2004 DAEWOO LACETTI brake light

PARKING BRAKE 4G – 9
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
PARKING BRAKE
This braking system uses a BRAKE warning light located
in the instrument panel cluster. When the ignition switch
is in the START position, the BRAKE warning light shouldglow and go OFF when the the ignition switch returns to
the RUN position. Whenever the parking brake is applied
and the ignition switch is ON, the BRAKE warning light
should glow.
When the brake is firmly applied, the parking brake should
hold the vehicle with ample pedal travel remaining. Check
for frayed cables, rust, etc. or any condition that many in-
hibit present (or future) free movement of the parking
brake lever assembly.

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.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 61
DAEWOO V–121 BL4
DTCDefault Action Indication Description
P0703Brake Switch Circuit
MalfunctionNo ChangeS TCM assume that the brake light always active.
S Open lock up clutch.
P0705Transmission Range Sen-
sor Circuit Malfunction
(PRNDL Input)MIL ONS 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic control,
position P, R and N also possible.
P0710S Transmission Fluid
Temperature Sensor
Circuit MalfunctionNo ChangeS TCM assume the transaxle fluid temperature is
140°F (60°C).
S No influence at vehicle running.
P0715S Input Speed Sensor
Circuit MalfunctionMIL ONS 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic control,
position P, R and N also possible.
S Open lock up clutch.
P0716S Input Speed Sensor
Circuit Range/Perfor-
manceMIL ONS 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic control,
position P, R and N also possible.
S Open lock up clutch.
P0717S Input Speed Sensor
Circuit Range/Perfor-
manceMIL ONS 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic control,
position P, R and N also possible.
S Open lock up clutch.
P0720Output Speed Sensor Cir-
cuit MalfunctionMIL ONS 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.
P0721Output Speed Sensor Cir-
cuit Range/PerformanceMIL ONS 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.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 83
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0703
BRAKE SWITCH CIRCUIT MALFUNCTION
Circuit Description
The brake switch is used to indicate brake pedal status to
the transaxle control module(TCM). The brake switch is a
normally open switch. Applying the brake pedal closes the
switch, supplying voltage to the TCM. Releasing the brake
pedal interrupts voltage to the TCM.
This DTC is stored at start–up. If the TCM receives a brake
switch signal after start–up, the DTC will be stored in
memory.
Conditions for Setting The DTC
S Brake switch stuck to closed.
S Brake switch wiring harness shortage to ground.
S Brake switch wiring harness shortage to power.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 TCM assume that the brake light always active.
Conditions For Clearing The MIL/DTC
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 damage terminals.

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.