2003 DAEWOO MATIZ ECU

1F–208 ENGINE CONTROLS
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0420 CATALYST LOW EFFICIENCY
Circuit Description
In order to control exhaust emissions of Hydrocarbons
(HC), Carbon Monoxide (CO) and Nitrogen Oxide
(NOx), a Three-Way Catalytic Converter (TWC) is used.
The catalyst within the converter promotes a chemical
reaction which oxidizes the HC and CO present in the
exhaust gas, converting them into harmless water vapor
and carbon dioxide, it also reduces NOx, converting it
into nitrogen. The catalytic converter also has the ability
to store oxygen. The Engine Control Module (ECM) has
the capability to monitor this process using a Heated
Oxygen Sensor (HO2S) located in the exhaust stream
past the TWC. The HO2S produces an output signal
which indicates the oxygen storage capacity of the cata-
lyst; this in turn indicates the catalyst’s ability to convert
exhaust emissions effectively. The ECM monitors the
catalyst efficiency by first allowing the catalyst to heat
up, waiting for a stabilization period while the engine is
idling, and then adding and removing fuel while monitor-
ing the reaction of the HO2S. When the catalyst is func-
tioning properly, the HO2S response to the extra fuel is
slow compared to the Oxygen Sensor (O2S). When the
HO2S response is close to that of the O2S, the Oxygen
storage capability or efficiency of the catalyst is consid-
ered to be bad, and the Malfunction Indicator Lamp
(MIL) will illuminate.
Conditions for Setting the DTC

Oxygen Sensor Capacity test condition:

Closed loop stoichiometry.

Engine is running more than 300 seconds.

Airflow is between 25~50kg/h.

Engine Coolant Temperature (ECT) is more than
70°C(176°F) .

Engine speed between 2,400rpm and 3,000rpm.

Vehicle speed is between 64km/h(28.6mph) and
80km/h(49.7mph).
Note: Test is aborted for this idle if:

Change in engine speed is greater than 80 rpm.

A/C status changed.

Cooling fan status changed.
Insufficient air/fuel shift.

DTC(s) P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0125, P0131, P0132, P0133,
P1133, P0134, P1134, P0137, P0138, P0140,
P0141, P1167, P1171, P0171, P0172, P0201,
P0202, P0203, P0204, P0300, P0336, P0337,
P0341, P0342, P0351, P0352, P0402, P0404,
P0405, P0406, P0506, P0507, and P0562 are NOT
SET.
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.
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
The catalyst test may abort due to a change in the en-
gine load. Do not change the engine load (i.e. A/C, cool-
ant fan, heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor con-
nection, rubbed-through wire insulation, or a wire that is
broken inside the insulation.
Any circuitry, that is suspected as causing the intermit-
tent complaint, should be thoroughly checked for the fol-
lowing conditions:

Backed-out terminals

Improper mating

Broken locks

Improperly formed

Damaged terminals

Poor terminal-to-wire connection.

ENGINE CONTROLS 1F–211
DAEWOO M-150 BL2

The EVAP system in unable to achieve or maintain
vacuum during the diagnostic test. The amount of
decay will vary within the fuel level.
Action Taken When The DTCs 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.
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
Although this DTC is considered a type. A diagnostic, it
acts like a type B diagnostic under certain conditions.
Whenever this diagnostic reports the system has
passed, or if the battery is disconnected, the diagnostic
must fail twice before setting a DTC. The initial failure is
not reported to the diagnostic executive or displayed on
a scan tool. A passing system always reports to the
diagnostic executive immediately.Check for the following conditions :

Missing or damaged fuel cap.

Missing or damaged O-rings at fuel vapor and EVAP
purge line canister fittings.

Cracked or punctured EVAP canister.

Damaged source vacuum line, EVAP purge line,
EVAP vent hose or fuel tank vapor line.

Poor connection at the ECM. Inspect the harness
connectors for the following conditions.

Backed-out terminals.

Improper mating.

Broken locks.

Improperly formed.

Damaged terminals.

Poor terminal-to-wire connection.

Damaged harness. Inspect the wiring harness to the
EVAP vent solenoid, EVAP canister purge valve, and
the fuel tank pressure sensor for an intermittent open
or short circuit.

Kinked, pinched or plugged vacuum source, EVAP
purge, or fuel tank vapor line. Verify that the lines are
not restricted.

ENGINE CONTROLS 1F–215
DAEWOO M-150 BL2

The EVAP system in unable to achieve or maintain
vacuum during the diagnostic test. The amount of
decay will vary within the fuel level.
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.

Coolant fan turns ON.
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
Although this DTC is considered a type. A diagnostic, it
acts like a type B diagnostic under certain conditions.
Whenever this diagnostic reports the system has
passed, or if the battery is disconnected, the diagnostic
must fail twice before setting a DTC. The initial failure is
not reported to the diagnostic executive or displayed ona scan tool. A passing system always reports to the
diagnostic executive immediately.
Check for the following conditions :
Missing or damaged fuel cap.
Missing or damaged O-rings at fuel vapor and EVAP
purge line canister fittings.
Cracked or punctured EVAP canister.
Damaged source vacuum line, EVAP purge line, EVAP
vent hose or fuel tank vapor line.
Poor connection at the ECM. Inspect the harness con-
nectors for the following conditions.

Backed-out terminals.

Improper mating.

Broken locks.

Improperly formed.

Damaged terminals.

Poor terminal-to-wire connection.

Damaged harness. Inspect the wiring harness to the
EVAP vent solenoid, EVAP canister purge valve, and
the fuel tank pressure sensor for an intermittent open
or short circuit.

Kinked, pinched or plugged vacuum source, EVAP
purge, or fuel tank vapor line. Verify that the lines are
not restricted.
DTC P0445 – EVAP Purge Control Circuit Fault
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Disconnect the evaporative emission (EVAP)
canister purge valve connector.
2. Measure the resistance of the EVAP canister
purge valve connector.
Does the resistance measure near within the value
specified?
30ΩGo to Step 3Go to Step 9
3
Connect a test light between EVAP canister purge
valve connector terminal 2 and ground.
Is the test light ON?
–
Go to Step 4Go to Step 6
4
1. Disconnect the ECM connector.
2. Connect a test light between the ECM connector
terminal 66 and ground.
Is the test light ON?
–
Go to Step 5Go to Step 7

1F–218 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F250
DIAGNOSTIC TROUBLE CODE (DTC) – P0462 FUEL LEVEL SENSOR LOW
V O LTA G E
Circuit Description
The engine control module(ECM) uses the fuel level in-
put from the Fuel Level Sensor to calculate expected va-
por pressures within the fuel system. Vapor pressure
vary as the fuel level changes. Vapor pressure is critical
in determining if the evaporative emission (EVAP) sys-
tem is operating properly. Fuel Level is also used to de-
termine if the Fuel level is too high or too low to be able
to accurately detect EVAP system faults. This Diagnos-
tic Trouble Code(DTC) detects a stuck fuel level sender.
Conditions for Setting the DTC

Fuel Level Sensor voltage is less than 0.05V.

Fuel Level Sensor circuit low voltage.
Action Taken When The DTCs Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.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
Inspect harness connectors for backed-out terminal, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal-to-wire connection.
Inspect the wiring harness for damage.
A stuck Fuel Level Sensor may cause the DTC to set. If
DTC P0463 cannot be duplicated, the information in-
cluded in the Freeze Frame data can be useful in deter-
mining vehicle operating conditions when the DTC was
first set.
Resistance check for the Fuel Level Sensor.
Empty = 100 ohms or over.
Half full = about 32.5 ohms.
Full = 10 ohms or less.

1F–222 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F250
DIAGNOSTIC TROUBLE CODE (DTC) – P0463 FUEL LEVEL SENSOR HIGH
V O LTA G E
Circuit Description
The engine control module(ECM) uses the fuel level in-
put from the Fuel Level Sensor to calculate expected va-
por pressures within the fuel system. Vapor pressure
vary as the fuel level changes. Vapor pressure is critical
in determining if the evaporative emission (EVAP) sys-
tem is operating properly. Fuel Level is also used to de-
termine if the Fuel level is too high or too low to be able
to accurately detect EVAP system faults. This Diagnos-
tic Trouble Code(DTC) detects a stuck fuel level sender.
Conditions for Setting the DTC

Fuel Level Sensor voltage is higher than 4.9V.

Fuel Level Sensor circuit high voltage.
Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.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
Inspect harness connectors for backed-out terminal, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal-to-wire connection.
Inspect the wiring harness for damage.
A stuck Fuel Level Sensor may cause the DTC to set. If
DTC P0463 cannot be duplicated, the information in-
cluded in the Freeze Frame data can be useful in deter-
mining vehicle operating conditions when the DTC was
first set.
Resistance check for the Fuel Level Sensor.
Empty = 100 ohms or over.
Half full = about 32.5 ohms.
Full = 10 ohms or less.

1F–226 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
DIAGNOSTIC TROUBLE CODE (DTC) – P0480 LOW SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITHOUT A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC

Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.

Ignition ON.
Ignition voltage is greater than 10 volts.

Engine run time is greater than 5 seconds.
Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.
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
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported

1F–230 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F270
DIAGNOSTIC TROUBLE CODE (DTC) – P0480 LOW SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITH A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC

Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.

Ignition ON.
Ignition voltage is greater than 10 volts.

Engine run time is greater than 5 seconds.
Action Taken When The DTCs Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.
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
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported

1F–234 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
DIAGNOSTIC TROUBLE CODE (DTC) – P0481 HIGH SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITHOUT A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC

Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.

Ignition ON.
Ignition voltage is greater than 10 volts.

Engine run time is greater than 5 seconds.
Action Taken When The DTCs Sets

The Malfunction Indicator Lamp (MIL) will not illumi-
nate.

The ECM will store conditions which were present
when the DTC was set as Failure Records data only.

This information will not be stored in the Freeze
Frame data.
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
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported