2004 DAEWOO NUBIRA Engine Electrical

1F – 32IENGINE CONTROLS
DAEWOO V–121 BL4
ON–BOARD DIAGNOSTIC (EOBD) SYSTEM CHECK
(1.4L/1.6L DOHC)
Circuit Description
The On–Board Diagnostic (EOBD) system check is the
starting point for any driveability complaint diagnosis. Be-
fore using this procedure, perform a careful visual/physi-
cal check of the engine control module (ECM) and the en-
gine grounds for cleanliness and tightness.
The EOBD system check is an organized approach to
identifying a problem created by an electronic engine con-
trol system malfunction.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for poor connections or a damaged har-
ness. Inspect the ECM harness and connections for im-
proper mating, broken locks, improperly formed or dam-
aged terminals, poor terminal–to–wire connection, and
damaged harness.Test Description
Numbers below refer to the step number on the Diagnostic
Chart:
1. The Malfunction Indicator Lamp (MIL) should be
ON steady with the ignition ON and the engine
OFF. If not, go to ”Diagnostic Aids”.
2. Checks the Class 2 data circuit and ensures that
the ECM is able to transmit serial data.
3. This test ensures that the ECM is capable of con-
trolling the MIL and the MIL driver circuit is not
shorted to ground.
4. If the engine will not start, refer to ”Engine Cranks
But Will Not Run” in this section.
7. A scan tool parameter which is not within the typical
range may help to isolate the area which is causing
the problem.
10. This vehicle is equipped with a ECM which utilizes
an Electrically Erasable Programmable Read Only
Memory (EEPROM). The replacement ECM must
be programmed. Refer to the latest Techline proce-
dure for ECM reprogramming.

1F – 34IENGINE CONTROLS
DAEWOO V–121 BL4
ON–BOARD DIAGNOSTIC (EOBD) SYSTEM CHECK
(1.8L DOHC)
Circuit Description
The On–Board Diagnostic (EOBD) system check is the
starting point for any driveability complaint diagnosis. Be-
fore using this procedure, perform a careful visual/physi-
cal check of the engine control module (ECM) and the en-
gine grounds for cleanliness and tightness.
The EOBD system check is an organized approach to
identifying a problem created by an electronic engine con-
trol system malfunction.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for poor connections or a damaged har-
ness. Inspect the ECM harness and connections for im-
proper mating, broken locks, improperly formed or dam-
aged terminals, poor terminal–to–wire connection, and
damaged harness.Test Description
Numbers below refer to the step number on the Diagnostic
Chart:
1. The Malfunction Indicator Lamp (MIL) should be
ON steady with the ignition ON and the engine
OFF. If not, go to”Diagnostic Aids”.
2. Checks the Class 2 data circuit and ensures that
the ECM is able to transmit serial data.
3. This test ensures that the ECM is capable of con-
trolling the MIL and the MIL driver circuit is not
shorted to ground.
4. If the engine will not start, refer to ”Engine Cranks
But Will Not Run” in this section.
7. A scan tool parameter which is not within the typical
range may help to isolate the area which is causing
the problem.
10. This vehicle is equipped with a ECM which utilizes
an Electrically Erasable Programmable Read Only
Memory (EEPROM). The replacement ECM must
be programmed. Refer to the latest Techline proce-
dure for ECM reprogramming.

1F – 40IENGINE CONTROLS
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN (1.4L/1.6L DOHC)
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the occurred. The information is then stored on the
scan tool for later reference.
2. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
3. It is important to check for the presence of sparkfrom all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the Crank-
shaft Position (CKP) sensor is OK.
19. In checking the engine control module (ECM) out-
puts for the electronic spark timing signal, it recom-
mended to use an oscilloscope to view the varying
voltage signals. In measuring these outputs with a
voltmeter, intermittent errors may occur that cannot
be seen by a voltmeter.
35. This step checks for proper operation of the ECM’s
control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the ECM to operate the fuel injectors. If there is
no ground present during the cranking of the en-
gine, and the fuel injector wiring is OK, the ECM is
at fault.
Engine Cranks But Will Not Run (1.4L/1.6L DOHC)
CAUTION : Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines.Damage to the lines could cause a fuel leak, resulting
in possible fire or personal injury.
Step
ActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the check complete.–Go to Step 2Go to
”Euro On–
Board Diagnos-
tic System
Check”
2Crank the engine.
Does the engine start and continue to run?–System OKGo to Step 3
3Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?689 kPa
(100 psi)Go to Step 7Go to Step 4
4Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 6Go to Step 5
5Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 2–
6Repair internal engine damage as needed.
Is the repair complete?–Go to Step 2–
7Inspect the fuel pump fuse.
Is the problem found?–Go to Step 8Go to Step 9
8Replace the fuse.
Is the repair complete?–Go to Step 2–
9Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
Is spark present from all of the ignition wires?–Go to Step 23Go to Step 10
101. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a resist-
ance above the value specified.
3. Check for the presence of spark from all of the
ignition wire.
Is spark present from all of the ignition wires?30000 WGo to Step 2Go to Step 11

ENGINE CONTROLS 1F – 41
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the ignition OFF.
2. Disconnect the crankshaft position (CKP) sen-
sor connector.
3. Turn the ignition ON.
4. Measure the voltage between following termi-
nals:
S Terminal 1 and 3 of the CKP sensor con-
nector.
S Terminal 2 and 3 of the CKP sensor con-
nector.
S Terminal 1 of the CKP sensor connector
and ground.
S Terminal 2 of the CKP sensor connector
and ground.
Are the voltage measure within the value specified?
1.4 VGo to Step 13Go to Step 12
12Check for an open or short in the wires between CKP
sensor connector and ECM connector and repair as
need.
Is the repair complete?–Go to Step 2–
131. Disconnect electronic Ignition (EI) system igni-
tion coil connector to prevent the vehicle from
starting.
2. Measure the voltage at ECM connector termi-
nal 85 and 54 by backprobing the ECM con-
nector.
Are the voltage readings near the value specified?1.4V with
ignition ON,
1.6V during
crankingGo to Step 15Go to Step 14
14Replace the CKP sensor.
Is the repair complete?–Go to Step 2–
151. Turn the ignition OFF.
2. Disconnect the electrical connector at EI sys-
tem ignition coil.
3. Connect a test light between terminal 2 of the
EI system ignition coil connector and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 17Go to Step 16
16Check for open in wire between the battery and EI
system ignition coil connector terminal 2 and repair
as needed.
Is the repair complete?–Go to Step 2–
171. Turn the ignition OFF.
2. Disconnect ECM connect and EI system igni-
tion coil connector.
3. Measure the resistance between following ter-
minals:
S Terminal 1 of ignition coil and terminal 31 of
ECM connector.
S Terminal 1 of ignition coil and terminal 32 of
ECM connector.
Are the resistance within the value specified?0 WGo to Step 19Go to Step 18
18Check for open circuit and repair as needed.
Is the repair complete?–Go to Step 2–

1F – 42IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
191. Measure the resistance between following ter-
minals:
S Terminal 1 and 2 of ignition coil.
S Terminal 2 and 1 of ignition coil.
Are the resistance within the value specified.
1. Remove the high tension cable.
2. Measure the resistance between second coil.
S Between 1 and 4
S Between 2 and 3
Are the resistance within the value specified.0.9 W
5.3 kWGo to Step 21Go to Step 20
20Replace the EI system ignition coil.
Is the repair complete?–Go to Step 2–
211. Check for any damages or poor connection in
ignition wires and repair as needed.
2. Connect the EI system ignition coil connector
and ECM connector.
3. Check for the presence of spark from all of the
ignition wires.
Is the spark present from all of the ignition wires?–Go to Step 2Go to Step 22
22Replace ECM.
Is the repair complete?–Go to Step 2–
231. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 26Go to Step 24
241. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump ter-
minals 2 and 3.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 sec.Go to Step 25Go to 34
25Replace the fuel pump.
Is the repair complete?–Go to Step 2–
26Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 27Go to Step 29
27Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 28Go to Step 41
281. Remove the contaminated fuel from the fuel
tank.
2. Clean the fuel tank as needed.
Is the repair complete?–Go to Step 2–
291. Check the fuel filter for restriction.
2. Inspect the fuel lines for kinks and restrictions.
3. Repair or replace as needed.
4. Measure the fuel pressure.
Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 2Go to Step 30

ENGINE CONTROLS 1F – 47
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN (1.8L DOHC)
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the occurred. The information is then stored on the
scan tool for later reference.
2. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
3. It is important to check for the presence of sparkfrom all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the Crank-
shaft Position (CKP) sensor is OK.
19. In checking the engine control module (ECM) out-
puts for the electronic spark timing signal, it recom-
mended to use an oscilloscope to view the varying
voltage signals. In measuring these outputs with a
voltmeter, intermittent errors may occur that cannot
be seen by a voltmeter.
35. This step checks for proper operation of the ECM’s
control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the ECM to operate the fuel injectors. If there is
no ground present during the cranking of the en-
gine, and the fuel injector wiring is OK, the ECM is
at fault.
Engine Cranks But Will Not Run (1.8L DOHC)
CAUTION : Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines.Damage to the lines could cause a fuel leak, resulting
in possible fire or personal injury.
Step
ActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic
(EOBD) Sys-
tem Check”
2Check for set Diagnostic Trouble Code (DTC)
P0601.
Is the DTC set?–Go to applica-
ble DTC tableGo to Step 4
3Crank the engine.
Does the engine start and continue to run?–System OKGo to Step 5
4Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?689 kPa
(100 psi)Go to Step 8Go to Step 5
5Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 7Go to Step 6
6Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 3–
7Repair the internal engine damage as needed.
Is the repair complete?–Go to Step 3–
8Inspect the fuel pump fuse.
Is the problem found?–Go to Step 9Go to Step 10
9Replace the fuse.
Is the repair complete?–Go to Step 3–
101. Install a scan tool.
2. Turn the ignition ON, the engine OFF and close
the throttle.
Does the Throttle Position (TP) sensor read less
than the specified value.1.0 vGo to Step 11Go to ”DTC
P0123 Throttle
Position Sensor
High Voltage”

ENGINE CONTROLS 1F – 49
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
24Check for an open or short in the wire between the
CKP connector terminal 2 and the ECM connector
terminal M5.
Is the problem found?–Go to Step 25Go to 40
25Repair the wiring as needed.
Is the repair complete?–Go to Step 3–
261. Disconnect the Electronic Ignition (EI) system
ignition coil connector to prevent the vehicle
from starting.
2. Measure the voltage at the ECM connector
terminal M21 by backprobing the ECM connec-
tor.
Are the voltage readings near the values specified?1.4 v (2.5 v)*
with ignition
ON, 1.6 v (2.6
v)* during
crankingGo to Step 27Go to Step 28
27Measure the voltage at the ECM connector terminal
M5 by backprobing the ECM connector.
Are the voltage readings near the values specified?1.4 v (2.5 v)*
with ignition
ON, 1.6 v (2.6
v)* during
crankingGo to Step 29Go to Step 28
28Replace the CKP sensor.
Is the repair complete?–Go to Step 3–
291. Turn the ignition OFF.
2. Disconnect the electrical connector at the EI
system ignition coil.
3. Connect a test light between terminal 2 of the
EI system ignition coil connector and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 30Go to Step 31
30Connect a test light of the EI system ignition coil con-
nector and battery positive.
Is the test light on?–Go to Step 34Go to Step 32
31Check for an open in the wiring between the ignition
switch and the EI system ignition coil connector ter-
minal 3.
Is the problem found?–Go to Step 33–
32Check for an open in the wire from the EI system
ignition coil to ground.
Is the problem found?–Go to Step 2–
331. Repair the wiring as needed.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?–Go to Step 3Go to Step 34
341. Turn the ignition OFF.
2. Disconnect the EI system ignition coil connec-
tor.
3. While cranking the engine, measure the volt-
age at the EI system ignition coil connector
terminal 1.
Does the voltage fluctuate within the values speci-
fied?0.2–2.0 vGo to Step 39Go to Step 37

1F – 50IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
35While cranking the engine, measure the voltage at
the EI system ignition coil connector terminal 3 .
Does the voltage fluctuate within the values speci-
fied?0.2–2.0 vGo to Step 39Go to Step 37
36Check for an open in the wire from the EI system
ignition coil connector terminal 1 to the ECM connec-
tor terminal M51.
Is the problem found?–Go to Step 38Go to Step 40
37Check for an open in the wire from the EI system
ignition coil connector terminal 3 to the ECM connec-
tor terminal M1.
Is the problem found?–Go to Step 38Go to Step 40
381. Repair the wiring as needed.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?–Go to Step 3Go to Step 39
39Replace the EI system ignition coil.
Is the repair complete?–Go to Step 3–
401. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 3–
411. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 44Go to Step 42
421. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump
connector terminals 3 and 2.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 secGo to Step 43Go to Step 53
43Replace the fuel pump.
Is the repair complete?–Go to Step 3–
44Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 48Go to Step 45
451. Check the fuel filter for a restriction.
2. Inspect the fuel lines for kinks and restrictions.
Is the problem found?–Go to Step 46Go to Step 47
461. Disconnect the vacuum line from the fuel pres-
sure regulator.
2. Inspect the vacuum line for the presence of
fuel.
3. Inspect the fuel pressure regulator vacuum port
for the presence of fuel.
Is any fuel present?283–324 kPa
(41–47 psi)Go to Step 3Go to Step 47