knock DAEWOO LACETTI 2004 Service Owner's Guide

1F – 448IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
3Listen to the engine while rising and lowing the en-
gine speed.
Is a knock or audible noise present?–Go to Step 4Go to Step 5
4Repair mechanical engine problem or a loose brack-
et or components as needed.
Is the repair complete?–Go to Step 6–
51. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 6–
61. 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 7Go to Step 2
7Check 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 – 449
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0327
KNOCK SENSOR CIRCUIT FAULT
System Description
The Knock Sensor (KS) system is used to detect engine
detonation, allowing the Engine Control Module (ECM) to
retard the ignition control 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 cir-
cuit measures about 0.007 volts AC. The KS signal’s am-
plitude and frequency depend upon the amount of knock
being experienced. The ECM monitors the KS signal and
can diagnose the KS and circuitry.
Conditions for Setting the DTC
S Minimum difference between cylinders is greater
than 0.4%.
S Vacuum is less than the predetermined value (10 to
50 kPa, based on rpm).
S The rpm is greater than 1600.
S DTC(s) P0106, P0107, P0108 are not set.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffers.
S A history DTC is stored.
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
Check and correct any abnormal engine noise before us-
ing the diagnostic table.
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.
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. If the conditions for the test as described above are
met, a DTC P0327 will set and MIL will illuminate.
3. If the engine has an internal knock or audible noise
that causes a knocking type noise on the engine
block, the KS may be responding to the noise.
5. Checking the internal resistance of the KS or the
wiring to the KS is OK.
6. Any circuitry, that is suspected as causing the com-
plaint, should be thoroughly checked for backed–
out terminals, improper mating, broken locks, im-

1F – 450IENGINE CONTROLS
DAEWOO V–121 BL4
properly formed or damaged terminals, poor
terminal–to–wiring connections or physical damage
to the wiring harness.
7. The replacement ECM must be reprogrammed.Refer to the latest Techline procedure for ECM re-
programming.
DTC P0327 – Knock Sensor Circuit Fault
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. Install a scan tool to the Data Link Connector
(DLC).
2. Clear the Diagnostic Trouble Codes (DTCs).
3. Start the engine.
4. Operate the vehicle within the Conditions for
Setting the DTC as noted.
Is the DTC set again.–Go to Step 3Go to Step 6
3Listen to the engine while rising and lowing the en-
gine speed.
Is a knock or audible noise present?–Go to Step 4Go to Step 5
4Repair mechanical engine problem or a loose brack-
et or components as needed.
Is the repair complete?–Go to Step 11–
51. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector.
3. With a ohmmeter connected ground, measure
the resistance of the Knock Sensor (KS)
through the KS signal circuit, terminal M18.
Is the resistance between the specified value?90–110 kΩGo to Step 6Go to Step 8
6Check for a poor connection at the ECM connector
KS signal circuit and repair as needed.
Is the repair complete?–Go to Step 11Go to Step 7
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 11 –
8Check the KS connector for a poor connection and
repair as needed.
Is the repair complete?–Go to Step 11Go to Step 9
9Check the KS signal circuit for an open or a short to
ground or voltage and repair as needed.
Is the repair complete?–Go to Step 11–
101. Turn the ignition OFF.
2. Replace the KS.
Is the repair complete?–Go to Step 11–

1F – 612IENGINE CONTROLS
DAEWOO V–121 BL4
Installation Procedure
1. Install the EEGR valve with the bolts.
Tighten
Tighten the electrical exhaust gas recirculation valve
retaining bolts to 30 NSm (22 lb–ft).
2. Connect the EEGR valve electrical connector.
3. Connect the negative battery cable.
EXHAUST GAS RECIRCULATION
VALVE (1.8L DOHC)
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the vacuum hose from the exhaust gas
recirculation (EGR) valve.
3. Remove the EGR valve retaining bolts.
4. Remove the EGR valve from the electronic ignition
(EI) system ignition coil adapter.
Installation Procedure
1. Clean the EI system ignition coil adapter mating
surface.
2. Install a new EGR valve gasket.
3. Install the EGR valve with the bolts.
Tighten
Tighten the exhaust gas recirculation valve retaining
bolts to 30 NSm (22 lb–ft).
4. Connect the vacuum hose to the EGR valve.
5. Connect the negative battery cable.
KNOCK SENSOR (1.4L/1.6L DOHC)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the intake manifold support bracket bolts.
3. Remove the intake manifold support bracket.

ENGINE CONTROLS 1F – 613
DAEWOO V–121 BL4
4. Disconnect the knock sensor electrical connector.
5. Remove the knock sensor bolt.
6. Remove the knock sensor.
Installation Procedure
1. Install the knock sensor with the bolt.
Tighten
Tighten the knock sensor bolt to 20 NSm (15 lb–ft).
2. Connect the knock sensor electrical connector.
3. Install the intake manifold support bracket with the
bolts.
Tighten
Tighten the intake manifold support bracket upper
bolts to 25 NSm (18 lb–ft).
Tighten the intake manifold support bracket lower
bolts to 45 NSm (33 lb–ft).
4. Connect the negative battery cable.
KNOCK SENSOR (1.8L DOHC)
Removal Procedure
1. Disconnect the negative battery cable.
2. Raise and suitably support the vehicle.
3. Disconnect electrical connector at the knock sen-
sor.

1F – 614IENGINE CONTROLS
DAEWOO V–121 BL4
4. Remove the bolt and the knock sensor.
Installation Procedure
1. Install the knock sensor with the bolt.
Tighten
Tighten the knock sensor bolt to 20 NSm (15 lb–ft).
2. Connect the electrical connector at the knock sen-
sor.
3. Lower the vehicle.
4. Connect the negative battery cable.
EVAPORATIVE EMISSION CANISTER
Removal Procedure
CAUTION : Canister and vacuum hoses contain fuel
vapors. Do not smoke in the area or permit an open
flame.
1. Remove the bolt that secures the canister flange to
the vehicle.
2. Slide the canister out of the track holder.
3. Disconnect the canister fuel vapor hoses.
4. Remove the canister cover.
5. Remove the canister.

1F – 626IENGINE CONTROLS
DAEWOO V–121 BL4
EXHAUST GAS RECIRCULATION
VA LV E
The Exhaust Gas Recirculation (EGR) system is used on
engines equipped with an automatic transaxle to lower
NOx (oxides of nitrogen) emission levels caused by high
combustion temperature. The EGR valve is controlled by
the engine control module (ECM). The EGR valve feeds
small amounts of exhaust gas into the intake manifold to
decrease combustion temperature. The amount of ex-
haust gas recirculated is controlled by variations in vacu-
um and exhaust back pressure. If too much exhaust gas
enters, combustion will not take place. For this reason,
very little exhaust gas is allowed to pass through the valve,
especially at idle.
The EGR valve is usually open under the following condi-
tions:
S Warm engine operation.
S Above idle speed.
Results of Incorrect Operation
Too much EGR flow tends to weaken combustion, causing
the engine to run roughly or to stop. With too much EGR
flow at idle, cruise, or cold operation, any of the following
conditions may occur:
S The engine stops after a cold start.
S The engine stops at idle after deceleration.
S The vehicle surges during cruise.
S Rough idle.
If the EGR valve stays open all the time, the engine may
not idle. Too little or no EGR flow allows combustion tem-
peratures to get too high during acceleration and load con-
ditions. This could cause the following conditions:
S Spark knock (detonation)
S Engine overheating
S Emission test failure
INTAKE AIR TEMPERATURE
SENSOR
The Intake Air Temperature (IAT) sensor is a thermistor,
a resistor which changes value based on the temperature
of the air entering the engine. Low temperature produces
a high resistance (4,500 ohms at –40°F [–40°C]), while
high temperature causes a low resistance (70 ohms at
266°F [130°C]).
The engine control module (ECM) provides 5 volts to the
IAT sensor through a resistor in the ECM and measures
the change in voltage to determine the IAT. The voltage will
be high when the manifold air is cold and low when the air
is hot. The ECM knows the intake IAT by measuring the
voltage.
The IAT sensor is also used to control spark timing when
the manifold air is cold.
A failure in the IAT sensor circuit sets a diagnostic trouble
code P0112 or P0113.
IDLE AIR CONTROL VALVE
Notice : Do not attempt to remove the protective cap to
readjust the stop screw. Misadjustment may result in dam-
age to the Idle Air Control (IAC) valve or to the throttle
body.
The IAC valve is mounted on the throttle body where it
controls the engine idle speed under the command of the
engine control module (ECM). The ECM sends voltage
pulses to the IAC valve motor windings, causing the IAC
valve pintle to move in or out a given distance (a step or
count) for each pulse. The pintle movement controls the
airflow around the throttle valves which, in turn, control the
engine idle speed.
The desired idle speeds for all engine operating conditions
are programmed into the calibration of the ECM. These
programmed engine speeds are based on the coolant
temperature, the park/neutral position switch status, the
vehicle speed, the battery voltage, and the A/C system
pressure (if equipped).
The ECM ”learns” the proper IAC valve positions to
achieve warm, stabilized idle speeds (rpm) desired for the
various conditions (park/neutral or drive, A/C on or off, if
equipped). This information is stored in ECM ”keep alive”
memories. Information is retained after the ignition is
turned OFF. All other IAC valve positioning is calculated
based on these memory values. As a result, engine varia-
tions due to wear and variations in the minimum throttle
valve position (within limits) do not affect engine idle
speeds. This system provides correct idle control under all
conditions. This also means that disconnecting power to
the ECM can result in incorrect idle control or the necessity
to partially press the accelerator when starting until the
ECM relearns idle control.
Engine idle speed is a function of total airflow into the en-
gine based on the IAC valve pintle position, the throttle
valve opening, and the calibrated vacuum loss through ac-
cessories. The minimum throttle valve position is set at the
factory with a stop screw. This setting allows enough air-
flow by the throttle valve to cause the IAC valve pintle to
be positioned a calibrated number of steps (counts) from
the seat during ”controlled” idle operation. The minimum
throttle valve position setting on this engine should not be
considered the ”minimum idle speed,” as on other fuel in-
jected engines. The throttle stop screw is covered with a
plug at the factory following adjustment.
If the IAC valve is suspected as the cause of improper idle
speed, refer to ”Idle Air Control System Check” in this sec-
tion.
MANIFOLD ABSOLUTE PRESSURE
SENSOR
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes. It converts these to
a voltage output.

ENGINE CONTROLS 1F – 627
DAEWOO V–121 BL4
A closed throttle on engine coast down produces a rela-
tively low MAP output. MAP is the opposite of vacuum.
When manifold pressure is high, vacuum is low. The MAP
sensor is also used to measure barometric pressure. This
is performed as part of MAP sensor calculations. With the
ignition ON and the engine not running, the engine control
module (ECM) will read the manifold pressure as baromet-
ric pressure and adjust the air/fuel ratio accordingly. This
compensation for altitude allows the system to maintaindriving performance while holding emissions low. The
barometric function will update periodically during steady
driving or under a wide open throttle condition. In the case
of a fault in the barometric portion of the MAP sensor, the
ECM will set to the default value.
A failure in the MAP sensor circuit sets a diagnostic trouble
code P0107 or P0108.
The following tables show the difference between absolute pressure and vacuum related to MAP sensor output, which
appears as the top row of both tables.
MAP
Volts4.94.43.83.32.72.21.71.10.60.30.3
kPa1009080706050403020100
in. Hg29.626.623.720.717.714.811.88.95.92.90
VACUUM
Volts4.94.43.83.32.72.21.71.10.60.30.3
kPa0102030405060708090100
in. Hg02.95.98.911.814.817..720.723.726.729.6
ENGINE CONTROL MODULE
The engine control module (ECM), located inside the pas-
senger kick–panel, is the control center of the fuel injection
system. It constantly looks at the information from various
sensors and controls the systems that affect the vehicle’s
performance. The ECM also performs the diagnostic func-
tions of the system. It can recognize operational problems,
alert the driver through the Malfunction Indicator Lamp
(MIL), and store diagnostic trouble code(s) which identify
problem areas to aid the technician in making repairs.
There are no serviceable parts in the ECM. The calibra-
tions are stored in the ECM in the Programmable Read–
Only Memory (PROM).
The ECM supplies either 5 or 12 volts to power the sensors
or switches. This is done through resistances in the ECM
which are so high in value that a test light will not come on
when connected to the circuit. In some cases, even an or-
dinary shop voltmeter will not give an accurate reading be-
cause its resistance is too low. You must use a digital volt-
meter with a 10 megohm input impedance to get accurate
voltage readings. The ECM controls output circuits such
as the fuel injectors, the idle air control valve, the A/C
clutch relay, etc., by controlling the ground circuit through
transistors or a device called a ”quad–driver.”
FUEL INJECTOR
The Multiport Fuel Injection (MFI) assembly is a solenoid–
operated device controlled by the engine control module
(ECM). It meters pressurized fuel to a single engine cylin-
der. The ECM energizes the fuel injector or the solenoid
to a normally closed ball or pintle valve. This allows fuel toflow into the top of the injector, past the ball or pintle valve,
and through a recessed flow director plate at the injector
outlet.
The director plate has six machined holes that control the
fuel flow, generating a conical spray pattern of finely atom-
ized fuel at the injector tip. Fuel from the tip is directed at
the intake valve, causing it to become further atomized
and vaporized before entering the combustion chamber.
A fuel injector which is stuck partially open will cause a loss
of fuel pressure after the engine is shut down. Also, an ex-
tended crank time will be noticed on some engines. Diesel-
ing can also occur because some fuel can be delivered to
the engine after the ignition is turned OFF.
KNOCK SENSOR
The knock sensor detects abnormal knocking in the en-
gine. The sensor is mounted in the engine block near the
cylinders. The sensor produces an AC output voltage
which increases with the severity of the knock. This signal
is sent to the engine control module (ECM). The ECM then
adjusts the ignition timing to reduce the spark knock.
ROUGH ROAD SENSOR
The engine control module (ECM) receives rough road in-
formation from the VR sensor. The ECM uses the rough
road information to enable or disable the misfire diagnos-
tic. The misfire diagnostic can be greatly affected by
crankshaft speed variations caused by driving on rough
road surfaces. The VR sensor generates rough road infor-
mation by producing a signal which is proportional to the
movement of a small metal bar inside the sensor.
If a fault occurs which causes the ECM to not receive
rough road information between 30 and 80 mph (50 and
132 km/h), DTC P1391 will set.

POSITION OF CONNECTORS AND GROUNDSW2–11
16) W/H AIR BAG
17) SPLICE PACK
S101 (BLACK) : MR–140
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ECT Sensor ”2” Ter
TP Sensor ”1” Ter
Knock Sensor ”2” TerIAT Sensor ”1” TerLEGR ”2” Ter ECM ”M48” Ter
ECM ”M51” Ter ECM ”M35” Ter ECM ”M64” TerMAP Sensor ”3” Ter
ECM ”M1” Ter B
B
B
B
GW GW
GWOrB
OrB
OrB
EI System ”3” Ter
EI System ”1” TerSb Sb Sb
ECM ”M33” Ter
J3B1S001
S101 (BLACK) : HV–240
S202 (BLACK)
S203 (RED)

SECTION 5
ELECTRICAL WIRING DIAGRAMS
CONTENTS
1. STARTING & CHARGING SYSTEM5–8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) BATTERY, IGNITION SWITCH, STARTER MOTOR, GENERATOR & PNP SWITCH CIRCUIT 5–8. . . . . . . . . .
2. ECM (ENGINE CONTROL MODULE) : MR–140 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) BATTERY POWER SUPPLY, GROUND, EI SYSTEM & CKP SENSOR CIRCUIT 5–10. . . . . . . . . . . . . . . . . . . . .
2) FUEL PUMP, INJECTOR & HEATED O2 SENSOR CIRCUIT 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3) IAC, SENSOR(MAP, ECT, TP, KNOCK, ACP & ROUGH ROAD) & LEGR CIRCUIT 5–14. . . . . . . . . . . . . . . . . . .
4) EVAP CANISTER PURGE SOLENOID, CMP SENSOR, CLUSTER & VSS CIRCUIT 5–16. . . . . . . . . . . . . . . . .
5) CLUSTER, FUEL PUMP & TCM CIRCUIT 5–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6) DLC, MIL LAMP & IMMOBILIZER CONTROL CIRCUIT 5–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. ECM (ENGINE CONTROL MODULE) : HV–240 5–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1) BATTERY POWER SUPPLY, GROUND, EI SYSTEM & CKP SENSOR CIRCUIT 5–22. . . . . . . . . . . . . . . . . . . . .
2) FUEL PUMP, INJECTOR & O2 SENSOR CIRCUIT 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3) IAC, SENSOR(MAP, ECT, TP, IAT, KNOCK & ACP) & EGR VALVE CIRCUIT 5–26. . . . . . . . . . . . . . . . . . . . . . . .
4) EVAP CANISTER PURGE SOLENOID, CMP SENSOR, CLUSTER & VSS CIRCUIT 5–28. . . . . . . . . . . . . . . . .
5) CLUSTER, FUEL PUMP & TCM CIRCUIT 5–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6) DLC, MIL LAMP, IMMOBILIZER CONTROL & RON SWITCH CIRCUIT 5–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . .