2004 DAEWOO LACETTI ignition

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 139
DAEWOO V–121 BL4
DTC P1673 – CAN Receive ECM Message Failure
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. Turn the ignition OFF.
2. Disconnect the TCM wiring connector and
ECM wiring connector.
3. Measure the resistance between terminal A8 of
the TCM wiring connector and terminal K14 of
the ECM wiring connector.
4. Measure the resistance between terminal A16
of the TCM wiring connector and terminal K15
of the ECM wiring connector.
Is the resistance within the values shown?0ΩGo to Step 4Go to Step 3
3Repair the malfunctioning terminals as necessary.
Is the action complete?–System OK–
41. Turn the ignition ON.
2. Measure the voltage of terminal A8.
3. Measure the voltage of terminal A16.
Is the voltage within the values shown?11–14VGo to Step 5Go to Step 6
5Repair the short to power on the terminal(s) as nec-
essary.
Is the action complete?–System OK–
61. Replace the TCM.
2. Turn the ignition OFF and turn the ignition ON.
3. Check if P1673 DTC is set.
Is The DTC set?–Go to Step 7Go to Step 8
71. Replace the ECM.
2. Is the action complete?–Go to Step 8–
81. 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

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 – 142IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1840
EDS 3 OUTPUT 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 Output voltage of the EDS 3(at ON) is 12 volts.
S No DTC P1839, 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 P1840 sets, the possible cause of fault
could be EDS3.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 143
DAEWOO V–121 BL4
DTC P1840 – EDS 3 Output Shorted To Power
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. Remove the oil pan.
2. Disconnect the wiring connector of the EDS 3.
3. Turn the ignition ON, with the engine OFF.
4. Measure the voltage of the EDS3 wiring con-
nector terminal 1.
Is the voltage within the values shown?11–14VGo to Step 4Go to Step 5
4Repair the internal line(EDS 3) for a short to power.
Is the repair complete?–System OK–
5Replace the EDS 3.
Is the replacement complete?–Go to Step 6–
61. 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 – 144IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P1841
EDS 3 OUTPUT OPEN
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 10mA.
S No DTC P1839, P1840.
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 P1841 sets, the possible cause of fault
could be EDS3 valve.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 145
DAEWOO V–121 BL4
DTC P1841 – EDS 3 Output Open
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 terminal 5 of the transaxle con-
nector.
4. Measure the resistance between terminal 1 of
the EDS 3 and terminal 6 of the transaxle con-
nector.
Is the resistance within the values shown? 0 WGo to Step 6Go to Step 5
51. Repair the circuit(between terminal 2 and ter-
minal 5) for an open.
2. Repair the circuit(between terminal 1 and ter-
minal 6) for an open.
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 transaxle wiring connector and terminal C7
of the TCM wiring connector.
3. Measure the resistance between terminal 6 of
the transaxle wiring connector and terminal
A11 of the TCM wiring connector.
Is the resistance within the values shown? 0 WGo to Step 9Go to Step 8
8Repair the transaxle wiring harness for an open.
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 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

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.