Page 675 of 2643
ENGINE CONTROLS 1F – 429
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
271. 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 as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 28Go to Step 2
28Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK
Page 680 of 2643
1F – 434IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
271. 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 as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 28Go to Step 2
28Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK
Page 685 of 2643
ENGINE CONTROLS 1F – 439
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
271. 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 as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 28Go to Step 2
28Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK
Page 690 of 2643
1F – 444IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
271. 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 as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 28Go to Step 2
28Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK
Page 710 of 2643

1F – 464IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0351
IGNITION CONTROL CIRCUIT A FAULT (CYLINDER 1 & 4)
Circuit Description
The Engine Control Module (ECM) provides a ground for
the electronic spark timing A circuit. When the ECM re-
moves the ground path of the ignition primary coil, the
magnetic field produced by the coil collapses. The collaps-
ing magnetic field produces a voltage in the secondary coil
which fires the spark plug.
The circuit between the ECM and the electronic ignition
system ignition coil is monitored for an open circuit, short
to voltage, and short to ground. When the ECM detects a
problem in the electronic spark timing A circuit, it will set
Diagnostic Trouble Code (DTC) P0351.
Conditions for Setting the DTC
S Monitor fault feedback signal.
S Ignition ON.
S Fault flag increments fail count.
S Must receive more than 200 failures within 255 test
cycles.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S Low speed coolant fan turns on.
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
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for:
S Poor connection – Inspect the ECM harness and
connectors for improper mating, broken locks, im-
properly formed or damaged terminals, and poor
terminal–towire connection.
Page 711 of 2643

ENGINE CONTROLS 1F – 465
DAEWOO V–121 BL4
S Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, discon-
nect the ECM, turn the ignition on, and observe a
voltmeter connected to the 58X reference circuit at
the ECM harness connector while moving connec-
tors and wiring harnesses related to the ECM. A
change in voltage will indicate the location of thefault.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
DTC P0351 – Ignition Control Circuit A Fault (Cylinder 1 and 4)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Check for a faulty connection or damaged terminal
C at the Electronic Ignition (EI) system ignition coil
and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 3
3Check for a faulty connection or damaged terminal
M51/M35 at the Engine Control Module (ECM) and
repair as needed.
Is the repair complete?–Go to Step 8Go to Step 4
41. Ignition OFF.
2. Disconnect the ECM connector.
3. Check the ignition control circuit for a short to
ground and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 5
5Check the ignition control circuit for a short to voltage
and repair as necessary.
Is the repair complete?–Go to Step 8Go to Step 6
6Check an open ignition control circuit and repair as
needed.
Is the repair complete?–Go to Step 8Go to Step 7
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 8–
81. 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 supported in the text.
Does the scan tool indicate that this diagnostic ran
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 applica-
ble DTC tableSystem OK
Page 712 of 2643

1F – 466IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0352
IGNITION CONTROL CIRCUIT B FAULT (CYLINDER 2 & 3)
Circuit Description
The Engine Control Module (ECM) provides a ground for
the electronic spark timing A circuit. When the ECM re-
moves the ground path of the ignition primary coil, the
magnetic field produced by the coil collapses. The collaps-
ing magnetic field produces a voltage in the secondary coil
which fires the spark plug.
The circuit between the ECM and the electronic ignition
system ignition coil is monitored for an open circuit, short
to voltage, and short to ground. When the ECM detects a
problem in the electronic spark timing A circuit, it will set
Diagnostic Trouble Code (DTC) P0351.
Conditions for Setting the DTC
S Monitor fault feedback signal.
S Ignition ON.
S Fault flag increments fail count.
S Must receive more than 200 failures within 255 test
cycles.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S Low speed coolant fan turns on.
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
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for:
S Poor connection – Inspect the ECM harness and
connectors for improper mating, broken locks, im-
properly formed or damaged terminals, and poor
terminal–towire connection.
Page 713 of 2643

ENGINE CONTROLS 1F – 467
DAEWOO V–121 BL4
S Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, discon-
nect the ECM, turn the ignition on, and observe a
voltmeter connected to the 58X reference circuit at
the ECM harness connector while moving connec-
tors and wiring harnesses related to the ECM. A
change in voltage will indicate the location of thefault.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
DTC P0352 – Ignition Control Circuit B Fault (Cylinder 2 and 3)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Check for a faulty connection or damaged terminal
A at the Electronic Ignition (EI) system ignition coil
and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 3
3Check for a faulty connection or damaged terminal
M33/M1 at the Engine Control Module (ECM) and
repair as needed.
Is the repair complete?–Go to Step 8Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the ECM connector.
3. Check the ignition control circuit for a short to
ground and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 5
5Check the ignition control circuit for a short to voltage
and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 6
6Check for an open in the ignition control circuit and
repair as needed.
Is the repair complete?–Go to Step 8Go to Step 7
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 8–
81. 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 supported in the text.
Does the scan tool indicate that this diagnostic ran
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 applica-
ble DTC tableSystem OK