
1F–34 ENGINE CONTROLS
DAEWOO M-150 BL2
FUEL SYSTEM DIAGNOSIS
Circuit Description
The fuel pump is an in-tank type mounted to a fuel send-
er assembly. The fuel pump will remain on as long as the
engine is cranking or running and the Engine Control
Module (ECM) is receiving reference pulses from the
crankshaft position (CKP) sensor. If there are no refer-
ence pulses, the ECM will turn off the fuel pump two sec-
onds after the ignition switch is turned ON or two
seconds after the engine stops running. The fuel pump
delivers fuel to the fuel rail and the fuel injectors, where
the fuel system pressure is controlled from 380 kPa (55
psi) by the fuel pressure regulator. The excess fuel is re-
turned to the fuel tank.
Caution: The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury orfire, it is necessary to relieve the fuel system pres-
sure before disconnecting the fuel lines.
Caution: Do not pinch or restrict nylon fuel lines.
Damage to the lines could cause a fuel leak, result-
ing in possible fire or personal injury.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump fuse EF23 from the engine
fuse block.
3. Start the engine and allow the engine to stall.
4. Crank the engine for an additional 10 seconds.
Fuel System Pressure Test
Step Action Value(s) Yes No
1
1. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
Go to Step 2
2
1. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified but
not holding steady?
380 kPa
(55 psi)
Go to Step 13
Go to Step 3
3
Inspect the fuel lines for a leak.
Is the problem found?
–
Go to Step 4
Go to Step 5
4
1. Replace the fuel line(s) as needed.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
–
5
1. Remove the fuel pump assembly.
2. With the fuel pump under pressure, inspect the
fuel pump coupling hoses for leaking.
Is the problem found?
–
Go to Step 6
Go to Step 7
6
1. Tighten or replace the fuel pump coupling hoses
as needed.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
Go to Step 8
7
With the fuel system under pressure, inspect the fuel
return outlet for leaking.
Is the problem found?
–
Go to Step 8
Go to Step 9

1F–38 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F050
MAIN RELAY CIRCUIT CHECK
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 EF25 and EF26.
The Electronic Ignition (EI) system ignition coil is sup-
plied voltage through the engine fuse block fuse EF26.
The fuel injectors are supplied voltage through the en-
gine fuse block fuse EF25.Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed through wire insulation, or a bro-
ken wire inside the insulation.
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 sup-
plied to these components, they will not operate.

ENGINE CONTROLS 1F–45
DAEWOO M-150 BL2
IGNITION SYSTEM CHECK
Circuit Description
The Electronic Ignition (EI) system uses a waste spark
method of spark distribution. In this type of EI system,
the Crankshaft Position (CKP) sensor is mounted to the
oil pump near a slotted wheel that is a part of the crank-
shaft pulley. The CKP sensor sends reference pulses to
the Engine Control Module (ECM). The ECM then trig-gers the EI system ignition coil. Each cylinder is individu-
al with coil per cylinder in sequence.
This leaves the remainder of the high voltage to be used
to fire the spark plug in the cylinder on its compression
stroke. Since the CKP sensor is in a fixed position, tim-
ing adjustments are not possible or needed.
Ignition System Check
Caution: Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
StepActionValue(s)YesNo
1
1. Remove the spark plugs.
2. Inspect for wet spark plugs, cracks, wear,
improper gap, burned electrodes, or heavy
deposits.
3. Replace the spark plugs as needed.
Is the repair complete?
–
System OKGo to Step 2
2
Check for the presence of spark from all of the
ignition wires while cranking the engine.
Is spark present from all of the ignition wires?
–
System OKGo to Step 3
3
1. Measure the resistance of the ignition wires.
2. Replace any ignition wire(s) with a resistance
above the value specified.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
30000 ΩSystem OKGo to Step 4
4Is spark present from at least one of the ignition
wires, but not all of the ignition wires?Go to Step 5Go to Step 12
5
1. Turn the ignition OFF.
2. Disconnect the Electronic Ignition (EI) system
ignition coil connector.
3. While cranking the engine, measure the voltage
at the EI system ignition coil connector terminal 1.
Does the voltage fluctuate within the values
specified?
0.2–2.0 VGo to Step 8Go to Step 6
6
Check for an open in the wire from EI system
ignition coil connector terminal 1 to the Engine
Control Module (ECM) connector terminal 66.
Is the problem found?
–
Go to Step 7Go to Step 11
7
1. Repair the wiring as needed.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
–
System OK
–
8
While cranking the engine, measure the voltage at
the EI system ignition coil connector terminal 2.
Does the voltage fluctuate within the values
specified?
0.2–2.0 VGo to Step 10Go to Step 9

1F–46 ENGINE CONTROLS
DAEWOO M-150 BL2
Ignition System Check (Cont’d)
StepActionValue(s)YesNo
9
Check for an open in the wire from EI system
ignition coil connector terminal 2 to the Engine
Control Module (ECM) connector terminal 1.
Is the problem found?
–
Go to Step 7Go to Step 11
10
1. Replace the EI system ignition coil.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
–
System OK
–
11
1. Replace the ECM.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
–
System OK
–
12
1. Turn the ignition OFF.
2. Disconnect the crankshaft position (CKP) sensor
connector.
3. Measure the resistance between the CKP sensor
terminals 1 and 2.
Is the resistance within the value specified?
4. Measure the resistance between following
terminals.
Terminals 1 and 3 of CKP sensor.
Terminals 2 and 3 of CKP sensor.
Is the resistance within the value specified?
400–600 Ω
∞
Go to Step 14Go to Step 13
13Replace the crankshaft position sensor.
Is the repair complete?–System OK–
14
1. Turn the ignition ON.
2. Measure the voltage between the CKP sensor
connector terminals 1 and 3.
Is the voltage within the value specified?
0.95–1.10 VGo to Step 20Go to Step 15
15
Measure the voltage between the CKP sensor
connector terminal 1 and ground.
Is the voltage within the value specified?
0.95–1.10 VGo to Step 18Go to Step 16
16
Check the wire between the CKP sensor connector
terminal 1 and the ECM connector terminal 54 for an
open or short.
Is the problem found?
–
Go to Step 17Go to Step 10
17
Repair the wire between the CKP sensor connector
terminal 1 and the ECM connector terminal 54.
Is the repair complete?
–
System OK
–
18
Check the wire between the CKP sensor connector
terminal 3 and ground for an open or short.
Is the problem found?
–
Go to Step 19Go to Step 11
19
Repair the wire between the CKP sensor connector
terminal 3 and ground.
Is the repair complete?
–
System OK
–
20
1. Turn the ignition ON.
2. Measure the voltage between the CKP sensor
connector terminals 2 and 3.
Is the voltage within the value specified?
0.95–1.10 VGo to Step 24Go to Step 21

1F–54 ENGINE CONTROLS
DAEWOO M-150 BL2
FUEL INJECTOR BALANCE TEST
A fuel injector tester is used to energize the injector for a
precise amount of time, thus spraying a measured
amount of fuel into the intake manifold. This causes adrop in the fuel rail pressure that can be recorded and
used to compare each of the fuel injectors. All of the fuel
injectors should have the same pressure drop.
Fuel Injector Balance Test Example
Cylinder123
First Reading380 kPa
(55 psi)380 kPa
(55 psi)380 kPa
(55 psi)
Second Reading215 kPa
(31 psi)201 kPa
(29 psi)230 kPa
(33 psi)
Amount Of Drop165 kPa
(24 psi)179 kPa
(26 psi)151 kPa
(22 psi)
Average Range: 156-176 kPa
(22.5-25.5 psi)Injector OKFaulty Injector –
Too Much
Pressure DropFaulty Injector –
Too Little
Pressure Drop
Caution: The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pres-
sure before disconnecting the fuel lines.
Caution: Do not pinch or restrict fuel lines. Damage
to the lines could cause a fuel leak, resulting in pos-
sible fire or personal injury.
Notice: In order to prevent flooding of the engine, do not
perform the Injector Balance Test more than once (in-
cluding any retest on faulty fuel injectors) without run-
ning the engine.
Test
Notice: An engine cool down period of 10 minutes is
necessary in order to avoid irregular readings due to hot
soak fuel boiling.
1. Connect the fuel pressure gauge carefully to avoid
any fuel spillage.
2. The fuel pump should run about 2 seconds after the
ignition is turned to the ON position.
3. Insert a clear tube attached to the vent valve of the
fuel pressure gauge into a suitable container.
4. Bleed the air from the fuel pressure gauge and hose
until all of the air is bled from the fuel pressure gauge.
5. The ignition switch must be in the OFF position at
least 10 seconds in order to complete the electronic
control module (ECM) shutdown cycle.6. Turn the ignition ON in order to get the fuel pressure
to its maximum level.
7. Allow the fuel pressure to stabilize and then record
this initial pressure reading. Wait until there is no
movement of the needle on the fuel pressure gauge.
8. Follow the manufacturer’s instructions for the use of
the adapter harness. Energize the fuel injector test-
er once and note the fuel pressure drop at its lowest
point. Record this second reading. Subtract it from
the first reading to determine the amount of the fuel
pressure drop.
9. Disconnect the fuel injector tester from the fuel in-
jector.
10. After turning the ignition ON, in order to obtain maxi-
mum pressure once again, make a connection at
the next fuel injector. Energize the fuel injector test-
er and record the fuel pressure reading. Repeat this
procedure for all the injectors.
11. Retest any of the fuel injectors that the pressure
drop exceeds the 10 kPa (1.5 psi) specification.
12. Replace any of the fuel injectors that fail the retest.
13. If the pressure drop of all of the fuel injectors is with-
in 10 kPa (1.5 psi), then the fuel injectors are flowing
normally and no replacement should be necessary.
14. Reconnect the fuel injector harness and review the
symptom diagnostic tables.

ENGINE CONTROLS 1F – 55
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE DIAGNOSIS
CLEARING TROUBLE CODES
Notice: To prevent Engine Control Module (ECM) dam-
age, the key must be OFF when disconnecting or recon-
necting the power to the ECM (for example battery
cable, ECM pigtail connector, ECM fuse, jumper cables,
etc.).When the ECM sets a Diagnostic Trouble Code
(DTC), the Malfunction Indicator Lamp (MIL) lamp will
be turned on only for type A, B and E but a DTC will be
stored in the ECM’s memory for all types of DTC. If theproblem is intermittent, the MIL will go out after 10 sec-
onds if the fault is no longer present. The DTC will stay
in the ECM’s memory until cleared by scan tool. Remov-
ing battery voltage for 10 seconds will clear some stored
DTCs.
DTCs should be cleared after repairs have been com-
pleted. Some diagnostic tables will tell you to clear the
codes before using the chart. This allows the ECM to set
the DTC while going through the chart, which will help to
find the cause of the problem more quickly.
DIAGNOSTIC TROUBLE CODES
DTCFunctionError TypeIlluminate MIL
P0107Manifold Absolute Pressure Sensor Low VoltageAYES
P0108Manifold Absolute Pressure Sensor High voltageAYES
P0112Intake Air Temperature Sensor Low VoltageEYES
P0113Intake Air Temperature Sensor High voltageEYES
P0117Engine Coolant Temperature Sensor Low VoltageAYES
P0118Engine Coolant Temperature Sensor High voltageAYES
P0122Throttle Position Sensor Low VoltageAYES
P0123Throttle Position Sensor Hig voltageAYES
P0131Oxygen Sensor Low VoltageAYES
P0132Oxygen Sensor High VoltageAYES
P0133Oxygen Sensor No ActivityEYES
P0137Heated Oxygen Sensor Low VoltageEYES
P0138Heated Oxygen Sensor high voltageEYES
P0140Heated Oxygen Sensor No ActivityEYES
P0141Heated Oxygen Sensor Heater MalfuctionEYES
P0171Fuel Trim System Too LeanEYES
P0172Fuel Trim System Too RichEYES
P1230Fuel Pump Relay Low VoltageAYES
P1231Fuel Pump Relay High VoltageAYES
P0261Injector 1 Low VoltageAYES
P0262Injector 1 high voltageAYES
P0264Injector 2 Low VoltageAYES
P0265Injector 2 high voltageAYES
P0267Injector 3 Low VoltageAYES
P0268Injector 3 high voltageAYES
P0300Multifle Cylinder MisfireA/EBLINKING/ON
P1320Crankshatft Segment Period Segment Adaptation At LimitEYES
P1321Crankshatft Segment Period Tooth ErrorEYES
P0327Knock Sensor Circuit FaultEYES
P0335Magnetic Crankshaft Position Sensor Electrical ErrorEYES

1F–56 ENGINE CONTROLS
DAEWOO M-150 BL2
Diagnostic Trouble Codes (Cont’d)
DTCFunctionError TypeIlluminate MIL
P033658X Crankshaft Position Sensor Extra/missing PulseEYES
P033758X Crankshaft Sensor No SignalEYES
P0341Camshaft Position Sensor RationalityEYES
P0342Camshaft Position Sensor No SignalEYES
P0351Ignition Signal Coil A FaultAYES
P0352Ignition Signal Coil B FaultAYES
P0353Ignition Signal Coil C FaultAYES
P1382Rough Road Data Invalid (Non ABS)CnlNO
P1382Rrough Road Data Invalid (ABS)CnlNO
P1385Rough Road Sensor Circuit Fault (Non ABS)CnlNO
P1385Rough Road Sensor Circuit Fault (ABS)CnlNO
P0400Exhaust Gas Recirculation Out of LimitEYES
P1402Exhaust Gas Recirculation BlockedEYES
P1403Exhaust Gas Recirculation Valve FailureEYES
P0404Electric Exhaust Gas Recirculation (EEGR) OpendEYES
P1404Electric Exhaust Gas Recirculation (EEGR) ClosedEYES
P0405EEGR Pintle Position Sensor Low VoltageEYES
P0406EEGR Pintle Position Sensor High voltageEYES
P0420Catalyst Low EfficiencyEYES
P0444EVAP Purge Control Circuit No SignalEYES
P0445EVAP Purge Control Circuit FaultEYES
P0462Fuel Level Sensor Low VoltageCnlNO
P0463Fuel Level Sensor High voltageCnlNO
P0480Low Speed Cooling Fan Relay Circuit Fault (Without A/C)CnlNO
P0480Low Speed Cooling Fan Relay Circuit Fault (With A/C)CnlNO
P0481High Speed Cooling Fan Relay High Voltage (Without A/C)CnlNO
P0481High Speed Cooling Fan Relay High Voltage (With A/C)CnlNO
P0501Vehicle Speed No Signal (M/T Only)AYES
P0505Idle Air Control Valve (IACV) ErrorEYES
P1535Evaporator Temperature Sensor High VoltageCnlNO
P1536Evaporator Temperature Sensor Low VoltageCnlNO
P1537A/C Compressor Relay High VoltageCnlNO
P1538A/C Compressor Relay Low VoltageCnlNO
P0562System Voltage (Engine Side) Too LowCnlNO
P0563System Voltage (Engine Side) Too HighCnlNO
P0601Engine Control Module Checksum ErrorEYES
P0604Engine Control Module RAM ErrorEYES
P0605Engine Control Module NMVY Write ErrorEYES
P1610Main Relay High VoltageAYES
P1611Main Relay Low VoltageAYES
P1628Immobilizer No Successful CommunicationCnlNO
P1629Immobilizer Wrong ComputationCnlNO
P0656Fuel Level Gauge High Circuit FaultCnlNO

1F–58 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F060
DIAGNOSTIC TROUBLE CODE (DTC) – P0107
MANIFOLD ABSOLUTE PRESSURE SENSOR LOW VOLTAGE
Circuit Description
The engine control module (ECM) uses the Manifold Ab-
solute Pressure (MAP) sensor to control the fuel deliv-
ery and the ignition timing. The MAP sensor measures
the changes in the intake manifold pressure, which re-
sults from engine load (intake manifold vacuum) and the
rpm changes; and converts these into voltage outputs.
The ECM sends a 5 volt-reference voltage to the MAP
sensor. As the manifold pressure changes, the output
voltage of the MAP sensor also changes. By monitoring
the MAP sensor output voltage, the ECM knows the
manifold pressure. A low-pressure (low voltage) output
voltage will be about 1.0 to 1.5 volts at idle, while higher
pressure (high voltage) output voltage will be about 4.5
to 5.0 at wide open throttle (WOT). The MAP sensor is
metric pressure, allowing the ECM to make adjustments
for different altitudes.
Conditions for Setting the DTC
This DTC can be stored in “key-on” status.
(Case A)
When the engine idling.
No throttle position(TP) sensor fail conditions pres-
ent.
Engine speed(rpm) is less than 2,500rpm.
The MAP is less than 15kPA.
(Case A)
When the engine part load.
The engine revolution speed is less than 4,000rpm.
No Throttle Position (TP) Sensor fails conditions
present.
The Throttle Position (TP) angle greather than 20.0The MAP is less than 15 kPA.
An open or low voltage condition exists.
Action Taken when the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.
The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Failure Records buffers.
A history DTC is stored.
The coolant fan turns ON.
The ECM will substitutes a fixed MAP value and use
TP to control the fuel delivery (the scan tool will not
show defaulted)
Conditions for Clearing the MIL/DTC
The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
With the ignition ON and the engine stopped, the man-
ifold pressure is equal to atmosphere pressure and the
signal voltage will be high.
The ECM as an indication of vehicle altitude uses this
information. Comparison of this reading with a known
good vehicle with the same sensor is a good way to
check the accuracy of a suspect sensor. Readings
should be the same ±0.4volt.
If a DTC P 0107 is intermittent, refer to “Manifold Abso-
lute Pressure Check” in this Section for further diagno-
sis.