
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

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

1F–166 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F210
DIAGNOSTIC TROUBLE CODE (DTC) – P1382 ROUGH ROAD DATA INVALID
(NON ABS)
Circuit Description
The VR sensor is used to detecting the road situation.
By sensing difference of wheel rotation duration caused
by bumps or potholes in the road, the Engine Control
Module (ECM) can determine if the changes in crank-
shaft speed are due to engine misfire or are driveline in-
duced. If the VR sensor detects a rough road condition,
the ECM misfire detection diagnostic will be de-acti-
vated.
The VR sensor is located in front–right wheel.
Conditions for Setting the DTC
Vehicle speed is higher than 10km/h(6.21mph).
No Vehicle Speed Sensor error not set.
VR sensor output signal is higher than 0.26.VR sensor output signal is not change for 30seconds.
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.
Disconnecting the ECM battery feed for more than 10
seconds.

ENGINE CONTROLS 1F–167
DAEWOO M-150 BL2
DTC P1382 – Rough Road Data Invalid (NON ABS)
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Turn the ignition ON, with engine OFF.
2. Install a scan tool to the Data Link Connector
(DLC).
3. Review and record the scan tool Failure Records
data.
4. Operate the vehicle within Failure Records
conditions as noted.
5. Using the scan tool, monitor specific Diagnostic
Trouble Code (DTC) info for DTC P1382.
Does the scan tool indicate that DTC P1382 failed?
–
Go to Step 4Go to Step 3
3
1. Check for the following conditions and repair as
needed:
2. VR sensor seal missing or damaged.
3. VR sensor mounting flanges cracked, missing, or
incorrectly installed.
Is the repair complete?
–
Go to Step 14
Go to
“Diagnostic
Aids”
4
1. Turn the ignition OFF.
2. Disconnect the VR sensor electrical connector.
3. Turn the ignition ON, with the engine OFF.
4. Observe the VR sensor value displayed on the
scan tool.
Is the VR sensor value near the specified value?
0VGo to Step 5Go to Step 12
5
1. Jumper the 5 volt reference circuit, terminal 1 and
the VR sensor signal circuit, terminal 2 together at
the VR sensor harness connector.
2. Observe the VR sensor value displayed on the
scan tool.
Is the VR sensor value near the specified value?
4.95VGo to Step 6Go to Step 7
6
1. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM) and
check the sensor ground circuit for high
resistance, an open between the ECM and the
wheel speed sensor, or for a poor connection at
the terminal 85 of the ECM and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 10
7
Check the 5 volt reference circuit for high resistance,
an open between the ECM and the VR sensor, or a
poor connection at the terminal 55 of the ECM and
repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 8
8
1 Turn the ignition OFF.
2. Disconnect the ECM and check the VR sensor
signal circuit for high resistance, an open, a low
voltage, or a short to the sensor ground circuit
and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 9

1F–168 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P1382 – Rough Road Data Invalid (NON ABS) (Cont’d)
StepActionValue(s)YesNo
9
Check the VR sensor signal circuit for a poor
connection at the ECM and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 13
10
Check for a poor connection at terminal 2 of the VR
sensor and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 11
11Replace the VR sensor.
Is the repair complete?–Go to Step 14–
12
1. Turn the ignition OFF.
2. Disconnect the ECM.
3. Turn the ignition ON.
4. Check the VR sensor signal circuit for a short to
battery voltage or a short to the 5 volt reference
circuit and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 13
13
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
–
Go to Step 14
–
14
1. Using the scan tool, clear the 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 ran
and passed?
–
Go to Step 15Go to Step 2
15
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
Applicable DTC
table
System OK

1F–170 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F220
DIAGNOSTIC TROUBLE CODE (DTC) – P1382 ROUGH ROAD DATA INVALID
(ABS)
Circuit Description
The wheel speed sensor is used to detecting the road
situation.
As the wheel is rotated, the wheel speed sensor pro-
duces an AC voltage that increase with wheel speed.
The EBCM uses the frequency of the AC signal to calcu-
late wheel speed. The wheel speed sensor is connected
to EBCM by a “twisted pair” of wires. Twisting reduces
noise susceptibility than may cause a DTC to se.If the
wheel speed sensor detects a rough road condition, the
ECM misfire detection diagnostic will be de-activated.
Conditions for Setting the DTC
Vehicle speed is higher than 10km/h(6.21mph).
No Vehicle Speed Sensor error not set.
VR sensor output signal is higher than 0.26.VR sensor output signal is not change for 30seconds.
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.
Disconnecting the ECM battery feed for more than 10
seconds.

ENGINE CONTROLS 1F–171
DAEWOO M-150 BL2
DTC P1382 – Rough Road Data Invalid (ABS)
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Turn the ignition On, with engine OFF.
2. Install a scan tool to the Data Link Connector
(DLC).
3. Review and record the scan tool Failure Records
data.
4. Operate the vehicle within Failure Records
conditions as noted.
5. Using the scan tool, monitor specific Diagnostic
Trouble Code (DTC) info for DTC P1382.
Does the scan tool indicate that DTC P1382 failed?
–
Go to Step 4Go to Step 3
3
1. Check for the following conditions and repair as
needed:
2. Wheel speed sensor seal missing or damaged.
3. Wheel speed sensor mounting flanges cracked,
missing, or incorrectly installed.
Is the repair complete?
–
Go to Step 14
Go to
“Diagnostic
Aids”
4
1. Turn the ignition OFF.
2. Disconnect the defected Wheel speed sensor
electrical connector.
3. Turn the ignition ON, with the engine OFF.
4. Observe the wheel speed sensor value displayed
on the scan tool.
Is the Wheel speed sensor value near the specified
value?
0VGo to Step 5Go to Step 12
5
1. Jumper the 5 volt reference circuit, the Wheel
speed sensor signal circuit, together at the
defected wheel speed sensor harness connector.
2. Observe the defected Wheel speed sensor value
displayed on the scan tool.
Is the wheel speed sensor value near the specified
value?
4.95VGo to Step 6Go to Step 7
6
1. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM) and
check the sensor ground circuit for high
resistance, an open between the ECM and the
Wheel speed sensor, or for a poor connection of
the ECM and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 10
7
Check the 5 volt reference circuit for high resistance,
an open between the ECM and the wheel speed
sensor, or a poor connection of the ECM and repair
as needed.
Is the repair complete?
–
Go to Step 14Go to Step 8
8
1. Turn the ignition OFF.
2. Disconnect the ECM and check the wheel speed
sensor signal circuit for high resistance, an open,
a low voltage, or a short to the sensor ground
circuit and repair as needed.
Is the repair complete?
–
Go to Step 14Go to Step 9