OBD port DAEWOO LACETTI 2004 Service Owner's Manual

1F – 274IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0601
ENGINE CONTROL MODULE CHECKSUM ERROR
Circuit Description
The engine control module (ECM) is the control center of
the fuel injection system. It constantly looks at the informa-
tion from various sensors, and controls the systems that
after vehicle performance. The ECM also performs the
diagnostic function of the system. It can recognize opera-
tional problems, alert the driver through the Malfunction In-
dicator Lamp (MIL), and store a Diagnostic Trouble Code
(DTC) or DTCs which identify the problem areas to aid the
technician in making repairs. An electrically erasable pro-
grammable read only memory (EEPROM) is used to
house the program information and the calibrations re-
quired for engine, transaxle, transaxle diagnostics opera-
tion. The ECM uses a value called a checksum for error
detection of the software. The checksum is a value that is
equal to all the numbers in the software added together.
The ECM adds all the values in the software and if that val-
ue does not equal the checksum value, a checksum error
is indicated.Conditions for Setting the DTC
S The ECM detects incorrect checksum.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycle in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
DTC P0601 – Engine Control Module Checksum Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
31. Using the scan tool, clear the DTCs.
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC ad specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 4Go to Step 2
4Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 275
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0604
ENGINE CONTROL MODULE INTERNAL/EXTERNAL RAM
ERROR
Circuit Description
The engine control module (ECM) is the control center of
the fuel injection system. It constantly looks at the informa-
tion from various sensors, and controls the systems that
after vehicle performance. The ECM also performs the
diagnostic function of the system. It can recognize opera-
tional problems, alert the driver through the Malfunction In-
dicator Lamp (MIL), and store a Diagnostic Trouble Code
(DTC) or DTCs which identify the problem areas to aid the
technician in making repairs. An electrically erasable pro-
grammable read only memory (EEPROM) is used to
house the program information and the calibrations re-
quired for engine, transaxle, transaxle diagnostics opera-
tion. The ECM uses a value called a checksum for error
detection of the software. The checksum is a value that is
equal to all the numbers in the software added together.
The ECM adds all the values in the software and if that val-
ue does not equal the checksum value, a checksum error
is indicated.
Conditions for Setting the DTCS The ECM detects an internal or external Random
Acess Memory (RAM) error.
Action Taken When the DTCs Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
DTC P0604 – Engine Control Module Internal/External RAM Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
31. Using the scan tool, clear the DTCs.
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC ad specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 4Go to Step 2
4Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 276IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0605
ENGINE CONTROL MODULE INMVY WRITE ERROR
Circuit Description
The engine control module (ECM) is the control center of
the fuel injection system. It constantly looks at the informa-
tion from various sensors, and controls the systems that
after vehicle performance. The ECM also performs the
diagnostic function of the system. It can recognize opera-
tional problems, alert the driver through the Malfunction In-
dicator Lamp (MIL), and store a Diagnostic Trouble Code
(DTC) or DTCs which identify the problem areas to aid the
technician in making repairs. An electrically erasable pro-
grammable read only memory (EEPROM) is used to
house the program information and the calibrations re-
quired for engine, transaxle, transaxle diagnostics opera-
tion. The ECM uses a value called a checksum for error
detection of the software. The checksum is a value that is
equal to all the numbers in the software added together.
The ECM adds all the values in the software and if that val-
ue does not equal the checksum value, a checksum error
is indicated.Conditions for Setting the DTC
S The ECM detects a INMVY write error.
Action Taken When the DTCs Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
DTC P0605 – Engine Control Module INMVY Write Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
31. Using the scan tool, clear the DTCs.
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC ad specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 4Go to Step 2
4Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 278IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0656 – Fuel Level Gauge Circuit Fault
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Connect the scan tool to the DLC.
3. Turn the Turn the ignition switch to ON.
Are any Diagnostic Trouble Codes (DTCs) dis-
played?–Go to Step 3Try with
another scan
tool
3Refer to the applicable DTC table. Start with the
DTC with the lowest numerical value and move up.
Is the DTC identified as valid trouble code P0656?–Go to Step 4Go to
applicable DTC
table
41. Disconnect the cluster connector.
2. Turn the ignition switch to LOCK.
3. Check for an open or short to ground in the
wire between the ECM connector 40 and clus-
ter connector terminal B3.
Is the problem found?–Go to Step 6Go to Step 5
51. Turn the ignition switch to LOCK.
2. Check for short to battery in the wire between
the the ECM connector 40 and cluster connec-
tor terminal B3.
Is the problem found?–Go to Step 6Go to Step 7
61. Change the between cluster and ECM or repair
the connector terminal as needed.
2. Clear any DTCs from ECM.
3. Perform the diagnostic system check.
Is the repair complete?–System OK–
71. Replace the cluster.
2. Clear any DTCs from ECM.
3. Perform the diagnostic system check.
Are any Diagnostic Trouble Codes (DTCs) dis-
played?–Go to Step 8System OK
8Replace the ECM.
Is the replcement complete?–Go to Step 9–
91. Using the scan tool, clear the Diagnostic
Trouble Codes(DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 280IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1181 – Variable Intake Manifold Solenoid Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Variable Intake Manifold(VIM)
solenoid connector.
3. Measure the resistance of the VIM solenoid.
Does the resistance near the specified value?0 WGo to Step 3Go to Step 6
31. Disconnect the ignition relay connector.
2. Check for an open or a short to ground in the
wire between the VIM solenoid connector ter-
minal 2 and the engine connector terminal 13.
Is the problem found?–Go to Step 4Go to Step 5
4Repair the wire and the connector terminal.
Is the repair complete?–Go to Step 8–
51. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module(ECM)
connector.
3. Check for an open or a short to ground in the
wire between the VIM solenoid connector ter-
minal 1 and the ECM connector terminal 37.
Is the problem found?–Go to Step 4Go to Step 7
6Replace the VIM solenoid.
Is the replacement complete?–Go to Step 8–
7Replace the ECM.
Is the replacement complete?–Go to Step 9–
81. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine.
3. Run the engine until it reaches normal operat-
ing temperature at idle.
4. Operating the vehicle within the conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 282IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1182 – Variable Intake Manifold Solenoid High Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Variable Intake Manifold(VIM)
solenoid connector.
3. Measure the resistance of the VIM solenoid.
Does the resistance near the specified value?0 WGo to Step 3Go to Step 6
31. Disconnect the ignition relay connector.
2. Check for a short to battery in the wire between
the VIM solenoid connector terminal 2 and the
engine connector terminal 13.
Is the problem found?–Go to Step 4Go to Step 5
4Repair the wire and the connector terminal.
Is the repair complete?–Go to Step 8–
51. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module(ECM)
connector.
3. Check for a short to battery voltage in the wire
between the VIM solenoid connector terminal 1
and the ECM connector terminal 37.
Is the problem found?–Go to Step 4Go to Step 7
6Replace the VIM solenoid.
Is the replacement complete?–Go to Step 8–
7Replace the ECM.
Is the replacement complete?–Go to Step 9–
81. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine.
3. Run the engine until it reaches normal operat-
ing temperature at idle.
4. Operating the vehicle within the conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 309
DAEWOO V–121 BL4
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EGR valve may freeze and stick in cold weather at times.
After the vehicle is brought into a warm shop for repairs,
the valve warms and the problem disappears.
By watching the Actual EGR and desired EGR positions
on a cold vehicle with a scan tool, the fault can be easily
verified. Check the Freeze Frame data to determine if the
DTC set when the vehicle was cold by viewing the Engine
Coolant Temperature (ECT).
DTC P1402 – Exhaust Gas Recirculation Blocked
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Start the engine and allow the engine to idle.
2. Install the scan tool.
3. Command the exhaust gas recirculation (EGR)
valve to the specified values.
Does the engine stall or attempt to stall?50%Go to Step 5Go to Step 3
31. Turn the ignition switch to LOCK.
2. Remove the EGR valve assembly.
3. Inspect the EGR valve, passages and pipe for
a restriction or damage and repair as neces-
sary.
Is a repair necessary?–Go to Step 5Go to Step 4
4Replace the EGR valve.
Is the replacement complete?–Go to Step 5–
51. Start the engine.
2. Disconnect the battery for the specified time.
3. Drive the vehicle to the specified value.
4. Release the throttle and allow the vehicle to
decelerate to the specified value.
Is the EGR Decel Filter Values less than the speci-
fied value?10 secnds
60mph
(27km/h)
20mph
(32km/h)
0mphGo to Step 3Go to Step 6
61. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 7Go to Step 2

1F – 320IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1512 – Idle Charge Actuator Mechanical Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Turn the Turn the ignition switch to ON.
Is the Malfunction Indicator Lamp(MIL) on steady?–Go to Step 4Go to Step 3
31. Connect the scan tool the DLC.
2. Turn the Turn the ignition switch to ON.
Does the scan tool display serial data?–Go to Step 4Try with
another scan
tool
4Start the engine.
Does the engine start?–Go to Step 5Go to
”Engine Cranks
But Will Not
Run”
51. Turn the ignition switch to LOCK.
2. Connect the scan tool to the DLC.
3. Turn the Turn the ignition switch to ON.
Are any Diagnostic Trouble Codes (DTCs) dis-
played?–Go to Step 6Try with
another scan
tool
6Refer to the applicable DTC table.
Is only one DTC identified as valid trouble code
P1512?–Go to Step 7Go to Applica-
ble DTC Table
and Go to
”Multiple DTC”
7Check if the accel cable of MTIA is not on accel cable
stop repair the accel cable as necessary.
Is it necessary?–Go to Step 9Go to Step 8
81. Turn the ignition switch to LOCK.
2. Replace the throttle body assembly.
3. Clear any DTCs from ECM.
4. Perform the diagnostic system check.
Is the repair complete?–Go to Step 10–
91. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 325
DAEWOO V–121 BL4
If DTC P1537 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.
DTC P1537 – A/C Compressor Relay High Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete? –Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the A/C compressor relay.
3. Measure the resistance between A/C compres-
sor relay terminals 85 and 86.
Does the resistance within the specified value?0WGo to Step 3Go to Step 7
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 86 in the
relay harness connector.
Does the test light illuminate?–Go to Step 5Go to Step 4
4Repair a short to battery voltage between the ignition
switch terminal and A/C compressor relay terminal
86.
Is the repair complete?–Go to Step 9–
51. Turn the ignition switch to LOCK.
2. Disconnect the ECM.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 8Go to Step 6
6Repair a short to battery voltage between the ECM
wiring connector terminal 41 and A/C compressor
relay terminal 86.
Is the repair complete?–Go to Step 9–
7Replace the A/C compressor relay.
Is the replacement complete?–Go to Step 9–
81. Turn the ignition switch to LOCK.
2. Replace the ECM.
Is the repair complete?–Go to Step 9–
91. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 327
DAEWOO V–121 BL4
If DTC P1538 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.
DTC P1538 – A/C Compressor Relay Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete? –Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the A/C compressor relay.
3. Measure the resistance between A/C compres-
sor relay terminals 85 and 86.
Does the resistance within the specified value?0WGo to Step 3Go to Step 7
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 86 in the
relay harness connector.
Does the test light illuminate?–Go to Step 5Go to Step 4
4Repair a short to ground between the ignition switch
and A/C compressor relay terminal 86.
Is the repair complete?–Go to Step 9–
51. Turn the ignition switch to LOCK.
2. Disconnect the ECM.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 86 in the
relay harness connector.
Does the test light illuminate?–Go to Step 8Go to Step 6
6Repair a short to ground between the ECM wiring
connector terminal 41 and A/C compressor relay ter-
minal 86.
Is the repair complete?–Go to Step 9–
7Replace the A/C compressor relay.
Is the replacement complete?–Go to Step 9–
81. Turn the ignition switch to LOCK.
2. Replace the ECM.
Is the repair complete?–Go to Step 9–
91. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK