1F–282 ENGINE CONTROLS
DAEWOO M-150 BL2
Intermittent (Cont’d)
StepActionValue(s)YesNo
9
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
–
System OK
–
10Does the vehicle stall while driving?–Go to Step 11Go to Step 12
11
Monitor the oxygen sensor and the injector base
pulse width with the scan tool.
Does the scan tool display a steady low voltage
(about 0 millivolts) for the oxygen sensor with the
control module commanding an injector base pulse
width of the value specified?
8 msGo to Step 9Go to Step 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–283
DAEWOO M-150 BL2
HARD START
Definition: 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
bulletins for updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Connect the scan tool to the Data Link Connector
(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
ambient temperature by more than the value
specified?
3C (5F)Go to Step 3Go to Step 4
3
1. Measure the resistance of the ECT sensor and
the IAT sensor.
2. Compare the resistance value to specifications
using the Temperature Vs. Resistance tables for
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
specified?
0.4–0.8 VGo to Step 5Go to Step 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 OKGo to Step 6
6
Check the fuel pump operation.
Does the fuel pump operate for the specified time
when the ignition switch is turned ON?
2 secGo to Step 7
Go to “Fuel
Pump Relay
Circuit Check”
7Check the fuel system pressure.
Is the fuel pressure within the specifications?380 kPa
(55 psi)
Go to Step 8Go to Step 27
8Check for water contamination in the fuel.
Is fuel contaminated?–Go to Step 9Go to Step 10
9Replace the contaminated fuel.
Is the repair complete?–System OK–
1F–284 ENGINE CONTROLS
DAEWOO M-150 BL2
Hard Start (Cont’d)
StepActionValue(s)YesNo
10
1. Check the fuel injector driver circuit.
2. Disconnect all of the fuel injector harness
connectors at the fuel injectors.
3. Connect an injector test light between the
harness terminals of each fuel injector connector.
4. Note the test light while cranking the engine.
Does the test light blink at all connectors?
–
Go to Step 13Go to Step 11
11
Check the fuel injector driver wiring harness, the
connectors, and the connector terminals for the
proper connections.
Is the problem found?
–
Go to Step 12Go to Step 28
12
Repair the wiring harness, the connector, or the
connector terminal as needed.
Is the repair complete?
–
System OK
–
13
Measure the resistance of each fuel injector.
Is the fuel injector resistance within the value
specified at 20C (68F)
Note: The resistance will increase slightly at higher
temperatures)?
11.6–12.4 ΩGo to Step 15Go to Step 14
14
Replace any fuel injector with a resistance that is out
of specifications.
Is the repair complete?
–
System OK
–
15Perform an injector diagnosis.
Is the problem found?–Go to Step 16Go to Step 17
16
Replace any restricted or leaking fuel injectors as
needed.
Is the repair complete?
–
System OK
–
17
1. Check for the proper ignition voltage output for
each cylinder with a spark tester.
2. Inspect the spark plugs for cracks, wear, improper
gap, burned electrodes, or heavy deposits.
3. Inspect the ignition wires for short conditions.
4. Inspect all of the ignition grounds for loose
connections.
5. Inspect the Engine Control Module (ECM) for the
proper operation.
Is the problem found?
–
Go to Step 18Go to Step 19
18Correct or replace any faulty ignition components.
Is the repair complete?–System OK–
19Does the engine misfire or cut out under load or at
idle?–Go to “Ignition
System Check”
Go to Step 20
20Does the engine start, but then immediately stall?–Go to Step 21Go to Step 23
21
1. Remove the Crankshaft Position (CKP) sensor.
2. Inspect for faulty connections and repair as
needed.
Is the problem found?
–
Go to Step 22Go to Step 25
22Repair the faulty connections as needed.
Is the repair complete?–System OK–
ENGINE CONTROLS 1F–285
DAEWOO M-150 BL2
Hard Start (Cont’d)
StepActionValue(s)YesNo
23
1. Check for the proper valve timing.
2. Check the cylinder compression.
3. Inspect the pushrods, the rocker arms, the valve
springs, and the camshaft lobes for excessive
wear.
4. Inspect the intake manifold and the exhaust
manifold passages for casting flash.
Is the problem found?
–
Go to Step 24Go to Step 25
24Repair or replace any components as needed.
Is the repair complete?–System OK–
25
Check the idle air control valve operation. Repair or
replace components as needed.
Is the repair complete?
–
System OK
–
26
Check the throttle position sensor circuit for proper
operation. Repair or replace components as needed.
Is the repair complete?
–
System OK
–
27Repair the fuel system as needed.
Is the repair complete?–System OK–
28
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
–
System OK
–
1F–286 ENGINE CONTROLS
DAEWOO M-150 BL2
SURGES OR CHUGGLES
Definition: Engine power variation under steady throttle
or cruise. Feels like the vehicle speeds up and slows
down with no change in the accelerator pedal position.Important: Make sure the driver understands A/C com-
pressor operation as described in the owner’s manual.
The speedometer reading and the speed reading on the
scan tool should be equal.
Before diagnosing the symptom, check service bulletins
for updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
Connect the scan tool to the Data Link Connector
(DLC).
Does the oxygen sensor (O2S) respond quickly to
different throttle positions?
–
Go to Step 4Go to Step 3
3
1. Check the O2S for silicone or other contaminants
from fuel or use of improper Room Temperature
Vulcanizing (RTV) sealant.
2. Replace the contaminated O2S.
Is the repair complete?
–
System OK
–
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?
–20–25%Go to Step 7Go to Step 5
5
Is the long term fuel trim reading below the value
specified?
–20%
Go to
“Diagnostic Aids
for DTC P0172”
Go to Step 6
6
Is the long term fuel trim reading above the value
specified?
25%
Go to
“Diagnostic Aids
for DTC P0171”
–
7
Check the fuel system pressure while the condition
exists.
Is the fuel system pressure within specifications?
380 kPa
(55 psi)
Go to Step 8Go to Step 17
8Check the in-line fuel filter.
Is the filter dirty or plugged?–Go to Step 18Go to Step 9
9Perform an injector diagnosis.
Did the injector diagnosis pinpoint the problem?–Go to Step 19Go to Step 10
10
1. Check for proper ignition voltage output using a
spark tester.
2. Inspect the spark plugs for cracks, wear, improper
gap, burned electrodes, or heavy deposits.
Is the problem found?
–
Go to Step 11Go to Step 12
11
Repair or replace any ignition system components
as needed.
Is the repair complete?
–
System OK
–
12
1. Inspect the ECM grounds for being clean, tight,
and in their proper locations.
2. Inspect the vacuum lines for kinks or leaks.
Is the problem found?
–
Go to Step 13Go to Step 14
ENGINE CONTROLS 1F–287
DAEWOO M-150 BL2
Surges or Chuggles (Cont’d)
StepActionValue(s)YesNo
13
Repair the electrical connections or the vacuum
lines as needed.
Is the repair complete?
–
System OK
–
14Check the generator output voltage.
Is the generator voltage within the value specified?12–16 V
Go to Step 16Go to Step 15
15Repair the generator.
Is the repair complete?–System OK–
16
1. Check for intermittent Electric Exhaust Gas
Recirculation (EEGR) valve operation.
2. Repair or replace any components as needed.
Is the repair complete?
–
System OK
–
17Repair the fuel system as needed.
Is the repair complete?–System OK–
18Replace the fuel filter.
Is the repair complete?–System OK–
19Replace the leaking or restricted fuel injectors.
Is the repair complete?–System OK–
1F–288 ENGINE CONTROLS
DAEWOO M-150 BL2
LACK OF POWER, SLUGGISHNESS, OR SPONGINESS
Definition: The engine delivers less than expected pow-
er. There is little or no increase in speed when the accel-
erator pedal is partially applied.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Verify the customer’s complaint.
2. Compare the performance of the customer’s
vehicle with a similar unit.
Does the problem exist?
–
Go to Step 3System OK
3
1. Inspect the air filter for excessive contamination.
2. Replace the air filter as needed.
3. Check the transaxle shift pattern and down shift
operation.
Does the transaxle operate properly?
–
Go to Step 4Go to Step 5
4Check the fuel system pressure.
Is the fuel system pressure within specifications?380 kPa
(55 psi)
Go to Step 7Go to Step 6
5Repair the transaxle as needed.
Is the repair complete?–System OK–
6Repair the fuel system as needed.
Is the repair complete?–System OK–
7Check for a restricted fuel filter or contaminated fuel.
Is the problem found?–Go to Step 8Go to Step 9
8Repair or replace any components as needed.
Is the repair complete?–System OK–
9
1. Check the ignition system output for all of the
cylinders using a spark tester.
2. Check for proper ignition control operation.
Is the ignition system operating properly?
–
Go to Step 10Go to Step 11
10
1. With the engine at normal operating temperature,
connect a vacuum gauge to a vacuum port on the
intake manifold.
2. Operate the engine at 1000 rpm.
3. Record the vacuum reading.
4. Increase the engine speed to 2500 rpm.
5. Note the vacuum reading at a steady 2500 rpm.
Does the vacuum decrease more than the value
specified?
10 kPa
(3 in Hg)
Go to Step 12Go to Step 15
11
Repair or replace any ignition system components
as needed.
Is the repair complete?
–
System OK
–
12
Inspect the exhaust system for restrictions and
damaged or collapsed pipes.
Is the problem found?
–
Go to Step 13Go to Step 14
13Repair or replace any components as needed.
Is the repair complete?–System OK–
14
1. Check the cylinder compression and valve timing.
2. Inspect the camshaft for excessive wear.
Is the problem found?
–
Go to Step 15Go to Step 16
ENGINE CONTROLS 1F–289
DAEWOO M-150 BL2
Lack of Power, Sluggishness, or Sponginess (Cont’d)
StepActionValue(s)YesNo
15
Repair or replace any engine components as
needed.
Is the repair complete?
–
System OK
–
16
1. Check the Engine Control Module (ECM) grounds
for being clean, tight, and in their proper location.
2. Check the exhaust recirculation valve for being
open or partially open all the time.
3. Check the torque converter clutch operation.
4. Check the A/C system operation.
5. Check the generator output.
6. Repair the generator if the output is not within the
specified range.
Are all checks and repairs complete?
12–16 VSystem OK
–