2004 DAEWOO LACETTI torque

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.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 57
DAEWOO V–121 BL4
Symptom ActionPossible Cause
Sealing Ring Selector ShaftS Check sealing ring.
S Replace sealing ring as described in the repair
instruction.
O–ring at Socket OutletS Check O–ring.
S Replace O–ring as described in the repair in-
struction.
O–ring and Speed Sensor ConnectionS Check O–ring.
S Replace O–ring as described in the repair in-
struction.
Oil Leak Incorrectly IdentifiedS No oil leak is possible at this point.
Speed Sensor Itself Is LeakingS Check speed sensor.
S Replace speed sensor as described in the re-
pair instruction.
Hair Line Crack at the Piping in the Con-
nection Area, Sealing Ring Fit in Trans-
axle HousingS Pressurize the line with compressed air and
check it.
S Replace lines as described in the repair in-
struction.
O–ring Defective, IncorrectCheck O–ring.
Replace O–rings as described in the repair instruc-
tion.
Plug LooseCheck the Tightening Torque for the screw plug.
Tighten to torque specified in the repair instruction.
Noise
SymptomPossible CauseAction
NoiseTFT Level Too LowS When the TFT level is too low, the gear wheels
from the transaxle oil pump might generate
noise.
S Check the TFT level as described in the repair
instruction and fill to the proper level.
Monolith in Catalytic Converter Has
BrokenS Check according to the exhaust gas diagnostic
procedure or by shaking the catalytic converter
casing.
S Replace catalytic converter if necessary.
Noise from Auxiliaries (e.g. exhaust
system, alternator, drive shafts.)S Check these components; if necessary, elimi-
nate the faults as described in the repair in-
struction
Noise from Tires or Wheel BearingsS Eliminate fault if necessary
Noise from Planetary GearsS Whistling noise on traction and overrun(in first
gear only)caused by high rotating speeds(func-
tionally unavoidable)
Cumulative Tooth Backlash in the Com-
plete Drive LineS Production status. Customer must be con-
vinced.
Jerky Noise of the Parking Lock (e.g.
when the car is standing on a gradient)S Load–reversal reaction
S Apply the handbrake before selection the park-
ing Lock (position P)

5A1 – 58IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Symptom ActionPossible Cause
NoiseThe Engine’s Torsional Vibrations are
Being Transmitted to the Drive ShaftsS At low speeds in fourth gear, vibration can
arise (driving at too low an engine speed)
S Noise is functionally unavoidable; due to toler-
ances. Convince the customer.
NoiseTorque Reaction Strut LooseS Check mounting and repair if necessary.
Shift quality
Notice :
– The assessment of shaft quality is, to a large ex-
tent, an individual, subjective matter. Take careful
note of how the customer describes the complaint
and of the manner in which he or she handles the
vehicle and the controls.
– A sudden deterioration of shift quality may also
be caused by the transaxle selecting an emergency
or substitute program
Test Steps :– Carry out the general checks described in the
automatic transaxle diagnostic information.
– Perform a test drive to answer the following ques-
tions.
In which driving situations does the shift quality
complaint arise?
To which shifts does the complaint apply?
Is the complaint reproducible within a short period,
or has it only occurred sporadically or on a single
occasion?
– Check the oil level and oil quality
– Interrogate the fault memory and read out mea-
surement block data.
Symptom
Possible CauseAction
Shift QualityRapid Pressure Build–up in the ClutchS Operating error (position selected several times
in quick succession).
Jerk When Parking Lock Is ReleasedS Refer to ”Noise” in this section.
Incorrect Electronic Transaxle Control
moduleS Check the data status for transaxle control
module ; refer to ”TCM” in this section.
Emergency/Substitute Program Has
Been ActivatedS For checking and remedial action, refer to
”Emergency/Substitute program” in this sec-
tion.
Accelerator Pedal in Indefinite Position
Between Full Throttle and Kick DownS Persuade customer to choose clearly between
kick down and full throttle
S Check setting according go engine repair in-
struction ; adjust if necessary.
Control Overlap Between to Clutches
During ShiftS Production status
S Convince the customer
Temperature Sensor
(Not Fault Memory)S Check function according to ”Emergency/Sub-
stitute program” in this section.
Kick Down Setting IncorrectS Check
A) Floor mat is obstructing accelerator pedal
B) The kick down setting as described in the
Engine Section.
Malfunction
Notice :
The faults dealt with here concern transaxle functions
such as ”traction” (forwards and reverse) and all type of
shifts. Entries will not always be made in the fault memory.Test Steps :
Perform the general checks according to the automatic
transaxle diagnostic procedure.
– Test drive
– Check oil level and quality
– Interrogate fault memory

5A1 – 110IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0725
ENGINE SPEED INPUT CIRCUIT MALFUNCTION
Circuit Description
The transaxle control module(TCM) is an electronic de-
vice which monitors inputs to control various transaxle
functions including shift quality and transaxle sensors,
switches, and components to process for use within its’
control program. Based on this input information, the TCM
controls various transaxle output functions and devices.
DTC’s P0725, P0726 and P0727 are related to the same
circuit. These DTC’s will not illuminate the MIL, however,
the DTC will be stored in memory.
Information transmit between TCM and ECM through the
CAN line. information is as follows :
S Engine Malfunction Signal.
S Engine Speed.
S Engine Output Torque Reduction Signal.
S Engine Coolant Temperature.
Conditions for Setting The DTC
S The engine speed is greater than 7,000rpm.
S System voltage is too high or too low.
S CAN transmitting wiring harness shorted or open.S TCM or ECM is defective.
S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S No lamp control required but diagnostic information
should be stored immediately when malfunction is
detected.
S Adopt Emergency/ Substitute mode and constant
4th gear.
S Open lock up clutch.
Conditions for Clearing the MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.
Diagnostic Aids
S Inspect the poor wiring harness connection for TCM
connectors and transaxle wiring connectors.
S Inspect the improperly formed or damaged termi-
nals.

5A1 – 112IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0726
ENGINE SPEED INPUT CIRCUIT RANGE/PERFORMANCE
Circuit Description
The transaxle control module(TCM) is an electronic de-
vice which monitors inputs to control various transaxle
functions including shift quality and transaxle sensors,
switches, and components to process for use within its’
control program. Based on this input information, the TCM
controls various transaxle output functions and devices.
DTC’s P0725, P0726 and P0727 are related to the same
circuit. These DTC’s will not illuminate the MIL, however,
the DTC will be stored in memory.
Information transmit between TCM and ECM through the
CAN line. information is as follows :
S Engine Malfunction Signal.
S Engine Speed.
S Engine Output Torque Reduction Signal.
S Engine Coolant Temperature.
Conditions for Setting The DTC
S Gear position is D.
S The engine speed is greater than 7,000rpm.S System voltage is greater than 8.5 volts.
S Engine is running.
S No engine speed error DTCs P0727, P0725.
S CAN transmitting wiring harness shorted or open.
S TCM or ECM is defective.
S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
S The TCM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffer.
S Adopt Emergency/ Substitute mode and constant
4th gear.
S Open lock up clutch.
Conditions for Clearing the MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.

5A1 – 114IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0727
ENGINE SPEED INPUT CIRCUIT NO SIGNAL
Circuit Description
The transaxle control module(TCM) is an electronic de-
vice which monitors inputs to control various transaxle
functions including shift quality and transaxle sensors,
switches, and components to process for use within its’
control program. Based on this input information, the TCM
controls various transaxle output functions and devices.
DTC’s P0725, P0726 and P0727 are related to the same
circuit. These DTC’s will not illuminate the MIL, however,
the DTC will be stored in memory.
Information transmit between TCM and ECM through the
CAN line. information is as follows :
S Engine Malfunction Signal.
S Engine Speed.
S Engine Output Torque Reduction Signal.
S Engine Coolant Temperature.
Conditions for Setting The DTCS When turbine speed is more than 1,500 rpm, en-
gine speed is less than 400 rpm.
S System voltage is too high or too low.
S CAN transmitting wiring harness shorted or open.
S TCM or ECM is defective.
S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
S The TCM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffer.
S Adopt Emergency/ Substitute mode and constant
4th gear.
S Open lock up clutch.
Conditions for Clearing the MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.

5A1 – 124IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
RangePark/
Neutr
alRever
seD321
GearNR1st2nd3rd4th1st2nd3rd1st2nd1st
Solenoid Valve
1ONON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFF
Solenoid Valve
2ONONONOFFOFFOFFONOFFOFFONOFFON
Line Pressure
Control Sole-
noid Valve 3
(EDS 3)OFFOFFOFFONON/
OFFON/
OFFOFFONON/
OFFOFFONOFF
Line Pressure
Control Sole-
noid Valve 4
(EDS 4)ONOFFONONONOFFONONONONONON
Line Pressure
Control Sole-
noid Valve 5
(EDS 5)OFFOFFONONOFFOFFONONOFFONONON
Line Pressure
Control Sole-
noid Valve 6
(EDS 6)ONOFFONONONOFFONONONONONON
Brake BAAAAAAAA
Brake CH
Brake DH
Clutch EAAAAAA
Brake FHHHHHHH
Lock–up
ClutchA
A = Applied
H = Holding
ON = The solenoid is energized.
OFF = The solenoid is de–energized.
** = Manual Second–Third gear is only available above approximately 100 km/h (62 mph).
*** = Manual First–Second gear is only available above approximately 60 km/h (37 mph).
Note : Manual First–Third gear is also possible at high vehicle speed as a safety feature.
DIAGNOSTIC TROUBLE CODE(DTC) P0781
1–2 SHIFT MALFUNCTION
Circuit Description
The special feature of 4HP 16 Auto Transaxle is that it op-
erates without freewheels. Shifting between individual
gears takes place by means of overlapping clutch engage-
ment and release.
The advantage of overlap shifting are as follows:
–The transaxle can be of more compact design and
is lighter on account of the absence of freewheels
and the lower number of shift elements.–Lower drag losses, i.e. higher efficiency.
–Lower peak torque acting on the components and
driveline.
However, overlap shifting necessitates high–performance
hardware and software, and precision engine signals.
Conditions for Setting The DTC
S Transmission oil temperature is greater than –10°C
(14°F).
S Selector lever is not N(Neutral), P(Park) position.
S System voltage is greater than 9 volts.