2004 DAEWOO LACETTI ACC

ENGINE CONTROLS 1F – 227
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0406
EGR PINTLE POSITION SENSOR HIGH VOLTAGE
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced.
A linear EGR valve is used on this system. The linear EGR
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 through 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 EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a scan tool as the Desired
EGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The actual EGR position
should always be near the commanded or Desired EGR
position.
This Diagnostic Trouble Code(DTC) will detect an open or
short circuit.
Conditions for Setting the DTC
S EGR voltage is higher than 4.99V.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.

1F – 238IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0462
FUEL LEVEL SENSOR LOW VOLTAGE (1.6L DOHC ONLY)
Circuit Description
The engine control module(ECM) uses the fuel level input
from the Fuel Level Sensor to calculate expected vapor
pressures within the fuel system. Vapor pressure vary as
the fuel level changes. Vapor pressure is critical in deter-
mining if the evaporative emission (EVAP) system is oper-
ating properly. Fuel Level is also used to determine if the
Fuel level is too high or too low to be able to accurately de-
tect EVAP system faults. This Diagnostic Trouble
Code(DTC) detects a stuck fuel level sender.
Conditions for Setting the DTC
S Fuel Level Sensor voltage is less than 0.2V.
S Fuel Level Sensor circuit low voltage.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
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.

ENGINE CONTROLS 1F – 241
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0463
FUEL LEVEL SENSOR HIGH VOLTAGE
(1.6L DOHC ONLY)
Circuit Description
The engine control module(ECM) uses the fuel level input
from the Fuel Level Sensor to calculate expected vapor
pressures within the fuel system. Vapor pressure vary as
the fuel level changes. Vapor pressure is critical in deter-
mining if the evaporative emission (EVAP) system is oper-
ating properly. Fuel Level is also used to determine if the
Fuel level is too high or too low to be able to accurately de-
tect EVAP system faults. This Diagnostic Trouble
Code(DTC) detects a stuck fuel level sender.
Conditions for Setting the DTC
S Fuel Level Sensor voltage is higher than 4.8V.
S Fuel Level Sensor circuit high voltage.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
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.

ENGINE CONTROLS 1F – 257
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0501
VEHICLE SPEED NO SIGNAL (M/T ONLY)
Circuit Description
Vehicle speed information is provided to the engine control
module (ECM) by the voltage speed sensor (VSS) is a per-
manent magnet generator that is mounted in the transaxle
and produces a pulsing voltage whenever vehicle speed
is over 3 mph (5km/h). The A/C voltage level and the num-
ber of pulses increase with vehicle speed. The ECM con-
verts the pulsing voltage into mph (km/h) and than sup-
plies the necessary signal to the instrument panel for
speedometer/ odometer operation and to the cruise con-
trol module and multi–function alarm module operation.
The Diagnostic Trouble Code (DTC) will detect if vehicle
speed is reasonable according to engine rpm and load.
Conditions for Setting the DTC
S Vehicle speed is not change at least 25 seconds.
S Engine speed is greater than 2,500rpm.
S MAF is greater than 180mg/tdc.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.S 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.
S A history DTC is stored.
S Coolant fan turns on.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using the scan tool can clear DTC(s).
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
VSS signal circuit should be thoroughly checked for the
following conditions
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed

ENGINE CONTROLS 1F – 277
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0656
FUEL LEVEL GAUGE CIRCUIT FAULT
Circuit Description
The engine control module(ECM) uses the fuel level input
from the Fuel Level Sensor to calculate expected vapor
pressures within the fuel system. Vapor pressure vary as
the fuel level changes. Vapor pressure is critical in deter-
mining if the evaporative emission (EVAP) system is oper-
ating properly. Fuel Level is also used to determine if the
Fuel level is too high or too low to be able to accurately de-
tect EVAP system faults. This Diagnostic Trouble
Code(DTC) detects a stuck fuel level sender.
Conditions for Setting the DTC
S The fuel tank level output circuit is a short to ground
or a short to battery or an open condition exists.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
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 P0656 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.
S Empty = 100 ohms or over.
S Half full = about 32.5 ohms.
S Full = 10 ohms or less.

1F – 308IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1402
EXHAUST GAS RECIRCULATION BLOCKED
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced.
A linear EGR valve is used on this system. The linear EGR
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 through 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 EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a scan tool as the Desired
EGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The actual EGR position
should always be near the commanded or Desired EGR
position.
This Diagnostic Trouble Code(DTC) will detect an open or
short circuit.
Conditions for Setting the DTC
S The vehicle is part load.
S The engine controls system is in closed loop.
S Engine Coolant Temperature(ECT) is greater than
60°C(140°F).
S Intake Air Temperature(IAT) is greater than
15°C(59°F).
S Manifold Absolute Pressure is greater than 75kPA.
S The EGR is greater than 10%.
S Mass Air Flow is between 71~174mg/tdc.
S Engine Speed Is Between 1,950~2,600rpm.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.
S EGR is disabled.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.

1F – 310IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1403
EXHAUST GAS RECIRCULATION VALVE FAILURE
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced.
A linear EGR valve is used on this system. The linear EGR
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 through 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 EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a scan tool as the Desired
EGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The actual EGR position
should always be near the commanded or Desired EGR
position.
This Diagnostic Trouble Code(DTC) will detect an open or
short circuit.
Conditions for Setting the DTC
S The vehicle is part load.
S The engine controls system is in closed loop.
S Engine Coolant Temperature(ECT) is greater than
60°C(140°F).
S Intake Air Temperature(IAT) is greater than
15°C(59°F).
S Manifold Absolute Pressure is greater than 75kPA.
S The open EGR value is higher than 10%.
S Mass Air Flow is between 71~174mg/tdc.
S Engine Speed Is Between 1,950~2,600rpm.
S EGR potentiometer voltage is less than 0.4V.
S EGR potentiometer voltage is higher than 1.75V or
integral term of EGR controller blocked in high or
low limit.
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.

ENGINE CONTROLS 1F – 313
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1404
EXHAUST GAS RECIRCULATION CLOSED
Circuit Description
An Exhaust Gas Re–circulation (EGR) system is used to
lower oxides of nitrogen (NOx) emission levels caused by
high combustion temperatures. It accomplishes this by
feeding small amounts of exhaust gases back into the
combustion chamber. When the air/fuel mixture is diluted
with the exhaust gases, combustion temperatures are re-
duced.
A linear EGR valve is used on this system. The linear EGR
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 through 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 EGR valve to operate when
necessary by controlling an ignition signal through the
ECM. This can be monitored on a scan tool as the Desired
EGR position.
The ECM monitors the results of its command through a
feedback signal. By sending a 5 volt reference and a
ground to the EGR valve, a voltage signal representing the
EGR valve pintle position is sent to the ECM. This feed-back signal can also be monitored on a scan tool and is the
actual position of the EGR pintle. The actual EGR position
should always be near the commanded or Desired EGR
position.
This Diagnostic Trouble Code(DTC) will detect an open or
short circuit.
Conditions for Setting the DTC
S EGR circuit is a short to battery condition exist.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.