Ground DAEWOO LACETTI 2004 Service Repair Manual

5A1 – 82IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
121. Disconnect the C105 connector and TCM con-
nector.
2. Turn the ignition ON.
3. Measure the voltage of the terminal B3(TCM
wiring connector).
Is the voltage within the values shown?9–16VGo to Step 13Go to Step 14
13Repair the circuit from EF1 to terminal B3 of the TCM
for a short to power.
Is the repair complete?–System OK–
141. Turn the ignition OFF.
2. Disconnect the C206 connector.
3. Measure the resistance between F2 fuse and
terminal C15 or C16 of the TCM wiring connec-
tor.
Is the resistance within the values shown?0ΩGo to Step 16Go to Step 15
15Repair the circuit(between F2 and terminal C15 or
C16) for a short to ground and open.
Is the repair completed?–System OK–
161. Turn the ignition ON.
2. Measure the voltage of the terminal C15 or
C16(TCM wiring connector).
Is the voltage within the values shown?9–16VGo to Step 17Go to Step 18
17Repair the circuit(between F2 and terminal C15 or
C16) for short to power.
Is the repair complete?–System OK–
181. Inspect the transaxle wiring for poor electrical
connections at the transaxle connector.
2. Look for possible bent, backed out, deformed,
or damaged terminals.
3. Check for weak terminal tension.
Was a condition found?–Verify repair
and Go to Step
1Go to Step 19
19Replace the TCM.
Is the replacement complete?–Go to Step 20–
201. 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?–Begin diagno-
sis againRepair verified
exit DTC chart

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 – 84IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0703 – Brake Switch Circuit 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.
3. Record then clear DTC(s)
4. Select scan tool stransmission data display.
5. Disconnect the brake switch connector.
6. Did the brake switch status change from” on” to
”off”?–Go to Step 3Go to Step 4
31. Replace the brake switch.
2. Refer to Brake Replacement.
3. After the ignition OFF, turn ignition ON.
Is the DTC reset?–Go to Step 4Go to Step 15
4Inspect the EF13.
Is the fuse blown?–Go to Step 5Go to Step 6
5Replace the fuse.
Is the action complete?–System OK–
61. Turn the ignition OFF.
2. Disconnect the C102 wiring connector and the
brake switch wiring connector.
3. Measure the resistance between the terminal
D5 of the C102 connector and the terminal 3 of
the brake switch wiring connector.
Is the resistance within the values shown?0ΩGo to Step 8Go to Step 7
7Repair the open circuit between the C102 connector
and the brake switch connector.
Is the action complete?–System OK–
81. Turn the ignition ON.
2. Measure the voltage of the C102 connector, 6
terminal.
Is the voltage within the values shown?11–14vGo to Step 9Go to Step 10
9Repair the short to power between the C102 con-
nector and the brake switch connector.
Is the action complete?–System OK–
101. Turn the ignition OFF.
2. Disconnect the brake switch wiring connector
and TCM wiring connector.
3. Measure between the brake switch connector,
terminal 4 and TCM connector, terminal A5.
Is the resistance within the values shown?0ΩSystem OKGo to Step 11
11Repair the open or short to ground between brake
switch connector and TCM.
Is the action complete?–System OK–
121. Turn the ignition ON.
2. Measure the voltage of the brake switch wiring
connector, terminal 4.
Is the voltage within the values shown?11–14vGo to Step 13Go to Step 14

5A1 – 86IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0705
TRANSMISSION RANGE SENSOR CIRCUIT
MALFUNCTION (PRNDL INPUT)
Circuit Description
The Transmission range switch is located on the selector
shaft and informs the TCM of the current selector lever
position P–R–N–D–3–2–1.
The selector lever position is transmitted to the TCM in en-
coded form along 4 lines. The encoding is such that mal-
functions in the connecting lead are identified.
The TR switch is located on the selector shaft, which is
connected to the selector lever via a pull cable. In addition,
the TR switch controls the starter interlock, the reverse
lights and the selector lever position indicator on the in-
strument panel.
Conditions for Setting The DTC
S TR switch stuck to closed.
S TR switch wiring harness shortage to ground.
S TR switch wiring harness shortage to power.
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.
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 When DTC P0705 sets, the possible cause of TR
switch.

5A1 – 90IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DTC P0710 – Transmission Fluid Temperature Sensor Circuit
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.
3. Record then clear DTC(s) and turn the ignition
OFF, then turn the ignition ON.
4. Select TFT on the scan tool.
5. Drive the vehicle and observe the scan tool for
either of the flowing conditions:
6. The TFT does not change more than 1.5°C
(34.7°F) in 80 seconds since start–up.
7. The TFT changes more than 20°C (68°F) with-
in 7 seconds (unrealistic change).
Did either of the fail conditions occur?–Go to Step 3Go to ”Diag-
nostic Aids”
31. Turn the ignition OFF.
2. Disconnect the transaxle wiring connector.
3. Measure the resistance between terminals 9
and 4 of the transaxle wiring connector.
Is the resistance within the values shown?TFT 25°C
990 ΩGo to Step 7Go to Step 4
41. Remove the oil pan.
2. Disconnect the wiring connector of the trans-
axle fluid temperature sensor.
3. Inspect the automatic transaxle wiring harness
for an intermittent short or open.
Was a problem found?–Go to Step 5Go to Step 6
5Replace the automatic transaxle wiring harness.
Is the replacement complete?–System OK–
6Replace the TFT sensor.
Is the action complete?–System OK–
71. Disconnect the automatic transaxle wiring con-
nector and disconnect the wiring connector of
the TCM(transaxle control module).
2. Measure the resistance between terminal 4 of
the transaxle wiring connector and terminal B1
of the TCM wiring connector.
3. Measure the resistance between terminal 9 of
the transaxle wiring connector and terminal A4
of the TCM wiring connector.
Is the resistance within the values shown?0ΩGo to Step 9Go to Step 8
81. Inspect the automatic transaxle wiring harness
for an intermittent short to ground or open con-
dition.
2. Inspect the automatic TFT sensor wiring har-
ness for an intermittent short to ground or open
condition.
3. Repair the circuits if necessary.
Is the repair complete?–System OK–

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 133
DAEWOO V–121 BL4
DTC P1606 – Failure Of External Watchdog
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.
Does the scan tool display P1606?–Go to Step 3Go to ”Diag-
nostic Aids”
3Inspect EF1 or F2 fuse for open.
Was a problem found?–Go to Step 4Go to Step 5
4Replace the fuse as necessary.
Is the action completed?–System OK–
51. Turn the ignition OFF.
2. Disconnect the TCM wiring connector.
3. Inspect the wiring harness for short to battery
between the fuses (EF1 or F2) and the TCM
terminals (B3, C15, or C16).
Was a problem found?–Repair the wir-
ing harness.Go to Step 6
6Inspect the wiring harness for open between the
fuses (EF1 or F2) and the TCM terminals (B3, C15
or C16).
Was a problem found?–Repair the wir-
ing harness.Go to Step 7
7Inspect the wiring harness for open or short to
ground between TCM terminals (B12 or B13) and
G201.
Was a problem found?–Repair the wir-
ing harness.Go to Step 8
8Inspect the wiring harness for short to power be-
tween the terminals (B12 or B13) and G201.
Was a problem found?–Repair the wir-
ing harness.Go to Step 9
9Replace the TCM.
Is the replacement complete?–Go to Step 10–
101. Using the scan tool, clear the DTCs.
2. Road test the vehicle within the conditions for
setting this DTC as specified in the text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 11Go to Step 2
111. Check if any DTCs are set.
2. Are any DTCs displayed that have not been
diagnosed?–Go to ”Applica-
ble DTC table”System OK

5A1 – 140IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1839
EDS 3 OUTPUT SHORTED TO GROUND
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 Output voltage of the EDS 3 is less than 2 volts.
S No DTC P1840, P1841.
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.
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 P1839 sets, the possible cause of fault
could be EDS3 valve.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 141
DAEWOO V–121 BL4
DTC P1839 – EDS 3 Output Shorted To Ground
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.
3. Select ”Actuating” on the scan tool.
4. Actuate the EDS 3 ON/OFF.
Does the EDS 3 change ON/OFF?ON/OFFGo to ”Diag-
nostic Aids”Go to Step 3
31. Turn the ignition OFF.
2. Disconnect the transaxle wiring connector.
3. Measure the resistance between terminals 5
and 6 of the transaxle wiring connector.
Is the resistance within the values shown?TFT
25°C (77°F)
6 ΩGo to Step 7Go to Step 4
41. Remove the oil pan.
2. Disconnect the wiring connector of the EDS 3.
3. Measure the resistance between terminal 2 of
the EDS 3 and ground.
4. Measure the resistance between terminal 1 of
the EDS 3 and ground.
Is the resistance within the values shown?
Go to Step 6Go to Step 5
5Repair the internal line(EDS 3) for a short to ground.
Is the repair complete?–System OK–
6Replace the EDS 3.
Is the replacement complete?–System OK–
71. Disconnect the transaxle wiring connector and
TCM connector.
2. Measure the resistance between terminal 5 of
the EDS 3 and ground.
3. Measure the resistance between terminal 6 of
the EDS 3 and ground.
Is the resistance within the values shown?
Go to Step 9Go to Step 8
8Repair the transaxle wiring harness for a short to
ground.
Is the repair complete?–System OK–
9Replace the TCM.
Is the replacement complete?–Go to Step 10–
101. After the repair, use a scan tool ”clear info”
function and road tests the vehicle.
2. Review the ”DTC info”.
Has the last failed or is the current DTC displayed?–Begin diagno-
sis againRepair verified
exit DTC chart

5A1 – 146IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1850
SOLENOID 1 OUTPUT SHORTED TO GROUND
Circuit Description
The shift solenoids are two identical, normally open elec-
tronic exhaust valves that control upshifts and downshifts
in all forward gear ranges. These shift solenoids work to-
gether in a combination of ON and OFF sequences to con-
trol the line pressure and shift mechanisms(clutches,
brakes).
Solenoid 1 controls the high or low of the line pressure
(flow to each clutch valve) by the operation type (ON/
OFF), i.e. solenoid 1 is ON, line pressure will be low
(87~116psi (6~8bar)), solenoid 1 is OFF, line pressure will
be high (232~261psi (16~18bar)). Solenoid 2 controls the
oil flow to clutch valve E or lock–up clutch valve by the ON/
OFF signal.
The TCM monitors numerous inputs to determine the ap-
propriate solenoid state combination and transaxle gear
tor the vehicle operating conditions.
Conditions for Setting the DTC
S Solenoid wiring shorted to ground.
S No DTC P1851, P1852.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 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 P1850 sets, the possible cause of fault
could be solenoid 1.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 147
DAEWOO V–121 BL4
DTC P1850 – Solenoid 1 Output Shorted To Ground
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.
3. Record then clear DTC(s).
4. Select ”Actuating” on the scan tool.
5. Actuate solenoid 1 ON/OFF.
Does the solenoid 1 change ON/OFF?ON/OFFGo to ”Diag-
nostic Aids”Go to Step 3
31. Turn the ignition OFF.
2. Disconnect the transaxle wiring connector.
3. Measure the resistance between terminals 3
and 12 of the transaxle wiring connector.
Is the resistance within the values shown?TFT
25°C (77°F)
26~34.5 ΩGo to Step 7Go to Step 4
41. Remove the oil pan.
2. Disconnect the wiring connector of solenoid 1.
3. Measure the resistance between terminal 2 of
solenoid 1 and ground.
4. Measure the resistance between terminal 1 of
solenoid 1 and ground.
Is the resistance within the values shown?
Go to Step 6Go to Step 5
5Repair the internal line(solenoid 1) for a short to
ground.
Is the repair complete?–System OK–
6Replace the solenoid 1.
Is the replacement complete?–System OK–
71. Disconnect the transaxle wiring connector and
TCM connector.
2. Measure the resistance between terminal 3 of
the transaxle wiring connector and ground.
3. Measure the resistance between terminal 12 of
the transaxle wiring connector and ground.
Is the resistance within the values shown?
Go to Step 9Go to Step 8
8Repair the transaxle wiring harness for a short to
ground.
Is the repair complete?–System OK–
9Replace the TCM.
Is the replacement complete?–Go to Step 10–
101. After the repair, use a scan tool ”clear info”
function and road tests the vehicle.
2. Review the ”DTC info”.
3. Has the last test failed or is the current DTC
displayed?–Begin diagno-
sis againRepair verified
exit DTC chart