2004 DAEWOO LACETTI ignition

1F – 338IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1629
IMMOBILIZER WRONG COMPUTATION
Circuit Description
When the ignition switch is turned to ON, the key tested
by immobilizer anti–theft system. While the key code is be-
ing read by immobilizer control unit or integrated anti–theft
control unit, the engine can start run with any key that will
turn the lock cylinder. the key code is read and compared
with key codes that have been stored in the memory of the
immobilizer control unit. If a valid key is detected, the im-
mobilizer control unit sends a serial data release message
to the Engine Control Module (ECM). Included in the re-
lease message is an identification (ID) code which as-
sures that neither the immobilizer control unit nor the ECM
have been substituted to defeat the system. If the ECM re-
ceives an invalid release message, the ECM performs the
following action:
S Disable the fuel injector circuit.
S Disable the fuel pump circuit.
S Disable the ignition coil.A Diagnostic Trouble Code (DTC) will stored if detect com-
munication link failure between the ECM and immobilizer
control unit.
Conditions for Setting the DTC
S Wrong coded value from ICU.
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 was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.
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.

ENGINE CONTROLS 1F – 339
DAEWOO V–121 BL4
DTC P1629 – Immobilizer Wrong Computation
StepActionValue(s)YesNo
1Perform an 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 OFF.
2. Install a scan too to the Data Link Connector
(DLC).
3. Turn the ignition ON.
4. Select IMMOBILIZER DIAGNOSIS STATUS
from the scan tool menu.
Is the communication established between the scan
tool and the immobilizer control unit?–Go to Step 3Go to
Section 9T, Im-
mobillzer Anti–
Theft System
31. Turn the ignition OFF.
2. Disconnect the Immobilizer Control Unit and
Engine Control Module (ECM) connectors.
3. Measure the resistance between terminal 7 of
immoblizer control unit and terminal 56 of the
ECM.
Is the resistance within the specified value?0WGo to Step 5Go to Step 4
4Repair an open circuit between terminal 7 of immobi-
lizer control unit and terminal 56 of the ECM.
Is the repair complete?–Go to Step 8–
5Check the terminals in immobilizer control unit and
the ECM for damages and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 6
6Replace the immobilizer control unit.
Is the repair complete?–Go to Step 8Go to Step 7
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 8–
81. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 340IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1660
MALFUNCTION INDICATOR LAMP (MIL) HIGH VOLTAGE
Circuit Description
When the ignition switch to ON, the Malfunction Indicator
Lamp (MIL) is ON steady.
When the engine cranking, the Malfunction Indicator
Lamp (MIL) is OFF after one flashing time.
If a system have some difficulties, the Malfunction Indica-
tor Lamp (MIL) is ON.
Conditions for Setting the DTC
S The Malfunction Indicator Lamp (MIL) wiring har-
ness high voltage.
Action Taken When the DTCs 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 problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
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 terminals to wire connection
S Physical damage to the wiring harness

ENGINE CONTROLS 1F – 341
DAEWOO V–121 BL4
DTC P1660 – Malfunction Indicator Lamp (MIL) High Voltage
StepActionValue(s)YesNo
1Perform an 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 LOCK.
2. Disconnect the cluster wiring connector.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal B6 in the
harness connector.
Does the resistance within the specified value?0WGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at ECM wiring connec-
tor terminal 39.
Does the test light illuminate?–Go to Step 4–
41. Turn the ignition switch to LOCK.
2. Replace the cluster.
Is the replacement complete?–Go to Step 6–
5Repair a short to battery between the ECM wiring
connector terminal 39 and cluster wiring connector
terminal B6.
Is the repair complete?–Go to Step 6–
61. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run 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

1F – 342IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1661
MALFUNCTION INDICATOR LAMP (MIL) LOW VOLTAGE
Circuit Description
When the ignition switch to ON, the Malfunction Indicator
Lamp (MIL) is ON steady.
When the engine cranking, the Malfunction Indicator
Lamp (MIL) is OFF after one flashing time.
If a system have some difficulties, the Malfunction Indica-
tor Lamp (MIL) is ON.
Conditions for Setting the DTC
S The Malfunction Indicator Lamp (MIL) wiring har-
ness low voltage.
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 problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
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 terminals to wire connection
S Physical damage to the wiring harness

ENGINE CONTROLS 1F – 343
DAEWOO V–121 BL4
DTC P1661 – Malfunction Indicator Lamp (MIL) Low Voltage
StepActionValue(s)YesNo
1Perform an 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 LOCK.
2. Disconnect the cluster wiring connector.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal B6 in the
harness connector.
Does the resistance within the specified value?0WGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at ECM wiring connec-
tor terminal 39.
Does the test light illuminate?–Go to Step 4–
41. Turn the ignition switch to LOCK.
2. Replace the cluster.
Is the replacement complete?–Go to Step 6–
5Repair a short to ground or open between the ECM
wiring connector terminal 39 and cluster wiring con-
nector terminal B6.
Is the repair complete?–Go to Step 6–
61. 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 this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run 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 – 345
DAEWOO V–121 BL4
DTCIlluminate MIL Type Description
P0327Knock Sensor Circuit FaultCnlNo
P033658X Crank Position Sensor Extra/Missing PulsesEYe s
P033758X Crank Position Sensor No SignalAYe s
P0341Camshaft Position Sensor RationalityEYe s
P0342Camshaft Position Sensor No SignalAYe s
P0351Ignition Control Circuit A Fault (Cylinder 1 and 4)AYe s
P0352Ignition Control Circuit B Fault (Cylinder 2 and 3)AYe s
P0401Exhaust Gas Recirculation Insufficient FlowCnlNo
P0402Exhaust Gas Recirculation Excessive FlowEYe s
P0404Exhaust Gas Recirculation Open Valve Position ErrorEYe s
P0405Exhaust Gas Recirculation Pintle Position Low VoltageEYe s
P0406Exhaust Gas Recirculation Pintle Position High VoltageEYe s
P0420Catalyst Oxygen Sensor Low EfficiencyAYe s
P0443Evaporative Emission System Purge Solenoid Control CircuitEYe s
P0461Fuel Level StuckCnlNo
P0462Fuel Level Low VoltageCnlNo
P0463Fuel Level High VoltageCnlNo
P0502Vehicle Speed Sensor No Signal (Engine Side)EYe s
P0506Idle Speed rpm Lower Than Desired Idle SpeedEYe s
P0507Idle Speed rpm Higher Than Desired Idle SpeedEYe s
P0532A/C Pressure Sensor Low VoltageCnlNo
P0533A/C Pressure Sensor High VoltageCnlNo
P0562System Voltage Too Low (Engine Side)CnlNo
P0563System Voltage Too High (Engine Side)CnlNo
P0601ECM Checksum Error (Engine Side)AYe s
P0602ECM Reprogram ErrorAYe s
P0607Lower Power Counter ErrorCnlNo
P0700Transaxle Control Module MalfunctionAYe s
P1106Manifold Absolute Pressure Intermittent High VoltageCnlNo
P1107Manifold Absolute Pressure Intermittent Low VoltageCnlNo
P 1111Intake Air Temperature Intermittent High VoltageCnlNo
P1112Intake Air Temperature Intermittent Low VoltageCnlNo
P1114Engine Coolant Temperature Intermittent Low VoltageCnlNo
P1115Engine Coolant Temperature Intermittent High VoltageCnlNo
P1121Throttle Position Sensor Intermittent High VoltageCnlNo
P1122Throttle Position Sensor Intermittent Low VoltageCnlNo
P1133Front Heated Oxygen Sensor (HO2S1) Too Few TransitionsEYe s
P1134Front Heated Oxygen Sensor (HO2S1) Transition RatioEYe s
P1167Front Heated Oxygen Sensor (HO2S1) Rich in Decel Fuel Cut–off (DFCO)AYe s
P1171Fuel Trim System Lean During Power EnrichmentBYe s
P133658X Crank Position Tooth Error Not LearnedAYe s
P1391G Sensor Rough Road RationalityCnlNo

ENGINE CONTROLS 1F – 347
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0106
MANIFOLD ABSOLUTE PRESSURE RATIONALITY
Circuit Description
The Engine Control Module (ECM) uses the Manifold Ab-
solute Pressure (MAP) sensor to control the fuel delivery
and the ignition timing. The MAP sensor measures the
changes in the intake manifold pressure which results
from engine load (intake manifold vacuum) and the rpm
changes, and it converts these into voltage outputs. The
ECM can detect if the MAP sensor is not responding to the
Throttle Position (TP) changes by comparing the actual
MAP change to a predicted MAP change based on the
amount of TP change that occurs. If the ECM does not see
the expected MAP change or more, DTC P0106 will set.
Conditions for Setting the DTC
S Altitude compensated MAP reading is higher than
high threshold or lower than low threshold table
based on rpm and TP signal.
S DTCs P0107, P0108, P0117, P0118, P0122,
P0123, P0201, P0202, P0203, P0204, P0300,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406, P0506, P0507 are not set.
S Engine running.
S Valid Barometric Pressure (BARO) update.
S Torque Converter Clutch (TCC) steady (A/T).
S A/C steady state.
S No TP sensor fail conditions present.
S No MAP fail conditions present.
S Change in Idle Air Control (IAC) is less than 5%.
S Coolant temperature is greater than –10°C (14°F).
S Change in rpm is less than 200.
S Change in TP sensor is less than 3%.
S Change in Exhaust Gas Recirculation (EGR) value
is less than 6%.
S The rpm is between 1300 and 4500.
S All of the above are stabilized for 1.5 seconds.
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.
S The ECM will substitute a fixed MAP value and use
TP sensor to control the fuel delivery. (The scan
tool will not show defaulted value.)
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
With the ignition ON and the engine stopped, the manifold
pressure is equal to atmospheric pressure and the signal
voltage will be high. This information is used by the ECM
as an indication of vehicle altitude. Comparison of this
reading with a known good vehicle with the same sensor
is a good way to check the accuracy of a suspect sensor.
Readings should be the same +0.4 volt.
The MAP sensor vacuum source should be thoroughly
checked for restrictions at the intake manifold.
Test Description
Numbers below refer to the step numbers on the Diagnos-
tic 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 occurred. The information is then stored on the
scan tool for later reference.
2. A sensor that displays an ignition ON, engine OFF
BARO value that does not appear normal for the
altitude the vehicle is in should be considered to be
malfunctioning.
3. While starting the engine, the MAP sensor should
detect any changes in the manifold pressure. This
test is to determine if the sensor is stuck at a value.
4. A normal MAP sensor will react as quickly to the
throttle changes as they can be made. A sensor
should not appear to be lazy or catch up with the
throttle movements.
5. This step checks if the reason for no MAP change
was due to a faulty sensor or vacuum source to the
sensor.
6. The MAP sensor vacuum source should be thor-
oughly checked for restrictions. A drill bit can be
used to clean out any casting flash that may exist in
the vacuum port.
7. The MAP sensor vacuum source should be thor-
oughly checked for restrictions. A drill bit can be
used to clean out any casting flash that may exist in
the vacuum port.
9. The MAP Sensor System Performance diagnostic
may have to complete several tests before deter-
mining if the diagnostic has passed or failed the last
test. Operate the vehicle in the Conditions for Set-
ting the DTC several times to ensure that the diag-
nostic runs enough tests to pass or fail.
10. If no faults have been found at this point and no
additional DTCs were set, refer to ”Diagnostic
Aids”in this section for additional checks and infor-
mation.