ECO mode DAEWOO LACETTI 2004 Service Manual Online

5A1 – 178IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1874
SOLENOID VALVE POWER SUPPLY CIRCUIT SHORTED
TO POWER
Circuit Description
The pressure control valves (EDS valves 3,4,5 and 6) are
precision electronic pressure regulators that control the
operation of the clutches, brakes and lock–up clutch.
The valve reduces the system pressure with which the
downstream solenoid valves and electrical pressure regu-
lating valves are supplied. It is possible to use smaller so-
lenoid valves as a result. The EDS require a constant input
pressure.
Conditions for Setting the DTC
S No DTC P1873.
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 Power supply cut off to the EDS valve.
Conditions for Clearing the MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycle.
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 When DTC P1874 sets, the possible cause of fault
could be solenoid valve power supply line.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 181
DAEWOO V–121 BL4
S No input speed error DTCs P0715, P0716, or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S 2–1 gear shift is active.
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
3rd 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 cycle.
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 When DTC P1881 sets, the possible cause of fault
could be TCM.
DTC P1881 – 2–1 Shift Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
Then, start engine and allow it to warm up at
idle.
3. Observe ”idle rpm, TPS” on the scan tool.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 3
3Inspect ”ECM”. Refer to Section 1F, System Diagno-
sis, EOBD System Check.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Measure the voltage between terminal B3 and
B13 of the transaxle wiring connector.
4. Turn the ignition ON.
5. Measure the voltage between terminal C15 and
B13 of the transaxle wiring connector.
6. Measure the voltage between terminal C16 and
B13 of the transaxle wiring connector.
Is the voltage within the values shown?11–14VGo to Step 5Go to ”System
Voltage Low or
High”
5Replace the TCM.
Is the action complete?–Go to Step 6–
61. After the repair, use a scan tool ”clear info”
function and road test the vehicle.
2. Review the ”DTC info”.
Has the last test failed or is the current DTC dis-
played?–Replace the
transaxle as-
semblyRepair verified
exit DTC chart

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 183
DAEWOO V–121 BL4
S No input speed error DTCs P0715, P0716, or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S 3–2 gear shift is active.
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
3rd 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 cycle.
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 When DTC P1883 sets, the possible cause of fault
could be TCM.
DTC P1883 – 3–2 Shift Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
Then, start engine and allow it to warm up at
idle.
3. Observe ”idle rpm, TPS” on the scan tool.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 3
3Inspect ”ECM”. Refer to Section 1F, System Diagno-
sis, EOBD System Check.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Measure the voltage between terminal B3 and
B13 of the transaxle wiring connector.
4. Turn the ignition ON.
5. Measure the voltage between terminal C15 and
B13 of the transaxle wiring connector.
6. Measure the voltage between terminal C16 and
B13 of the transaxle wiring connector.
Is the voltage within the values shown?11–14VGo to Step 5Go to ”System
Voltage Low or
High”
5Replace the TCM.
Is the action complete?–Go to Step 6–
61. After the repair, use a scan tool ”clear info”
function and road test the vehicle.
2. Review the ”DTC info”.
Has the last test failed or is the current DTC dis-
played?–Replace the
transaxle as-
semblyRepair verified
exit DTC chart

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 185
DAEWOO V–121 BL4
S No input speed error DTCs P0715, P0716, or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S 4–3 gear shift is active.
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 cycle.
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 When DTC P1884 sets, the possible cause of fault
could be TCM.
DTC P1884 – 4–3 Shift Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
Then, start engine and allow it to warm up at
idle.
3. Observe ”idle rpm, TPS” on the scan tool.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 3
3Inspect ”ECM”. Refer to Section 1F, System Diagno-
sis, EOBD System Check.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Measure the voltage between terminal B3 and
B13 of the transaxle wiring connector.
4. Turn the ignition ON.
5. Measure the voltage between terminal C15 and
B13 of the transaxle wiring connector.
6. Measure the voltage between terminal C16 and
B13 of the transaxle wiring connector.
Is the voltage within the values shown?11–14VGo to Step 5Go to ”System
Voltage Low or
High”
5Replace the TCM.
Is the action complete?–Go to Step 6–
61. After the repair, use a scan tool ”clear info”
function and road test the vehicle.
2. Review the ”DTC info”.
Has the last test failed or is the current DTC dis-
played?–Replace the
transaxle as-
semblyRepair verified
exit DTC chart

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 187
DAEWOO V–121 BL4
S No input speed error DTCs P0715, P0716, or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S 3–1 gear shift is active.
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
3rd 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 cycle.
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 When DTC P1885 sets, the possible cause of fault
could be TCM.
DTC P1885 – 3–1 Shift Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
Then, start engine and allow it to warm up at
idle.
3. Observe ”idle rpm, TPS” on the scan tool.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 3
3Inspect ”ECM”. Refer to Section 1F, System Diagno-
sis, EOBD System Check.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Measure the voltage between terminal B3 and
B13 of the transaxle wiring connector.
4. Turn the ignition ON.
5. Measure the voltage between terminal C15 and
B13 of the transaxle wiring connector.
6. Measure the voltage between terminal C16 and
B13 of the transaxle wiring connector.
Is the voltage within the values shown?11–14VGo to Step 5Go to ”System
Voltage Low or
High”
5Replace the TCM.
Is the action complete?–Go to Step 6–
61. After the repair, use a scan tool ”clear info”
function and road test the vehicle.
2. Review the ”DTC info”.
Has the last test failed or is the current DTC dis-
played?–Replace the
transaxle as-
semblyRepair verified
exit DTC chart

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 189
DAEWOO V–121 BL4
S No input speed error DTCs P0715, P0716, or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S 4–2 gear shift is active.
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 cycle.
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 When DTC P1886 sets, the possible cause of fault
could be TCM.
DTC P1886 – 4–2 Shift Malfunction
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check completed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
Check”
21. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
Then, start engine and allow it to warm up at
idle.
3. Observe ”idle rpm, TPS” on the scan tool.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 3
3Inspect ”ECM”. Refer to Section 1F, System Diagno-
sis, EOBD System Check.
Was a problem found?–Go to ”Engine
Diagnostic In-
formation”Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Measure the voltage between terminal B3 and
B13 of the transaxle wiring connector.
4. Turn the ignition ON.
5. Measure the voltage between terminal C15 and
B13 of the transaxle wiring connector.
6. Measure the voltage between terminal C16 and
B13 of the transaxle wiring connector.
Is the voltage within the values shown?11–14VGo to Step 5Go to ”System
Voltage Low or
High”
5Replace the TCM.
Is the action complete?–Go to Step 6–
61. After the repair, use a scan tool ”clear info”
function and road test the vehicle.
2. Review the ”DTC info”.
Has the last test failed or is the current DTC dis-
played?–Replace the
transaxle as-
semblyRepair verified
exit DTC chart

5A1 – 238IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Transaxle Fluid Temperature (TFT) Sensor
The TFT sensor is a positive temperature coefficient
thermistor (temperature sensitive resistor) that provides
information to the TCM regarding transaxle fluid tempera-
ture. The temperature sensor is located in valve body. Cal-
culated temperature is a factor used to determine the shift
time and shift delay time.
The internal electrical resistance of the sensor varies in
relation to the operating temperature of the transaxle fluid
(see chart).
The TCM sends a 5 volt–reference signal to the tempera-
ture sensor and measures the voltage rise in the electrical
circuit. A higher fluid temperature creates a higher resist-
ance in the temperature sensor, thereby measuring a low-
er voltage signal.
The TCM measures this voltage as another input to help
control line pressure, shift schedules and TCC apply.
When transaxle fluid temperature reaches 140°C (284°F)
the TCM enters ”hot mode.” Above this temperature the
TCM modifies transaxle shift schedules and TCC apply in
an attempt to reduce fluid temperature by reducing trans-
axle heat generation. During hot mode the TCM applies
the TCC at all times in fourth gear.
Also, the TCM commands the 2–3 and 3–4 shifts earlier
to help reduce fluid heat generation. Hot mode may not be
available on some applications.
Transaxle Sensor – Temperature To
Resistance To Voltage (approximate)
°C (°F)R high (ohms)R low (ohms)°C (°F)R high (ohms)R low (ohms)
–40 (–40)58655650 (122)1,2061,173
–30 (–22)64161160 (146)1,2951,256
–20 (–4)69967070 (158)1,3881,341
–10 (14)76073280 (176)1,4851,430
0 (32)82579990 (194)1,5851,522
10 (50)893868100 (212)1,6901,617
20 (68)963942110 (230)1,7981,715
25 (77)1,000980120 (248)1,9101,816
30 (86)1,0391,017130 (266)2,0251,920
140 (284)2,1452,027
Transaxle Electrical Connector
The transaxle electrical connector is a very important part
of the transaxle operating system. Any interference with
the electrical connection can cause the transaxle to set
Diagnostic Trouble Codes (DTCs) and/or affect proper op-
eration.
The following items can affect the electrical connections:S Bent pins in the connector from rough handling dur-
ing connection and disconnection.
S Wires backing away from the pins or coming un-
clamped (in either internal or external wiring har-
ness).
S Dirt contamination entering the connector when dis-
connected.
S Pins in the internal wiring connector backing out of
the connector or pushed out during reconnection.

5A2 – 12IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
SHIFT MODE DIAGRAM
Economic Mode (1.6 DOHC)

5A2 – 72IAISIN AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0748
PRESSURE CONTROL SOLENOID (PCS) ELECTRICAL
Conditions for Setting the DTC
S TCM detects that the feed back voltage is greater
than 4.9 volts and detects the detection 500 milli-
seconds continuously.(When the PCS circuit is
short to battery).
S TCM detects that the feed back voltage is less than
70.mV for 70 milliseconds and detects the 12.5
seconds continuously.(When the PCS circuit is
short to ground or open).
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 lockup control
S No engine torque reduction control
S No engagement pressure control
S No 4th gearS No self–learning control
S After failure decision : emergency mode
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.
S TCM detects the feed back voltage is between
70mV and 4.9 v for 12.5 seconds continuously.
Cause of Failure
S Wiring harness or connector between Pressure
Control Solenoid (PCS) and TCM
S PCS
S TCM

AISIN AUTOMATIC TRANSAXLE 5A2 – 77
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0753
SHIFT SOLENOID 1 (SS1) ELECTRICAL
Conditions for Setting the DTC
S TCM detects that the ON signal of the Shift Sole-
noid 1 (SS1) monitor during 0.5 seconds when SS1
driver outputs the OFF signal.(When the SS1 circuit
is open or short to battery).
S TCM detects that the OFF signal of the Shift Sole-
noid 1 (SS1) monitor during 0.3 seconds when SS1
driver outputs the ON signal.(When the SS1 circuit
is short to ground).
S The above detection 2 times at shifting continuous-
ly.
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 lockup control
S No engine torque reduction control
S No engagement pressure control
S No timing solenoid control for N–D
S No self–learning control
S After failure decision : emergency modeTCM Shifting Pattern (Range : D)
Normal
SS1 FAIL
GearSS1SS2GearSS1SS2
1 stONON3 rdFAILOFF
2 ndONOFF3 rdFAILOFF
3 rdOFFOFF3 rdFAILOFF
4 thOFFON4 thFAILON
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.
S TCM detects the ON signal of the SS1 monitor dur-
ing 160 ms when SS1 driver outputs the ON signal
and TCM detects the OFF signal of the SS1 moni-
tor during 160 ms when SS1 driver outputs the
OFF signal.