2004 DAEWOO LACETTI driver

1F – 428IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #1 spark plug
cable.
4. Crank the engine and check for spark.
Is a spark observed on all four spark plug cables?–Go to Step 12Go to Step 20
12Replace the malfunctioning spark plug.
Is the repair complete?–Go to Step 27Go to Step 13
131. Turn the engine OFF.
2. Disconnect the cylinder #1 fuel injector connec-
tors from the injector.
3. Install an injector test light on the injector har-
ness connector, terminal 1.
4. Crank the engine and note the test light.
Does the injector test light blink?–Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
151. Disconnect the injector test light.
2. With a test light connected to ground, probe
the ignition feed terminal 2 of the injector har-
ness connector.
3. Crank the engine.
Does the test light illuminate?–Go to Step 17Go to Step 19
16Replace the malfunctioning fuel injector.
Is the repair complete?–Go to Step 26–
17Check the affected fuel injector driver circuit for an
open, short, or short to voltage.
Is a problem found?–Go to Step 18Go to Step 24
18Repair the open or the shorted fuel injector driver cir-
cuit.
Is the repair complete?–Go to Step 27–
19Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector con-
nector.
Is the repair complete?–Go to Step 27–
20Measure the resistance of the spark plug cable.
Is the resistance of the spark plug cable less than the
specified value?30,000 WGo to Step 21Go to Step 25
21Inspect the Engine Control Module (ECM) connec-
tor and connections.
Are the connections OK?–Go to Step 22Go to Step 23
22Check the affected cylinders ignition control circuit
for an open or short and repair as needed.
Is the repair complete?–Go to Step 27Go to Step 26
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
241. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 27–
25Replace the spark plug cable.
Is the action complete?–Go to Step 27–

1F – 432IENGINE CONTROLS
DAEWOO V–121 BL4
8. Check the fuel for water, alcohol, etc.
9. A basic engine problem that affects all cylinders is
the only possibility at this point. (Cam timing,
throttle body leak, restricted air flow, etc.)
11. Tests the ignition system voltage output using a
spark tester.
12. Replace any spark plugs that are worn, cracked or
fouled.
13. Checks for voltage at the ignition feed circuit.
18. Whenever the driver circuit is shorted to ground,
the light will be on steady. When the driver circuit is
shorted to voltage or open, the light will be off.19. Since voltage is supplied to the fuel injector on a
single circuit, the malfunction could only be a poor
connection or open in the fuel injector harness. An
open before the harness would result in an ”Engine
Cranks But Will Not Run” complaint.
28. Before replacing the ECM, check terminals for im-
proper mating, broken locks, or physical damage to
the wiring harness. The replacement ECM must be
programmed. Refer to the latest Techline procedure
for ECM reprogramming.
DTC P0302 – Cylinder 2 Misfire
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0202 or P300 set?–Go to applica-
ble DTCGo to Step 3
31. Perform a visual/physical inspection.
2. Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”
71. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine run-
ning.
Is the fuel pressure within the specified value?284–325 kPa
(41–47 psi)Go to Step 8Go to
”Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?–Go to Step 9Go to Step 10
9Check for a basic engine problem and repair as nec-
essary.
Is the repair complete?–Go to Step 27–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–

ENGINE CONTROLS 1F – 433
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #2 spark plug
cable.
4. Crank the engine and check for spark.
Is a spark observed on all four spark plug cables?–Go to Step 12Go to Step 20
12Replace the malfunctioning spark plug.
Is the repair complete?–Go to Step 27Go to Step 13
131. Turn the engine OFF.
2. Disconnect the cylinder #2 fuel injector connec-
tors from the injector.
3. Install an injector test light on the injector har-
ness connector, terminal 1.
4. Crank the engine and note the test light.
Does the injector test light blink?–Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
151. Disconnect the injector test light.
2. With a test light connected to ground, probe
the ignition feed terminal 2 of the injector har-
ness connector.
3. Crank the engine.
Does the test light illuminate?–Go to Step 17Go to Step 19
16Replace the malfunctioning fuel injector.
Is the repair complete?–Go to Step 27–
17Check the affected fuel injector driver circuit for an
open, short, or short to voltage.
Is a problem found?–Go to Step 18Go to Step 24
18Repair the open or the shorted fuel injector driver cir-
cuit.
Is the repair complete?–Go to Step 27–
19Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector con-
nector.
Is the repair complete?–Go to Step 27
20Measure the resistance of the spark plug cable.
Is the resistance of the spark plug cable less than the
specified value?30,000 WGo to Step 21Go to Step 25
21Inspect the Engine Control Module (ECM) connec-
tor and connections.
Are the connections OK?–Go to Step 22Go to Step 23
22Check the affected cylinders ignition control circuit
for an open or short and repair as needed.
Is the repair complete?–Go to Step 27Go to Step 26
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
241. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 27–
25Replace the spark plug cable.
Is the repair complete?–Go to Step 27–

ENGINE CONTROLS 1F – 437
DAEWOO V–121 BL4
8. Check the fuel for water, alcohol, etc.
9. A basic engine problem that affects all cylinders is
the only possibility at this point. (Cam timing,
throttle body leak, restricted air flow, etc.)
11. Tests the ignition system voltage output using a
spark tester.
12. Replace any spark plugs that are worn, cracked or
fouled.
13. Checks for voltage at the ignition feed circuit.
18. Whenever the driver circuit is shorted to ground,
the light will be on steady. When the driver circuit is
shorted to voltage or open, the light will be off.19. Since voltage is supplied to the fuel injector on a
single circuit, the malfunction could only be a poor
connection or open in the fuel injector harness. An
open before the harness would result in an ”Engine
Cranks But Will Not Run” complaint.
28. Before replacing the ECM, check terminals for im-
proper mating, broken locks, or physical damage to
the wiring harness. The replacement ECM must be
programmed. Refer to the latest Techline procedure
for ECM reprogramming.
DTC P0303 – Cylinder 3 Misfire
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0203 or P300 set?–Go to applica-
ble DTCGo to Step 3
31. Perform a visual/physical inspection.
2. Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”
71. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine run-
ning.
Is the fuel pressure within the specified value?284–325 kPa
(41–47 psi)Go to Step 8Go to
”Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?–Go to Step 9Go to Step 10
9Check for a basic engine problem and repair as nec-
essary.
Is the repair complete?–Go to Step 27–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–

1F – 438IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #3 spark plug
cable.
4. Crank the engine and check for spark.
Is a spark observed on all four spark plug cables?–Go to Step 12Go to Step 20
12Replace the malfunctioning spark plug.
Is the repair complete?–Go to Step 27Go to Step 13
131. Turn the engine OFF.
2. Disconnect the cylinder #3 fuel injector connec-
tors from the injector.
3. Install an injector test light on the injector har-
ness connector, terminal 1.
4. Crank the engine and note the test light.
Does the injector test light blink?–Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
151. Disconnect the injector test light.
2. With a test light connected to ground, probe
the ignition feed terminal 2 of the injector har-
ness connector.
3. Crank the engine.
Does the test light illuminate?–Go to Step 17Go to Step 19
16Replace the malfunctioning fuel injector.
Is the repair complete?–Go to Step 27–
17Check the affected fuel injector driver circuit for an
open, short, or short to voltage.
Is a problem found?–Go to Step 18Go to Step 24
18Repair the open or the shorted fuel injector driver cir-
cuit.
Is the repair complete?–Go to Step 27–
19Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector con-
nector.
Is the repair complete?–Go to Step 27–
20Measure the resistance of the spark plug cable.
Is the resistance of the spark plug cable less than the
specified value?30,000 WGo to Step 21Go to Step 25
21Inspect the Engine Control Module (ECM) connec-
tor and connections.
Are the connections OK?–Go to Step 22Go to Step 23
22Check the affected cylinders ignition control circuit
for an open or short and repair as needed.
Is the repair complete?–Go to Step 27Go to Step 26
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
241. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 27–
25Replace the spark plug cable.
Is the repair complete?–Go to Step 27–

1F – 442IENGINE CONTROLS
DAEWOO V–121 BL4
8. Check the fuel for water, alcohol, etc.
9. A basic engine problem that affects all cylinders is
the only possibility at this point. (Cam timing,
throttle body leak, restricted air flow, etc.)
11. Tests the ignition system voltage output using a
spark tester.
12. Replace any spark plugs that are worn, cracked or
fouled.
13. Checks for voltage at the ignition feed circuit.
18. Whenever the driver circuit is shorted to ground,
the light will be on steady. When the driver circuit is
shorted to voltage or open, the light will be off.19. Since voltage is supplied to the fuel injector on a
single circuit, the malfunction could only be a poor
connection or open in the fuel injector harness. An
open before the harness would result in an ”Engine
Cranks But Will Not Run” complaint.
28. Before replacing the ECM, check terminals for im-
proper mating, broken locks, or physical damage to
the wiring harness. The replacement ECM must be
programmed. Refer to the latest Techline procedure
for ECM reprogramming.
DTC P0304 – Cylinder 4 Misfire
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0201 or P300 set?–Go to applica-
ble DTCGo to Step 3
31. Perform a visual/physical inspection.
2. Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”
71. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine run-
ning.
Is the fuel pressure within the specified value?284–325 kPa
(41–47 psi)Go to Step 8Go to
”Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?Go to Step 9Go to Step 10
9Check for a basic engine problem and repair as nec-
essary.
Is the repair complete?–Go to Step 27–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–

ENGINE CONTROLS 1F – 443
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #4 spark plug
cable.
4. Crank the engine and check for spark.
Is a spark observed on all four spark plug cables?–Go to Step 12Go to Step 20
12Replace the malfunctioning spark plug.
Is the repair complete?–Go to Step 27Go to Step 13
131. Turn the engine OFF.
2. Disconnect the cylinder #4 fuel injector connec-
tors from the injector.
3. Install an injector test light on the injector har-
ness connector, terminal 1.
4. Crank the engine and note the test light.
Does the injector test light blink?–Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
151. Disconnect the injector test light.
2. With a test light connected to ground, probe
the ignition feed terminal 2 of the injector har-
ness connector.
3. Crank the engine.
Does the test light illuminate?–Go to Step 17Go to Step 19
16Replace the malfunctioning fuel injector.
Is the repair complete?–Go to Step 27 –
17Check the affected fuel injector driver circuit for an
open, short, or short to voltage.
Is a problem found?–Go to Step 18Go to Step 24
18Repair the open or the shorted fuel injector driver cir-
cuit.
Is the repair complete?–Go to Step 27–
19Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector con-
nector.
Is the repair complete?–Go to Step 27–
20Measure the resistance of the spark plug cable.
Is the resistance of the spark plug cable less than the
specified value?30,000 WGo to Step 21Go to Step 25
21Inspect the Engine Control Module (ECM) connec-
tor and connections.
Are the connections OK?–Go to Step 22Go to Step 23
22Check the affected cylinders ignition control circuit
for an open or short and repair as needed.
Is the repair complete?–Go to Step 27Go to Step 26
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
241. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 27–
25Replace the spark plug cable.
Is the repair complete?–Go to Step 27–

ENGINE CONTROLS 1F – 493
DAEWOO V–121 BL4
DTC P0462 – Fuel Level Low Voltage
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”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine and operate the vehicle within
Failure Record condition as noted.
Is Diagnostic trouble Codes (DTCs) P0462 set?–Go to Step 3Go to
”Diagnostic
Aids”
31. Turn the ignition OFF.
2. Disconnect the fuel pump connector.
3. Turn the ignition ON.
4. Using a voltmeter, measure the fuel level signal
voltage at the fuel level sensor connector ter-
minal 1.
Is the voltage within the specified value?0.4 – 4.5 VGo to Step 4Go to Step 6
4Check for a proper ground connection at the fuel
tank and repair as needed.
Is the repair complete?–Go to Step 11Go to Step 5
51. Remove the fuel pump from the fuel tank.
2. Reconnect the fuel pump connector.
3. Turn the ignition ON.
4. Monitor the fuel level sensor parameter on the
scan tool while moving the fuel sensor float
from empty position to full position.
5. Repeat procedure 4 several times.
Does the fuel level sensor vale on the scan tool in-
crease and then decrease steadily when the float is
moved?–Go to
”Diagnostic
Aids”Go to Step 8
6Check for an open or short to ground in the fuel level
sensor circuit and repair as needed.
Is the repair necessary?–Go to Step 11Go to Step 9
7Repair the open or short to ground in the fuel level
sensor circuit between the fuel level sensor harness
connector and fuel level sensor.
Is the repair complete?–Go to Step 11–
81. Turn the ignition OFF.
2. Replace the fuel pump assembly.
Is the repair complete?–Go to Step 11–
91. Turn the ignition OFF.
2. Connect the fuel pump connector.
3. Disconnect the engine Control Module (ECM)
connector.
4. Turn the ignition ON.
5. Using a digital voltmeter, measure the voltage
in the signal circuit at terminal K51.
Is the voltage within the specified value?4–5 VGo to Step 10Go to
Section 9E, In-
strumentation/
Driver Informa-
tion
10S Turn the ignition OFF.
S Replace the ECM.
Is the repair complete?–Go to Step 11–