Page 390 of 1184

1F–292 ENGINE CONTROLS
DAEWOO M-150 BL2
HESITATION, SAG, STUMBLE
Definition: Momentary lack of response as the accelera-
tor is pushed down. This can occur at any vehicle speed.
It is usually the most severe when first trying to make the
vehicle move, as from a stop. Hesitation, sag, or
stumble may cause the engine to stall if severe enough.Important: Before diagnosing this condition, check ser-
vice bulletins for PROM updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Check the fuel system pressure. If the pressure is
not within the value specified, service the fuel
system as needed.
2. Inspect the Throttle Position (TP) sensor for
binding or sticking. The TP sensor voltage should
increase at a steady rate as the throttle is moved
toward Wide Open Throttle (WOT).
Is the problem found?
380 kPa
(55 psi)
Go to Step 3Go to Step 4
3Repair or replace any components as needed.
Is the repair complete?–System OK–
4
1. Check the Manifold Absolute Pressure (MAP)
sensor response and accuracy.
2. Inspect the fuel for water contamination.
3. Check the Evaporative Emission (EVAP) Canister
Purge System for proper operation.
Is the problem found?
–
Go to Step 5Go to Step 6
5Repair or replace any components as needed.
Is the repair complete?–System OK–
6
1. Disconnect all of the fuel injector harness
connectors.
2. Connect an injector test light between the
harness terminals of each fuel injector.
3. Note the test light while cranking the engine.
Does the test light blink on all connectors?
–
Go to Step 8Go to Step 7
7
1. Repair or replace the faulty fuel injector drive
harness, the connector, or the connector terminal.
2. If the connections and the harnesses are good,
replace the Engine Control Module (ECM).
Is the repair complete?
–
System OK
–
8
Measure the resistance of each fuel injector.
Is the fuel injector resistance within the value
specified (the resistance will increase slightly at
higher temperatures)?
11.6–12.4 ΩGo to Step 10Go to Step 9
9
Replace any of the fuel injectors with a resistance
that is out of specifications.
Is the repair complete?
–
System OK
–
10Perform an injector diagnosis.
Is the problem found?–Go to Step 11Go to Step 12
11Replace any restricted or leaking fuel injectors.
Is the repair complete?–System OK–
12
Check the fuel system pressure after a cold start or
during moderate or full throttle acceleration.
Is the fuel pressure within specifications?
380 kPa
(55 psi)
Go to Step 14Go to Step 13
Page 395 of 1184

ENGINE CONTROLS 1F–297
DAEWOO M-150 BL2
ROUGH, UNSTABLE, OR INCORRECT IDLE, STALLING
Definition: The engine runs unevenly at idle. If the condi-
tion is bad enough, the vehicle may shake. Also, the idle
varies in rpm (called “hunting”). Either condition may be
severe enough to cause stalling. The engine idles at in-
correct idle speed.Important: Before diagnosing the symptom, check ser-
vice 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. Monitor the oxygen sensor (O2S) reading at
different throttle positions.
Does the O2S change quickly from rich to lean at
the different throttle positions?
–
Go to Step 5Go to Step 3
3
Check the O2S for contamination from fuel or
improper use of room temperature vulcanizing
sealant.
Is the O2S contaminated?
–
Go to Step 4Go to Step 5
4Replace the contaminated O2S as needed.
Is the repair complete?–System OK–
5
1. Check for a sticking throttle shaft or binding
throttle linkage that may cause incorrect Throttle
Position (TP) sensor voltage.
2. Check the TP sensor voltage reading with the
throttle closed.
Is the TP sensor voltage within the value specified?
0.4–0.8 VGo to Step 6
Go to
“Diagnostic
Aids for DTC
P0123”
6
1. Check the Engine Coolant Temperature (ECT)
sensor voltage reading using the scan tool.
2. Compare the ECT sensor reading with the
ambient temperature when the engine is cold.
Does the ECT sensor temperature reading differ
from the ambient temperature by more than the
value specified?
3C (5F)Go to Step 7Go to Step 9
7
Check for high resistance in the ECT sensor circuit
or the sensor itself.
Is the problem found?
–
Go to Step 8Go to Step 9
8
Replace the ECT sensor or repair the circuit as
needed.
Is the repair complete?
–
System OK
–
9
Check the Manifold Absolute Pressure (MAP)
sensor for response and accuracy.
Is the problem found?
–
Go to Step 10Go to Step 11
10
Replace the MAP sensor or repair the MAP sensor
circuit as needed.
Is the repair complete?
–
System OK
–
11
1. Road test 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 14Go to Step 12
Page 408 of 1184
1F–310 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F410
Disconnect the canister hoses (3).
Remove the evaporative emission casnister (4).
MAA1F420
Installation Procedure
1. Install in the reverse order of removal.
MAA1F430
EVAPORATIVE EMISSION CANISTER
PURGE SOLENOID
1. Disconnect the negative battery cable.
2. Disconnectthe evaporative (EVAP) emission canister
purge solenoid connector.
3. Disconnect the vacuum hoses from the EVAP canis-
ter purge solenoid.
4. Unclip the EVAP emission canister purge solenoid
from the mounting bracket.
5. Installation should follow the removal procedure in
the reverse order.
MAA1F440
MANIFOLD ABSOLUTE PRESSURE
SENSOR
Removal Procedure
1. Disconnect the manifold absolute pressure (MAP)
sensor connector and vacuum hose.
Disconnect the MAP connector (1).
Disconnect the vacuum hose from the MAP sensor
(2).
Page 409 of 1184
ENGINE CONTROLS 1F–311
DAEWOO M-150 BL2
MAA1F450
2. Remove the MAP sensor.
Remove the bolts (1).
Remove the MAP sensor with bracket (2).
MAA1F460
Installatin Procedure
1. Install in the reverse order of removal.
Inspect the MAP sensor vacuum hose for the tear
and damages.
2. Install the MAP sensor with the bolts and nuts.
Tighten
Tighten the MAP sensor bolts/nuts to 8–12 Nm
(71–106 lb-in).
Tighten the MAP sensor bracket bolt to 8–12 Nm
(71–106 lb-in).
D102F537
THROTTLE BODY
Removal Procedure
1. Remove the air cleaner/resonator assembly and air
intake tube. Refer to Section 1B, SOHC Engine Me-
chanical.
2. Drain the engine coolant. Refer to Section 1D, Engine
Cooling.
D102F538
3. Disconnect the throttle cable, the throttle position
sensor and the idle air control valve connectors.
Open the throttle valve (1).
Disconnect the throttle cable (2).
Disconnect the idle air control valve connector (3).
Disconnect the throttle position sensor connector
(4).
Page 410 of 1184

1F–312 ENGINE CONTROLS
DAEWOO M-150 BL2
D102F539
4. Disconnect the coolant hoses and vacuum hoses
from the throttle body.
Loosen the clamps from the coolant hoses (1).
Disconnect the coolant hoses from the throttle
body (2).
Disconnect the vacuum hoses (3).
D102F541
5. Remove the throttle body from the intake manifold.
Remove the throttle body bolts (1).
Remove the throttle body (2).
Discard the throttle body gasket (3).
Inspect the throttle body gasket for the deforma-
tion and the damages.
9–12 Nm
D12F542A
Installation Procedure
1. Install in the reverse order of removal.
Important: Make sure the throttle control cable do not
hold the throttle open. With the engine OFF, check to
see that the accelerator pedal is free.
2. Install the throttle body with the bolts.
Tighten
Tighten the throttle body bolts to 9–12 Nm (80–106
lb-in).
D12F543A
ENGINE COOLANT TEMPERATURE
(ECT) SENSOR
Removal Procedure
1. Remove the engine coolant temperature (ECT) sen-
sor. Refer to Section 1D, Engine Coolings.
Page 411 of 1184
ENGINE CONTROLS 1F–313
DAEWOO M-150 BL2
D12F543B
Installation Procedure
1. Install the engine coolant temperature sensor.
Tighten
Tighten the engine coolant temperature sensor to
8–12 Nm (71–106 lb-ft).
D102F544
INTAKE AIR TEMPERATURE (IAT)
SENSOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the intake air temperature (IAT) sensor.
Disconnect the IAT sensor connector (1)
Disconnect the IAT sensor.
20–30 Nm
D12F545A
Installation Procedure
1. Install in the reverse order of removal.
2. Install the IAT sensor.
Tighten
Tighten the IAT sensor to 20–30 Nm (15–22 lb-ft).
Page 412 of 1184

1F–314 ENGINE CONTROLS
DAEWOO M-150 BL2
D102F546
OXYGEN SENSOR (O2S1)
Removal Procedure
1. Remove the air cleaner/resonator assembly. Refer to
Section 1B, SOHC Engine Mechanical.
2. Remove the oxygen sensor.
Disconnect the oxygen sensor connector (1).
Remove the oxygen sensor (2).
Notice: The oxygen sensor uses a permanently at-
tached pigtail and connector. This pigtail should not be
removed from the oxygen sensor. Damage or removal
of the pigtail or the connector could affect proper opera-
tion of the oxygen sensor. Take care when handling the
oxygen sensor. Do not drop the oxygen sensor.
D12F547A
Installation Procedure
1. Install in the reverse order of removal.
Important: A special anti–seize compound is used on
the oxygen sensor threads. This compound consists of
a liquid graphite and glass beads. The graphite will burn
away, but the glass beads will remain, making the sen-
sor easier to remove. New or service sensors will al-
ready have the compound applied to the threads. If a
sensor is removed from any engine and if for any reason
it is to be reinstalled, the threads must have anti–seize
compound applied before reinstallation.
2. Install the oxygen sensor.
Tighten
Tighten the oxygen sensor to 35~44 Nm (26~33 lb-
ft).
MAA1F470
HEATED OXYGEN SENSOR (HO2S2)
Removal and Installation Procedure
1. Disconnect the negative battery cable.
2. Remove the front center console.
3. Disconnect the HO2S2 connector.
4. Remove the front exhaust pipe. Refer to Section 1G,
Engine Exhaust.
5. Remove the HO2S2 from the front exhaust pipe.
Installation Procedure
1. Install in the reverse order of removal.
Page 413 of 1184

ENGINE CONTROLS 1F–315
DAEWOO M-150 BL2
Important: A special anti–seize compound is used on
the oxygen sensor threads. This compound consists of
a liquid graphite and glass beads. The graphite will burn
away, but the glass beads will remain, making the sen-
sor easier to remove. New or service sensors will al-
ready have the compound applied to the threads. If a
sensor is removed from any engine and if for any reason
it is to be reinstalled, the threads must have anti–seize
compound applied before reinstallation.
2. Install the oxygen sensor.
Tighten
Tighten the oxygen sensor to 35~44 Nm (26~33 lb-
ft).
MAA1F480
EXHAUST GAS RECIRCULATION
VA LV E
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the air cleaner assembly.
3. Disconnect the electric exhaust gas recirculation
(EEGR) valve connector.
D21F008
KNOCK SENSOR
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the starter. Refer to Section 1E, Engine
Electrical.
3. Disconnect the electrical connector at the knock sen-
sor (1).
D21F009
4. Remove the knock sensor.
Remove the knock sensor retaining bolt (1).
Remove the knock sensor.