engine electrical DAEWOO LACETTI 2004 Service Manual PDF

ENGINE CONTROLS 1F – 163
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
3With 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
41. 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 spe-
cified value while operating under the specified con-
ditions?–30%Go to Step 21Go to Step 5
5Visually/physically check the air cleaner filter for ex-
cessive dirt or being plugged and repair as needed.
Is the repair complete?–Go to Step 21Go to Step 6
6Visually/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
7Inspect the throttle body inlet for damaged or foreign
objects which may partially block the airflow and re-
pair as needed.
Is the repair complete?–Go to Step 21Go to Step 8
81. 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
9Start 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
111. 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 moni-
toring 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
12Check 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

1F – 196IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0327 – Knock Sensor Circuit Fault (1.4L DOHC)
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Start the engine.
2. Install a scan tool.
3. Clear the Diagnostic Trouble Codes (DTCs).
4. Operate the vehicle within the Freeze Frame
conditions and conditions for setting the DTC
as noted.
Does the Malfunction Indicator (MIL) illuminate?–Go to Step 4Go to Step 3
31. 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 Malfunction Indicator (MIL) illuminate?–Go to Step 4Go to Step 12
4Listen to the engine while raising and lowering the
engine speed.
Is a knock or audible noise present?–Go to Step 5Go to Step 6
5Repair the mechanical engine problem or a loose
bracket or component.
Is the repair complete?–Go to Step 12–
61. Turn the ignition switch to lock.
2. Disconnect the engine control module(ECM).
3. With a digital voltmeter (DVM) connected to
ground, measure the resistance of the knock
sensor through the knock sensor signal circuit,
terminal 42.
Is the measured value within the specified value?90–100KWGo to Step 7Go to Step 9
7Check for a poor connection at the ECM connector,
knock sensor (KS) signal circuit and repair as neces-
sary.
Is a repair necessary?–Go to Step 12Go to Step 8
8Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 12Go to Step 10
9Check the KS electrical connector for a poor connec-
tion and repair an necessary.
Is a repair necessary?–Go to Step 12Go to Step 10
10Check the KS signal circuit for an open or a low volt-
age or voltage and repair as necessary.
Is a repair necessary?–Go to Step 12Go to Step 11
11Replace the KS.
Is the replacement complete?–Go to Step 12–

ENGINE CONTROLS 1F – 199
DAEWOO V–121 BL4
DTC P0327 – Knock Sensor Circuit Fault (1.6L DOHC)
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Start the engine.
2. Install a scan tool.
3. Clear the Diagnostic Trouble Codes (DTCs).
4. Operate the vehicle within the Freeze Frame
conditions and conditions for setting the DTC
as noted.
Does the Malfunction Indicator (MIL) illuminate?–Go to Step 4Go to Step 3
31. 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 Malfunction Indicator (MIL) illuminate?–Go to Step 4Go to Step 12
4Listen to the engine while raising and lowering the
engine speed.
Is a knock or audible noise present?–Go to Step 5Go to Step 6
5Repair the mechanical engine problem or a loose
bracket or component.
Is the repair complete?–Go to Step 12–
61. Turn the ignition switch to lock.
2. Disconnect the engine control module(ECM).
3. With a digital voltmeter (DVM) connected to
ground, measure the resistance of the knock
sensor through the knock sensor signal circuit,
terminal 42.
Is the measured value within the specified value?90–100KWGo to Step 7Go to Step 9
7Check for a poor connection at the ECM connector,
knock sensor (KS) signal circuit and repair as neces-
sary.
Is a repair necessary?–Go to Step 12Go to Step 8
8Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 12Go to Step 10
9Check the KS electrical connector for a poor connec-
tion and repair an necessary.
Is a repair necessary?–Go to Step 12Go to Step 10
10Check the KS signal circuit for an open or a low volt-
age or voltage and repair as necessary.
Is a repair necessary?–Go to Step 12Go to Step 11
11Replace the KS.
Is the replacement complete?–Go to Step 12–

ENGINE CONTROLS 1F – 201
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0335
MAGNETIC CRANKSHAFT POSITION SENSOR
ELECTRICAL ERROR
Circuit Description
The 58X reference signal is produced by the crankshaft
position (CKP) sensor. During one crankshaft revolution,
58 crankshaft pulses will be produced. The transaxle con-
trol module(TCM)/engine control module(ECM) uses the
58X reference signal to calculate engine rpm and CKP.
The ECM constantly monitors the number of pulses on the
58X reference circuit and compares them to the number
of camshaft position (CKP) signal pulses being received.
If the ECM receive and incorrect number of pulses on the
58X reference circuit, DTC P0335 will set.
Conditions for Setting the DTC
S The magnetic crankshaft position sensor is greater
than 0.2V.
Or
S The minimum value of magnetic crankshaft position
sensor is less than 1.5V.
Or
S The maximum value of magnetic crankshaft posi-
tion sensor is higher than 2.2V.
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.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for :
Poor connection – inspect the ECM harness and connec-
tors for improper mating, broken locks, improperly formed
or damaged terminals, and poor terminal–to–wire connec-
tion.
Damaged harness – inspect the wiring harness for dam-
age. If the harness appears to be OK, disconnect the
ECM, turn the ignition ON and observe a voltmeter con-
nected to the 58X reference circuit at the ECM harness
connector while moving the connectors and the wiring har-
ness related to the ECM. A change in voltage will indicate
the location of the fault.
Review the failure records vehicle mileage since the diag-
nostic test failed may help determine how often the condi-
tion that caused the DTC to be set occurs. This may assist
in diagnosing the condition.

1F – 202IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0335 – Magnetic Crankshaft Position Sensor Electrical Error
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Attempt to start the engine.
Does the engine start?–Go to Step 3Go to
”Engine Cranks
But Will Not
Run”
31. Review and record Failure Records informa-
tion.
2. Clear the DTC P0335.
3. Start the engine and idle for 1 minute.
4. Observe the diagnostic trouble codes (DTCs).
Is the DTC P0335 set?–Go to Step 4Go to
”Diagnostic
Aids”
41. Disconnect the engine control module(ECM)
and the crankshaft position (CKP) sensor.
2. Check for an open or an open or short to
ground in the CKP sensor connector and the
ECM harness connector.
Is the problem found?–Go to Step 5Go to Step 6
5Repair the open or an open or short to ground in the
58X reference circuit between the CKP sensor con-
nector and the ECM harness connector.
Is the repair complete?–Go to Step 11–
61. Reconnect the ECM and CKP sensor.
2. Connect a digital voltmeter (DVM) to measure
voltage on the 58X reference circuit, terminal
54 at the ECM connector.
3. Observe the voltage while cranking the engine.
Is the voltage near the specified value?2.5VGo to Step 9Go to Step 7
7Check the connection at the CKP sensor and re-
place the terminals if necessary.
Do any terminals require replacement?–Go to Step 11Go to Step 8
8Replace the CKP sensor.
Is the replacement complete?–Go to Step 11–
9Check the connections at the ECM and replace the
terminals if necessary.
Do any terminal require replacement?–Go to Step 11Go to Step 10
10Replace the ECM.
Is the replacement complete?–Go to Step 11–

ENGINE CONTROLS 1F – 219
DAEWOO V–121 BL4
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0300, P0335,
P0336, P0341, P0342, P1671, P1672, P1673 are
NOT SET.
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 Recordsbuffers.
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.
DTC P0400 – Exhaust Gas Recirculation Out of Limit
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to with the engine OFF.
2. Install the scan tool.
3. Command the exhaust gas recirculation (EGR)
valve to the specified values.
Does the Actual EGR Position follow the desired
EGR position?25%, 50%
75%, 100%Go to Step 19Go to Step 3
31. Turn the ignition switch to ON.
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the
ground circuit to the EGR valve.
Does the test light illuminate?–Go to Step 4Go to Step 5
41. Connect the test light to ground.
2. Probe the EGR control circuit at terminal 3 to
the EGR valve.
3. Command the EGR valve to the specified val-
ues using a scan tool.
After the command is raised, does the test light glow
brighter, flash or maintain a steady glow?25%, 50%
75%, 100%Go to Step 6Go to Step 7
5Repair the open or poor connection in the EGR
ground circuit.
Is the repair complete?–Go to Step 19–
6With a test light still connected to ground, probe the
signal circuit at terminal 3.
Does the test light illuminate?–Go to Step 8Go to Step 9
7With a test light still connected to ground, again
probe the signal circuit without commanding the
EGR valve with the scan tool.
Does the test light illuminate?–Go to Step 10Go to Step 11
8Check the signal circuit for a short to voltage and re-
pair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
9With a digital voltmeter (DVM) connected to ground,
probe the 5V reference circuit at terminal 1.
Is the voltage measured near the specified value?5VGo to Step 13Go to Step 14

1F – 220IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
10Check the control circuit for a short to battery voltage
and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
11Connect the test light to B+ and again probe the con-
trol circuit at terminal 4.
Does the test light illuminate?–Go to Step 15Go to Step 16
12Replace the engine control module (ECM).
Is the replacement complete?–Go to Step 19–
13Check the EGR ground circuit for a poor connection
or proper terminal tension at the ECM and repair as
necessary.
Is a repair necessary?–Go to Step 19Go to Step 17
14Check the 5V reference circuit for a shortage to bat-
tery voltage and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
15Check the control circuit for a shortage to ground
and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
16Check the control circuit for an open or poor connec-
tion at the EGR valve electrical connector and repair
as necessary.
Is a repair necessary?–Go to Step 19Go to Step 18
17Replace the EGR valve.
Is the replacement complete?–Go to Step 19–
18Check the ECM electrical connector for a poor con-
nection and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
191. 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 the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 20Go to Step 2
20Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 222IENGINE CONTROLS
DAEWOO V–121 BL4
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EGR valve may freeze and stick in cold weather at times.
After the vehicle is brought into a warm shop for repairs,the valve warms and the problem disappears. By watching
the Actual EGR and desired EGR positions on a cold ve-
hicle with a scan tool, the fault can be easily verified.
Check the Freeze Frame data to determine if the DTC set
when the vehicle was cold by viewing the Engine Coolant
Temperature (ECT).
DTC P0404 – Exhaust Gas Recirculation Opened
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to with the engine OFF.
2. Install the scan tool.
3. Command the exhaust gas recirculation (EGR)
valve to the specified values.
Does the Actual EGR Position follow the desired
EGR position?25%, 50%
75%, 100%Go to Step 19Go to Step 3
31. Turn the ignition switch to ON.
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the
ground circuit to the EGR valve.
Does the test light illuminate?–Go to Step 4Go to Step 5
41. Connect the test light to ground.
2. Probe the EGR control circuit at terminal 3 to
the EGR valve.
3. Command the EGR valve to the specified val-
ues using a scan tool.
After the command is raised, does the test light glow
brighter, flash or maintain a steady glow?25%, 50%
75%, 100%Go to Step 6Go to Step 7
5Repair the open or poor connection in the EGR
ground circuit.
Is the repair complete?–Go to Step 19–
6With a test light still connected to ground, probe the
signal circuit at terminal 3.
Does the test light illuminate?–Go to Step 8Go to Step 9
7With a test light still connected to ground, again
probe the signal circuit without commanding the
EGR valve with the scan tool.
Does the test light illuminate?–Go to Step 10Go to Step 11
8Check the signal circuit for a short to voltage and re-
pair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
9With a digital voltmeter (DVM) connected to ground,
probe the 5V reference circuit at terminal 1.
Is the voltage measured near the specified value?5VGo to Step 13Go to Step 14
10Check the control circuit for a short to battery voltage
and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
11Connect the test light to B+ and again probe the con-
trol circuit at terminal 4.
Does the test light illuminate?–Go to Step 15Go to Step 16

ENGINE CONTROLS 1F – 223
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
12Replace the engine control module (ECM).
Is the replacement complete?–Go to Step 19–
13Check the EGR ground circuit for a poor connection
or proper terminal tension at the ECM and repair as
necessary.
Is a repair necessary?–Go to Step 19Go to Step 17
14Check the 5V reference circuit for a shortage to bat-
tery voltage and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
15Check the control circuit for a shortage to ground
and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
16Check the control circuit for an open or poor connec-
tion at the EGR valve electrical connector and repair
as necessary.
Is a repair necessary?–Go to Step 19Go to Step 18
17Replace the EGR valve.
Is the replacement complete?–Go to Step 19–
18Check the ECM electrical connector for a poor con-
nection and repair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12
191. 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 the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 20Go to Step 2
20Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 225
DAEWOO V–121 BL4
Diagnostic Aids
Due to moisture associated with exhaust systems, the
EGR valve may freeze and stick in cold weather at times.
After the vehicle is brought into a warm shop for repairs,
the valve warms and the problem disappears. By watchingthe Actual EGR and desired EGR positions on a cold ve-
hicle with a scan tool, the fault can be easily verified.
Check the Freeze Frame data to determine if the DTC set
when the vehicle was cold by viewing the Engine Coolant
Temperature (ECT).
DTC P0405 – EGR Pintle Position Sensor Low Voltage
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch ON with the engine
OFF.
2. Install the scan tool.
3. Command the Exhaust Gas Recirculation
(EGR) valve to the specified values.
Does the Actual EGR Position follow the desired
EGR position?25%, 50%
75%, 100%Go to Step 15Go to Step 3
31. Turn the ignition switch ON with the engine
OFF.
2. Disconnect the EGR valve electrical connector.
3. With a Digital Voltmeter (DVM) connected to
ground, probe the 5 volt reference circuit at
terminal 1 to the EGR valve.
Does the DVM read near the specified value?5VGo to Step 4Go to Step 5
4Jumper the 5 volt reference circuit to the signal cir-
cuit at terminals 1 and 3.
Does the actual EGR position display the specified
value ?100%Go to Step 6Go to Step 7
51. Connect the test light to B+.
2. robe the 5 volt reference circuit to the EGR
valve.
Does the test light illuminate?–Go to Step 8Go to Step 9
6Check the 5 volt reference and signal circuit for a
poor connection or proper terminal tension and re-
pair as necessary.
Is a repair necessary?–Go to Step 15Go to Step 10
71. Connect the test light to B+.
2. Probe the signal circuit at terminal 3 to the
EGR valve.
Does the test light illuminate?–Go to Step 11Go to Step 12
8Check for a short to ground in the EGR valve 5 volt
reference circuit and repair as necessary.
Is a repair necessary?–Go to Step 15Go to Step 13
9Check for an open in the EGR valve 5 volt reference
circuit and repair as necessary.
Is a repair necessary?–Go to Step 15Go to Step 14
10Replace the EGR valve.
Is the action complete?–Go to Step 15–
11Check for a short to ground in the EGR valve signal
circuit and repair as necessary.
Is a repair necessary?–Go to Step 15Go to Step 13