Daewoo Nubira User Manual page 565

1F – 362IENGINE CONTROLS
Step
4
1. Drive the vehicle at the speed of the complaint.
2. Monitor the long term fuel trim reading using
the scan tool.
Is the long term fuel trim reading within the value
specified?
5 Is the long term fuel trim reading below the value
specified?
6 Is the long term fuel trim reading above the value
specified?
7 Check the fuel system pressure while the condition
exists.
Is the fuel system pressure within specifications?
8 Check the in–line fuel filter.
Is the filter dirty or plugged?
9 Perform an injector diagnosis.
Does the injector balance test pinpoint the problem?
10
1. Check for proper ignition voltage output using a
spark tester.
2. Inspect the spark plugs for cracks, wear, im-
proper gap, burned electrodes, or heavy de-
posits.
Is the problem found?
11 Repair or replace any ignition system components
as needed.
Is the repair complete?
12
1. Inspect the powertrain control module
(PCM)/engine control module (ECM) grounds
to make sure they are clean, tight, and in their
proper locations.
2. Inspect the vacuum lines for kinks or leaks.
Is the problem found?
13 Repair the electrical connections or the vacuum
lines as needed.
Is the repair complete?
14 Check the generator output voltage.
Is the generator voltage within the value specified?
15 Repair the generator.
Is the repair complete?
16
1. Check for intermittent Exhaust Gas Recircula-
tion (EGR) valve operation.
2. Check Torque Converter Clutch (TCC) opera-
tion.
3. Repair or replace any components as needed.
Is the repair complete?
17 Repair the fuel system as needed.
Is the repair complete?
Action Value(s) Yes
115–150 Go toStep 7
counts
115 counts Go to"Diagnos-
tic Aids for
DTC P0172"
150 counts Go to"Diagnos-
tic Aids for
DTC P0171"
41–47 psi Go toStep 8
(284–325 kPa)
Go toStep 18
Go toStep 19
Go toStep 11
System OK
Go toStep 13
System OK
12–16 v Go toStep 16
System OK
System OK
System OK
No
Go toStep 5
Go toStep 6
Go toStep 17
Go toStep 9
Go toStep 10
Go toStep 12
Go toStep 14
Go toStep 15
DAEWOO V–121 BL4