2003 DAEWOO MATIZ check engine

1F–104 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F140
DIAGNOSTIC TROUBLE CODE (DTC) – P0141 HEATED OXYGEN SENSOR
HEATER MALFUNCTION
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 44 and
13. The oxygen (O
2) sensor varies the voltage within a
range of about 1volt if the exhaust is rich, down to about
100mm volts if the exhaust is lean. The O
2 sensor is like
an open circuit and produces no voltage when it is below
360°C(600°F). An open O
2 sensor circuit or a cold O2
sensor causes “open loop” operation.
Conditions for Setting the DTC

Heated oxygen sensor 5V reference voltage supply
circuit high voltage or ground.

Heated oxygen sensor 5V reference voltage supply
circuit open.
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.
Diagnostic Aids

Normal scan tool voltage varies between 0.1volts and
0.9 volts while in closed loop.

Inspect the oxygen (O
2) sensor wire. The O2 sensor
may be positioned incorrectly and contacting the ex-
haust manifold.

Check for an intermittent ground in the wire between
the O
2 sensor and the engine control module.

Perform an injector 2alance test to determine if a re-
stricted fuel injector may be causing the lean condi-
tion.

Vacuum of crankcase leaks will cause a lean running
condition.

An exhaust manifold gasket leak of a cracked ex-
haust manifold may cause outside air to be pulled into
the exhaust and past the sensor.

ENGINE CONTROLS 1F–105
DAEWOO M-150 BL2
DTC P0141 – Heated Oxygen Sensor Heater Malfunction
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 LOCK.
2. Disconnect the Heated O2 sensor connector and
engine control module (ECM) connector.
3. Check the Heated O2 sensor heater wire
between the Heated O2 sensor connector
terminal 4 and ECM connector terminal 35 for an
open or short to ground.
Is the problem found?
–
Go to Step 3Go to Step 4
3
1. Repair the wire of the connector terminal as
needed.
2. Clear the DTCs from the ECM.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the repair complete?
–
System OK
–
4
1. Turn the ignition switch to LOCK.
2. Replace the Heated O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?
–
Go to Step 6
–
5
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

1F–106 ENGINE CONTROLS
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0171 FUEL TRIM SYSTEM TOO LEAN
System Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a Closed Loop air/
fuel metering system is used. While in Closed Loop, the
Engine Control Module (ECM) monitors the oxygen sen-
sor (O2S) signal voltage and adjusts fuel delivery based
on signal voltage. A change made to fuel delivery will be
indicated by the long and short term fuel trim values
which can be monitored with the scan tool. Ideal fuel trim
values are around 128 (0%). If the O2S signal is indicat-
ing a lean condition, the ECM will add fuel resulting in
fuel trim values above 128 (0% to 100%). If a rich condi-
tion is detected, the fuel trim values will be below 128
(0% to –100%), indicating that the ECM is reducing the
amount of fuel delivered. If exhaust emissions reach an
excessive level due to a lean or rich condition, a fuel trim
Diagnostic Trouble Code (DTC) is set.
Conditions for Setting the DTC

No intrusive tests active.

DTCs P0106, P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0125, P0131, P0132,
P0133, P0134, P0137, P0138, P0140, P0141,
P1167, P1171, P0201, P0202, P0203, P0204,
P0300, P0336, P0337, P0341, P0342, P0402,
P0404, P1404, P0405, P0406, P0443, P0506, and
P0507are not set.

The average of short term fuel trim value is greater
than or equal to 120.

Throttle Position (TP) is less than 95%.

Engine speed is between 700 and 6000 rpm.

Barometric Pressure (BARO) is greater than 92.0
kPa (10.4 psi).

Coolant temperature is between 80°C (176°F) and
11 5°C (239°F).

Manifold Absolute Pressure (MAP) is more than 90
kPa (10.2 psi).

System is in closed loop.

Adaptive index is ready.
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.
Diagnostic Aids
Important: After repairs, use the scan tool Fuel Trim
Reset function to reset the long-term fuel trim to 128
(0%).

Fuel pressure – The system will be lean if the pres-
sure is too low. It may be necessary to monitor fuel
pressure while driving the vehicle at various road
speeds and/or loads to confirm.

Map sensor – An output that causes the ECM to
sense a lower than normal manifold pressure (high
vacuum) can cause the system to go lean. Discon-
necting the MAP sensor will allow the ECM to substi-
tute a fixed (default) value for the MAP sensor. If the
lean condition is gone when the sensor is discon-
nected, substitute a known good sensor and recheck.

Fuel contamination – Water, in even small amounts,
near the in-tank fuel pump inlet can be delivered to
the injector. The water causes a lean exhaust and
can set DTC P0171.
Check for poor O2S or MAP sensor 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
Inspect the wiring harness for damage. If the harness
appears to be OK, observe the O2S display on the scan
tool while moving the connectors and the wiring harness
related to the engine harness. A change in the display
will indicate the location of the fault.
Check the brake power booster check valve for possible
leaks.

ENGINE CONTROLS 1F–107
DAEWOO M-150 BL2
DTC P0171 – Fuel Trim System Too Lean
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. Install the scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON.
Are any component related Diagnostic Trouble
Codes (DTCs) set?
–Go to
Applicable DTC
table
Go to Step 3
3
With the engine running, operate the vehicle until the
LOOP STATUS indicates closed.
Is the Long Term Fuel Trim value below the
specified value?
–22%Go to Step 4Go to Step 5
4
1. Turn the ignition switch ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and Conditions for Setting The DTC as
noted.
Does the Long Term Fuel Trim value go below the
specified value while operating under the specified
conditions?
–22%Go to Step 16Go to Step 5
5
Visually/physically check the following items:

Vacuum hoses for splits, kinks and improper
connections.

Crankcase ventilation oil/air separator for proper
installation.

Exhaust system for corrosion, leaks, loose or
missing hardware.

Oxygen sensor (O2S) is installed securely and
the pigtail harness is not contacting exhaust
manifold or engine.

Fuel for excessive water, alcohol, or other
contaminants.

Engine Control Module (ECM) and sensor
grounds are clean, tight, and in their proper
locations.
Do any of the above checks isolate a condition
requiring repair?
–
Go to Step 7Go to Step 6
6
1. Disconnect the Manifold Absolute Pressure
(MAP) sensor electrical connector.
2. Operate the vehicle in Closed Loop while
monitoring the Long Term Fuel Trim value.
Is the Long Term Fuel Trim value below the
specified value?
–22%Go to Step 15Go to Step 9
7
1. Repair the malfunction found in Step 5.
2. Recheck the Long Term Fuel Trim value while
operating the engine.
Is the Long Term Fuel Trim value below the
specified value?
–22%Go to Step 8Go to Step 9
8
Lean condition is not present.
Does a driveability problem exist?
–
Go to
“Symptom
Diagnosis”
Go to Step 16

1F–108 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0171 – Fuel Trim System Too Lean (Cont’d)
StepActionValue(s)YesNo
9
1. Visually/physically inspect the following items for
vacuum leaks:

Intake manifold.

Throttle body.

Injector O-rings.
2. Repair any leaks found as necessary.
Is the repair complete?
–
Go to Step 16Go to Step 16
10
Allow the engine to idle.
Are the Idle Air Control (IAC) counts above the
specified value?
5Go to Step 11Go to Step 12
11
Check the fuel for excessive water, alcohol, or other
contaminants and correct the contaminated fuel
condition if present.
Is the repair complete?
–
Go to Step 16Go to Step 13
12
Check the IAC valve performance. Refer to “DTC
P0506 Idle Speed RPM Lower Than Desired Idle
Speed” or “DTC P0507 Idle Speed RPM Higher
Than Desired Idle Speed” in this section and repair
as necessary.
Is the repair complete?
–
Go to Step 16Go to Step 13
13
1. Connect a fuel pressure gauge to the fuel system.
2. Turn the ignition OFF for at least 10 seconds.
3. Turn the ignition ON, with the engine OFF. The
fuel pump will run for approximately 2–3 seconds.
It may be necessary to cycle the ignition switch
ON more than once to obtain maximum fuel
pressure.
4. Note the fuel pressure with the fuel pump running.
The pressure should be within the specified value.
When the fuel pump stops, the pressure may vary
slightly then hold steady.
Is the fuel pressure steady and does the fuel
pressure hold?
380 KPa
(55 psi)
Go to Step 14
Go to
“Fuel System
Diagnosis”
14
1. Start and idle the engine at normal operating
temperature.
2. The fuel pressure noted in the above step should
drop by the indicated value.
Does the fuel pressure drop by the indicated value?
21–69 KPa
(3–10 psi)
Go to
“Fuel Injector
2alance Test”Go to
“Fuel System
Diagnosis”
15Replace the MAP sensor.
Is the action complete?–Go to Step 16–
16
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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?
–
Go to Step 17Go to Step 2
17
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

ENGINE CONTROLS 1F–109
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0172 FUEL TRIM SYSTEM TOO RICH
System Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a Closed Loop air/
fuel metering system is used. While in Closed Loop, the
Engine Control Module (ECM) monitors the oxygen sen-
sor (O2S) signal voltage and adjusts fuel delivery based
on signal voltage. A change made to fuel delivery will be
indicated by the long and short term fuel trim values
which can be monitored with the scan tool. Ideal fuel trim
values are around 128 (0%). If the O2S signal is indicat-
ing a lean condition, the ECM will add fuel resulting in
fuel trim values above 128 (0% to 100%). If a rich condi-
tion is detected, the fuel trim values will be below 128
(0% to –100%), indicating that the ECM is reducing the
amount of fuel delivered. If exhaust emissions reach an
excessive level due to a lean or rich condition, a fuel trim
Diagnostic Trouble Code (DTC) is set.
Conditions for Setting the DTC

No intrusive tests active.

DTCs P0106, P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0132, P0133,
P0134, P0137, P0138, P1167, P1171, P0300,
P0336, P0337, P0341, P0342, P0402, P0404,
P1404, P0405, P0406, P0443, P0506, and P0507are
not set.

The average of short term fuel trim value is greater
than or equal to 120.

Throttle Position (TP) is less than 95%.

Engine speed is between 700 and 6000 rpm.

Barometric Pressure (BARO) is greater than 90.0
kPa (10.4 psi).

Coolant temperature is between 80°C (176°F) and
11 5°C (239°F).

Manifold Absolute Pressure (MAP) is more than 70
kPa (10.2 psi).

System is in closed loop.

Adaptive index is ready.
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.
Diagnostic Aids
Important: After repairs, use the scan tool Fuel Trim
Reset function to reset the long-term fuel trim to 128
(0%).
Check for poor connection at the ECM. Inspect the har-
ness connectors for the following conditions:

Backed-out terminals.

Improper mating.

Broken locks.

Improperly formed.

Damaged terminals.

Poor terminal-to-wire connection.
Inspect the wiring harness for damage. If the harness
appears to be OK, observe the O2S display on the scan
tool while moving the connectors and the wiring harness
related to the engine harness. A change in the display
will indicate the location of the fault.
If a DTC P1404 is also set, check the 5 volt reference
circuits for a short to voltage.
Check for a restricted exhaust system.
A shorted 5 volt reference circuit may cause a DTC
P0172 to set. Check the 5 volt reference sensors for ab-
normal readings.

1F–110 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0172 – Fuel Trim System Too Rich
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
Install the scan tool to the Data Link Connector
(DLC).
Turn the ignition ON.
Are any component related Diagnostic Trouble
Codes (DTCs) set?
–Go to
Applicable DTC
table
Go to Step 3
3
1. With the engine running, operate the vehicle until
the LOOP STATUS indicates closed.
Is the Long Term Fuel Trim value above the
specified value?
30%Go to Step 4Go to Step 5
4
1. Turn the ignition switch ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and Conditions for Setting The DTC as
noted.
Does the Long Term Fuel Trim value above the
specified value while operating under the specified
conditions?
30%Go to Step 21Go to Step 5
5
Visually/physically check the air cleaner filter for
excessive dirt or being plugged and repair as
needed.
Is the repair complete?
–
Go to Step 21Go to Step 6
6
Visually/physically check the air intake system for
collapsed or restricted and repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 7
7
Inspect the throttle body inlet for damaged or foreign
objects which may partially block the airflow and
repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 8
8
1. Turn the ignition OFF.
2. Inspect the throttle bore, throttle plate and Idle Air
Control (IAC) passages for clocking and foreign
objects and repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 9
9
Start the engine with the vehicle in park or neutral
and A/C off and note the idle quality.
Is a low or unsteady idle being experienced?
–
Go to Step 10Go to Step 12
10Idle the engine.
Are the IAC counts below the specified value?
100Go to Step 12Go to Step 11
11
1. Turn the ignition OFF.
2. Disconnect the Manifold Absolute Pressure
(MAP) sensor electrical connector.
3. Start the engine.
4. Operate the vehicle in Closed Loop while
monitoring the Long Term Fuel Trim value.
Does the Long Term Fuel Trim value increase above
the specified value?
30%Go to Step 20Go to Step 12

ENGINE CONTROLS 1F–111
DAEWOO M-150 BL2
DTC P0172 – Fuel Trim System Too Rich (Cont’d)
StepActionValue(s)YesNo
12
Check the IAC valve performance. Refer to “DTC
P0506 Idle Speed RPM Lower Than Desired Idle
Speed” or “DTC P0507 Idle Speed RPM Higher
Than Desired Idle Speed” in this section and repair
as necessary.
Is the repair complete?
–
Go to Step 21Go to Step 13
13
1. Disconnect the vacuum hose from the fuel
pressure regulator and inspect the hose for the
presence of fuel.
2. If fuel is presence in the vacuum hose, replace
the fuel pressure regulator.
Is the repair complete?
–
Go to Step 21Go to Step 14
14
1. Turn the ignition ON.
2. Slowly press the acceleration pedal.
Does the Throttle Position (TP) sensor display
increase steady and evenly from its minimum
voltage at closed throttle to its maximum voltage at
Wide-Open Throttle (WOT).
–
Go to Step 15Go to Step 19
15
1. Perform the Fuel System Diagnosis.
2. If the table isolate a problem, repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 16
16
1. Perform the Evaporative Emission (EVAP)
Control System Diagnosis.
2. If the table isolate a problem, repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 17
17
1. Perform the Fuel Injector balance Test.
2. If the table isolate a problem, repair as needed.
Is the repair complete?
–
Go to Step 21Go to Step 18
18
1. Remove the Oxygen Sensor (O2S)
2. Visually/physically inspect the O2S for silicone
contamination.
3. Note: this will be indicated by a powdery white
deposit on the portion of the O2S exposed to the
exhaust stream.
4. If contamination is present on the O2S, find the
source and repair as needed.
Is the repair complete?
–
Go to Step 21
Go to
“Diagnostic
Aids”
19
1. Check the TP sensor mounting screws.
2. If they are too loose or missing tighten or replace
them as needed.
3. If the screws are OK, replace the TP sensor.
Is the repair complete?
–
Go to Step 21
–
20
1. Turn the ignition OFF.
2. Replace the MAP sensor.
Is the repair complete?
–
Go to Step 21
–