Daewoo Nubira. Manual - part 118

1F – 54

I

ENGINE CONTROLS

DAEWOO V–121 BL4

Step

No

Yes

Value(s)

Action

10

1.  Repair the wire between the fuel pump relay

connector terminal 85 to the PCM/ECM con-
nector terminal E13.

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 sec

System OK

11

1.  Repair the wire between the fuel pump relay

connector terminal 30 and the battery.

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 sec

System OK

12

1.  Replace the PCM/ECM.
2.  Turn the ignition OFF for 10 seconds.
3.  Turn the ignition ON.

Does the fuel pump operate for the time specified?

2 sec

System OK

13

Repair the wire between the fuel pump relay connec-
tor terminal 86 and the ignition 1 relay connector ter-
minal 86.
Is the repair complete?

System OK

 

ENGINE CONTROLS  1F – 357

DAEWOO V–121 BL4

SYMPTOM DIAGNOSIS

IMPORTANT PRELIMINARY CHECKS

Important : Several symptom procedures call for a careful visual/physical inspection. Always perform the visual/physical
test first. Visual inspections may lead to correcting a problem without further checks and can save valuable time.

Step

Action

Value(s)

Yes

No

1

Perform an On–Board Diagnostic (OBD II) System
Check.
Is the check complete?

Go toStep 2

Go to”On–

Board Diagnos-

tic System

Check”

2

1.  Inspect all of the powertrain control module

(PCM)/engine control module (ECM) ground
connections.

2.  Inspect all of the vacuum hoses for splits,

kinks, and proper connections.

3.  Check for air leaks at all of the mounting areas

of the intake manifold sealing surfaces.

4.  Inspect the ignition wires for cracking, hard-

ness, proper routing, and carbon tracking.

5.  Inspect the wiring for proper connections,

pinches, and cuts.

Are all checks complete?

Go to Appropri-

ate Symptom

Table

 

INTERMITTENTS

The problem may or may not illuminate the
Malfunction Indicator Lamp (MIL) or store a
diagnostic trouble code (DTC).

Important : Do not use the DTC tables for intermittent
problems. A fault must be present in order to locate the
problem. If a fault is intermittent, use of DTC tables may
result in the replacement of good parts.

Step

Action

Value(s)

Yes

No

1

Were the Important Preliminary Checks performed?

Go toStep 2

Go to”Impor-

tant Preliminary

Checks”

2

1.  Perform a careful inspection of any suspect

circuits.

2.  Inspect for poor mating of the connector

halves, or terminals not fully seated into the
connector body.

3.  Inspect for improperly formed or damaged ter-

minals.

4.  Inspect for poor terminal to wire connections.

This requires removing the terminal from the
connector body to inspect it.

Are any problems present?

Go toStep 3

Go toStep 4

3

Repair the electrical connections as needed.
Is the repair complete?

System OK

1F – 358

I

ENGINE CONTROLS

DAEWOO V–121 BL4

Step

No

Yes

Value(s)

Action

4

Road test the vehicle with a voltmeter connected to
a suspected circuit or a scan tool connected to the
Data Link Connector (DLC).
Did the voltmeter or the scan tool indicate an abnor-
mal voltage or scan reading?

Go toStep 5

Go toStep 6

5

Replace the sensor in the affected circuit, if a Diag-
nostic Trouble Code (DTC) was stored for this circuit
(except for the DTCs P0171 and P0172.
Is the repair complete?

System OK

6

Does an intermittent Malfunction Indicator Lamp
(MIL) or DTC occur?

Go toStep 7

Go toStep 8

7

1.  Check for a faulty relay, electronic control mod-

ule (ECM) driven solenoid, or switch.

2.  Check for improper installation of electrical de-

vices, such as lights, two–way radios, electric
motors, etc.

3.  Inspect the ignition control wires for proper

routing (away from ignition wires, ignition sys-
tem components, and the generator).

4.  Check for a short–to–ground in the MIL circuit

or the DLC ”test” terminal.

5.  Inspect the PCM/ECM ground connections.
6.  Correct or repair the affected circuits as need-

ed.

Is the repair complete?

System OK

8

1.  Check for a loss of DTC memory.
2.  Disconnect the Throttle Position Sensor.
3.  Run the engine at idle until the MIL comes on.
4.  Turn the ignition OFF.

Is DTC P0122 stored in memory?

Go toStep 10

Go toStep 9

9

Replace the PCM/ECM.
Is the repair complete?

System OK

10

Does the vehicle stall while driving?

Go toStep 11

Go toStep 12

11

Monitor the oxygen sensor (O2S) and the injector
base pulse width with the scan tool.
Does the scan tool display a steady low voltage
(about 0 mv) for the O2S sensor with the control
module commanding an injector base pulse width of
the value specified?

8 ms

Go toStep 9

Go toStep 12

12

1.  Check for an open diode across the A/C clutch

and for other open diodes.

2.  Repair or replace any components as needed.

Is the repair complete?

System OK

 

ENGINE CONTROLS  1F – 359

DAEWOO V–121 BL4

HARD START

The engine cranks OK, but does not start for a long
time. The engine eventually runs or may start and
immediately die.

Important : Ensure that the driver is using the correct
starting procedure. Before diagnosing, check service bul-
letins for updates.

Step

Action

Value(s)

Yes

No

1

Were the Important Preliminary Checks performed?

Go toStep 2

Go to”Impor-

tant Preliminary

Checks”

2

1.  Connect the scan tool to the Data Link Con-

nector (DLC).

2.  Check the Engine Coolant Temperature (ECT)

sensor and the Intake Air Temperature (IAT)
sensor using the scan tool.

3.  Compare the coolant temperature and the IAT

with the ambient temperature when the engine
is cold.

Do the ECT and the IAT readings differ from the am-
bient temperature by more than the value specified?

5

³

F (3

³

C)

Go toStep 3

Go toStep 4

3

1.  Measure the resistance of the ECT and the IAT

sensor.

2.  Compare the resistance value to specifications

using the Temperature Vs. Resistance tables
for diagnostic trouble codes (DTCs) P0118 and
P0113.

3.  If the resistance is not the same, replace the

faulty sensor.

Is the repair complete?

System OK

4

1.  Check for a sticking throttle shaft or a binding

linkage that may cause a high Throttle Position
(TP) sensor voltage. Repair or replace as
needed.

2.  Check the TP sensor voltage reading with the

throttle closed.

Does the voltage measure within the value speci-
fied?

0.4–0.8 v

Go toStep 5

Go toStep 26

5

1.  Check the Manifold Absolute Pressure (MAP)

sensor response and accuracy.

2.  Replace the MAP sensor as needed.

Is the repair complete?

System OK

Go toStep 6

6

Check the fuel pump operation.
Does the fuel pump operate for the specified time
when the ignition switch is turned ON?

2 sec

Go toStep 7

Go to”Fuel

Pump Relay

Circuit Check”

7

Check the fuel system pressure.
Is the fuel pressure within the specifications?

(284–325 kPa)

41–47 psi

Go toStep 29

Go toStep 8

8

Check for water contamination in the fuel.
Is fuel contaminated?

Go toStep 9

Go toStep 10

9

Replace the contaminated fuel.
Is the repair complete?

System OK