2003 DAEWOO MATIZ wheel

ENGINE ELECTRICAL 1E–35
DAEWOO M-150 BL2
D102E764
4. Remove the optical sensor cover and adaptor from
the distributor housing.

Remove the screw (1).

Remove the adaptor (2).

Remove the screws (3).

Remove the cover (4).

Remove the gasket (5).
D102E765
5. Remove the optical sensor unit from the distributor
housing.

Carefully remove the disc wheel (1).

Remove the bushing (2).

Remove the screws (3).

Remove the optical sensor unit plate (4).

Remove the optical sensor unit (5).
D102E766
6. Remove the bearing plate from the distributor hous-
ing.

Remove the screws (1).

Remove the bearing plate (2).
D102E767
7. Remove the coupling, shaft and bearing from the dis-
tributor housing.

Remove the coupling (1).

Remove the shaft using the press (2).

Remove the bearing (3).

1F–4 ENGINE CONTROLS
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
IGNITION SYSTEM OPERATION
This ignition system does not use a conventional distrib-
utor and coil. It uses a crankshaft position sensor input
to the Engine Control Module (ECM). The ECM then de-
termines Electronic Spark Timing (EST) and triggers the
electronic ignition system ignition coil.
This type of distributorless ignition system uses a “waste
spark’’ method of spark distribution. Each cylinder is in-
dividural with coil per cylinder.
These systems use the EST signal from the ECM to
control the EST. The ECM uses the following informa-
tion:

Engine load (manifold pressure or vacuum).

Atmospheric (barometric) pressure.

Engine temperature.

Intake air temperature.

Crankshaft position.

Engine speed (rpm).
ELECTRONIC IGNITION SYSTEM
IGNITION COIL
The Electronic Ignition (EI) system ignition coil is
mounted near on the cylinder head.
A terminals of the EI system ignition coil provides the
spark for each spark plug. The EI system ignition coil is
not serviceable and must be replaced as an assembly.
CRANKSHAFT POSITION SENSOR
This Electronic Ignition (EI) system uses a magnetic
crankshaft position sensor. This sensor protrudes
through its mount to within approximately 1.3 mm (0.05
inch) of the crankshaft reluctor. The reluctor is a special
wheel attached to the crankshaft with 58 slots machined
into it, 57 of which are equally spaced in 6-degree inter-
vals. The last slot is wider and serves to generate a
“sync pulse.” As the crankshaft rotates, the slots in the
reluctor change the magnetic field of the sensor, creat-
ing an induced voltage pulse. The longer pulse of the
58th slot identifies a specific orientation of the crank-
shaft and allows the Engine Control Module (ECM) to
determine the crankshaft orientation at all times. The
ECM uses this information to generate timed ignition
and injection pulses that it sends to the ignition coils and
to the fuel injectors.
CAMSHAFT POSITION SENSOR
The Camshaft Position (CMP) sensor sends a CMP sig-
nal to the Engine Control Module (ECM). The ECM uses
this signal as a “sync pulse” to trigger the injectors in the
proper sequence. The ECM uses the CMP signal to indi-
cate the position of the #1 piston during its power stroke.
This allows the ECM to calculate true sequential fuel in-jection mode of operation. If the ECM detects an incor-
rect CMP signal while the engine is running, Diagnostic
Trouble Code (DTC) P0341 will set. If the CMP signal is
lost while the engine is running, the fuel injection system
will shift to a calculated sequential fuel injection mode
based on the last fuel injection pulse, and the engine will
continue to run. As long as the fault is present, the en-
gine can be restarted. It will run in the calculated se-
quential mode with a 1-in-6 chance of the injector
sequence being correct.
IDLE AIR SYSTEM OPERATION
The idle air system operation is controlled by the base
idle setting of the throttle body and the Idle Air Control
(IAC) valve.
The Engine Control Module (ECM) uses the IAC valve to
set the idle speed dependent on conditions. The ECM
uses information from various inputs, such as coolant
temperature, manifold vacuum, etc., for the effective
control of the idle speed.
FUEL CONTROL SYSTEM
OPERATION
The function of the fuel metering system is to deliver the
correct amount of fuel to the engine under all operating
conditions. The fuel is delivered to the engine by the in-
dividual fuel injectors mounted into the intake manifold
near each cylinder.
The main fuel control sensors are the Manifold Absolute
Pressure (MAP) sensor, the oxygen sensor (O2S), and
the heated oxygen sensor (HO2S).
The MAP sensor measures or senses the intake man-
ifold vacuum. Under high fuel demands, the MAP sensor
reads a low vacuum condition, such as wide open
throttle. The Engine Control Module (ECM) uses this in-
formation to enrich the mixture, thus increasing the fuel
injector on-time, to provide the correct amount of fuel.
When decelerating, the vacuum increases. This vacuum
change is sensed by the MAP sensor and read by the
ECM, which then decreases the fuel injector on-time
due to the low fuel demand conditions.
The O2S is located in the exhaust manifold. The HO2S
is located in the exhaust pipe. The oxygen sensors indi-
cate to the ECM the amount of oxygen in the exhaust
gas, and the ECM changes the air/fuel ratio to the en-
gine by controlling the fuel injectors. The best air/fuel ra-
tio to minimize exhaust emissions is 14.7:1, which
allows the catalytic converter to operate most efficiently.
Because of the constant measuring and adjusting of the
air/fuel ratio, the fuel injection system is called a “closed
loop” system.
The ECM uses voltage inputs from several sensors to
determine how much fuel to provide to the engine. The

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–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

ENGINE CONTROLS 1F–135
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0300 MULTIPLE CYLINDER MISFIRE
System Description
The Engine Control Module (ECM) monitors the crank-
shaft and camshaft positions to detect if the engine is
misfiring. The ECM looks for a quick drop in crankshaft
speed. This test is executed in blocks of 100 engine rev-
olution tests. It may take between one to several tests to
store a Diagnostic Trouble Code (DTC) and illuminate
the Malfunction Indicator Lamp (MIL). Under light misfire
conditions, it may also take more than one trip to set a
DTC. Severe misfire will flash the MIL, indicating that
catalyst damage is possible.
Conditions for Setting the DTC

Emission threshold is 3.0% for manual transaxle.

20 engine cycles have occurred since cranking has
started.

A/C compressor clutch has not just engaged or disen-
gaged.

Engine load and engine speed are in a detectable re-
gion and are at or above zero torque.

Camshaft Position (CMP) sensor is in synchroniza-
tion.

Electric Exhaust Gas Recirculation (EEGR) flow
diagnostic is not in progress.

Fuel level is greater than or equal to 20% of rated
tank capacity.

Decel Fuel Cutoff (DFCO) not active.

Fuel is not shutoff from high engine speed of 6500
rpm for manual transaxle vehicle.

Fuel is not shutoff at 255 km/h (158 mph).

Throttle position change is less than 3% per 125 ms.

Vehicle has not encountered an abusive engine
speed of 7000 rpm.
Crankshaft speed patters are normal.

Throttle position is less than 4% when vehicle speed
is greater than 10 km/h (6 mph).

Engine speed is between 800 and 4500 rpm.

Vehicle voltage is between 11 and 16 volts.

Engine Coolant Temperature (ECT) is between –7°C
(20°F) and 120°C (248°F).

The engine speed is less than or equal to 1800 rpm or
the crank angle sensing error has not been learned.

There is the correct ratio between Crankshaft Posi-
tion (CKP) sensor pulses and CMP sensor pulses.

DTCs P0106, P0107, P0108, P0117, P0118, P0122,
P0123, P0320, P0337, P0341, P0342 and P0502 are
not set.
Action Taken when the DTC Sets

The malfunction Indicator Lamp (MIL) will blinking.

The ECM will record operating conditions at the time
the diagnostic fails. The information will be stored in
the Freeze Frame and failure records buffers.

A history DTC is stored.
Conditions for Clearing the MIL/DTC

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
An intermittent can also be the result of a defective re-
luctor wheel. Remove the CKP sensor and inspect the
reluctor wheel through the sensor mount hole. Check for
porosity and the condition of wheel. If the DTC is inter-
mittent refer to “Symptoms Diagnosis” in this section.
DTC P0300 – Multiple Cylinder Misfire
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0201, P0202, P0203, P0204 set?
–Go to
Applicable DTC
table
Go to Step 3
3
Perform a visual/physical inspection.
Make any repairs that are necessary.
Is the repair complete?–
Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–
Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11

ENGINE CONTROLS 1F–139
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0300 MULTIPLE CYLINDER MISFIRE
System Description
The Engine Control Module (ECM) monitors the crank-
shaft and camshaft positions to detect if the engine is
misfiring. The ECM looks for a quick drop in crankshaft
speed. This test is executed in blocks of 100 engine rev-
olution tests. It may take between one to several tests to
store a Diagnostic Trouble Code (DTC) and illuminate
the Malfunction Indicator Lamp (MIL). Under light misfire
conditions, it may also take more than one trip to set a
DTC. Severe misfire will flash the MIL, indicating that
catalyst damage is possible.
Conditions for Setting the DTC

Emission threshold is 3.0% for automatic transaxle
and 3.0% for manual transaxle.

20 engine cycles have occurred since cranking has
started.

A/C compressor clutch has not just engaged or disen-
gaged.

Engine load and engine speed are in a detectable re-
gion and are at or above zero torque.

Camshaft Position (CMP) sensor is in synchroniza-
tion.

Electric Exhaust Gas Recirculation (EEGR) flow
diagnostic is not in progress.

Fuel level is greater than or equal to 20% of rated
tank capacity.

Decel Fuel Cutoff (DFCO) not active.

Fuel is not shutoff from high engine speed of 6500
rpm for manual transaxle vehicle or 6500 rpm in drive
and 6250 rpm in park for automatic transaxle ve-
hicles.

Fuel is not shutoff at 255 km/h (158 mph).

An automatic transmission is not shifting.

Throttle position change is less than 3% per 125 ms.

Vehicle has not encountered an abusive engine
speed of 7000 rpm.

Crankshaft speed patters are normal.
Throttle position is less than 4% when vehicle speed
is greater than 10 km/h (6 mph).

Engine speed is between 600 and 4500 rpm.

Vehicle voltage is between 11 and 16 volts.

Engine Coolant Temperature (ECT) is between –7°C
(20°F) and 120°C (248°F).

The engine speed is less than or equal to 1800 rpm or
the crank angle sensing error has not been learned.

There is the correct ratio between Crankshaft Posi-
tion (CKP) sensor pulses and CMP sensor pulses.

DTCs P0106, P0107, P0108, P0117, P0118, P0122,
P0123, P0320, P0337, P0341, P0342 and P0502 are
not set.
Action Taken when the DTC Sets

Emission related.

“Armed” after two trip with a fail.

“Disarmed” after one trip with a pass.

MIL on if failure is detected in three consecutive trips.

Stores a History DTC on the third consecutive with a
fail (The DTC will be armed after the second fail).

Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).
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.

Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
An intermittent can also be the result of a defective re-
luctor wheel. Remove the CKP sensor and inspect the
reluctor wheel through the sensor mount hole. Check for
porosity and the condition of wheel. If the DTC is inter-
mittent refer to “Symptoms Diagnosis” in this section.
DTC P0300 – Multiple Cylinder Misfire
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0201, P0202, P0203, P0204 set?
–Go to
Applicable DTC
table
Go to Step 3