2004 DAEWOO NUBIRA check engine

ENGINE CONTROLS 1F – 69
DAEWOO V–121 BL4
Fuel Pump Relay Circuit Check (1.8L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition OFF for 10 seconds.
2. Turn the ignition ON.
3. Listen for in–tank fuel pump operation.
Does the fuel pump operate for the time specified?2 secSystem OKGo to Step 2
21. Turn the ignition OFF.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 30 and ground.
Turn the ignition ON. Is the test light on?–Go to Step 3Go to Step 8
31. Turn the ignition OFF.
2. Connect a test light between the fuel pump
relay connector terminal 85 and battery posi-
tive.
3. Turn the ignition ON.
4. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 secGo to Step 4Go to Step 9
41. Turn the ignition OFF.
2. Connect a test light between the fuel pump
relay connector terminal 30 and ground.
Is the test light on?–Go to Step 5Go to Step 11
5Check for an open or short to ground in the wire be-
tween the fuel pump relay connector terminal 87 and
the fuel pump connector terminal 3.
Is the problem found?–Go to Step 6Go to Step 7
61. Repair the wire between the fuel pump relay
connector terminal 87 and the fuel pump con-
nector terminal 3.
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
71. Replace the fuel pump relay.
2. Turn the ignition OFF for 10 seconds.
3. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
8Check for an open wire between the fuel pump relay
connector terminal 30 and the battery.
Is the problem found?–Go to Step 13–
9Check for an open wire between the fuel pump relay
connector terminal 85 to the engine control module
(ECM) connector terminal K54
Is the problem found.–Go to Step 10Go to Step 12
101. Repair the wire between the fuel pump relay
connector terminal 85 to the ECM connector
terminal K54.
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–

ENGINE CONTROLS 1F – 71
DAEWOO V–121 BL4
MAIN RELAY CIRCUIT CHECK (1.4L/1.6L DOHC)
Circuit Description
When the ignition is turned On or to the START position,
the main relay is energized. The main relay then supply
voltage to the engine fuse block fuse Ef11. The Electronic
Ignition (EI) system ignition coil, Evaporative Emission
(EVAP) Canister Purge Solenoid and Heated Oxygen
Sensor (HO2S) are supplied voltage through the engine
fuse block fuse Ef11. The fuel injectors are supplied volt-
age through the engine fuse block fuse Ef11.Diagnostic Aids
S An intermittent problem may be caused by a poor
connection, rubbed through wire insulation, or a
broken wire inside the insulation.
S A fault main relay will cause a no start condition.
There will be no voltage supplied to the EI system
ignition coil, or the fuel injectors. Without voltage
supplied to these components, they will not oper-
ate.
Main Relay Circuit Check (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Disconnect the engine fuse block fuse Ef11.
3. Turn the ignition ON.
4. With a test light connected to the ground,
probe the fuse terminals nearest the main relay
for fuse Ef11.
Is the light on at both terminal?–System OKGo to Step 2
2Is the light on at only one terminal?–Go to Step 3Go to Step 4
3Repair the open in the wiring between the main relay
connector terminal 87 and the fuse Ef11.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 73
DAEWOO V–121 BL4
MAIN RELAY CIRCUIT CHECK (1.8L DOHC)
Circuit Description
When the ignition is turned On or to the START position,
the main relay is energized. The main relay then supply
voltage to the engine fuse block fuse F2. The Electronic
Ignition (EI) system ignition coil, Evaporative Emission
(EVAP) Canister Purge Solenoid and Heated Oxygen
Sensor (HO2S) are supplied voltage through the engine
fuse block fuse F2. The fuel injectors are supplied voltage
through the engine fuse block fuse F2.Diagnostic Aids
S An intermittent problem may be caused by a poor
connection, rubbed through wire insulation, or a
broken wire inside the insulation.
S A fault main relay will cause a no start condition.
There will be no voltage supplied to the EI system
ignition coil, or the fuel injectors. Without voltage
supplied to these components, they will not oper-
ate.
Main Relay Circuit Check (1.8L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Disconnect the I/P fuse block fuse F2.
3. Turn the ignition ON.
4. With a test light connected to the ground,
probe the fuse terminals nearest the ignition
relay for fuse F2.
Is the light on at both terminal?–System OKGo to Step 2
2Is the light on at only one terminal?–Go to Step 3Go to Step 4
3Repair the open in the wiring between the ignition
relay connector terminal 87 and the fuse F2.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 75
DAEWOO V–121 BL4
MANIFOLD ABSOLUTE PRESSURE CHECK
(1.4L/1.6L DOHC)
Circuit Description
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load (intake manifold vacuum) and rpm
changes. The MAP sensor converts these changes into a
voltage output. The engine control module (ECM) sends
a 5–volt reference voltage to the MAP sensor. As the in-
take manifold pressure changes, the output voltage of the
MAP sensor also changes. A low voltage (high vacuum)
output of 1 to 2 volts is present at idle. A high voltage (low
vacuum) output of 4.0 to 4.8 volts is present at wide open
throttle. The MAP sensor is also used under certain condi-
tions to measure baro–metric pressure. This allows the
ECM to make adjustments for altitude changes. The ECMuses the MAP sensor for fuel delivery and ignition timing
changes.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. Applying 34 kPa (10 inches Hg) of vacuum to the
MAP sensor should cause the voltage to change.
Subtract the second voltage reading from the first.
That voltage value should be more than 1.5 volts.
When applying vacuum to the MAP sensor, the
change in the voltage should happen instantly. A
slow voltage change indicates a faulty MAP sensor.
3. Disconnect the MAP sensor from the bracket and
twist the MAP sensor. Output changes more than
0.1 volt indicate a faulty connector or connection.

1F – 76IENGINE CONTROLS
DAEWOO V–121 BL4
Manifold Absolute Pressure Check (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Connect a scan tool to the Data Link Connec-
tor (DLC).
3. Turn the ignition ON.
4. Compare the Manifold Absolute Pressure
(MAP) sensor voltage reading from the scan-
ner with that from a known good vehicle.
Is the difference in the two voltage readings less
than the value specified?0.4 vGo to Step 2Go to Step 5
21. Turn the ignition OFF.
2. Connect a scan tool to the DLC.
3. Disconnect the MAP sensor vacuum line.
4. Connect a hand vacuum pump to the MAP
sensor.
5. Turn the ignition ON.
6. Note the MAP sensor voltage.
7. Apply 10 in. Hg (34 kPa) of vacuum to the
MAP sensor and note the voltage change.
Is the difference in voltage readings more than the
value specified?1.5 vSystem OKGo to Step 3
3Inspect the MAP sensor connector terminals.
Is the problem found?–Go to Step 4Go to Step 5
4Repair the MAP sensor connector terminals as
needed.
Is the repair complete?–System OK–
5Replace the MAP sensor.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 77
DAEWOO V–121 BL4
MANIFOLD ABSOLUTE PRESSURE CHECK (1.8L DOHC)
Circuit Description
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load (intake manifold vacuum) and rpm
changes. The MAP sensor converts these changes into a
voltage output. The engine control module (ECM) sends
a 5–volt reference voltage to the MAP sensor. As the in-
take manifold pressure changes, the output voltage of the
MAP sensor also changes. A low voltage (high vacuum)
output of 1 to 2 volts is present at idle. A high voltage (low
vacuum) output of 4.0 to 4.8 volts is present at wide open
throttle. The MAP sensor is also used under certain condi-
tions to measure baro–metric pressure. This allows the
ECM to make adjustments for altitude changes. The ECMuses the MAP sensor for fuel delivery and ignition timing
changes.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. Applying 34 kPa (10 inches Hg) of vacuum to the
MAP sensor should cause the voltage to change.
Subtract the second voltage reading from the first.
That voltage value should be more than 1.5 volts.
When applying vacuum to the MAP sensor, the
change in the voltage should happen instantly. A
slow voltage change indicates a faulty MAP sensor.
3. Disconnect the MAP sensor from the bracket and
twist the MAP sensor. Output changes more than
0.1 volt indicate a faulty connector or connection.

1F – 78IENGINE CONTROLS
DAEWOO V–121 BL4
Manifold Absolute Pressure Check (1.8L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition OFF.
2. Connect a scan tool to the Data Link Connec-
tor (DLC).
3. Turn the ignition ON.
4. Compare the Manifold Absolute Pressure
(MAP) sensor voltage reading from the scan-
ner with that from a known good vehicle.
Is the difference in the two voltage readings less
than the value specified?0.4 vGo to Step 2Go to Step 5
21. Turn the ignition OFF.
2. Connect a scan tool to the DLC.
3. Disconnect the MAP sensor vacuum line.
4. Connect a hand vacuum pump to the MAP
sensor.
5. Turn the ignition ON.
6. Note the MAP sensor voltage.
7. Apply 10 in. Hg (34 kPa) of vacuum to the
MAP sensor and note the voltage change.
Is the difference in voltage readings more than the
value specified?1.5 vSystem OKGo to Step 3
3Inspect the MAP sensor connector terminals.
Is the problem found?–Go to Step 4Go to Step 5
4Repair the MAP sensor connector terminals as
needed.
Is the repair complete?–System OK–
5Replace the MAP sensor.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 79
DAEWOO V–121 BL4
IDLE AIR CONTROL SYSTEM CHECK (1.4L/1.6L DOHC)
Circuit Description
The aim of the MTIA (Main Throttle Idle Actuator) is to con-
trol the idle speed with the throttle body itself. The throttle
is motorized for low opening angle (0°C, 19°C). The char-
acteristics of the airflow are not the same for low and high
opening angles. As a matter of fact, the gradient of the
mass air flow function of TPS is lower for small angles that
permits to be more precise during the idle speed control.
Out of idle speed the throttle is actuated mechanically by
a classical bowdencable.
The main throttle idle actuator (MTIA) provides a voltagesignal that changes in relation to the throttle plate angle.
The signal voltage will vary from about nearly 5.0 V at idles
to about 0.2V to 0.4 V at wide–open throttle. The TPS is
one of the most important inputs used by the ECM for fuel
control and other functions such as idle, wide open
throttle, deceleration enleanment, and acceleration en-
richment.
Diagnostic Aids
If the idle is too high, stop the engine. Fully extend the main
throttle idle actuator (MTIA) with a IAC driver. Start the en-
gine. If the idle speed is above 800 rpm, locate and repair
the vacuum leak. Also, check for a binding throttle plate or
throttle linkage or an incorrect base idle setting.