2004 DAEWOO LACETTI Sensors

ENGINE CONTROLS 1F – 5
DAEWOO V–121 BL4
SYMPTOM DIAGNOSIS1F–574 . . . . . . . . . . . . . . . . . . .
Important Preliminary Checks 1F–574. . . . . . . . . . . . .
Intermittents 1F–574. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hard Start 1F–576. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surges or Chuggles 1F–579. . . . . . . . . . . . . . . . . . . . . .
Lack of Power, Sluggishness, or Sponginess 1F–581
Hesitation, Sag, Stumble 1F–583. . . . . . . . . . . . . . . . .
Cuts Out, Misses 1F–584. . . . . . . . . . . . . . . . . . . . . . . .
Poor Fuel Economy 1F–587. . . . . . . . . . . . . . . . . . . . . .
Rough, Unstable, or Incorrect Idle, Stalling 1F–588. .
Excessive Exhaust Emissions or Odors 1F–591. . . . .
Dieseling, Run–On 1F–592. . . . . . . . . . . . . . . . . . . . . . .
Backfire 1F–593. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR1F–594 . . . . . . . . . . . . .
ON–VEHICLE SERVICE 1F–594. . . . . . . . . . . . . . . . . . .
Fuel System Pressure Relief 1F–594. . . . . . . . . . . . . .
Fuel Tank 1F–594. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump 1F–596. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 1F–597. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail and Injectors (1.4L/1.6L DOHC) 1F–598. . .
Fuel Rail and Injectors (1.8L DOHC) 1F–600. . . . . . .
Engine Coolant Temperature Sensor
(1.4L/1.6L DOHC) 1F–602. . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature Sensor
(1.8L DOHC) 1F–602. . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Position Sensor (1.8L DOHC) 1F–603. . . . . .
Throttle Body (1.4L/1.6L DOHC) 1F–603. . . . . . . . . . .
Throttle Body (1.8L DOHC) 1F–604. . . . . . . . . . . . . . .
Front Heated Oxygen Sensor (HO2S 1)
(1.4L/1.6L DOHC) 1F–606. . . . . . . . . . . . . . . . . . . . . .
Front Heated Oxygen Sensor (HO2S 1)
(1.8L DOHC) 1F–607. . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Heated Oxygen Sensor (HO2S 2) 1F–607. . . . .
Intake Air Temperature Sensor
(1.4L/1.6L DOHC) 1F–608. . . . . . . . . . . . . . . . . . . . . .
Intake Air Temperature Sensor (1.8L DOHC) 1F–609
Idle Air Control Valve (1.8L DOHC) 1F–609. . . . . . . . .
Manifold Absolute Pressure Sensor
(1.4L/1.6L DOHC) 1F–610. . . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Sensor
(1.8L DOHC) 1F–611. . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation Valve
(1.4L/1.6L DOHC) 1F–611. . . . . . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation Valve (1.8L DOHC) 1F–612
Knock Sensor (1.4L/1.6L DOHC) 1F–612. . . . . . . . . .
Knock Sensor (1.8L DOHC) 1F–613. . . . . . . . . . . . . . .
Evaporative Emission Canister 1F–614. . . . . . . . . . . . Evaporative Emission Canister Purge Solenoid Valve 1
F–615
Crankshaft Position (CKP) Sensor
(1.4L/1.6L DOHC) 1F–615. . . . . . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor
(1.8L DOHC) 1F–616. . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft Position Sensor (1.4L/1.6L DOHC) 1F–618
Camshaft Position Sensor (1.8L DOHC) 1F–619. . . .
Engine Control Module (1.4L/1.6L DOHC) 1F–620. . .
Engine Control Module (1.8L DOHC) 1F–621. . . . . . .
Electronic Ignition System Ignition Coil
(1.4L/1.6L DOHC) 1F–621. . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition System Ignition Coil
(1.8L DOHC) 1F–622. . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION1F–623 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition System Operation 1F–623. . . . . . . . . . . . . . . .
Electronic Ignition System Ignition Coil 1F–623. . . . . .
Crankshaft Position Sensor 1F–623. . . . . . . . . . . . . . .
Camshaft Position Sensor 1F–623. . . . . . . . . . . . . . . .
Idle Air System Operation 1F–623. . . . . . . . . . . . . . . . .
Fuel Control System Operation 1F–623. . . . . . . . . . . .
Evaporative Emission Control System
Operation 1F–624. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Evaporative Emission Canister 1F–625. . . . . . . . . . . .
Positive Crankcase Ventilation System
Operation 1F–625. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature Sensor 1F–625. . . . . . .
Throttle Position Sensor 1F–625. . . . . . . . . . . . . . . . . .
Catalyst Monitor Oxygen Sensors 1F–625. . . . . . . . . .
Exhaust Gas Recirculation Valve 1F–626. . . . . . . . . . .
Intake Air Temperature Sensor 1F–626. . . . . . . . . . . .
Idle Air Control Valve 1F–626. . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Sensor 1F–626. . . . . . . .
Engine Control Module 1F–627. . . . . . . . . . . . . . . . . . .
Fuel Injector 1F–627. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Knock Sensor 1F–627. . . . . . . . . . . . . . . . . . . . . . . . . . .
Rough Road Sensor 1F–627. . . . . . . . . . . . . . . . . . . . .
Strategy–Based Diagnostics 1F–628. . . . . . . . . . . . . .
EOBD Serviceability Issues 1F–628. . . . . . . . . . . . . . .
Serial Data Communications 1F–629. . . . . . . . . . . . . .
On–Board Diagnostic (EOBD) 1F–629. . . . . . . . . . . . .
Comprehensive Component Monitor Diagnostic
Operation 1F–630. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common EOBD Terms 1F–630. . . . . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes 1F–632. . . . . . . . .
Primary System–Based Diagnostics 1F–633. . . . . . . .

1F – 28IENGINE CONTROLS
DAEWOO V–121 BL4
COMPONENT LOCATOR
COMPONENT LOCATOR (1.4L/1.6L DOHC)
Components on ECM Harness
11. Engine Control Module (ECM)
12. Data Link Connector (DLC)
13. Malfunction Indicator Lamp (MIL)
14. ECM/ABS Harness Ground
15. Fuse Panel (2)
ECM Controlled Devices
20. Exhaust Gas Recirculation (EGR) Valve
21. Fuel Injector (4)
22. Main Throttle Idle Actuator (MTIA)
23. Fuel Pump Relay
24. Cooling Fan Relays (High)
25. Cooling Fan Control Relay (A/C Only)
26. Electronic Ignition System Ignition Coil
27. Evaporative Emission (EVAP) Control Purge Sole-
noid
28. Main Relay
29. A/C Compressor Relay30. Cooling Fan Relays (Low)
Information Sensors
31. Manifold Absolute Pressure (MAP) Sensor
32. Front Heated Oxygen Sensor (HO2S1)
33. Variable Geometry Induction System (VGIS) Sole-
noid
34. Engine Coolant Temperature (ECT) Sensor
35. Intake Air Temperature (IAT) Sensor
36. Vehicle Speed Sensor (VSS)
38. Crankshaft Position (CKP) Sensor
39. Knock Sensor
40. Rear Heated Oxygen Sensor (HO2S2)
41. Camshaft Position (CMP) Sensor
Not PCM/ECM Connected
42. Evaporative Emission Canister (under vehicle, be-
hind right rear wheel)
43. Engine Oil Pressure Switch
44. Air Cleaner

ENGINE CONTROLS 1F – 29
DAEWOO V–121 BL4
COMPONENT LOCATOR (1.8L DOHC)
Components on ECM Harness
11. Engine Control Module (ECM)
12. Data Link Connector (DLC)
13. Malfunction Indicator Lamp (MIL)
14. ECM/ABS Harness Ground
15. Fuse Panel (2)
ECM Controlled Devices
20. Exhaust Gas Recirculation (EGR) Valve
21. Fuel Injector (4)
22. Idle Air Control (IAC) Valve
23. Fuel Pump Relay
24. Cooling Fan Relays (High)
25. Cooling Fan Control Relay (A/C Only)
26. Electronic Ignition System Ignition Coil
27. Evaporative Emission (EVAP) Control Purge Sole-
noid
28. Main Relay
29. A/C Compressor Relay30. Cooling Fan Relays (Low)
Information Sensors
31. Manifold Absolute Pressure (MAP) Sensor
32. Front Heated Oxygen Sensor (HO2S1)
33. Throttle Position (TP) Sensor
34. Engine Coolant Temperature (ECT) Sensor
35. Intake Air Temperature (IAT) Sensor
36. Vehicle Speed Sensor (VSS)
38. Crankshaft Position (CKP) Sensor
39. Knock Sensor
40. Rear Heated Oxygen Sensor (HO2S2)
41. Camshaft Position (CMP) Sensor
Not PCM/ECM Connected
42. Evaporative Emission Canister (under vehicle, be-
hind right rear wheel)
43. Engine Oil Pressure Switch
44. Air Cleaner

1F – 36IENGINE CONTROLS
DAEWOO V–121 BL4
MULTIPLE ECM INFORMATION SENSOR DTCS SET
Circuit Description
The Engine Control Module (ECM) monitors various sen-
sors to determine engine operating conditions. The ECM
controls fuel delivery, spark advance, transaxle operation,
and emission control device operation based on the sen-
sor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull–up resistor and
monitors the voltage present between the sensor and the
resistor to determine the status of the Engine Coolant
Temperature (ECT) sensor, the Intake Air Temperature
(IAT) sensor. The ECM provides the Exhaust Gas Recir-
culation (EGR) Pintle Position Sensor, the Throttle Posi-
tion (TP) sensor, the Manifold Absolute Pressure (MAP)
sensor, and the Fuel Tank Pressure Sensor with a 5 volt
reference and a sensor ground signal. The ECM monitors
the separate feedback signals from these sensors to de-
termine their operating status.
Diagnostic Aids
Be sure to inspect the ECM and the engine grounds for be-
ing secure and clean.
A short to voltage in one of the sensor circuits can cause
one or more of the following DTCs to be set: P0108,
P0113, P0118, P0123, P1106, P1111, P1115, P1121,
P0463, P0533.
If a sensor input circuit has been shorted to voltage, en-
sure that the sensor is not damaged. A damaged sensor
will continue to indicate a high or low voltage after the af-
fected circuit has been repaired. If the sensor has been
damaged, replace it.
An open in the sensor ground circuit between the ECM and
the splice will cause one or more of the following DTCs to
be set: P0107, P0108, P0113, P0118, P0122, P0123,
P1106, P1111, P1115, P1121, P0462, P0532.
A short to ground in the 5 volt reference circuit or an open
in the 5 volt reference circuit between the ECM and the
splice will cause one or more of the following DTCs to be
set: P0107, P0112, P0117, P0122, P1107, P1112, P1114,
P1122, P0462, P0532.Check for the following conditions:
S Inspect for a poor connection at the ECM. Inspect
harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire con-
nection.
S Inspect the wiring harness for damage. If the har-
ness appears to be OK, observe an affected sen-
sor ’s displayed value on the scan tool with the igni-
tion ON and the engine OFF while moving
connectors and wiring harnesses related to the af-
fected sensors. A change in the affected sensor’s
displayed value will indicate the location of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The Powertrain On–Board Diagnostic (EOBD) Sys-
tem Check prompts the technician to complete
some basic checks and 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.
9. A faulty EGR valve can leak a small amount of cur-
rent from the ignition feed circuit to the 5 volt refer-
ence circuit. If the problem does not exist with the
EGR valve disconnected, replace the EGR valve.
0. If a sensor input circuit has been shorted to voltage,
ensure that the sensor has not been damaged. A
damaged IAT or ECT sensor will continue to indi-
cate a high voltage or low temperature after the
affected circuit has been repaired. A damaged ACT,
TP, MAP, Fuel Tank Pressure, or EGR Pintle Posi-
tion sensor will indicate a high or low voltage or
may be stuck at a fixed value after the affected cir-
cuit has been repaired. If the sensor has been dam-
aged, replace it.
21. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.

ENGINE CONTROLS 1F – 37
DAEWOO V–121 BL4
Multiple ECM Information Sensor DTCs Set
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) system
check.
Is the check complete.–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Check the 5V reference circuit for the following
conditions:
S Poor connection at the ECM.
S Open between the ECM connector affected
sensors shorted to ground or voltage.
5. If a problem is found, locate and repair the
open or short circuit as needed.
Is a problem found?–Go to Step 19Go to Step 3
31. Check the sensor ground circuit for the follow-
ing conditions:
S Poor connection at the ECM or affected
sensors.
S Open between the ECM connector and the
affected sensors.
2. If a problem is found, repair it as needed.
Is a problem found?–Go to Step 19Go to Step 4
4Measure the voltage of the Exhaust Gas Recircula-
tion (EGR) Pintle Position Sensor signal circuit be-
tween ECM harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 5Go to Step 9
5Measure the voltage of the Manifold Absolute Pres-
sure (MAP) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 6Go to Step 12
6Measure the voltage of the Throttle Position (TP)
sensor signal circuit between the ECM harness con-
nector and ground.
Does the voltage near the specified value?0 VGo to Step 7Go to Step 12
7Measure the voltage of the Intake Air Temperature
(IAT) sensor signal circuit between the ECM har-
ness connector and ground.
Does the voltage near the specified value?0 VGo to Step 8Go to Step 13
8Measure the voltage of the Engine Coolant Temper-
ature (ECT) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 16Go to Step 14
91. Disconnect the EGR valve connector.
2. Measure the voltage of the EGR Pintle Position
sensor signal circuit between the ECM harness
connector and ground.
Does the voltage near the specified value?0 VGo to Step 10Go to Step 15

ENGINE CONTROLS 1F – 145
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0135
FRONT HEATED OXYGEN SENSOR HEATER CIRCUIT
NOT FUNCTIONING
Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control
and post catalyst monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen con-
tent in the exhaust stream. The HO2S must reach operat-
ing temperature to provide an accurate voltage signal. A
heating element inside the HO2S minmizes the time re-
quired for the sensor to reach operating temperature. Volt-
age is provided to the heater by the ignition 1 voltage cir-
cuit through a fuse. With the engine running, ground is
provided to the heater by the HO2S heater low control cir-
cuit, through a low side driver within the engine control
module (ECM). The ECM monitors the current flow
through the heater for diagnosis.
If the ECM detects that the HO2S heater current is above
or blelow a specified range, DTC P0135 seats.
Conditions for Setting the DTC
S DTCs P0106, P0117, P0118, P1017 are not set.
S Engine run time is greater than 30 seconds.
S Filtered O2 heater current is less than 0.1 amps.
Action Taken When the DTC SetsS 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 fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history Diagnostic Trouble Code (DTC) is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after three 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.
Diagnostic Aids
An intermittent may be caused by rubbed through wire in-
sulation or a wire contacting the exhaust.
Check for poor connection or damaged harness – inspect
harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection

1F – 162IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0172
FUEL TRIM SYSTEM TOO RICH
System Description
If the adaptation value threshold is permanently exceed-
ed, the deviation of the adaptive terms enables to detect
a slow default coming out. Two time counters (one for the
rich side and another one for the lean side) are increased
while the lambda controller exceeds the adaptation
thresholds. As soon as one of the time counters reaches
its maximum value, the error is detected.The aim of this
test is to simulate a failure that would result in exceeding
the adaptive terms. Two kinds of failure must be created.
S A lean side deviation: P0171
S A rich side deviation : P0172
It is thus necessary to determine, for each kind of failure,
the limit good and the limit bad. For a given failure, mea-
sure the emission threshold until the legal emission
thresholds are exceeded.Note that the problem is due to
the emission thresholds required, it is not simple to disturb
the system so that the emission thresholds will be exceed-
ed. The tuning has been made thanks to a dedicated cal-
ibration but, as such a procedure is not permitted by the
regulation, it is necessary to create some material mal-
function (fuel pressure regulator, fuel injector, air leak-
age...).
Conditions for Setting the DTC
S DTCs P0107, P0108, P0112, P0113, P0117,
P0118, P0122, P0123, P0131, P0132, P0337,
P0338, P0341, P0342, P0400, P1319, P1402,
P1404, P1405, P1671 and P1672 are not set.
S Coolant temperature is greater than 20°C (68°F).
(1.4L DOHC)
S Coolant temperature is greater than 80°C (176°F).
(1.6L DOHC)
S Manifold Absolute Pressure (MAP) is greater than
70 kPa (10.2 psi).
S System is in closed loop.
Action Taken When the DTC SetsS 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 10 sec-
onds.
Diagnostic Aids
Important : After repairs, use the scan tool Fuel Trim Re-
set function to reset the long–term fuel trim to 128 (0%).
Check for poor connection at the ECM. Inspect the har-
ness connectors 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.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the O2S display on the scan tool
while moving the connectors and the wiring harness re-
lated to the engine harness. A change in the display will
indicate the location of the fault.
If a DTC P1404 is also set, check the 5 volt reference cir-
cuits for a short to voltage.
Check for a restricted exhaust system.
A shorted 5 volt reference circuit may cause a DTC P0172
to set. Check the 5 volt reference sensors for abnormal
readings.
DTC P0172 – Fuel Trim System Too Rich
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. Install the scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON.
Are any component related Diagnostic Trouble
Codes (DTCs) set?–Go to
applicable DTC
tableGo to Step 3

1F – 264IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0532
A/C PRESSURE SENSOR LOW VOLTAGE
Circuit Description
The Air Conditioning (A/C) system uses an A/C refrigerant
pressure sensor mounted in the high pressure side of the
A/C refrigerant system to monitor A/C refrigerant pres-
sure. The Engine Control Module (ECM) uses this infor-
mation to turn ON the engine coolant fans when the A/C
refrigerant pressure is high and to keep the compressor
disengaged when A/C refrigerant pressure is excessively
high or low.
The Air Conditioning Pressure (ACP) sensor operates like
other 3–wire sensors. The ECM applies a 5.0 volt refer-
ence and a sensor ground to the sensor. Changes in the
A/C refrigerant pressure will cause the ACP sensor input
to the ECM to vary. The ECM monitors the ACP sensor
signal circuit and can determine when the signal is outside
of the possible range of the sensor. When the signal is out
of range for a prolonged period of time, the ECM will not
allow the A/C compressor clutch to engage. This is done
to protect the compressor.
Conditions for Setting the DTC
S A/C pressure is less than 12.16 kpa.
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.
S The A/C compressor operation will be disabled
while the low voltage indication exists.
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 terminals, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal–to–wire connection at
the ECM.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the A/C pressure display on the
scan tool while moving the connectors and wiring har-
nesses related to the A/C Pressure sensor. A change in
the A/C pressure display will indicate the location of the
fault.
If DTC P0532 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.