OBD port DAEWOO LACETTI 2004 Service Manual PDF

1F – 538IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1122 – Throttle Position Sensor Intermittent Low Voltage
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. Turn the ignition ON.
Is Diagnostic Trouble Code (DTC) P0123 also set?–Go to
applicable DTC
tableGo to Step 3
3Check for poor 5 volt reference circuit terminal 2 con-
nection at the Throttle Position (TP) sensor.
Is a problem found?–Step 7Step 4
4Check the TP signal circuit between TP sensor con-
nector and the Engine Control Module (ECM) for an
intermittent open or short to ground.
Is a problem found?–Go to Step 8Go to Step 5
5Check for a poor 5 volt reference circuit terminal M32
at the ECM.
Is a problem found?–Go to Step 7Go toStep 6
6Check for an intermittent open in the 5 volt reference
circuit.
Is a problem found?–Go to Step 8Go to Step 4
7Repair or replace the faulty harness connector ter-
minal for 5 volt reference circuit and/or the TP signal
circuit as needed.
Is the repair complete?–Go to Step 9–
8Repair the intermittent open/short circuit in wiring
harness as needed.
Is the repair complete?–Go to Step 9–
91. 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 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 544IENGINE CONTROLS
DAEWOO V–121 BL4
S The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
A malfunction in the HO2S1 ignition feed or ground circuit
may cause a DTC P1134 to set. Check HO2S1 circuitry for
intermittent faults or poor connections. If connections and
wiring are OK and DTC P1134 continues to set, replace
the HO2S1.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how open
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Chart.
3. A condition that affects pre–converter and post–
converter oxygen sensors indicates probable con-
tamination. To avoid damaging replacement sen-
sors, correct the condition which caused the
contamination before replacing the affected sen-
sors.
5. This step checks for conditions which may cause
the oxygen sensor to appear faulty. Correct any of
the described conditions if present.
8. To avoid damaging replacement sensors, correct
the condition which caused the contamination be-
fore replacing the affected sensors
DTC P1134 – Front Heated Oxygen Sensor (HO2S1) Transition
Ratio
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”
2Important : If any Diagnostic Trouble Codes (DTCs)
are set, refer to those DTCs before processing with
this diagnostic chart.
1. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine and idle at normal operating
temperature.
3. Operate the engine within parameters specified
under Conditions for Setting the DTC.
4. Using a scan tool, monitor specific DTC info for
DTC P1134 until the DTC P1134 test runs.
5. Note the test result.
Does the scan tool indicate DTC P1134 failed this
ignition?–Go to Step 3Go to
”Diagnostic
Aids”
3Perform an exhaust system leak test.
If an exhaust leak is found, repair as needed.
The exhaust leak isolated?–Go to Step 14Go to Step 4
4Visually/physically inspect for the following items:
S Front Heated Oxygen Sensor (HO2S1) is se-
curely installed.
S Corrosion on the terminals.
S Terminal tension.
S HO2S1 wiring harness for poor terminal con-
nection or damaged wiring.
Is a problem found in any of the above areas?–Go to Step 7Go to Step 5

ENGINE CONTROLS 1F – 547
DAEWOO V–121 BL4
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
The DTC P1167 or rich exhaust is most likely caused by
one of the following items:S Leaking injector – A leaking or malfunctioning injec-
tor can cause the system to go rich causing a DTC
P0132.
S Pressure regulator – Check for a leaking fuel pres-
sure regulator diaphragm by checking for the pres-
ence of liquid fuel in the vacuum line to the regula-
tor.
DTC P1167 – Front Heated Oxygen Sensor (HO2S1) Rich in Decel
Fuel Cutoff (DFCO)
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. Turn the ignition ON.
Any other component related Diagnostic Trouble
Codes (DTCs) set?–Go to
applicable DTC
tableGo to Step 3
31. Using a scan tool, observe the Front Heated
Oxygen Sensor (HO2S1) voltage while decel-
erating the engine.
2. The HO2S1 voltage should vary from specified
voltage (100–900 mV) and while decelerating
occasionally toggle below the specified voltage.
Is the HO2S1 voltage toggle?550 mVGo to Step 4Go to
”DTC P0134
Oxygen Sensor
No Activity”
4Check the items in ”Diagnostic Aids” and repair or re-
place component as needed. Refer to ”Fuel System
Diagnosis”.
Is the repair complete?–Go to Step 6Go to Step 5
51. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
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 – 549
DAEWOO V–121 BL4
DTC P1171 – Fuel Trim Supply System Lean During Power
Enrichment
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. Install a 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
31. Check the vehicle for an adequate amount of
fuel.
2. Add fuel to the vehicles fuel tank if the tank is
almost empty.
Did the fuel tank require fuel?–Go to Step 5Go to Step 4
41. Using a scan tool, observe the Front Heated
Oxygen Sensor (HO2S1) voltage while acceler-
ating the engine over 1200 rpm.
2. The HO2S1 voltage should vary from specified
voltage (100––900 mV) and occasionally toggle
above the specified voltage while accelerating.
Is the HO2S1 voltage toggle?3507 mVGo to
”Fuel System
Diagnosis”Go to
”DTC P0134
Oxygen Sensor
No Activity”
51. 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 6Go to Step 2
6Check 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 – 551
DAEWOO V–121 BL4
DTC P1336 – 58X Crank Position Tooth Error Not Learned
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 tool to the Data Link Connector
(DLC).
3. Put the vehicle in PARK or NEUTRAL.
4. Start the engine and operate to normal operat-
ing temperature.
5. Turn all accessories OFF.
6. Enable the TEC (Tooth Error Correction)
LEARN PROCEDURE with the scan tool.
7. Raise the engine rpm to the specified value,
then release the throttle as soon as the engine
cuts out.
Does the scan tool indicate that the Crankshaft Posi-
tion (CKP) system variation has been learned?65°C (149°F)
4000 rpmGo to Step 5Go to Step 3
3Attempt the CKP system variation procedure as
many times as the specified value.
Does the scan tool indicate that the CKP system
variation has been learned?10Go to Step 5Go to Step 4
4Check for a problem with the CKP sensor to crank-
shaft relationship.
Is the repair complete?–Go to Step 5–
51. Turn the ignition OFF and wait above specified
value.
2. Turn the ignition ON, with engine OFF.
3. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
4. Start the engine and idle at normal operating
temperature.
5. 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?10 secGo to Step 6Go to Step 2
6Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 562IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1396 – ABS WSS Signal Variation
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. Turn the ignition ON, with the engine OFF.
2. Install a scan too.
Are any additional Diagnostic Trouble Codes
(DTCs) set?–Go to
applicable DTC
tableGo to Step 3
31. Review and record the scan tool Failure Re-
cords data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using the scan tool, monitor specific DTC info
for DTC P1391.
Does the scan tool indicate that DTC P1391 failed?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition OFF.
2. Disconnect the engine control module (ECM)
and check for an open or short in the wire be-
tween ECM connector terminal K7 and Elec-
tronic Brake Control Module (EBCM) connector
terminal 25.
Is the problem found?–Go to Step 5Go to Step 6
5Repair an open or short in the wire between ECM
connector terminal K7 and EBCM connector termi-
nal 25.
Is the repair complete?–Go to Step 7–
61. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 7–
71. 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 8Go to Step 2
8Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 564IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1397 – ABS WSS No Signal
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. Turn the ignition ON, with the engine OFF.
2. Install a scan too.
Are any additional Diagnostic Trouble Codes
(DTCs) set?–Go to
applicable DTC
tableGo to Step 3
31. Review and record the scan tool Failure Re-
cords data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using the scan tool, monitor specific DTC info
for DTC P1391.
Does the scan tool indicate that DTC P1391 failed?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition OFF.
2. Disconnect the engine control module (ECM)
and check for an open or short in the wire be-
tween ECM connector terminal K7 and Elec-
tronic Brake Control Module (EBCM) connector
terminal 25.
Is the problem found?–Go to Step 5Go to Step 6
5Repair an open or short in the wire between ECM
connector terminal K7 and EBCM connector termi-
nal 25.
Is the repair complete?–Go to Step 7–
61. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 7–
71. 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 8Go to Step 2
8Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 566IENGINE CONTROLS
DAEWOO V–121 BL4
freeze frame data to determine if the DTC set when the ve-
hicle was cold by viewing the Engine Coolant Temperature
(ECT).
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. Commanding the EGR valve open determines
whether the EGR system can control the EGR
valve accurately and if the fault is present.
3. When the EGR valve electrical connector is discon-
nected, the scan tool should display the Actual
EGR Position as 0%. If it does not, the fault lies
either in the EGR signal circuit or the ECM.
5. If the ERG valve 5 volt reference is shorted to volt-
age, the Digital Voltmeter (DVM) will read battery
voltage and additional DTCs may be set and engine
performance will be poor.6. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
10. An open or poor connection condition may have
caused this DTC to set. Be sure to check the termi-
nals for being backed out, improperly formed or
damaged, and for poor tension.
11. All circuits to the EGR valve are OK at this point.
The fault lies internally in the EGR valve and there-
fore must be replaced. Be sure all gasket material
is removed from the EGR mounting surface. Even
a small amount of material may cause a DTC
P0401 to set.
12. Check the terminals for being backed out, improp-
erly formed or damaged, and for poor tension.
13. Clearing DTCs is a very important step for this
diagnostic. The clearing function allows the EGR
valve to relearn a new pintle position as the old
pintle position was inaccurate due to the failure that
caused the DTC. The DTC must be cleared with
the ignition ON, engine OFF or when the engine is
idling. If the ECM sees a EGR command, the new
pintle will not be learned.
14. If no malfunctions 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.
DTC P1404 – Exhaust Gas Recirculation Closed Valve Pintle Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was tht 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. Turn the ignition ON.
3. Command the Exhaust Gas Recirculation
(EGR) valve to the specific values.
Does the Actual EGR Position follow the Desired
EGR Position?25%, 50%,
75%, 100%Go to Step 13Go to Step 3
31. Turn the ignition OFF.
2. Disconnect the EGR valve.
Is the Actual EGR Position near the specified value?100%Go to Step 4Go to Step 5
4Check the signal circuit terminal 3 at the EGR wiring
harness connector for a short to voltage and repair
as needed.
Is a repair complete?–Go to Step 13Go to Step 6
5With a voltmeter connected to the ground, probe the
5 volt reference circuit at terminal 4 of the EGR valve
wiring harness connector.
Is the voltage near the specified value?5 vGo to Step 7Go to Step 8
61. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 13–

1F – 568IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1601
SPI COMMUNICATIONS BETWEEN ECM AND TCM
Circuit Description
The Serial Peripheral Interface (SPI) communication is
used internally by the Engine Control Module (ECM) to
send message between the engine processor and the au-
tomatic transaxle processor. Included in each message
sent between the two processor is a checksum of the mes-
sage. Both the engine processor automatic transaxle
processor will compare this checksum value with calcu-
lated checksum. If the checksum do not match, the proc-
essor will review the new data as being corrupted and ig-
nore the value. The processor then use the previous
message. The receiving processor will then send a mes-
sage to the sending processor informing it that its last mes-
sage was corrupted.
The ECM monitor periodic TCM status message and if
message is not received fail counter incremented and
Diagnostic trouble Code (DTC) will stored.
Conditions for Setting the DTC
S Ignition switch is turned to ON.S Ignition voltage is greater than 11 volts.
S Engine is running more than 2 seconds.
S Device Control not active.
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.
Conditions for Clearing the MIL/DTC
S The MIL 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 P1601 SPI Communications Between ECM and TCM
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. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 3–
31. 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 4Go to Step 2
4Check 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 – 569
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1607
LOWER POWER COUNTER RESET
Circuit Description
The Engine Control Module (ECM) is the control center of
the fuel injection system. It constantly looks at the informa-
tion from various sensors, and controls the systems that
affect vehicle performance. The ECM also performs the
diagnostic function of the system. It can recognize opera-
tional problems, alert the driver through the Malfunction In-
dicator Lamp (MIL) (Check Engine), and store a Diagnos-
tic Trouble Code (DTC) or DTCs which identify the
problem areas to aid the technician in making repairs. An
Electrically Erasable Programmable Read Only Memory
(EEPROM) is used to house the program information and
the calibrations required for engine, transmission, and
powertrain diagnostics operation. The ECM monitors EE-
PROM reset flag and Lower Power Counter I/C overflow
bits. If the ECM detects if Lower Power Counter I/C has
been reset due to battery disconnect or Lower Power
Counter I/C malfunction, the Diagnostic Trouble Code
(DTC) will stored.Conditions for Setting the DTC
S Ignition switch is turned to ON.
S Engine is not running.
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 Freeze Frame and 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.
DTC P1607 – Lower Power Counter Reset
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. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the repair complete?–Go to Step 3–
31. 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 4Go to Step 2
4Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK