1) Stuck Off 5A2–75
DTC P0753 Shift Solenoid 1 (SS1) Electrical 5A2–77
DTC P0756 Shift Solenoid 2 (SS2) Stuck Off 5A2–80
DTC P0758 Shift Solenoid 2 (SS2) Electrical 5A2–82
DTC P0785 Timing Solenoid (ST) Electrical 5A2–85.
DTC P1781 Engine Torque Signal Error 5A2–88. . . . .
DTC P1791 Throttle Position Signal Error 5A2–91. . .
DTC P1792 Engine Coolant Temperature (ECT)
Signal Error 5A2–93. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC U2105 Can Error 5A2–95. . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR5A2–97 . . . . . . . . . . . . .
ON–VEHICLE SERVICE 5A2–97. . . . . . . . . . . . . . . . . . .
Transaxle Fluid Level Checking Procedure 5A2–97. .
Fluid Drain Procedure 5A2–97. . . . . . . . . . . . . . . . . . . .
Locating Fluid Leaks 5A2–98. . . . . . . . . . . . . . . . . . . . .
Case Porosity Repair 5A2–98. . . . . . . . . . . . . . . . . . . . .
Fluid Cooler Flushing 5A2–99. . . . . . . . . . . . . . . . . . . . .
Control Cable Adjustment 5A2–99. . . . . . . . . . . . . . . . .

5A2 – 2IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Shift Control Lever Assembly 5A2–100. . . . . . . . . . . . .
Transmission Range (TR) Switch 5A2–101. . . . . . . . .
Shift Control Cable 5A2–104. . . . . . . . . . . . . . . . . . . . . .
Shift Select Cover 5A2–105. . . . . . . . . . . . . . . . . . . . . .
Input Shaft Speed (ISS) Sensor 5A2–106. . . . . . . . . .
Output Shaft Speed (OSS) Sensor 5A2–107. . . . . . . .
Transmission Control Module (TCM) 5A2–108. . . . . .
Fluid Cooler Inlet Pipes and Hoses 5A2–109. . . . . . . .
Fluid Cooler Outlet Pipes and Hoses 5A2–110. . . . . .
Transaxle Assembly 5A2–111. . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 5A2–117. . . . . . . . . . . . . . . . . . . . . . . . . . .
Major Component Disassembly 5A2–117. . . . . . . . . . .
Major Component Assembly 5A2–137. . . . . . . . . . . . .
Oil Pump 5A2–167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Clutch 5A2–171. . . . . . . . . . . . . . . . . . . . . . . . . . .
Planetary Ring Gear 5A2–178. . . . . . . . . . . . . . . . . . . .
One–Way Clutch 5A2–180. . . . . . . . . . . . . . . . . . . . . . .
Forward and Reverse Clutch 5A2–183. . . . . . . . . . . . .
Counter Driven Gear 5A2–192. . . . . . . . . . . . . . . . . . . .
Valve Body 5A2–195. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Case 5A2–208. . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION5A2–218 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transaxle Description 5A2–218. . . . . . . . . . . . . . . . . . .
Electronical Components 5A2–218. . . . . . . . . . . . . . . .
Hydraulic Control System 5A2–221. . . . . . . . . . . . . . . .
Automatic Transaxle System 5A2–222. . . . . . . . . . . . .

AISIN AUTOMATIC TRANSAXLE 5A2 – 3
DAEWOO V–121 BL4
SPECIFICATIONS
GENERAL SPECIFICATIONS
Definition
1.6 DOHC
Transaxle Fluid TypeISU DEXRON III or ESSO JWS 3309
Transaxle Fluid Capacity5.77L (6.1 qts)
TRANSAXLE GEAR RATIO
GearRatio
1.6 DOHC
First2.875
Second1.568
Third1.000
Fourth0.697
Reverse2.300
Counter1.020
Differential3.750
FLUID CAPACITY
Capacity
1.6 DOHC
Transaxle Fluid (dry fill)5.77L (6.1 qts)
Transaxle Fluid (drain and refill)2.1L (2.2 qts)
Notice : Fluid capacity (drain and refill) could be changed according to the some condition, therefore be sure to check
the fluid using the oil stick guage.
LINE PRESSURE SPECIFICATION
ApplicationIdlingStall
At ”D” range3.9–4.2 kg/cm2 (55–60 psi)11.3–12.5 kg/cm2 (161–178 psi)
At ”R” range6.0–6.9 kg/cm2 (85–98 psi)16.2–18.6 kg/cm2 (230–265 psi)