2004 DAEWOO LACETTI Gear

5A2 – 88IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1781
ENGINE TORQUE SIGNAL ERROR
Conditions for Setting the DTC
S TCM detects that malfunction of engine speed sig-
nal for 2 seconds.
S No DTC U2105
Action Taken When the DTC Sets
S TCM will request the illumination of MIL and store
DTC when TCM detects a failure on the first ignition
cycle.
S No engine torque reduction control
S No engagement pressure control
S No 4th gear
S No self–learning controlConditions for Clearing the DTC
S The TCM turns off the MIL when no further failures
detected for three consecutive ignition cycles.
S The scan tool can clear the DTC from the TCM his-
tory.
S The TCM clears the DTC from the TCM history
memory after forty consecutive warm up cycles
without fault.
Cause of Failure
S Wiring harness or connector between ECM and
TCM
S ECM
S TCM

AISIN AUTOMATIC TRANSAXLE 5A2 – 91
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1791
THROTTLE POSITION SIGNAL ERROR
Conditions for Setting the DTC
S TCM detects that malfunction of throttle position
signal for 2 seconds continuously.
S No DTC U2105
Action Taken When the DTC Sets
S TCM will request the illumination of MIL and store
DTC when TCM detects a failure on the first ignition
cycle.
S TCM judges the throttle opening is 0% for shift
point control.
S TCM judges the throttle opening is 100% for line
pressure control.
S No lock–up
S No 4th gear
S No self–learning controlS No timing solenoid control for N–D
Conditions for Clearing the DTC
S The TCM turns off the MIL when no further failures
detected for three consecutive ignition cycles.
S The scan tool can clear the DTC from the TCM his-
tory.
S The TCM clears the DTC from the TCM history
memory after forty consecutive warm up cycles
without fault.
Cause of Failure
S Wiring harness or connector between ECM and
TCM
S ECM
S TCM

AISIN AUTOMATIC TRANSAXLE 5A2 – 95
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) U2105
CAN ERROR
Conditions for Setting the DTC
S TCM detects that the BUS OFF signal. This detec-
tion is continued for 0.2 seconds.
S TCM detects that nothing of ECM signal on CAN
BUS for 0.2 seconds. This detection is continued
for 2.0 seconds.
Action Taken When the DTC Sets
S TCM will request the illumination of MIL and store
DTC when TCM detects a failure on the first ignition
cycle.
S TCM judges the throttle opening is 0% for shift
point and lock–up point control.
S TCM judges the throttle opening is 100% for line
pressure control.
S No lock–upS No self–learning control
S No 4th gear
S TCM judges the engine revolution is 0 rpm.
Conditions for Clearing the DTC
S The TCM turns off the MIL when no further failures
detected for three consecutive ignition cycles.
S The scan tool can clear the DTC from the TCM his-
tory.
S TCM detects the BUS normal signal for 2 seconds
continuously.
Cause of Failure
S Wiring harness or connector between ECM and
TCM
S ECM
S TCM

5A2 – 98IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Filling Procedure
1. Remove the drainage container and lower the ve-
hicle.
2. Add three–fourths of the recommended amount of
ISU DEXRON III.
3. Start the engine and allow it to reach normal oper-
ating temperature.
4. Shift the gear selector through all positions.
5. Check the fluid level and add fluid until the dipstick
indicates a safe level.
LOCATING FLUID LEAKS
General Method
1. Verify that the material leaking is transaxle fluid.
2. Thoroughly clean the suspected leak area.
3. Allow the transaxle to reach the normal operating
temperature of 176–194°F (80–90°C).
4. Park the vehicle over a clean paper or a clean card-
board.
5. Turn the engine OFF and look for fluid spots on the
paper.
6. Make the necessary repairs to correct that leak.
Powder Method
1. Thoroughly clean the suspected leak area.
2. Apply an aerosol type powder, such as foot powder,
to the suspected leak area.
3. Allow the transaxle to reach the normal operating
temperature of 176–194°F (80–90°C).
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 to correct the leak.
Once the leak point is found, the source of the leak must
be determined and repaired.
CASE PORSITY REPAIR
1. Determine the leak area. Refer to ”Locating Fluid
Leaks” in this section.
2. Clean the leak area with the solvent. Air dry.
CAUTION : Epoxy cement may cause skin irritations
and eye damage. Read and follow all information on
the container label as provided by the manufacturer.
3. Mix a sufficient amount of epoxy cement following
the manufacturer’s recommendations.
4. While the transaxle case is hot, apply epoxy ce-
ment with a clean, dry soldering acid brush.
5. Allow the epoxy cement to dry for 3 hours before
starting the engine.

AISIN AUTOMATIC TRANSAXLE 5A2 – 117
DAEWOO V–121 BL4
UNIT REPAIR
MAJOR COMPONENT DISASSEMBLY
Tools Required
DW240–020 Brake/Clutch Spring Compressor
DW240–050 Overdrive Brake Adapter
DW240–060–01 Brake Spring Compressor Bolt/Nut
DW240–070 1st & Reverse Brake Adapter
DW240–080 2nd Brake Adapter
DW240–090 Planetary Ring Gear Remover
DW240–150 Transaxle Case Side Bearing Outer Race
Adapter
DW240–170 Adapter Handle
DW260–021–02 Automatic Transaxle Overhaul Fixture
(81–40 LE)
DW260–041 Planetary Ring Gear Nut Removal/Installa-
tion Socket
Disassembly Procedure
1. Remove the transaxle assembly from the vehicle.
Refer to”Transaxle Assembly” in this section.
2. Install the transaxle assembly to the transaxle sup-
port stand using Automatic Transaxle Overhaul Fix-
ture DW260–021–02 (81–40 LE).
3. Remove the nut, washer and control lever.
4. Using a screwdriver, unstake the lock washer.
5. Remove the two bolts and nut and pull out the
transmission range (TR) switch.
6. Remove the two unions the transaxle case.
7. Remove the two O–rings from the unions.

AISIN AUTOMATIC TRANSAXLE 5A2 – 123
DAEWOO V–121 BL4
36. Remove the 16 bolts and tap on the circumference
of the transaxle housing with a plastic hammer to
remove the transaxle housing from the transaxle
case.
Important : Be careful not to drop the differential gear as-
sembly when the transaxle housing is removed.
37. Using a dial indicator, measure the input shaft end
play.
S End play : 0.3
0.9 mm (0.012–0.035 in.)
38. Remove the 6 bolts and oil pump.
39. Remove the differential gear assembly from the
transaxle case.

AISIN AUTOMATIC TRANSAXLE 5A2 – 125
DAEWOO V–121 BL4
44. Remove the counter driven gear assembly from the
transaxle case.
45. Remove the 9 bolts and tap on the circumference
of the transaxle rear cover with a plastic hammer to
remove the transaxle rear cover from the transaxle
case.
46. Remove the 4 apply gaskets.
47. Remove 2nd coast & O/D brake (B1) flange, 2
discs and 2 plates from the transaxle case.

AISIN AUTOMATIC TRANSAXLE 5A2 – 127
DAEWOO V–121 BL4
52. Remove rear planetary sun gear and one–way
clutch assembly.
53. Remove the thrust bearing race from the rear plan-
etary sun gear and one–way clutch assembly.
54. Remove the thrust needle roller bearing and plane-
tary carrier thrust washer from the rear planetary
sun gear and one–way clutch assembly.
55. Remove the one–way clutch assembly and thrust
washer from the rear planetary sun gear.