spark DAEWOO MATIZ 2003 Service Owner's Manual

1F–8 ENGINE CONTROLS
DAEWOO M-150 BL2
tions. With the ignition ON and the engine not running,
the Engine Control Module (ECM) will read the manifold
pressure as barometric pressure and adjust the air/fuel
ratio accordingly. This compensation for altitude allows
the system to maintain driving performance while hold-
ing emissions low. The barometric function will update
periodically during steady driving or under a wide open
throttle condition. In the case of a fault in the barometric
portion of the MAP sensor, the ECM will set to the de-
fault value.
A failure in the MAP sensor circuit sets a diagnostic
trouble codes P0107, P0108 or P0106.
ENGINE CONTROL MODULE
The Engine Control Module (ECM), is the control center
of the fuel injection system. It constantly looks at the in-
formation from various sensors and controls the sys-
tems that affect the vehicle’s performance. The ECM
also performs the diagnostic functions of the system. It
can recognize operational problems, alert the driver
through the Malfunction Indicator Lamp (MIL), and store
diagnostic trouble code(s) which identify the problem
areas to aid the technician in making repairs.
There are no serviceable parts in the ECM. The calibra-
tions are stored in the ECM in the Programmable Read
Only Memory (PROM).
The ECM supplies either 5 or 12 volts to power the sen-
sors or switches. This is done through resistance in the
ECM which are so high in value that a test light will not
come on when connected to the circuit. In some cases,
even an ordinary shop voltmeter will not give an accu-
rate reading because its resistance is too low. You must
use a digital voltmeter with a 10 megohm input imped-
ance to get accurate voltage readings. The ECM con-
trols output circuits such as the fuel injectors, the Idle Air
Control (IAC) valve, the A/C clutch relay, etc., by control-
ling the ground circuit through transistors or a device
called a “quad-driver.”
FUEL INJECTOR
The Multi-port Fuel Injection (MFI) assembly is a sole-
noid-operated device controlled by the Engine Control
Module (ECM) that meters pressurized fuel to a single
engine cylinder. The ECM energizes the fuel injector or
solenoid to a normally closed ball or pintle valve. This al-
lows fuel to flow into the top of the injector, past the ball
or pintle valve, and through a recessed flow director
plate at the injector outlet.
The director plate has six machined holes that control
the fuel flow, generating a conical spray pattern of finely
atomized fuel at the injector tip. Fuel from the tip is di-
rected at the intake valve, causing it to become further
atomized and vaporized before entering the combustion
chamber. A fuel injector which is stuck partially open
would cause a loss of fuel pressure after the engine is
shut down. Also, an extended crank time would be no-
ticed on some engines. Dieseling could also occur be-cause some fuel could be delivered to the engine after
the ignition is turned off.
FUEL CUT-OFF SWITCH
The fuel cutoff switch is a safety device. In the event of a
collision or a sudden impact, it automatically cuts off the
fuel supply and activates the door lock relay. After the
switch has been activated, it must be reset in order to
restart the engine. Reset the fuel cutoff switch by press-
ing the rubber top of the switch. The switch is located
near the right side of the passenger’s seat.
KNOCK SENSOR
The knock sensor detects abnormal knocking in the en-
gine. The sensor is mounted in the engine block near the
cylinders. The sensor produces an AC output voltage
which increases with the severity of the knock. This sig-
nal is sent to the Engine Control Module (ECM). The
ECM then adjusts the ignition timing to reduce the spark
knock.
VARIABLE RELUCTANCE (VR)
SENSOR
The variable reluctance sensor is commonly refered to
as an “inductive” sensor.
The VR wheel speed sensor consists of a sensing unit
fixed to the left side front macpherson strut, for non-ABS
vehicle.
The ECM uses the rough road information to enable or
disable the misfire diagnostic. The misfire diagnostic
can be greatly affected by crankshaft speed variations
caused by driving on rough road surfaces. The VR sen-
sor generates rough road information by producing a
signal which is proportional to the movement of a small
metal bar inside the sensor.
If a fault occurs which causes the ECM to not receive
rough road information between 30 and 70 km/h (1.8
and 43.5 mph), Diagnostic Trouble Code (DTC) P1391
will set.
OCTANE NUMBER CONNECTOR
The octane number connector is a jumper harness that
signal to the engine control module (ECM) the octane
rating of the fuel.
The connector is located on the next to the ECM. There
are two different octane number connector settings
available. The vehicle is shipped from the factory with a
label attached to the jumper harness to indicate the oc-
tane rating setting of the ECM. The ECM will alter fuel
delivery and spark timing based on the octane number
setting. The following table shows which terminal to
jump on the octane number connector in order to
achieve the correct fuel octane rating. Terminal 2 is
ground on the octane number connector. The find the

1F–10 ENGINE CONTROLS
DAEWOO M-150 BL2
fuels use alcohol to increase the octane rating of the
fuel. Although alcohol-enhanced fuels may raise the oc-
tane rating, the fuel’s ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
The EOBD system has been calibrated to run with Origi-
nal Equipment Manufacturer (OEM) parts. Something
as simple as a high performance-exhaust system that
affects exhaust system back pressure could potentially
interfere with the operation of the Electric Exhaust Gas
Recirculation (EEGR) valve and thereby turn on the
MIL. Small leaks in the exhaust system near the heated
oxygen sensor (HO2S) can also cause the MIL to turn
on.
Aftermarket electronics, such as cellular phones, ster-
eos, and anti-theft devices, may radiate Electromagnet-
ic Interference (EMI) into the control system if they are
improperly installed. This may cause a false sensor
reading and turn on the MIL.
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition sys-
tem. If the ignition system is rain-soaked, it can tempo-
rarily cause engine misfire and turn on the MIL.
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of opera-
tion contributes to the fuel fouling of the spark plugs and
will turn on the MIL with a set DTC P0300.
Poor Vehicle Maintenance
The sensitivity of the EOBD will cause the MIL to turn on
if the vehicle is not maintained properly. Restricted air fil-
ters, fuel filters, and crankcase deposits due to lack of oil
changes or improper oil viscosity can trigger actual ve-
hicle faults that were not previously monitored prior to
EOBD. Poor vehicle maintenance can not be classified
as a “non-vehicle fault,” but with the sensitivity of the
EOBD, vehicle maintenance schedules must be more
closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline
vibrations in the vehicle, such as caused by an exces-
sive amount of mud on the wheels, can have the same
effect on crankshaft speed as misfire and, therefore,
may set DTC P0300.
Related System Faults
Many of the EOBD system diagnostics will not run if the
Engine Control Module (ECM) detects a fault on a re-
lated system or component. One example would be thatif the ECM detected a Misfire fault, the diagnostics on
the catalytic converter would be suspended until the
Misfire fault was repaired. If the Misfire fault is severe
enough, the catalytic converter can be damaged due to
overheating and will never set a Catalyst DTC until the
Misfire fault is repaired and the Catalyst diagnostic is al-
lowed to run to completion. If this happens, the custom-
er may have to make two trips to the dealership in order
to repair the vehicle.
SERIAL DATA COMMUNICATIONS
Keyword 2000 Serial Data
Communications
Government regulations require that all vehicle
manufacturers establish a common communication sys-
tem. This vehicle utilizes the “Keyword 2000” commu-
nication system. Each bit of information can have one of
two lengths: long or short. This allows vehicle wiring to
be reduced by transmitting and receiving multiple sig-
nals over a single wire. The messages carried on Key-
word 2000 data streams are also prioritized. If two
messages attempt to establish communications on the
data line at the same time, only the message with higher
priority will continue. The device with the lower priority
message must wait. The most significant result of this
regulation is that it provides scan tool manufacturers
with the capability to access data from any make or
model vehicle that is sold.
The data displayed on the other scan tool will appear the
same, with some exceptions. Some scan tools will only
be able to display certain vehicle parameters as values
that are a coded representation of the true or actual val-
ue. On this vehicle, the scan tool displays the actual val-
ues for vehicle parameters. It will not be necessary to
perform any conversions from coded values to actual
values.
EURO ON-BOARD DIAGNOSTIC
(EOBD)
Euro On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which
is a pass or fail reported to the diagnostic executive.
When a diagnostic test reports a pass result, the diag-
nostic executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not cur-
rently active.
When a diagnostic test reports a fail result, the diagnos-
tic executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

1F–16 ENGINE CONTROLS
DAEWOO M-150 BL2
the obstruction of the reference air and degrade the O2S
performance.
Misfire Monitor Diagnostic Operation
The misfire monitor diagnostic is based on crankshaft
rotational velocity (reference period) variations. The En-
gine Control Module (ECM) determines crankshaft rota-
tional velocity using the Crankshaft Position (CKP)
sensor and the Camshaft Position (CMP) sensor. When
a cylinder misfires, the crankshaft slows down momen-
tarily. By monitoring the CKP and CMP sensor signals,
the ECM can calculate when a misfire occurs.
For a non-catalyst damaging misfire, the diagnostic will
be required to monitor a misfire present for between
1000–3200 engine revolutions.
For catalyst-damaging misfire, the diagnostic will re-
spond to misfire within 200 engine revolutions.
Rough roads may cause false misfire detection. A rough
road will cause torque to be applied to the drive wheels
and drive train. This torque can intermittently decrease
the crankshaft rotational velocity. This may be falsely
detected as a misfire.
A rough road sensor, or “G sensor,” works together with
the misfire detection system. The rough road sensor
produces a voltage that varies along with the intensity of
road vibrations. When the ECM detects a rough road,
the misfire detection system is temporarily disabled.
Misfire Counters
Whenever a cylinder misfires, the misfire diagnostic
counts the misfire and notes the crankshaft position at
the time the misfire occurred. These “misfire counters”
are basically a file on each engine cylinder. A current
and a history misfire counter are maintained for each
cylinder. The misfire current counters (Misfire Current
#1–4) indicate the number of firing events out of the last
200 cylinder firing events which were misfires. The mis-
fire current counter will display real time data without a
misfire DTC stored. The misfire history counters (Misfire
Histtory #1–4) indicate the total number of cylinder firing
events which were misfires. The misfire history counters
will display 0 until the misfire diagnostic has failed and a
DTC P0300 is set. Once the misfire DTC P0300 is set,
the misfire history counters will be updated every 200
cylinder firing events. A misfire counter is maintained for
each cylinder.
If the misfire diagnostic reports a failure, the diagnostic
executive reviews all of the misfire counters before re-
porting a DTC. This way, the diagnostic executive re-
ports the most current information.
When crankshaft rotation is erratic, a misfire condition
will be detected. Because of this erratic condition, the
data that is collected by the diagnostic can sometimes
incorrectly identify which cylinder is misfiring.
Use diagnostic equipment to monitor misfire counter
data on EOBD compliant vehicles. Knowing which spe-
cific cylinder(s) misfired can lead to the root cause, evenwhen dealing with a multiple cylinder misfire. Using the
information in the misfire counters, identify which cylin-
ders are misfiring. If the counters indicate cylinders
numbers 1 and 4 misfired, look for a circuit or compo-
nent common to both cylinders number 1 and 4.
The misfire diagnostic may indicate a fault due to a tem-
porary fault not necessarily caused by a vehicle emis-
sion system malfunction. Examples include the following
items:

Contaminated fuel.

Low fuel.

Fuel-fouled spark plugs.

Basic engine fault.
Fuel Trim System Monitor Diagnostic
Operation
This system monitors the averages of short-term and
long-term fuel trim values. If these fuel trim values stay
at their limits for a calibrated period of time, a malfunc-
tion is indicated. The fuel trim diagnostic compares the
averages of short-term fuel trim values and long-term
fuel trim values to rich and lean thresholds. If either val-
ue is within the thresholds, a pass is recorded. If both
values are outside their thresholds, a rich or lean DTC
will be recorded.
The fuel trim system diagnostic also conducts an intru-
sive test. This test determines if a rich condition is being
caused by excessive fuel vapor from the controlled char-
coal canister. In order to meet EOBD requirements, the
control module uses weighted fuel trim cells to deter-
mine the need to set a fuel trim DTC. A fuel trim DTC
can only be set if fuel trim counts in the weighted fuel
trim cells exceed specifications. This means that the ve-
hicle could have a fuel trim problem which is causing a
problem under certain conditions (i.e., engine idle high
due to a small vacuum leak or rough idle due to a large
vacuum leak) while it operates fine at other times. No
fuel trim DTC would set (although an engine idle speed
DTC or HO2S DTC may set). Use a scan tool to observe
fuel trim counts while the problem is occurring.
A fuel trim DTC may be triggered by a number of vehicle
faults. Make use of all information available (other DTCs
stored, rich or lean condition, etc.) when diagnosing a
fuel trim fault.
Fuel Trim Cell Diagnostic Weights
No fuel trim DTC will set regardless of the fuel trim
counts in cell 0 unless the fuel trim counts in the
weighted cells are also outside specifications. This
means that the vehicle could have a fuel trim problem
which is causing a problem under certain conditions (i.e.
engine idle high due to a small vacuum leak or rough
due to a large vacuum leak) while it operates fine at oth-
er times. No fuel trim DTC would set (although an en-
gine idle speed DTC or HO2S DTC may set). Use a
scan tool to observe fuel trim counts while the problem is
occurring.

ENGINE CONTROLS 1F–21
DAEWOO M-150 BL2
MULTIPLE ECM INFORMATION SENSOR DTCS SET
Circuit Description
The Engine Control Module (ECM) monitors various
sensors to determine engine operating conditions. The
ECM controls fuel delivery, spark advance, transaxle op-
eration, and emission control device operation based on
the sensor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull-up resistor and
monitors the voltage present between the sensor and
the resistor to determine the status of the Engine Cool-
ant Temperature (ECT) sensor, the Intake Air Tempera-
ture (IAT) sensor. The ECM provides the Electric
Exhaust Gas Recirculation (EEGR) Pintle Position Sen-
sor, the Throttle Position (TP) sensor, the Manifold Ab-
solute Pressure (MAP) sensor, and the Fuel Tank
Pressure Sensor with a 5 volt reference and a sensor
ground signal. The ECM monitors the separate feed-
back signals from these sensors to determine their oper-
ating status.
Diagnostic Aids
Be sure to inspect the ECM and the engine grounds for
being secure and clean.
A short to voltage in one of the sensor circuits can cause
one or more of the following DTCs to be set: P0108,
P0113, P0118, P0123, P1106.If a sensor input circuit has been shorted to voltage, en-
sure that the sensor is not damaged. A damaged sensor
will continue to indicate a high or low voltage after the
affected circuit has been repaired. If the sensor has
been damaged, replace it.
An open in the sensor ground circuit between the ECM
and the splice will cause one or more of the following
DTCs to be set: P0108, P0113, P0118, P0123, P1106.
A short to ground in the 5 volt reference circuit or an
open in the 5 volt reference circuit between the ECM
and the splice will cause one or more of the following
DTCs to be set: P0107, P0112, P0117, P0122, P1107.
Check for the following conditions:

Inspect for a poor connection at the ECM. Inspect
harness connectors for backed-out terminals, im-
proper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire con-
nection.

Inspect the wiring harness for damage. If the harness
appears to be OK, observe an affected sensor’s dis-
played value on the scan tool with the ignition ON and
the engine OFF while moving connectors and wiring
harnesses related to the affected sensors. A change
in the affected sensor’s displayed value will indicate
the location of the fault.

ENGINE CONTROLS 1F–25
DAEWOO M-150 BL2
ENGINE CRANKS BUT WILL NOT RUN
Caution: Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
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.Important: If a no start condition exists, ensure the fuel
cutoff switch has not been tripped prior to further diagno-
sis.
Engine Cranks But Will Not Run
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the check complete.
–
Go to Step 2
Go to “Euro
On-Board
Diagnostic
System Check”
2Crank the engine.
Does the engine start and continue to run?–System OkGo to Step 3
3
Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?
1250 kPa
(181 psi)
Go to Step 7Go to Step 4
4Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 6Go to Step 5
5Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 2–
6Repair internal engine damage as needed.
Is the repair complete?–Go to Step 2–
7Inspect the fuel pump fuse.
Is the problem found?–Go to Step 8Go to Step 9
8Replace the fuse.
Is the repair complete?–Go to Step 2–
9
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?
–
Go to Step 23Go to Step 10
10
1. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a
resistance above the value specified.
3. Check for the presence of spark from all of the
ignition wire.
Is spark present from all of the ignition wires?
5 kΩGo to Step 2Go to Step 11
11
1. Turn the ignition OFF.
2. Disconnect the crankshaft position (CKP) sensor
connector.
3. Turn the ignition ON.
4. Measure the voltage between following terminals:

Terminal 1 and 3 of the CKP sensor connector.

Terminal 2 and 3 of the CKP sensor connector.

Terminal 1 of the CKP sensor connector and
ground.

Terminal 2 of the CKP sensor connector and
ground.
Are the voltage measure within the value specified?
≈ 0.4 VGo to Step 13Go to Step 12

ENGINE CONTROLS 1F–27
DAEWOO M-150 BL2
Engine Cranks But Will Not Run (Cont’d)
StepActionValue(s)YesNo
21
1. Check for any damages or poor connection in
ignition wires and repair as needed.
2. Connect the Ei system ignition coil connector and
ECM connector.
3. Check for the presence of spark from all of the
ignition wires.
Is the spark present from all of the ignition wires?
–
Go to Step 2Go to Step 22
22Replace ECM
Is the repair complete?–Go to Step 2–
23
1. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?
–
Go to Step 26Go to Step 24
24
1. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump
terminals 2 and 3.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light for
the time specified.
Is the test light on?
2 sec.Go to Step 25Go to Step 32
25Replace the fuel pump.
Is the repair complete?–Go to Step 2–
26
Is the fuel pressure within the value specified?
380 kPa
(55 psi)
Go to Step 27Go to Step 29
27Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 28Go to Step 41
28
1. Remove the contaminated fuel from the fuel tank.
2. Clean the fuel tank as needed.
Is the repair complete?
–
Go to Step 2
–
29
1. Check the fuel filter for restriction.
2. Inspect the fuel lines for kinks and restrictions.
3. Repair or replace as needed.
4. Measure the fuel pressure.
Is the fuel pressure within the value specified?
380 kPa
(55 psi)
Go to Step 2Go to Step 30
30
1. Disconnect vacuum line from the fuel pressure
regulator.
2. Inspect the vacuum line for the presence of fuel.
3. Inspect the fuel pressure regulator vacuum port
for the presence of fuel.
Is any fuel present?
–
Go to Step 31Go to Step 32
31Replace the fuel pressure regulator.
Is the repair complete?–Go to Step 2–
32
1. Remove the fuel pump assembly from the fuel
tank.
2. Inspect the fuel pump sender and the fuel
coupling hoses for a restriction.
3. Inspect the in-tank fuel filter for restriction.
Is the problem found?
–
Go to Step 33Go to Step 25

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–136 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0300 – Multiple Cylinder Misfire (Cont’d)
StepActionValue(s)YesNo
6
1. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data, and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and conditions for setting this DTC as
noted.
Are any Misfire Current counters incrementing?
–
Go to Step 5
Go to
“Diagnostic
Aids”
7
1. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine
running.
Is the fuel pressure within the specified value?
284–325 kPa
(41–47 psi)Go to Step 8
Go to
“Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?–Go to Step 9Go to Step 10
9
Check for a basic engine problem and repair as
necessary.
Is the repair complete?
–
Go to Step 27
–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–
11
1. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #1 spark plug
cable.
4. Crank the engine and check for spark.
5. Repeat the above procedure on cylinders #2, #3.
Is a spark observed on all four spark plug cables?
–
Go to Step 12Go to Step 20
12
Replace any malfunctioning spark plugs if
necessary.
Is the repair complete?
–
Go to Step 27Go to Step 13
13
1. Turn the engine OFF.
2. Disconnect the fuel injector connectors from the
injectors.
3. Install an injector test light on the injector harness
connector for the cylinders that had misfired.
4. Crank the engine and note the test light.
Does the injector test light blink?
–
Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
15
1. Disconnect the injector test light.
2. With a test light connected to ground, probe the
ignition feed terminal 1 of the injector harness
connector for each cylinder that had misfire.
3. Crank the engine.
Does the test light illuminate?
–
Go to Step 17Go to Step 19
16Replace any malfunctioning fuel injectors.
Is the repair complete?–Go to Step 27–
17
Check the affected fuel injector driver circuit at
terminals 90, 58 and 89 for an open, short, or short
to voltage.
Is a problem found?
–
Go to Step 18Go to Step 24

ENGINE CONTROLS 1F–137
DAEWOO M-150 BL2
DTC P0300 – Multiple Cylinder Misfire (Cont’d)
StepActionValue(s)YesNo
18
Repair the open or the shorted fuel injector driver
circuit.
Is the repair complete?
–
Go to Step 27
–
19
Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector
connector.
Is the repair complete?
–
Go to Step 27
–
20
Measure the resistance of the spark plug cable that
the spark plug tester did not spark.
Is the resistance of the spark plug cable less than
the specified value?
30000ΩGo to Step 21Go to Step 25
21
Inspect the Engine Control Module (ECM) connector
and connections.
Are the connections OK?
–
Go to Step 22Go to Step 23
22
Check the affected cylinders ignition control circuit
for an open or short and repair as necessary.
Is the repair complete?
–
Go to Step 27Go to Step 26
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
24
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
–
Go to Step 27
–
25Replace the spark plug cable.
Is the repair complete?–Go to Step 27–
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
27
1. Using the scan tool, clear the DTCs.
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?
–
Go to Step 28Go to Step 2
28
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
Applicable DTC
table
System OK