2004 DAEWOO LACETTI transaxle

ENGINE CONTROLS 1F – 181
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0268
INJECTOR 3 HIGH VOLTAGE
Circuit Description
The transaxle control module(TCM)/engine control mod-
ule (ECM) has four individual injector driver circuits, each
of which controls an injector. When a driver circuit is
grounded by the ECM, the injector is activated. The ECM
monitors the current in each driver circuit. The ECM mea-
sures a voltage drop through a fixed resistor and controls
it. The voltage on each driver is monitored to detect a fault.
If the voltage is not what the ECM expects to monitor on
the circuit, a Diagnostic Trouble Code (DTC) is set. This
DTC detects a low voltage and/or an open circuit and high
voltage conditions for low–side drive injector outputs.
Conditions for Setting the DTC
S The injector 3 circuit is a short to battery condition
exists.
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 Records buffers.S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after 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 10 sec-
onds.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will causes a DTC P0268 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–terms fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel Injector Balance Test” in this
section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5W.

ENGINE CONTROLS 1F – 183
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0270
INJECTOR 4 LOW VOLTAGE
Circuit Description
The transaxle control module(TCM)/engine control mod-
ule (ECM) has four individual injector driver circuits, each
of which controls an injector. When a driver circuit is
grounded by the ECM, the injector is activated. The ECM
monitors the current in each driver circuit. The ECM mea-
sures a voltage drop through a fixed resistor and controls
it. The voltage on each driver is monitored to detect a fault.
If the voltage is not what the ECM expects to monitor on
the circuit, a Diagnostic Trouble Code (DTC) is set. This
DTC detects a low voltage and/or an open circuit and high
voltage conditions for low–side drive injector outputs.
Conditions for Setting the DTC
S The injector 4 circuit is an open or a short to ground
condition exists.
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 Records buffers.S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after 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 10 sec-
onds.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will causes a DTC P0270 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–terms fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel Injector Balance Test” in this
section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5W.

ENGINE CONTROLS 1F – 185
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0271
INJECTOR 4 HIGH VOLTAGE
Circuit Description
The transaxle control module(TCM)/engine control mod-
ule (ECM) has four individual injector driver circuits, each
of which controls an injector. When a driver circuit is
grounded by the ECM, the injector is activated. The ECM
monitors the current in each driver circuit. The ECM mea-
sures a voltage drop through a fixed resistor and controls
it. The voltage on each driver is monitored to detect a fault.
If the voltage is not what the ECM expects to monitor on
the circuit, a Diagnostic Trouble Code (DTC) is set. This
DTC detects a low voltage and/or an open circuit and high
voltage conditions for low–side drive injector outputs.
Conditions for Setting the DTC
S The injector 4 circuit is a short to battery condition
exists.
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 Records buffers.S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after 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 10 sec-
onds.
Diagnostic Aids
An injector driver circuit that is open or shorted to voltage
will causes a DTC P0271 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–terms fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel Injector Balance Test” in this
section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5W.

1F – 198IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0327
KNOCK SENSOR CIRCUIT FAULT (1.6L DOHC)
Circuit Description
The knock sensor (KS) system is used to detect engine
detonation, allowing the transaxle control module
(TCM)/engine control module (ECM) to retard ignition con-
trol spark timing based on the KS signal being received.
The KS produces an AC signal so that under a no knock
condition the signal on the KS circuit measures about
0.007V AC. The KS signal’s amplitude and frequency de-
pend upon the amount of knock being experienced. The
ECM contains a non–replaceable knock filter module
called a signal–to–noise enhancement filter (SNEF) mod-
ule. This filter module in the ECM determines whether
knock is occurring by comparing the signal level on the KS
circuit with the voltage level on the noise channel. The
noise channel allows the ECM to reject any false knock
signal by knowing the amount of normal engine mechani-
cal noise present. Normal engine noise varies depending
on engine speed and load. When the ECM determines that
an abnormally low noise channel voltage level is being ex-
perienced, a DTC P0327 will set.
Conditions for Setting the DTC
S The knock sensor SPI bus in failure during 10 sec-
onds.
Or
S The knock sensor voltage is less than 0.3V.
S The engine coolant temperature is greater than
60°C(145°F).
S The engine speed is greater than 1,500rpm.
S The mass air flow is higer than 180mg/tdc.
Or
S When difference between a original signal valve
and filtering valve is less than 5%.S The engine coolant temperature is greater than
60°C(145°F).
S The mass air flow is greater than 170mg/tdc.
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
Check and correct any abnormal engine noise before us-
ing the diagnostic table.
Any circuitry that is suspected as causing engine noise
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

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 – 204IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0336
58X CRANKSHAFT POSITION SENSOR NO PLAUSIBLE
SIGNAL
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 P0336 will set.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S Detected number of teeth is differs by 3 or higher.
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/DTCS 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.

ENGINE CONTROLS 1F – 207
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0337
58X CRANKSHAFT POSITION SENSOR NO SIGNAL
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 P0336 will set.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S No crankshaft teeth detected.
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/DTCS 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.

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