engine coolant DAEWOO LACETTI 2004 Service Repair Manual

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 – 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 – 134IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1671
CAN TRANSMIT MESSAGE FAILURE
Circuit Description
The transaxle control module(TCM)is an electronic device
which monitors inputs to control various transaxle func-
tions 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.
Information is transmitted between the TCM and ECM
through the CAN. 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 System voltage is too high or too low.
S CAN transmitting wiring harness shortage 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic con-
trol. Possible P, R and N also possible.
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 – 136IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1672
CAN BUS OFF FAILURE
Circuit Description
The transaxle control module(TCM)is an electronic device
which monitors inputs to control various transaxle func-
tions 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.
Information is transmitted between the TCM and ECM
through the CAN. 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 System voltage is too high or too low.
S CAN transmitting wiring harness shortage 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic con-
trol. Possible P, R and N also possible.
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 – 138IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1673
CAN RECEIVE ECM MESSAGE FAILURE
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.
Information is transmitted between the TCM and ECM
through the CAN. 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 System voltage is too high or too low.
S CAN transmitting wiring harness shortage 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 by hydraulic control.
S After ignition OFF/ON : 3rd gear by hydraulic con-
trol. Possible P, R and N also possible.
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.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 193
DAEWOO V–121 BL4
Repairing the Fluid Leak
The following are potential causes for fluid leaks. Check
and repair, as necessary.
S Fasteners are not tightened to specifications.
S Fastener threads and tapped holes are dirty or cor-
roded.
S Gaskets, seals or sleeves are misaligned, dam-
aged, or warped, or scratched.
S The manual shaft is nicked or damaged.
S There is a loose or worn bearing causing excess
seal or sleeve wear.
S Case or component porosity.
S The fluid level is too high.
S There is a plugged vent or a damaged vent tube.
S There is water or coolant in the fluid.
S Fluid drain back holes are plugged.
CASE POROSITY REPAIR
CAUTION : Epoxy adhesive may cause skin irritations
and eye damage. Read and follow all information on
the container label as provided by the manufacturer.
1. Thoroughly clean the area to be repaired with a
cleaning solvent. Air dry the area.
2. Using instructions from the manufacturer, mix a
sufficient amount of epoxy to make the repair.
3. While the transaxle case is still hot, apply the
epoxy. You can use a clean, dry soldering acid
brush to clean the area and also apply the epoxy
cement. Make certain that the area to be repaired is
fully covered.
4. Allow the epoxy cement to dry for 3 hours before
starting the engine.
5. Repeat the fluid leak diagnosis procedures. Refer
to ”Fluid Leak Diagnosis and Repair” in this sec-
tion.
SHIFT CONTROL LEVER ASSEMBLY
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the floor console. Refer to Section 9G,
Interior Trim.
3. Disconnect the electrical switch connectors.

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.