2004 DAEWOO LACETTI sensor

1F – 458IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0341
CAMSHAFT POSITION SENSOR RATIONALITY
System Description
The Camshaft Position (CMP) Sensor is used to correlate
crankshaft to camshaft position so that the Engine Control
Module (ECM) can determine which cylinder is ready to be
fueled by the injector. The CMP is also used to determine
which cylinder is misfiring when a misfire is present. When
the ECM cannot use the information from the CMP sensor,
a Diagnostic Trouble Code (DTC) is set, and the ECM will
fuel the engine using the Alternating Synchronous Double
Fire (ASDF) method.
Conditions for Setting the DTC
S CMP Sensor reference pulse is not detected at the
correct interval every 4 cylinders.
S Engine is running.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive ignition cycle with a fail.
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.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.
Diagnostic Aids
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
S Physical damage to the wiring harness
Anytime a poor connection is present, the CMP Reference
Activity counter will stop incrementing.

ENGINE CONTROLS 1F – 459
DAEWOO V–121 BL4
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
2. This step determines if DTC P0341 is the result of
a hard failure or an intermittent condition.
3. The counter should stop incrementing with the sen-sor electrical connector disconnected and set a
DTC P0342 with the sensor disconnected. If it still
increments the ECM is malfunctioning.
4. By moving the CMP sensor electrical connector, the
connections at the sensor are checked. Make sure
the electrical connector remains securely fastened.
5. A poor connection in any of the circuits at the CMP
will cause the CMP Resync Counter to increment.
Anytime a poor connection is present, the CMP
Reference Activity counter will stop incrementing
and the CMP Resync Counter will increment.
8. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0341 – Camshaft Position Sensor Rationality
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition OFF.
2. Install a scan tool to the Data Link Connector
(DLC).
3. Start the engine and operate the vehicle within
the Freeze Frame Conditions and Conditions
for Setting the DTC as noted.
Is Diagnostic Trouble Code (DTC) P0341 set?–Go to Step 3Go to
”Diagnostic
Aids”
31. Turn the ignition OFF.
2. Disconnect the Camshaft Position (CMP) sen-
sor connector.
3. Turn the ignition ON.
4. Using a voltmeter, check the voltage between
the CMP sensor harness connector (Engine
Control Module [ECM] side) terminal 3 and
ground.
Does the voltage near the specified value?5 VGo to Step 4Go to Step 5
4Using a voltmeter, check the voltage between the
CMP sensor wiring harness connector terminal 1
and ground.
Is the voltage over the specified value?10 voltsGo to Step 6Go to Step 10
5With a test light connected to ground, probe the
CMP harness connector terminal 3.
Does the test light illuminate?–Go to Step 8Go to Step 9
6With a test light connected to B+, probe the CMP
sensor harness connector terminal 2.
Does the test light illuminate?–Go to Step 7Go to Step 11
7Check for poor connections at the CMP sensor elec-
trical connectors and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 13

1F – 460IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
81. Turn the ignition OFF.
2. Disconnect the ECM connector.
3. Repair the short to voltage on the CMP signal
circuit.
Is the repair complete?–Go to Step 15Go to Step 14
9Check the CMP signal circuit for an open or short to
ground and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 12
10Check for a poor connection or open in the CMP B+
feed circuit and repair as needed.
Is the repair complete?–Go to Step 15–
11Check for a poor connection or open in the CMP
ground circuit and repair as needed.
Is the repair complete?–Go to Step 15–
12Check for a poor connection in the CMP signal circuit
terminal and repair as needed.
Is the repair complete?–Go to Step 15Go to Step 14
131. Turn the ignition OFF.
2. Replace the CMP sensor.
Is the repair complete?–Go to Step 15
141. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 15–
151. 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 supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 16Go to Step 2
16Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
table”System OK

ENGINE CONTROLS 1F – 461
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0342
CAMSHAFT POSITION SENSOR NO SIGNAL
System Description
The Camshaft Position (CMP) Sensor is used to correlate
crankshaft to camshaft position so that the Engine Control
Module (ECM) can determine which cylinder is ready to be
fueled by the injector. The CMP is also used to determine
which cylinder is misfiring when a misfire is present. When
the ECM cannot use the information from the CMP sensor,
a Diagnostic Trouble Code (DTC) is set, and the ECM will
fuel the engine using the Alternating Synchronous Double
Fire (ASDF) method.
Conditions for Setting the DTC
S CMP Sensor pulse is not detected at the correct
interval every 4 cylinders.
S Engine is running.
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.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.
Diagnostic Aids
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
S Physical damage to the wiring harness
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.

1F – 462IENGINE CONTROLS
DAEWOO V–121 BL4
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and to store the freeze frame and failure
records data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
2. This step determines if DTC P0342 is the result ofa hard failure or an intermittent condition.
4. Determines if voltage is available to the CMP.
7. This step checks for a voltage supplied by the ECM
to the CMP.
12. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0342 – Camshaft Position Sensor No Signal
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition OFF.
2. Install a scan tool to the Data Link Connector
(DLC).
3. Idle the engine.
Is the Camshaft Position (CMP) Active Count incre-
menting?–Go to Step 3Go to Step 4
31. Turn the ignition ON.
2. Review the Freeze Frame data and note the
parameters.
3. Start the engine and operate the vehicle within
the Freeze Frame Conditions and Conditions
for Setting the DTC as noted.
Is the CMP Active Counter incrementing?–Go to Step 13Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the CMP sensor connector.
3. Turn the ignition ON.
4. With a test light connected to ground, probe
the CMP sensor harness connector, terminal 1.
Does the test light illuminate?–Go to Step 5Go to Step 6
5With a test light connected to B+, probe the CMP
sensor harness connector, terminal 2.
Does the test light illuminate?–Go to Step 7Go to Step 8
6Check for a poor connection or open in the CMP sen-
sor B+ feed circuit and repair as necessary.
Is the repair complete?–Go to Step 13Go to
”Diagnostic
Aids”
7Using a Digital Voltmeter (DVM), check the voltage
between the CMP sensor harness connector, termi-
nal 3 and ground.
Does the DVM display near the specified values?5 VGo to Step 11Go to Step 9
8Check for a poor connection or open in the CMP sen-
sor ground circuit and repair as necessary.
Is the repair complete?–Go to Step 13–
91. Turn the ignition OFF.
2. Disconnect the engine Control Module (ECM)
connector.
3. Check for the CMP signal circuit for an open or
short to round or short to B+, and repair as
needed.
Is the repair complete?–Go to Step 13Go to Step 10

ENGINE CONTROLS 1F – 463
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
10Check the CMP signal circuit for an open or short to
ground and repair as needed.
Is the repair complete?–Go to Step 13Go to Step 12
111. Turn the ignition OFF.
2. Replace the CMP sensor.
Is the repair complete?–Go to Step 13–
121. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 13–
131. 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 supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 14Go to Step 2
14Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
”Applicable
DTC table”System OK

1F – 468IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0401
EXHAUST GAS RECIRCULATION INSUFFICIENT FLOW
Circuit Description
An Exhaust Gas Recirculation (EGR) system is used to
lower Nitrogen Oxide (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 an En-
gine Control Module (ECM) controlled pintle. The ECM
controls the pintle position using inputs from the Throttle
Position (TP) and Manifold Absolute Pressure (MAP) sen-
sors. 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 De-
sired 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 will determine if there is a reduction in EGR
flow.
Conditions for Setting the DTC
S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0201, P0202, P0203, P0204,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406 and P0502 are not set.
S Test in Decel Fuel Cutoff (DFCO) mode.
S Barometric Pressure (BARO) is greater than 72
kPa (10.4 psi).
S Vehicle speed is greater than 18 km/h (11.2
mph).
S A/C clutch/transmission clutch are unchanged.
S Rpm is between 1400 and 3000 for manual
transaxle.
S Rpm is between 1300 and 2900 for automatic
transaxle.
S Compensated MAP is with 10.3 to 32 kpa (1.5 to
4.6 psi) range.
S Start test
S Throttle position (TP) sensor is less then 1%.
S EGR is less than 1%.
S Change in MAP is less than 1.0 kpa (0.15 psi)Note : Test will be aborted when:
S Change in vehicle speed is greater than 5km/h (3.1
mph).
S Rpm is increased more than 75.
S EGR opened less than 90% commanded position.
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 set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
S A history Diagnostic Trouble Code (DTC) is stored.
S EGR is disabled.
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
The EGR Decel Filter value can be a great aid in determin-
ing if a problem exists and to verify repairs. The EGR De-
cel Filter is an average of the difference in the expected
MAP change and the actual MAP change caused by open-
ing the EGR valve during a deceleration, and is used to de-
termine when the MIL is illuminated. By driving the vehicle
up to approximately 97 km/h (60 mph) and decelerating to
32 km/h (20 mph), it can be determined if the EGR system
is OK, partially restricted, or fully restricted.
A more negative number (less than –3) indicates that the
system is working normally, whereas a positive number in-
dicates that the system is being restricted and that the ex-
pected amount of EGR flow is was not seen. A number
that falls between negative 3 and positive 2 indicates that
the system is partially restricted but not restricted enough
to cause an emissions impact.
The EGR Decel Filter value should always be at –3 or low-
er. If the EGR Decel Filter number becomes more positive
(towards 0 or more), then the EGR system is becoming re-
stricted. Look for possible damage to the EGR pipe or for
a restriction caused by carbon deposits in the EGR pas-
sages or on the EGR valve.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This

1F – 484IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST OXYGEN SENSOR 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 cat-
alyst 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
Rear Heated Oxygen Sensor (HO2S2) located in the ex-
haust stream past the TWC. The HO2S2 produces an out-
put signal which indicates the oxygen storage capacity of
the catalyst; 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 id-
ling, and then adding and removing fuel while monitoring
the reaction of the HO2S2. When the catalyst is function-
ing properly, the HO2S2 response to the extra fuel is slow
compared to the Front Heated Oxygen Sensor (HO2S1).
When the HO2S2 response is close to that of the HO2S1,
the Oxygen storage capability or efficiency of the catalyst
is considered to be bad, and the Malfunction Indicator
Lamp (MIL) will illuminate.
Conditions for Setting the DTC
S Oxygen storage capacity index time is less than 0.3
seconds.
S Before idle test, the vehicle needs to be driven for
at least:
S 15 seconds at airflow is greater than 9.2 g/sec.
for manual transaxle.
S 11 seconds at airflow is greater than 12 g/sec
for automatic transaxle.
S Oxygen Sensor Capacity test condition:
S Closed loop stoichiometry.
S Purge concentration learned.
S Engine is running more than 330 seconds.
S Airflow is between 2.5 and 7.25 g/sec.
S Throttle Position (TP) sensor is less than 1.5%.
S Intake Air Temperature (IAT) is between –7°C
(19.4°F) and 105°C (221°F).
S Barometric pressure (BARO) is greater than 72 kPa
(10.4 psi).
S Catalyst temperature is between 500°C (932°F)
and 850°C (1562°F) for automatic transaxle.
S Catalyst temperature is between 450°C (842°F)
and 850°C (1562°F) for automatic transaxle.
S Closed Loop integrator change is less than 0.03.
S Idle time is less than 1 minute.
S Vehicle speed is less than 3 km/h (1.9 mph).S Block Learn Mode is learned.
S Above condition is stabilized for 5 seconds.
Note : Test is aborted for this idle if:
S Change in engine speed is greater than 80 rpm.
S A/C status changed.
S Cooling fan status changed.
S Insufficient air/fuel shift.
S DTC(s) P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0133, P1133,
P0134, P0135, P0137, P0138, P0140, P0141,
P1167, P1171, P0171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0341,
P0342, P0351, P0352, P0402, P0404, P1404,
P0405, P0406, P0443, P0502, P0506, P0507, and
P0562 are not set.
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.
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.
Diagnostic Aids
The catalyst test may abort due to a change in the engine
load. Do not change the engine load (i.e. A/C, coolant fan,
heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the intermittent
complaint, should be thoroughly checked for the following
conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.