2003 DAEWOO MATIZ fuel pressure

1F–62 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F060
DIAGNOSTIC TROUBLE CODE (DTC) – P0108 MANIFOLD ABSOLUTE
PRESSURE SENSOR HIGH VOLTAGE
Circuit Description
The engine control module (ECM) uses the Manifold Ab-
solute Pressure (MAP) sensor to control the fuel deliv-
ery and the ignition timing. The MAP sensor measures
the changes in the intake manifold pressure, which re-
sults from engine load (intake manifold vacuum) and the
rpm changes; and converts these into voltage outputs.
The ECM sends a 5 volt-reference voltage to the MAP
sensor. As the manifold pressure changes, the output
voltage of the MAP sensor also changes. By monitoring
the MAP sensor output voltage, the ECM knows the
manifold pressure. A low-pressure (low voltage) output
voltage will be about 1.0 to 1.5 volts at idle, while higher
pressure (high voltage) output voltage will be about 4.5
to 4.8 at wide open throttle (WOT). The MAP sensor is
metric pressure, allowing the ECM to make adjustments
for different altitudes.
Conditions for Setting the DTC

This DTC can be stored in “key-on” status.

Engine speed is greater than 2,000rpm.

No throttle position sensor (TPS) fail conditions pres-
ent.

The MAP is greater than 600m bar.

A high voltage condition exists.
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.

The ECM will substitutes a fixed MAP value and use
TP to control the fuel delivery (the scan tool will not
show defaulted)
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
With the ignition ON and the engine stopped, the man-
ifold pressure is equal to atmosphere pressure and the
signal voltage will be high.
The ECM as an indication of vehicle altitude uses this
information. Comparison of this reading with a known
good vehicle with the same sensor is a good way to
check the accuracy of a suspect sensor. Readings
should be the same ±0.4volt.
If a DTC P 0108 is intermittent, refer to “manifold abso-
lute pressure check” in this Section for further diagnosis.
If the connections are OK monitor the manifold absolute
pressure(MAP) sensor signal voltage while moving re-
lated connectors and the wiring harness. If the failure is
induced, the display on the scan tool will change. This
may help to isolate the location of an intermittent mal-
function.

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
–

1F–136 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0300 – Multiple Cylinder Misfire (Cont’d)
StepActionValue(s)YesNo
6
1. Turn the ignition 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 this DTC as
noted.
Are any Misfire Current counters incrementing?
–
Go to Step 5
Go to
“Diagnostic
Aids”
7
1. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine
running.
Is the fuel pressure within the specified value?
284–325 kPa
(41–47 psi)Go to Step 8
Go to
“Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?–Go to Step 9Go to Step 10
9
Check for a basic engine problem and repair as
necessary.
Is the repair complete?
–
Go to Step 27
–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–
11
1. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #1 spark plug
cable.
4. Crank the engine and check for spark.
5. Repeat the above procedure on cylinders #2, #3.
Is a spark observed on all four spark plug cables?
–
Go to Step 12Go to Step 20
12
Replace any malfunctioning spark plugs if
necessary.
Is the repair complete?
–
Go to Step 27Go to Step 13
13
1. Turn the engine OFF.
2. Disconnect the fuel injector connectors from the
injectors.
3. Install an injector test light on the injector harness
connector for the cylinders that had misfired.
4. Crank the engine and note the test light.
Does the injector test light blink?
–
Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
15
1. Disconnect the injector test light.
2. With a test light connected to ground, probe the
ignition feed terminal 1 of the injector harness
connector for each cylinder that had misfire.
3. Crank the engine.
Does the test light illuminate?
–
Go to Step 17Go to Step 19
16Replace any malfunctioning fuel injectors.
Is the repair complete?–Go to Step 27–
17
Check the affected fuel injector driver circuit at
terminals 90, 58 and 89 for an open, short, or short
to voltage.
Is a problem found?
–
Go to Step 18Go to Step 24