2003 DAEWOO MATIZ service

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

ENGINE CONTROLS 1F–9
DAEWOO M-150 BL2
appropriate wiring diagram. Refer to “ECM Wiring Dia-
grams” in this Section.
9591
Terminal 49GroundOpen
STRATEGY-BASED DIAGNOSTICS
Strategy-Based Diagnostics
The strategy-based diagnostic is a uniform approach to
repair all Electrical/Electronic (E/E) systems. The diag-
nostic flow can always be used to resolve an E/E system
problem and is a starting point when repairs are neces-
sary. The following steps will instruct the technician on
how to proceed with a diagnosis:
Verify the customer complaint. To verify the customer
complaint, the technician should know the normal op-
eration of the system.

Perform preliminary checks as follows:

Conduct a thorough visual inspection.

Review the service history.

Detect unusual sounds or odors.

Gather Diagnostic Trouble Code (DTC) information to
achieve an effective repair.

Check bulletins and other service information. This
includes videos, newsletters, etc.

Refer to service information (manual) system
check(s).

Refer to service diagnostics.
No Trouble Found
This condition exists when the vehicle is found to oper-
ate normally. The condition described by the customer
may be normal. Verify the customer complaint against
another vehicle that is operating normally. The condition
may be intermittent. Verify the complaint under the con-
ditions described by the customer before releasing the
vehicle.
Re-examine the complaints.
When the complaints cannot be successfully found or
isolated, a re-evaluation is necessary. The complaint
should be re-verified and could be intermittent as de-
fined in “intermittents,” or could be normal.
After isolating the cause, the repairs should be made.
Validate for proper operation and verify that the symp-
tom has been corrected. This may involve road testing
or other methods to verify that the complaint has re-
solved under following conditions:

Conditions noted by the customer.

If a DTC was diagnosed, verify the repair be duplicat-
ing conditions present when the DTC was set as
noted in Failure Records or Freeze Frame data.
Verifying Vehicle Repair
Verification of the vehicle repair will be more compre-
hensive for vehicles with Euro On-Board Diagnostic
(EOBD) system diagnostics. Following a repair, the
technician should perform the following steps:
Important: Follow the steps below when you verify re-
pairs on EOBD systems. Failure to follow these steps
could result in unnecessary repairs.

Review and record the Failure Records and the
Freeze Frame data for the DTC which has been diag-
nosed (Freeze Fame data will only be stored for an A,
B and E type diagnostic and only if the Malfunction
Indicator Lamp has been requested).

Clear the DTC(s).

Operate the vehicle within conditions noted in the
Failure Records and Freeze Frame data.

Monitor the DTC status information for the specific
DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.
EOBD SERVICEABILITY ISSUES
Based on the knowledge gained from Euro On-Board
Diagnostic (OBD) experience in the 1994 and 1995
model years in United Status, this list of non-vehicle
faults that could affect the performance of the Euro On-
Board Diagnostic (EOBD) system has been compiled.
These non-vehicle faults vary from environmental condi-
tions to the quality of fuel used. With the introduction of
EOBD across the entire passenger car, illumination of
the Malfunction Indicator Lamp (MIL) due to a non-ve-
hicle fault could lead to misdiagnosis of the vehicle, in-
creased warranty expense and customer
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Fuel quality is not a new issue for the automotive indus-
try, but its potential for turning on the MIL with EOBD
systems is new.
Fuel additives such as “dry gas” and “octane enhancers”
may affect the performance of the fuel. If this results in
an incomplete combustion or a partial burn, it will set
Diagnostic Trouble Code (DTC) P0300. The Reed Vapor
Pressure of the fuel can also create problems in the fuel
system, especially during the spring and fall months
when severe ambient temperature swings occur. A high
Reed Vapor Pressure could show up as a Fuel Trim
DTC due to excessive canister loading.
Using fuel with the wrong octane rating for your vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using “premium” gasoline will
improve the performance of your vehicle. Most premium

1F–12 ENGINE CONTROLS
DAEWOO M-150 BL2
The enable criteria for each diagnostic is listed on the
first page of the Diagnostic Trouble Code (DTC) descrip-
tion under the heading “Conditions for Setting the DTC.”
Enable criteria varies with each diagnostic and typically
includes, but is not limited to the following items:

Engine speed.

Vehicle speed

Engine Coolant Temperature (ECT)

Manifold Absolute Pressure (MAP)

Barometric Pressure (BARO)

Intake Air Temperature (IAT)

Throttle Position (TP)

High canister purge

Fuel trim

A/C on
Trip
Technically, a trip is a key-on run key-off cycle in which
all the enable criteria for a given diagnostic are met, al-
lowing the diagnostic to run. Unfortunately, this concept
is not quite that simple. A trip is official when all the en-
able criteria for a given diagnostic are met. But because
the enable criteria vary from one diagnostic to another,
the definition of trip varies as well. Some diagnostics are
run when the vehicle is at operating temperature, some
when the vehicle first starts up; some require that the
vehicle cruise at a steady highway speed, some run only
when the vehicle is at idle. Some run only immediately
following a cold engine start-up.
A trip then, is defined as a key-on run-key off cycle in
which the vehicle is operated in such a way as to satisfy
the enable criteria for a given diagnostic, and this diag-
nostic will consider this cycle to be one trip. However,
another diagnostic with a different set of enable criteria
(which were not met) during this driving event, would not
consider it a trip. No trip will occur for that particular
diagnostic until the vehicle is driven in such a way as to
meet all the enable criteria.
Diagnostic Information
The diagnostic charts and functional checks are de-
signed to locate a faulty circuit or component through a
process of logical decisions. The charts are prepared
with the requirement that the vehicle functioned correct-
ly at the time of assembly and that there are not multiple
faults present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complimented by
the diagnostic procedures contained in this manual. The
language of communicating the source of the malfunc-
tion is a system of diagnostic trouble codes. When a
malfunction is detected by the control module, a DTC is
set, and the Malfunction Indicator Lamp (MIL) is illumi-
nated.
Malfunction Indicator Lamp (MIL)
The Malfunction Indicator Lamp (MIL) is required by
Euro On-Board Diagnostics (EOBD) to illuminate under
a strict set of guidelines.
Basically, the MIL is turned on when the Engine Control
Module (ECM) detects a DTC that will impact the vehicle
emissions.
The MIL is under the control of the Diagnostic Execu-
tive. The MIL will be turned on if an emissions-related
diagnostic test indicates a malfunction has occurred. It
will stay on until the system or component passes the
same test for three consecutive trips with no emissions
related faults.
Extinguishing the MIL
When the MIL is on, the Diagnostic Executive will turn
off the MIL after three consecutive trips that a “test
passed” has been reported for the diagnostic test that
originally caused the MIL to illuminate. Although the MIL
has been turned off, the DTC will remain in the ECM
memory (both Freeze Frame and Failure Records) until
forty (40) warm-up cycles after no faults have been com-
pleted.
If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition
to the requirements stated in the previous paragraph,
these requirements are as follows:

The diagnostic tests that are passed must occur with
375 rpm of the rpm data stored at the time the last
test failed.

Plus or minus ten percent of the engine load that was
stored at the time the last test failed. Similar engine
temperature conditions (warmed up or warming up)
as those stored at the time the last test failed.
Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL is on the instrument panel and has the following
functions:

It informs the driver that a fault affecting the vehicle’s
emission levels has occurred and that the vehicle
should be taken for service as soon as possible.

As a system check, the MIL will come on with the key
ON and the engine not running. When the engine is
started, the MIL will turn OFF.

When the MIL remains ON while the engine is run-
ning, or when a malfunction is suspected due to a
driveability or emissions problem, an EOBD System
Check must be performed. The procedures for these
checks are given in EOBD System Check. These
checks will expose faults which may not be detected
if other diagnostics are performed first.

ENGINE CONTROLS 1F–13
DAEWOO M-150 BL2
Data Link Connector (DLC)
The provision for communicating with the control mod-
ule is the Data Link Connector (DLC). The DLC is used
to connect to a scan tool. Some common uses of the
scan tool are listed below:

Identifying stored DTCs.

Clearing DTCs.

Performing output control tests.

Reading serial data.
DTC TYPES
Each Diagnostic Trouble Code (DTC) is directly related
to a diagnostic test. The Diagnostic Management Sys-
tem sets DTCs based on the failure of the tests during a
trip or trips. Certain tests must fail two consecutive trips
before the DTC is set. The following are the three types
of DTCs and the characteristics of those codes:
Type A

Emissions related.

Requests illumination of the Malfunction Indicator.
Lamp (MIL) of the first trip with a fail.

Stores a History DTC on the first trip with a fail.

Stores a Freeze Frame (if empty).

Stores a Fail Record.

Updates the Fail Record each time the diagnostic test
fails.
Type B

Emissions related.

“Armed” after one trip with a fail.

“Disarmed” after one trip with a pass.

Requests illumination of the MIL on the second con-
secutive trip with a fail.

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

Stores a Freeze Frame on the second consecutive
trip with a fail (if empty).
Type Cnl

Non-Emissions related.

Does not request illumination of any lamp.

Stores a History DTC on the first trip with a fail .

Does not store a Freeze Frame.

Stores Fail Record when test fails.

Updates the Fail Record each time the diagnostic test
fails.
Type E

Emissions related.

“Armed” after two consecutive trip with a fail.

“Disarmed” after one trip with a pass.
Requests illumination of the MIL on the third consec-
utive trip with a fail.

Stores a History DTC on the third consecutive trip
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).
Important: For 0.8 SOHC engine eight fail records can
be stored. Each Fail Record is for a different DTC. It is
possible that there will not be Fail Records for every
DTC if multiple DTCs are set.
Special Cases of Type B Diagnostic Tests
Unique to the misfire diagnostic, the Diagnostic Execu-
tive has the capability of alerting the vehicle operator to
potentially damaging levels of misfire. If a misfire condi-
tion exists that could potentially damage the catalytic
converter as a result of high misfire levels, the Diagnos-
tic Executive will command the MIL to “flash” as a rate of
once per seconds during those the time that the catalyst
damaging misfire condition is present.
Fuel trim and misfire are special cases of Type B diag-
nostics. Each time a fuel trim or misfire malfunction is
detected, engine load, engine speed, and Engine Cool-
ant Temperature (ECT) are recorded.
When the ignition is turned OFF, the last reported set of
conditions remain stored. During subsequent ignition
cycles, the stored conditions are used as a reference for
similar conditions. If a malfunction occurs during two
consecutive trips, the Diagnostic Executive treats the
failure as a normal Type B diagnostic, and does not use
the stored conditions. However, if a malfunction occurs
on two non-consecutive trips, the stored conditions are
compared with the current conditions. The MIL will then
illuminate under the following conditions:

When the engine load conditions are within 10% of
the previous test that failed.

Engine speed is within 375 rpm, of the previous test
that failed.

ECT is in the same range as the previous test that
failed.
READING DIAGNOSTIC TROUBLE
CODES
The procedure for reading Diagnostic Trouble Code(s)
(DTC) is to use a diagnostic scan tool. When reading
DTC(s), follow instructions supplied by tool manufactur-
er.
Clearing Diagnostic Trouble Codes
Important: Do not clear DTCs unless directed to do so
by the service information provided for each diagnostic
procedure. When DTCs are cleared, the Freeze Frame
and Failure Record data which may help diagnose an in-

1F–14 ENGINE CONTROLS
DAEWOO M-150 BL2
termittent fault will also be erased from memory. If the
fault that caused the DTC to be stored into memory has
been corrected, the Diagnostic Executive will begin to
count the ‘‘warm-up” cycles with no further faults de-
tected, the DTC will automatically be cleared from the
Engine Control Module (ECM) memory.
To clear DTCs, use the diagnostic scan tool.
It can’t cleared DTCs without the diagnostic scan tool.
So you must use the diagnostic scan tool.
Notice: To prevent system damage, the ignition key
must be OFF when disconnecting or reconnecting bat-
tery power.

The power source to the control module. Examples:
fuse, pigtail at battery ECM connectors, etc.

The negative battery cable. (Disconnecting the nega-
tive battery cable will result in the loss of other Euro
On-Board memory data, such as preset radio tuning.)
DTC Modes
On Euro On-Board Diagnostic (EOBD) passenger cars
there are five options available in the scan tool DTC
mode to display the enhanced information available. A
description of the new modes, DTC Info and Specific
DTC, follows. After selecting DTC, the following menu
appears:

DTC Info.

Specific DTC.

Freeze Frame.

Fail Records (not all applications).

Clear Info.
The following is a brief description of each of the sub
menus in DTC Info and Specific DTC. The order in
which they appear here is alphabetical and not neces-
sarily the way they will appear on the scan tool.
DTC Information Mode
Use the DTC info mode to search for a specific type of
stored DTC information. There are seven choices. The
service manual may instruct the technician to test for
DTCs in a certain manner. Always follow published ser-
vice procedures.
To get a complete description of any status, press the
‘‘Enter” key before pressing the desired F-key. For ex-
ample, pressing ‘‘Enter” then an F-key will display a defi-
nition of the abbreviated scan tool status.
DTC Status
This selection will display any DTCs that have not run
during the current ignition cycle or have reported a test
failure during this ignition up to a maximum of 33 DTCs.
DTC tests which run and pass will cause that DTC num-
ber to be removed from the scan tool screen.
Fail This Ign. (Fail This Ignition)
This selection will display all DTCs that have failed dur-
ing the present ignition cycle.
History
This selection will display only DTCs that are stored in
the ECM’s history memory. It will not display Type B
DTCs that have not requested the Malfunction Indicator
Lamp (MIL). It will display all type A, B and E DTCs that
have requested the MIL and have failed within the last
40 warm-up cycles. In addition, it will display all type C
and type D DTCs that have failed within the last 40
warm-up cycles.
Last Test Fail
This selection will display only DTCs that have failed the
last time the test ran. The last test may have run during
a previous ignition cycle if a type A or type B DTC is dis-
played. For type C and type D DTCs, the last failure
must have occurred during the current ignition cycle to
appear as Last Test Fail.
MIL Request
This selection will display only DTCs that are requesting
the MIL. Type C and type D DTCs cannot be displayed
using this option. This selection will report type B and E
DTCs only after the MIL has been requested.
Not Run SCC (Not Run Since Code Clear)
This option will display up to 33 DTCs that have not run
since the DTCs were last cleared. Since the displayed
DTCs have not run, their condition (passing or failing) is
unknown.
Test Fail SCC (Test Failed Since Code
Clear)
This selection will display all active and history DTCs
that have reported a test failure since the last time DTCs
were cleared. DTCs that last failed more than 40 warm-
up cycles before this option is selected will not be dis-
played.
Specific DTC Mode
This mode is used to check the status of individual diag-
nostic tests by DTC number. This selection can be ac-
cessed if a DTC has passed, failed or both. Many EOBD
DTC mode descriptions are possible because of the ex-
tensive amount of information that the diagnostic execu-
tive monitors regarding each test. Some of the many
possible descriptions follow with a brief explanation.
The “F2” key is used, in this mode, to display a descrip-
tion of the DTC. The “Ye s” and “No” keys may also be
used to display more DTC status information. This
selection will only allow entry of DTC numbers that are
supported by the vehicle being tested. If an attempt is,

1F–210 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F240
DIAGNOSTIC TROUBLE CODE (DTC) – P0444 EVAP PURGE CONTROL
CIRCUIT NO SIGNAL
Circuit Description
The evaporative emission (EVAP) system includes the
following components :

Fuel tank.

EVAP vent solenoid.

Fuel pipes and hoses.

Fuel vapor lines.

Fuel cap.

EVAP canister.

Purge lines.

EVAP canister purge valve.

EVAP service port.
The evaporative emission system is checked by apply-
ing vacuum to the EVAP system and monitoring for a
vacuum decay. The engine control module(ECM) moni-
tors the vacuum level through the fuel tank pressure
sensor signal. At the appropriate time, the EVAP canis-
ter purge valve and the EVAP vent solenoid are turned
on, allowing the engine to draw a small vacuum on the
entire EVAP system. After the desired vacuum level has
been achieved, the EVAP canister purge valve is turned
OFF, sealing the system. If a sufficient vacuum level
cannot be achieved, a large leak is indicated. This can
be caused by the following conditions :
Missing or faulty fuel cap.
Disconnected or faulty fuel tank pressure sensor.
Disconnected, damaged, pinched, or blocked EVAP
purge line.
Disconnected or faulty EVAP canister purge valve.
Disconnected or faulty EVAP vent solenoid.Open ignition feed circuit to the EVAP vent or purge so-
lenoid.
Damaged EVAP canister.
Leaking fuel sensor assembly O-ring.
Leaking fuel tank or fuel filler beck.
Any of the above conditions can set DTC P0444.
The test is failed if the tank vacuum is less than 10 in
H20 for 15 seconds and the manifold vacuum integral is
greater than 49512 (proportional to purge mass from the
tank).
Conditions for Setting the DTC

Intake Air Temperature(IAT) is between 4°C and
34°C(39°F and 93°F).at engine start up.

Engine Coolant Temperature(ECT) is between 4°C
and 34°C(39°F and 93°F).at engine start up.

Barometric pressure (BARO) is greater than 68kPA.

IAT is not more than 8°C(46°F) greater than the ECT
at start up.

Fuel level is between 10% and 90%.

The throttle position (TP) sensor is less than or equal
to 100%.

No fuel slosh, and the change in fuel level percent is
21 counts on 0.125 sec.

Manifold vacuum is greater than or equal to 10kPA.

Fuel level or change in tank pressure is less than or
equal to 24.9 in H2O.

System voltage is between 11V and 16V.

1F–214 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F240
DIAGNOSTIC TROUBLE CODE (DTC) – P0445 EVAP PURGE CONTROL
CIRCUIT FAULT
Circuit Description
The evaporative emission (EVAP) system includes the
following components :

Fuel tank.

EVAP vent solenoid.

Fuel tank pressure sensor.

Fuel pipes and hoses.

Fuel vapor lines.

Fuel cap.

EVAP canister.

Purge lines.

EVAP canister purge valve.

EVAP service port.
The evaporative emission system is checked by apply-
ing vacuum to the EVAP system and monitoring for a
vacuum decay. The engine control module(ECM) moni-
tors the vacuum level through the fuel tank pressure
sensor signal. At the appropriate time, the EVAP canis-
ter purge valve and the EVAP vent solenoid are turned
on, allowing the engine to draw a small vacuum on the
entire EVAP system. After the desired vacuum level has
been achieved, the EVAP canister purge valve is turned
OFF, sealing the system. If a sufficient vacuum level
cannot be achieved, a large leak is indicated. This can
be caused by the following conditions :
Missing or faulty fuel cap.
Disconnected or faulty fuel tank pressure sensor.
Disconnected, damaged, pinched, or blocked EVAP
purge line.
Disconnected or faulty EVAP canister purge valve.Disconnected or faulty EVAP vent solenoid.
Open ignition feed circuit to the EVAP vent or purge so-
lenoid.
Damaged EVAP canister.
Leaking fuel sensor assembly O-ring.
Leaking fuel tank or fuel filler beck.
Any of the above conditions can set DTC P0445.
The test is failed if the tank vacuum is less than 10 in
H20 for 15 seconds and the manifold vacuum integral is
greater than 49512 (proportional to purge mass from the
tank).
Conditions for Setting the DTC

Intake Air Temperature(IAT) is between 4°C and
34°C(39°F and 93°F).at engine start up.

Engine Coolant Temperature(ECT) is between 4°C
and 34°C(39°F and 93°F).at engine start up.

Barometric pressure (BARO) is greater than 68kPA.

IAT is not more than 8°C(46°F) greater than the ECT
at start up.

Fuel level is between 10% and 90%.

The throttle position (TP) sensor is less than or equal
to 100%.

No fuel slosh, and the change in fuel level percent is
21 counts on 0.125 sec.

Manifold vacuum is greater than or equal to 10kPA.

Fuel level or change in tank pressure is less than or
equal to 24.9 in H2O.

System voltage is between 11V and 16V.

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?
3
C (5
F)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–