check engine DAEWOO NUBIRA 2004 Service Repair Manual

5A1 – 2IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0722 – Output Speed Sensor(OSS)
Circuit No Signal 5A1–107. . . . . . . . . . . . . . . . . . . . . .
DTC P0725 – Engine Speed Input Circuit
Malfunction 5A1–110. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0726 – Engine Speed Input Circuit
Range/Performance 5A1–112. . . . . . . . . . . . . . . . . . .
DTC P0727 – Engine Speed Input Circuit No
Signal 5A1–114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0731 – Gear 1 Incorrect Ratio 5A1–116. . . . . .
DTC P0732 – Gear 2 Incorrect Ratio 5A1–118. . . . . .
DTC P0733 – Gear 3 Incorrect Ratio 5A1–120. . . . . .
DTC P0734 – Gear 4 Incorrect Ratio 5A1–122. . . . . .
DTC P0781 – 1–2 Shift Malfunction 5A1–124. . . . . . .
DTC P0782 – 2–3 Shift Malfunction 5A1–126. . . . . . .
DTC P0783 – 3–4 Shift Malfunction 5A1–128. . . . . . .
DTC P1604 – Data Check of Internal &
Extended Ram Failed 5A1–130. . . . . . . . . . . . . . . . . .
DTC P1606 – Failure Of External Watchdog 5A1–132
DTC P1671 – CAN Transmit Message
Failure 5A1–134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1672 – CAN Bus Off Failure 5A1–136. . . . . . . .
DTC P1673 – CAN Receive ECM Message
Failure 5A1–138. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1839 – EDS 3 Output Shorted To
Ground 5A1–140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1840 – EDS 3 Output Shorted To
Power 5A1–142. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1841 – EDS 3 Output Open 5A1–144. . . . . . . .
DTC P1850 – Solenoid 1 Output Shorted To
Ground 5A1–146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1851 – Solenoid 1 Output Shorted To
Power 5A1–148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1852 – Solenoid 1 Output Open 5A1–150. . . .
DTC P1853 – Solenoid 2 Output Shorted To
Ground 5A1–152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1854 – Solenoid 2 Output Shorted To
Power 5A1–154. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1855 – Solenoid 2 Output Open 5A1–156. . . .
DTC P1861 – EDS 4 Output Shorted To
Ground 5A1–158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1862 – EDS 4 Output Shorted To
Power 5A1–160. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1863 – EDS 4 Output Open 5A1–162. . . . . . . .
DTC P1864 – EDS 5 Output Shorted To
Ground 5A1–164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1865 – EDS 5 Output Shorted To
Power 5A1–166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1866 – EDS 5 Output Open 5A1–168. . . . . . . .
DTC P1867 – EDS 6 Output Shorted To
Ground 5A1–170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DTC P1868 – EDS 6 Output Shorted To
Power 5A1–172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1869 – EDS 6 Output Open 5A1–174. . . . . . . .
DTC P1871 – EDS Valve Power Supply
Circuit Shorted to Power 5A1–176. . . . . . . . . . . . . . .
DTC P1874 – Solenoid Valve Power Supply
Circuit Shorted to Power 5A1–178. . . . . . . . . . . . . . .
DTC P1881 – 2–1 Shift Malfunction 5A1–180. . . . . . .
DTC P1883 – 3–2 Shift Malfunction 5A1–182. . . . . . .
DTC P1884 – 4–3 Shift Malfunction 5A1–184. . . . . . .
DTC P1885 – 3–1 Shift Malfunction 5A1–186. . . . . . .
DTC P1886 – 4–2 Shift Malfunction 5A1–188. . . . . . .
MAINTENANCE AND REPAIR5A1–190 . . . . . . . . . . . .
ON–VEHICLE SERVICE 5A1–190. . . . . . . . . . . . . . . . . .
Transaxle Fluid Level Checking Procedure 5A1–190.
Changing the Fluid 5A1–191. . . . . . . . . . . . . . . . . . . . . .
Fluid Level Set After Service 5A1–192. . . . . . . . . . . . .
Repairing Fluid Leaks 5A1–192. . . . . . . . . . . . . . . . . . .
Case Porosity Repair 5A1–193. . . . . . . . . . . . . . . . . . . .
Shift Control Lever Assembly 5A1–193. . . . . . . . . . . . .
Shift Control Cable 5A1–195. . . . . . . . . . . . . . . . . . . . . .
Shift Control Cable Adjustment 5A1–196. . . . . . . . . . .
Transaxle Control Module(TCM) 5A1–197. . . . . . . . . .
Park/Neutral Start Switch 5A1–198. . . . . . . . . . . . . . . .
Oil Cooler Pipes/Hoses 5A1–199. . . . . . . . . . . . . . . . . .
Drive Axle Oil Seal 5A1–201. . . . . . . . . . . . . . . . . . . . . .
Oil Pan, Oil Pan Gasket 5A1–201. . . . . . . . . . . . . . . . .
Control Valve Body Assembly 5A1–203. . . . . . . . . . . .
Left Transaxle Mounting Bracket 5A1–205. . . . . . . . . .
Transaxle Assembly 5A1–206. . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 5A1–212. . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque Converter 5A1–212. . . . . . . . . . . . . . . . . . . . . . .
Transaxle Holding Fixture Assembly 5A1–212. . . . . . .
Valve Body 5A1–212. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Cover 5A1–213. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch B/E 5A1–214. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch B/E Measurement Procedure 5A1–217. . . . . .
Planetary Gear Set 5A1–220. . . . . . . . . . . . . . . . . . . . .
Brake C/D 5A1–221. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential 5A1–224. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Side Shaft 5A1–224. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake F, Slotted Nut 5A1–225. . . . . . . . . . . . . . . . . . . . .
Torque Converter Housing 5A1–227. . . . . . . . . . . . . . .
Shift Mechanism 5A1–228. . . . . . . . . . . . . . . . . . . . . . . .
Parking Lock System 5A1–229. . . . . . . . . . . . . . . . . . . .
Bearing Plate(With Spur Gear) Assembly 5A1–229. .
Oil Pump Assembly 5A1–229. . . . . . . . . . . . . . . . . . . . .
Differential/Side Shaft Outer Race, Bearing
Shim 5A1–230. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 43
DAEWOO V–121 BL4
DIAGNOSTIC INFORMATION AND
PROCEDURES DIAGNOSIS
BASIC KNOWLEDGE REQUIRED
You must be familiar with some basic electronics to use
this section of the Service Manual. They will help you to
follow diagnostic procedures.
Notice : Lack of the basic knowledge of this transaxle
when performing diagnostic procedures could result in in-
correct diagnostic performance or damage to transaxle
components.
Do not, under any circumstances, attempt to diagnose a
transaxle problem without this basic knowledge.
Notice : If a wire is probed with a sharp instrument and not
properly sealed afterward, the wire will corrode and an
open circuit will result.
Diagnostic test probes are now available that allow you to
probe individual wires without leaving the wire open to the
environment. These probe devices are inexpensive and
easy to install, and they permanently seal the wire from
corrosion.
Special Tools
You should be able to use a Digital Volt Meter (DVM), a cir-
cuit tester, jumper wires or leads and a line pressure gauge
set.
The functional check procedure is designed to verify the
correct operation of electronic components in the trans-
axle.
This will eliminate the unnecessary removal of transaxle
components.
FUNCTIONAL CHECK PROCEDURE
Begin with the Functional Check Procedure which pro-
vides a general outline of how to diagnose automatic
transaxle. The following functional check procedure will in-
dicate the proper path of diagnosing the transaxle by de-
scribing the basic checks and then referencing the loca-
tions of the specific checks.
S Check the fluid level according to the Fluid Level
Service Procedure.
S Check the transaxle for fluid leaks.
S Check if the transaxle fluid is not burnt by color and
smell.
S Ensure that the transaxle is not in Limp Home
Mode(LHM).
S Check the battery terminals and the ground con-
nections for corrosion or looseness.
S Check that the cooler flow is not restricted.S Check all electrical connections for tightness.
S Use on–board diagnostic tool or a scan tool to see
if any transaxle trouble codes have been set. Refer
to the appropriate ”Diagnostic Trouble Code (DTC)”
information and repair the vehicle as directed. After
repairing the vehicle, perform the road test and
verify that the code has not set again.
S Perform the Electrical/Garage Shift Tests.
S Perform the Road Test Procedure in this section.
S Inspect the oil and check for metal or other contam-
inants in the oil pan.
LINE PRESSURE CHECK
PROCEDURE
The 4HP 16 A/T uses a trochoid type oil pump to produce
hydraulic pressure, and a pressure control solenoid (sole-
noid 1) to control that pressure at the pressure regulator
valve, after it leaves the pump. The transaxle pressure
control solenoid is controlled by an electrical signal that
ranges from 0 to 12 volts corresponds to minimum line
pressure (approx. 89.9 to 124.7 psi (6.2 to 8.6 bar)) and
0 volt corresponds to a maximum line pressure (approx.
221.9 to 252.4 psi (15.3 to 17.4 bar)) in all range.
Line pressures are calculated for two sets of gear ranges
– Drive–Park–Neutral and Reverse. This allow the trans-
axle line pressure to be appropriate for different pressure
needs in different gear ranges:
Gear
Range
Solenoid
1RPMPressure
Drive,
ReverseOff2,500221.9~252.4psi
(15.3~17.4 bar)
On2,50017.4~269.8psi
(1.2~18.6 bar)
Neutral,
ParkOff2,500221.9~252.4psi
(15.3~17.4 bar)
On2,50089.9~269.8 psi
(6.2~18.6 bar)
Before performing a line pressure check, verify that the
pressure control solenoid is receiving the correct electrical
signal from the TCM:
1. Install a scan tool.
2. Start the engine and set parking brake.
3. Check for a stored pressure control solenoid diag-
nostic trouble code, and other diagnostic trouble
codes.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 45
DAEWOO V–121 BL4
CLUTCH PLATE DIAGNOSIS
Composition Plates
Dry the plate and inspect the plates for the following condi-
tions :
S Pitting
S Flaking
S Wear
S Glazing
S Cracking
S Charring
Chips or metal particles embedded in the lining
Replace a composition plate which shows any of these
conditions.
Steel Plates
Wipe the plates dry and check the plates for heat discolor-
ation. If the surfaces are smooth, even if colorsmear is in-
dicated, you can reuse the plate. If the plate is discolored
with hot spots or if the surface is scuffed, replace the plate.
Important : If the clutch shows evidence or extreme heat
or burning, replace the springs.
Causes of Burned Clutch Plates
The following conditions can result in a burned clutch
plate:
S Incorrect usage of clutch plates.
S Engine coolant in the transaxle fluid.
S A cracked clutch piston.
S Damaged or missing seals.
S Low line pressure.
S Valve problems.
– The valve body face is not flat
– Porosity between channels
– The valve bushing clips are improperly installed.
– The check balls are misplaced.
S The seal rings are worn or damaged
Engine Coolant in Transaxle
Notice : Antifreeze will deteriorate the O–ring seals and
the glue used to bond the clutch material to the pressure
plate. Both conditions may cause transaxle damage.
Perform the following steps if the transaxle oil cooler has
developed a leak, allowing engine coolant to enter the
transaxle:
1. Because the coolant will attach to the seal material
causing leakage, disassemble the transaxle and
replace all rubber type seals.
2. Because the facing material may become sepa-
rated from the steel center portion, replace the
composition faced clutch plate assemblies.
3. Replace all nylon parts including washers.
4. Replace the torque converter.
5. Thoroughly clean and rebuild the transaxle, using
new gaskets and oil filter.6. Flush the cooler lines after you have properly re-
paired or replaced the transaxle.
COOLER FLUSHING AND FLOW
TEST
Notice : You must flush the cooler whenever you receive
a transaxle for service. Cooler flushing is essential for
SRTA installation, major overhaul, whenever you replace
a pump or torque converter, or whenever you suspect that
the fluid has been contaminated.
After filling the transaxle with fluid, start the engine and run
for 30 seconds. This will remove any residual moisture
from the oil cooler. Disconnect the return line at the trans-
axle and observe the flow with the engine running. If the
fluid flow is insufficient, check the fluid flow by disconnect-
ing the feed line at the cooler. Observe the flow with the
engine running.
S If the flow from the cooler return line at the trans-
axle is insufficient, check the flow rate from the feed
line to the cooler. BLockage exists in the transaxle
or the cooler.
S If the flow from the transaxle feed line to the cooler
is insufficient, the transaxle is the cause of the fluid
flow problem.
S If the flow the transaxle feed line to the cooler is
insufficient, but flow from the cooler return line to
the transaxle is insufficient, inspect the cooler pipes
and fittings. Then repeat the cooler flushing proce-
dure. If the flow is still insufficient, replace the cool-
er.
TRANSAXLE FLUID LEVEL SERVICE
PROCEDURE
This procedure is to be used when checking a concern
with the fluid level in a vehicle. A low fluid level will result
in slipping and loss of drive/ reverse or delay on engage-
ment of drive/ reverse when the vehicle is cold.
The vehicle is first checked for transaxle diagnostic mes-
sages on the scan tool. If the oil level is low, it is possible
to register a vehicle speed signal fault.
The vehicle is to be test driven to determine if there is an
abnormal delay when selecting drive or reverse, or loss of
drive. One symptom of low fluid level is a momentary loss
of drive when driving the vehicle around a corner. Also
when the transaxle fluid level is low, a loss of drive may oc-
cur when the transaxle fluid temperature is low.
When adding or changing transaxle fluid use only ESSO
LT 71141 automatic transaxle fluid or other approved
fluids. The use of incorrect fluid will cause the performance
and durability of the transaxle to be severely degraded.
Fluid Level Diagnosis Procedure
1. If the vehicle is at operating temperature allow the
vehicle to cool down for two hours, but no greater
than four hours. Or if the vehicle is at cool status,
start the engine and allow the engine to idle for
approximately 5 minutes (825~875 rpm), if pos-

5A1 – 46IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
sible, drive the vehicle for a few kilometers (N–D,
N–R, shift until two gear). This will allow the trans-
axle to be within the correct temperature range.
Transaxle fluid level should be checked at tempera-
ture 20 to 45°C (68 to 113°F).
CAUTION : Removal of the fluid filler plug when the
transaxle fluid is hot may cause injury if fluid drains
from the filler hole.
2. Switch off accessories, especially air conditioner,
heater.
3. With the brake pedal pressed, move the gear shift
control lever through the gear ranges, pausing a
few seconds in each range. Return the gearshift
lever to P(Park). Turn the engine OFF.
4. Park the vehicle on a hoist, inspection pit or similar
raised level surface. The vehicle must be level to
obtain a correct fluid level measurement.
5. Place a fluid container below the fluid filler plug.
6. Clean all dirt from around the fluid filler plug.
Remove the fluid filler plug. Clean the filler plug and
check that there is no damage to the ”O” ring.
S If fluid drains through the filler hole the transaxle
may have been overfilled. When the fluid stops
draining the fluid level is correct. Install the fluid
filler plug and tighten it to 45NSm(34 lb–ft).
S If fluid does not drain through the filler hole, the
transaxle fluid level may be low. Lower the ve-
hicle, and start the vehicle in P(Park) with the
parking brake and the brake applied. With the
engine idling, move the gear shift lever through
the gear ranges, pausing a few seconds in each
range and adding the fluid until gear application
is felt. Return the gear shift lever to P(Park).
Turn the engine OFF and raise the vehicle.
Check if the fluid level is aligned with the bottom
of the filler hole. If not, add a small quantity of
fluid to the correct level. Install the fluid filler
plug and tighten it to 45NSm(34 lb–ft).
7. When the fluid level checking procedure is com-
pleted, wipe any fluid around the filler plug with a
rag or shop towel.
Fluid Level Set After Service
1. Depending on the service procedure performed,
add the following amounts of fluid through the filler
plug hole prior to adjusting the fluid level:
Oil pan removal – 4 liters (4.23 quarts)
Converter removal – 2 liters ( 2.11 quarts)
Overhaul – 6.9liters (7.3 quarts)
Oil drain plug removal – 4 liters (4.23 quarts)
2. Follow steps 1 through 4 of the Fluid Level Diagno-
sis Procedure.
3. Clean all dirt from around the fluid filler plug.
Remove the fluid filler plug. Clean the filler plug and
check that there is no damage to the ”O” ring.
4. Lower the vehicle with the filler plug still removed
and start the vehicle in P(Park) with the parking
brake and the brake applied. With the engine idling,move the gear shift lever through the gear ranges,
pausing a few seconds in each range and adding
the fluid until gear application is felt. Then add an
additional 0.5 liters of fluid. Return the gear shift
lever to P(Park). Turn the engine OFF and raise the
vehicle. Install the fluid filler plug and tighten it to
45NSm (34 lb–ft).
5. Drive the vehicle at 2.2 miles(3.5km) to 2.8
miles(4.5 km) with light throttle so that the engine
does not exceed 2500 rpm. This should result in
the transaxle temperature being in the range 20 to
45°C (68 to 11°F). With the brake applied, move
the shift lever through the gear ranges, pausing a
few seconds in each range at the engine idling.
6. Return the gear shift lever to P(Park). Turn the en-
gine OFF and raise the vehicle on the hoist, if appli-
cable, ensuring the vehicle is level. When the three
minutes passed after the engine stopped, remove
the filler plug. Check if the fluid level is aligned with
the bottom of the filler hole. If not, add a small
quantity of fluid to the correct level. Install the fluid
filler plug and tighten it to 45NSm (34 lb–ft).
7. Wipe any fluid around the filler plug with a rag or
shop towel.
Fluid Leak Diagnosis and Repair
The cause of most external leaks can generally be Lo-
cated and repaired with the transaxle in the vehicle.
Methods for Locating Leaks
General Method
1. Verify that the leak is transaxle fluid.
2. Thoroughly clean the suspected leak area.
3. Drive the vehicle for approximately 25 km (15
miles) or until the transaxle reaches normal operat-
ing temperature (88°C, 190°F).
4. Park the vehicle over clean paper or cardboard.
5. Turn the engine OFF and look for fluid spots on the
paper.
6. Make the necessary repairs to correct the leak.
Powder Method
1. Thoroughly clean the suspected leak area.
2. Apply an aerosol type powder (foot powder) to the
suspected leak area.
3. Drive the vehicle for approximately 25 km (15
miles) or until the transaxle reaches normal operat-
ing temperature (88°C, 190°F).
4. Turn the engine OFF.
5. Inspect the suspected leak area and trace the leak
path through the powder to find the source of the
leak.
6. Make the necessary repairs.
Dye and Black Light Method
1. Add dye to the transaxle though the transaxle fluid
filler plug. Follow the manufacturer’s recommenda-
tion for the amount of dye to be used.
2. Use the black light to find the fluid leak.
3. Make the necessary repairs.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 47
DAEWOO V–121 BL4
Repairing the Fluid Leak
Once the leak point is found the source of the leak must
be determined. The following list describes the potential
causes for the leak:
S Fasteners are not torqued to specification.
S Fastener threads and fastener holes are dirty or
corroded.
S Gaskets, seals or sleeves are misarranged, dam-
aged or worn.
S Damaged, warped or scratched seal bore or gasket
surface.
S Loose or worn bearing causing excess seal or
sleeve wears.
S Case or component porosity.
S Fluid level is too high.
S Plugged vent or damaged vent tube.
S Water or coolant in fluid.
S Fluid drain back holes plugged.
ELECTRICAL/GARAGE SHIFT TEST
This preliminary test should be performed before a hoist
or road test to make sure electronic control inputs is con-
nected and operating. If the inputs are not checked before
operating the transaxle, a simple electrical condition could
be misdiagnosed as a major transaxle condition.
A scan tool provides valuable information and must be
used on the automatic transaxle for accurate diagnosis.
1. Move gear selector to P (Park) and set the parking
brake.
2. Connect scan tool to Data Link Connector (DLC)
terminal.
3. Start engine.
4. Turn the scan tool ON.
5. Verify that the appropriate signals are present.
These signals may include:
S ENGINE SPEED
S VEHICLE SPEED
S THROTTLE POSITION
S TRANSAXLE GEAR STATE
S GEAR SHIFT LEVER POSITION
S TRANSAXLE FLUID TEMPERATURE
S CLOSED THROTTLE POSITION LEARN
S OPEN THROTTLE POSITION LEARNT
S CLOSED ACCEL. PEDAL POSITION LEARNT
S OPEN ACCEL. PEDAL POSITION LEARNT
S A/C COMPRESSOR STATUS
S MODE SWITCH
S THROTTLE POSITION VOLTAGE
S GEAR SHIFT LEVER POSITION VOLTAGE
S TRANS. FLUID TEMPERATURE VOLTAGE
S A/C SWITCH
S MODE SWITCH VOLTAGE
S BATTERY VOLTAGE
6. Monitor the A/C COMPRESSOR STATUS signal
while pushing the A/C switch.S The A/C COMPRESSOR STATUS should come
ON when the A/C switch is pressed, and turns
OFF when the A/C switch is repushed.
7. Monitor the GEAR SHIFT LEVER POSITION signal
and move the gear shift control lever through all the
ranges.
S Verify that the GEAR SHIFT LEVER POSITION
value matches the gear range indicated on the
instrument panel or console.
S Gear selections should be immediate and not
harsh.
8. Move gear shift control lever to neutral and monitor
the THROTTLE POSITION signal while increasing
and decreasing engine speed with the accelerator
pedal.
S THROTTLE POSITION should increase with
engine speed.
ROAD TEST PROCEDURE
S Perform the road test using a scan tool.
S This test should be performed when traffic and road
conditions permit.
S Observe all traffic regulations.
The TCM calculates upshift points based primarily on two
inputs : throttle angle and vehicle speed. When the TCM
wants a shift to occur, an electrical signal is sent to the shift
solenoids which in turn moves the valves to perform the
upshift.
The shift speed charts reference throttle angle instead of
”min throttle” or ”wot” to make shift speed measurement
more uniform and accurate. A scan tool should be used to
monitor throttle angle. Some scan tools have been pro-
grammed to record shift point information. Check the
introduction manual to see if this test is available.
Upshift Procedure
With gear selector in drive(D)
1. Look at the shift speed chart contained in this sec-
tion and choose a percent throttle angle of 10 or
25%.
2. Set up the scan tool to monitor throttle angle and
vehicle speed.
3. Accelerate to the chosen throttle angle and hold the
throttle steady.
4. As the transaxle upshifts, note the shift speed and
commanded gear changes for :
S Second gear.
S Third gear.
S Fourth gear.
Important : Shift speeds may vary due to slight hydraulic
delays responding to electronic controls. A change from
the original equipment tire size affects shift speeds.
Note when TCC applies. This should occur in fourth gear.
If the apply is not noticed by an rpm drop, refer to the
”Lock–up Clutch Diagnosis” information contained in this
section.

5A1 – 48IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
The Lock up clutch should not apply unless the transaxle
has reached a minimum operating temperature of 8°C
(46°F) TRANS TEMP AND engine coolant temp of 50°C
(122°F).
5. Repeat steps 1–4 using several different throttle
angles.
Part Throttle Detent Downshift
At vehicle steeds of 55 to 65km/h (34 to 40mph) in Fourth
gear, quickly increase throttle angle to greater than 50%.
Verify that :
S TCC apply.
S Transaxle downshift to 3rd gear.
S Solenoid 1 turns ON to OFF.
S Solenoid 2 turns OFF.
Full Throttle Detent Downshift
At vehicle speeds of 55 to 65km/h (34 to 40mph)in Fourth
gear, quickly increase throttle angle to its maximum posi-
tion (100%)
Verify that :
S TCC release.
S Transaxle downshift to Second gear immediately.
S Solenoid 1 turns ON to OFF
S Solenoid 2 turns OFF.
Manual Downshifts
1. At vehicle speeds of 60km/h (40mph)in Fourth
gear, release accelerator pedal while moving gear
selector to Manual Third (3). Observe that :
S Transaxle downshift to Third gear immediately.
S Engine slows vehicle down.
2. Move gear selector back to overdrive(D) and accel-
erate to 31mph (50km/h). Release the accelerator
pedal and move the gear selector to Manual
First(1) and observe that :
S Transaxle downshift to second gear immediate-
ly.
S Engine slows vehicle down
Notice : A Manual First––Third Gear Ratio will occur at
high speeds as an upshift safety feature. Do not attempt
to perform this shift.
Coasting Downshifts
1. With the gear selector in Overdrive(D), accelerate
to Fourth gear with TCC applied.
2. Release the accelerator pedal and lightly apply the
brakes, and observe that :
S TCC release.
S Down shifts occur at speeds shown ON the shift
speed chart.
Manual Gear Range Selection
Upshifts in the manual gear ranges are controlled by the
shift solenoids. Perform the following tests by accelerating
at 25 percent TP sensor increments.
Manual Third (3)
S With vehicle stopped, move the gear selector to
Manual third(3) and accelerate to observe :
– 1–2 shift.
– 2–3 shift.
Manual Second (2)
S With vehicle stopped, move the gear selector to
Manual second(2) and accelerate to observe :
– 1–2 shift.
S Accelerate to 40km/h(25mph) and observe :
– 2–3 shift does not occur
– TCC does not apply
Manual First (1)
S With vehicle stopped, move gear selector to Manu-
al First(1). Accelerate to 30km/h(19mph) and ob-
serve :
– No upshifts occur
Reverse (R)
S With vehicle stopped, move gear selector to R(Re-
verse) and observe :
– Solenoid 1 is OFF
– Solenoid 2 is OFF
Use a scan tool to see if any transaxle trouble codes have
been set. Refer to ”Diagnostic Trouble Codes”in this sec-
tion and repair the vehicle as directed. After repairing the
vehicle, perform the hoist test and verify that the code has
not set again.
If the transaxle is not performing well and no trouble codes
have been set, there may be an intermittent condition.
Check all electrical connections for damage or a loose fit.
You also have to perform a snapshot test which can help
catch an intermittent condition that dose not occur long
enough to set a code.
You may want to read ”Electronic Component Diagnosis”
in this section to become familiar with transaxle conditions
caused by transaxle electrical malfunction.
If no trouble codes have been set and the condition is sus-
pected to be hydraulic, take the vehicle on a road test.
TORQUE CONVERTER LOCK–UP
CLUTCH(TCC) DIAGNOSIS
To properly diagnosis the lock–up clutch(TCC) system,
perform all electrical testing first and then the hydraulic
testing.
The TCC is applied by fluid pressure which is controlled by
a solenoid Located inside the valve body. The solenoid is
energized by completing an electrical circuit through a
combination of switches and sensors.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 49
DAEWOO V–121 BL4
Functional Check Procedure
Inspect
1. Install a tachometer or scan tool.
2. Operate the vehicle unit proper operating tempera-
ture is reached.
3. Drive the vehicle at 80 to 88km/h (50 to 55 mph)
with light throttle(road load).
4. Maintaining throttle position, lightly touch the brake
pedal and check for release of the TCC and a slight
increase in engine speed(rpm).
5. Release the brake slowly accelerate and check for
a reapply of the Lock up clutch and a slight de-
crease in engine speed(rpm).
Torque Converter Evaluation
Torque Converter Stator
The torque converter stator roller clutch can have one of
two different type malfunctions :
A. Stator assembly freewheels in both directions.
B. Stator assembly remains Locked up at all times.
Condition A – Poor Acceleration Low
Speed
The car tends to have poor acceleration from a stand still.
At speeds above 50 to 55km/h(30 to 35mph), the car may
act normal. If poor acceleration is noted, it should first be
determined that the exhaust system is not blocked, and
the transaxle is in 1st(First) gear when starting out.
If the engine freely accelerates to high rpm in N(Neutral),
it can be assumed that the engine and exhaust system are
normal. Checking for poor performance in ”Drive” and ”Re-
verse” will help determine if the stator is freewheeling at all
times.
Condition B – Poor Acceleration High
Speed
Engine rpm and car speed limited or restricted at high
speeds. Performance when accelerating from a standstill
is normal. Engine may overheat. Visual examination of the
converter may reveal a blue color from overheating.
If the converter has been removed, the stator roller clutch
can be checked by inserting two fingers into the splined in-
ner race of the roller clutch and trying to turn freely clock-
wise, but not turn or be very difficult to turn counter clock-
wise.
Noise
Torque converter whine is usually noticed when the ve-
hicle is stopped and the transaxle is in ”Drive” or ”Re-
verse”. The noise will increase when engine rpm is in-
creased. The noise will stop when the vehicle is moving or
when the torque converter clutch is applied because both
halves of the converter are turning at the same speed.
Perform a stall test to make sure the noise is actually com-
ing from the converter :1. Place foot on brake.
2. Put gear selector in ”Drive”.
3. Depress accelerator to approximately 1200rpm for
no more than six seconds.
Notice : If the accelerator is depressed for more than six
seconds, damage to the transaxle may occur.
A torque converter noise will increase under this load.
Important : This noise should not be confused with pump
whine noise which is usually noticeable in P (Park), N
(Neutral) and all other gear ranges. Pump whine will vary
with pressure ranges.
The torque converter should be replaced under any of the
following conditions:
S External leaks in the hub weld area.
S Converter hub is scored or damaged.
S Converter pilot is broken, damaged or fits poorly
into crankshaft.
S Steel particles are found after flushing the cooler
and cooler lines.
S Pump is damaged or steel particles are found in the
converter.
S Vehicle has TCC shudder and/or no TCC apply.
Replace only after all hydraulic and electrical diag-
noses have been made.(Lock up clutch material
may be glazed.)
S Converter has an imbalance which cannot be cor–
rected. (Refer To Converter Vibration Test Proce-
dure.)
S Converter is contaminated with engine coolant con-
taining antifreeze.
S Internal failure of stator roller clutch.
S Excess end play.
S Heavy clutch debris due to overheating (blue con-
verter).
S Steel particles or clutch lining material found in fluid
filter or on magnet when no internal parts in unit are
worn or damaged(indicates that lining material
came from converter).
The torque converter should not be replace if :
S The oil has an odor, is discolored, and there is no
evidence of metal or clutch facing particles.
S The threads in one or more of the converter bolt
holes are damaged.
–correct with thread insert.
S Transaxle failure did not display evidence of dam-
age or worn internal parts, steel particles or clutch
plate lining material in unit and inside the fluid filter.
S Vehicle has been exposed to high mileage(only).
The exception may be where the Lock up clutch
damper plate lining has seen excess wear by ve-
hicles operated in heavy and/or constant traffic,
such as taxi, delivery or police use.
Lock–Up Clutch Shudder Diagnosis
The key to diagnosing lock–up clutch(TCC) shudder is to
note when it happens and under what conditions.

5A1 – 50IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
TCC shudder should only occur during the APPLY and/or
RELEASE of the Lock up clutch.
While TCC Is Applying Or Releasing
If the shudder occurs while TCC is applying, the problem
can be within the transaxle or torque converter.
Something is not allowing the clutch to become fully en-
gaged, not allowing clutch to release, or is trying to release
and apply the clutch at the same time. This could be
caused by leaking turbine shaft seals, a restricted release
orifice, a distorted clutch or housing surface due to long
converter bolts, or defective friction material on the TCC
plate.
Shudder Occurs After TCC Has Applied :
In this case, most of the time there is nothing wrong with
the transaxle! As mentioned above, once the TCC has
been applied, it is very unlikely that will slip. Engine prob-
lems may go unnoticed under light throttle and load, but
become noticeable after TCC apply when going up a hill
or accelerating, due to the mechanical coupling between
engine and transaxle.
Important : Once TCC is applied there is no torque con-
verter assistance. Engine or driveline vibrations could be
unnoticeable before TCC engagement.
Inspect the following components to avoid misdiagnosis of
TCC shudder and possibly disassembling a transaxle and/
or replacing a torque converter unnecessarily :
S Spark plugs – Inspect for cracks, high resistance or
broken insulator.
S Plug wires – Lock in each end, if there is red dust
(ozone) or black substance (carbon) present, then
the wires are bad. Also look for a white discolor-
ation of the wire indicating arcing during hard accel-
eration.
S Distributor cap and rotor – look for broken or un–
crimped parts.
S Coil – look for black on bottom indication arcing
while engine is misfiring.
S Fuel injector – filter may be plugged.
S Vacuum leak – engine won’t get correct amount of
fuel. May run rich or lean depending on where the
leak is.S EGR valve – valve may let it too much unburnable
exhaust gas and cause engine to run lean.
S MAP sensor – like vacuum leak, engine won’t get
correct amount of fuel for proper engine operation.
S Carbon on intake valves – restricts proper flow or
air/fuel mixture into cylinders.
S Flat cam – valves don’t open enough to let proper
fuel/air mixture into cylinders.
S Oxygen sensor – may command engine too rich or
too lean for too long.
S Fuel pressure – may be too low.
S Engine mounts – vibration of mounts can be multi-
plied by TCC engagement.
S Axle joints – checks for vibration.
S TPS – TCC apply and release depends on the TPS
in many engines. If TPS is out of specification, TCC
may remain applied during initial engine starting.
S Cylinder balance – bad piston rings or poorly seal-
ing valves can cause low power in a cylinder.
S Fuel contamination – causes poor engine perfor-
mance.
TCM INITIALIZATION PROCEDURE
When one or more operations such as shown below are
performed, all learned contents which are stored in TCM
memory should be erased after the operations.
S When A/T H/W is replaced in a vehicle,
S When a used TCU is installed in other vehicle,
S When a vehicle condition is unstable (engine RPM
flare, TPS toggling and so on; at this kind of unsta-
ble conditions, mis–adaptation might be done).
1. Connect the Scan 100 with a DLC connector in a
vehicle.
2. Turn ignition switch ON.
3. Turn the power on for the Scan 100.
4. Follow the ”TCM LEARNED INITIALIZE” procedure
on the Scan 100 menu.
Notice : Before pushing ”Yes” Button for TCM initialization
on the Scan 100 screen, make sure that the condition is
as follows:
Condition :
1. Engine idle.
2. Select lever set ”P” range.

5A1 – 56IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
SYMPTOM DIAGNOSIS
Oil Leakage
Notice :
– Careful localization of leakage points may make it
possible to prevent incorrect or cost–intensive re-
pairs.
Test Steps :– Thoroughly clean the transaxle, engine, and sur-
rounding area(using a steam jet, for example).
– To locate leakage, use a suitable identifying spray
or similar product.
– Depending on the amount of leakage, take the
car for a short or a longer test drive – It may prove
sufficient to place the car on a hoist and run the
engine at idle speed to trace the leak.
– If possible, determine exactly which type of oil is
escaping.
Symptom
Possible CauseAction
Transaxle Oil Leak-
ageOil Pump(Torque Converter Sealing)S Visually check torque converter sealing.
S Replace the converter sealing as described in
the transaxle repair on the vehicle service.
Crankshaft Sealing RingS Check whether engine oil or TFT is leaking out.
S If leak is engine oil, replace the sealing ring as
described in the engine repair instruction.
Torque ConverterS Visual check.
S Fit an exchange converter as described in the
repair instruction.
Oil Content Too HighS Check oil level(TFT and axle oil) as described
in this chapter.
S Correct oil level, and recheck after a test drive.
Notice : Comply with the measuring procedure (fill-
ing procedure) in the repair instruction. Check the oil
level at the overflow plug adjust to proper level if nec-
essary.
O–ring at Bolt Head Damaged or Miss-
ingS Check O–ring.
S Replace O–ring as described in the repair in-
struction.
Shaft SealS Visually check the shaft seal.
S Replace the sealing ring as described in the
repair instruction.
Hose Clamp LooseS Check to ensure that the hose clamp fits tightly.
S If necessary, retighten clamp.
Oil Pan Gasket Not Installed ProperlyS Check to see if the gasket was positioned
properly.
S Install gasket properly as described in the re-
pair instruction.
Oil Pan Gasket DamagedS Check the gasket visually.
S Replace gasket as described in the repair in-
struction.
Bolt at Bracket LooseCheck the Tightening Torque
Retighten bolt
Sealing Ring at Oil DipstickS Check O–ring.
S If necessary, replace O–ring.
Sealing Ring Near End–Cover Connec-
tion DefectiveS Check sealing rings.
S Put in new sealing ring Check O–ring as de-
scribed in the repair instruction.