engine coolant DAEWOO MATIZ 2003 Service Workshop Manual

1F–182 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P0400 ELECTRIC EXHAUST GAS
RECIRCULATION OUT OF LIMIT
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A EEGR valve is used on this system. The linear EEGR
valve is designed to accurately supply exhaust gases to
the engine without the use of intake manifold vacuum.
The valve controls exhaust flow going into the intake
manifold from the exhaust manifold fhrough an orifice
with a engine control module(ECM) controlled pintle.
The ECM controls the pintle position using inputs from
the Throttle Position (TP) and the Manifold Absolute
Pressure (MAP) sensor. The ECM then commands the
EEGR valve to operate when necessary by controlling
an ignition signal through the ECM. This can be moni-
tored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.Conditions for Setting the DTC

Engine Coolant Temperature(ECT) is higher than
80°C(176°F).

Intake Air Temperature(IAT) is higher than 15°C
(59°F).

Manifold Absolute Pressure is greater than 75kPA.

The EEGR is higher than 3%.

Mass Air Flow is between 92 ~157mg/tdc.

Engine Speed Is Between 2,500~2,900rpm.

DTCs P0107, P0108, P0112, P0113, P0117, P0118,
P0122, P0123, P0131, P0300, P0335, P0336,
P0341, P0342, P1671, P1672, P1673 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.

1F–186 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P1402 ELECTRIC EXHAUST GAS
RECIRCULATION BLOCKED
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A EEGR valve is used on this system. The linear EEGR
valve is designed to accurately supply exhaust gases to
the engine without the use of intake manifold vacuum.
The valve controls exhaust flow going into the intake
manifold from the exhaust manifold fhrough an orifice
with a engine control module(ECM) controlled pintle.
The ECM controls the pintle position using inputs from
the Throttle Position (TP) and the Manifold Absolute
Pressure (MAP) sensor. The ECM then commands the
EEGR valve to operate when necessary by controlling
an ignition signal through the ECM. This can be moni-
tored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.
Conditions for Setting the DTC

Engine Coolant Temperature(ECT) is greater than
80°C(176°F).
Intake Air Temperature(IAT) is greater than 15°C
(59°F).

Manifold Absolute Pressure is greater than 75kPA.

The EEGR differential rate is less than 3%.

Mass Air Flow is between 92 ~157mg/tdc.

Engine Speed Is Between 2,500~2,900rpm.

DTCs P0107, P0108, P0112, P0113, P0117, P0118,
P0122, P0123, P0131, P0300, P0335, P0336,
P0341, P0342, P1671, P1672, P1673 are NOT SET.

EEGR is disabled.
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
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can be

ENGINE CONTROLS 1F–187
DAEWOO M-150 BL2
easily verified. Check the Freeze Frame data to deter- mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).
DTC P1402 – Electric Exhaust Gas Recirculation Blocked
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. Start the engine and allow the engine to idle.
2. Install the scan tool.
3. Command the electric exhaust gas recirculation
(EEGR) valve to the specified values.
Does the engine stall or attempt to stall?
50%Go to Step 5Go to Step 3
3
1. Turn the ignition switch to LOCK.
2. Remove the EEGR valve assembly.
3. Inspect the EEGR valve, passages and pipe for a
restriction or damage and repair as necessary.
Is a repair necessary?
–
Go to Step 5Go to Step 4
4Replace the EEGR valve.
Is the replacement complete?–Go to Step 5–
5
1. Start the engine.
2. Disconnect the battery for the specified time.
3. Drive the vehicle to the specified value.
4. Release the throttle and allow the vehicle to
decelerate to the specified value.
Is the EEGR Decel Filter Values less than the
specified value?
10 secnds
60mph
(97km/h)
20mph
(32km/h)
0mph
Go to Step 3Go to Step 6
6
1. Using the scan tool, clear the Diagnostic Trouble
Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?
–
Go to Step 7Go to Step 2

1F–188 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P1403 ELECTRIC EXHAUST GAS
RECIRCULATION VALVE FAILURE
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A linear EEGR valve is used on this system. The linear
EEGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold from the exhaust manifold fhrough an
orifice with a engine control module(ECM) controlled
pintle. The ECM controls the pintle position using inputs
from the Throttle Position (TP) and the Manifold Abso-
lute Pressure (MAP) sensor. The ECM then commands
the EEGR valve to operate when necessary by control-
ling an ignition signal through the ECM. This can be
monitored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.
Conditions for Setting THE DTC

Engine Coolant Temperature(ECT) is greater than
80°C(176°F).
Intake Air Temperature(IAT) is greater than 15°C
(59°F).

Manifold Absolute Pressure is greater than 75kPA.

The open EEGR value is higher than 3%.

Mass Air Flow is between 92 ~157mg/tdc.

Engine Speed Is Between 2,500~2,900rpm.

EEGR potentiometer voltage is less than 0.4V.

EEGR potentiometer voltage is higher than 1.75V or
integral term of EEGR controller blocked in high or
low limit.

DTCs P0107, P0108, P0112, P0113, P0117, P0118,
P0122, P0123, P0131, P0300, P0335, P0336,
P0341, P0342, P1671, P1672, P1673 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
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for

ENGINE CONTROLS 1F–189
DAEWOO M-150 BL2
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can beeasily verified. Check the Freeze Frame data to deter-
mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).
DTC P1403 – Electric Exhaust Gas Recirculation Valve Failure
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. Turn the ignition switch to with the engine OFF.
2. Install the scan tool.
3. Command the electric exhaust gas recirculation
(EEGR) valve to the specified values.
Does the Actual EEGR Position follow the desired
EEGR position?
25%, 50%,
75%, 100%
Go to Step 19Go to Step 3
3
1. Turn the ignition switch to ON.
2. Disconnect the EEGR valve electrical connector.
3. With a test light connected to B+, probe the
ground circuit to the EEGR valve.
Does the test light illuminate?
–
Go to Step 4Go to Step 5
4
1. Connect the test light to ground.
2. Probe the EEGR control circuit at terminal 1 to
the EEGR valve.
3. Command the EEGR valve to the specified
values using a scan tool.
After the command is raised, does the test light glow
brighter, flash or maintain a steady glow?
25%, 50%,
75%, 100%
Go to Step 6Go to Step 7
5
Repair the open or poor connection in the EEGR
ground circuit.
Is the repair complete?
–
Go to Step 19
–
6
With a test light still connected to ground, probe the
signal circuit at terminal 1.
Does the test light illuminate?
–
Go to Step 8Go to Step 9
7
With a test light still connected to ground, again
probe the signal circuit without commanding the
EEGR valve with the scan tool.
Does the test light illuminate?
–
Go to Step 10Go to Step 11
8
Check the signal circuit for a short to voltage and
repair as necessary.
Is a repair necessary?
–
Go to Step 19Go to Step 12
9
With a digital voltmeter (DVM) connected to ground,
probe the 5V reference circuit at terminal 3.
Is the voltage measured near the specified value?
5VGo to Step 13Go to Step 14
10
Check the control circuit for a short to battery
voltage and repair as necessary.
Is a repair necessary?
–
Go to Step 19Go to Step 12
11
Connect the test light to B+ and again probe the
control circuit at terminal 4.
Does the test light illuminate?
–
Go to Step 15Go to Step 16
12Replace the engine control module (ECM).
Is the replacement complete?–Go to Step 19–

1F–192 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P0404 ELECTRIC EXHAUST GAS
RECIRCULATION OPENED
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A linear EEGR valve is used on this system. The linear
EEGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold from the exhaust manifold fhrough an
orifice with a engine control module(ECM) controlled
pintle. The ECM controls the pintle position using inputs
from the Throttle Position (TP) and the Manifold Abso-
lute Pressure (MAP) sensor. The ECM then commands
the EEGR valve to operate when necessary by control-
ling an ignition signal through the ECM. This can be
monitored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.Conditions for Setting THE DTC

EEGR circuit low voltage.
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.

EEGR is disabled.
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
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can be
easily verified. Check the Freeze Frame data to deter-
mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).

1F–196 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P1404 ELECTRIC EXHAUST GAS
RECIRCULATION CLOSED
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A linear EEGR valve is used on this system. The linear
EEGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold from the exhaust manifold fhrough an
orifice with a engine control module(ECM) controlled
pintle. The ECM controls the pintle position using inputs
from the Throttle Position (TP) and the Manifold Abso-
lute Pressure (MAP) sensor. The ECM then commands
the EEGR valve to operate when necessary by control-
ling an ignition signal through the ECM. This can be
monitored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.Conditions for Setting THE DTC

EEGR circuit high voltage.
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.

EEGR is disabled.
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 more than 10
seconds.
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can be
easily verified. Check the Freeze Frame data to deter-
mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).

1F–200 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P0405 EEGR PINTLE POSITION
SENSOR LOW VOLTAGE
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A linear EEGR valve is used on this system. The linear
EEGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold from the exhaust manifold fhrough an
orifice with a engine control module(ECM) controlled
pintle. The ECM controls the pintle position using inputs
from the Throttle Position (TP) and the Manifold Abso-
lute Pressure (MAP) sensor. The ECM then commands
the EEGR valve to operate when necessary by control-
ling an ignition signal through the ECM. This can be
monitored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
ThisDiagnostic Trouble Code(DTC) will detect an open
or short circuit.Conditions for Setting THE DTC

EEGR voltage is less than 0.01V.

EEGR potentiometer circuit low voltage.
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.

EEGR is disabled.
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 more than 10
seconds.
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can be
easily verified. Check the Freeze Frame data to deter-
mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).

1F–204 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F230
DIAGNOSTIC TROUBLE CODE (DTC) – P0406 EEGR PINTLE POSITION
SENSOR HIGH VOLTAGE
Circuit Description
An Electric Exhaust Gas Re-circulation (EEGR) system
is used to lower oxides of nitrogen (NOX) emission lev-
els caused by high combustion temperatures. It a ac-
complishes this by feeding small amounts of exhaust
gases back into the combustion chamber. When the air/
fuel mixture is diluted with the exhaust gases, combus-
tion temperatures are reduced.
A linear EEGR valve is used on this system. The linear
EEGR valve is designed to accurately supply exhaust
gases to the engine without the use of intake manifold
vacuum. The valve controls exhaust flow going into the
intake manifold from the exhaust manifold fhrough an
orifice with a engine control module(ECM) controlled
pintle. The ECM controls the pintle position using inputs
from the Throttle Position (TP) and the Manifold Abso-
lute Pressure (MAP) sensor. The ECM then commands
the EEGR valve to operate when necessary by control-
ling an ignition signal through the ECM. This can be
monitored on a scan tool as the Desired EEGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EEGR valve, a voltage signal representing
the EEGR valve pintle position is sent to the ECM. This
feedback signal can also be monitored on a scan tool
and is the actual position of the EEGR pintle. The actual
EEGR position should always be near the commanded
or Desired EEGR position.
This Diagnostic Trouble Code(DTC) will detect an open
or short circuit.Conditions for Setting THE DTC

EEGR voltage is higher than 4.99V.

EEGR potentiometer circuit high voltage.
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.

EEGR is disabled.
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
Due to moisture associated with exhaust systems, the
EEGR valve may freeze and stick in cold weather at
times. After the vehicle is brought into a warm shop for
repairs, the valve warms and the problem disappears.
By watching the Actual EEGR and desired EEGR posi-
tions on a cold vehicle with a scan tool, the fault can be
easily verified. Check the Freeze Frame data to deter-
mine if the DTC set when the vehicle was cold by view-
ing the Engine Coolant Temperature (ECT).

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.