tran DAEWOO LACETTI 2004 Service Manual PDF

1F – 502IENGINE CONTROLS
DAEWOO V–121 BL4
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. A normally operating IAC system will be able to be
extended and retracted by a scan tool and change
the engine idle rpm. Valve movement is verified by
an engine rpm change.
3. If the scan tool was able to command the IAC valve
smoothly, a malfunction may still exist internally
within the IAC valve. This can be checked by
checking the IAC valves internal resistance.
5. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to voltage or open.6. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to ground or open
8. The IAC circuits are constantly switched between
ground and voltage so the test light should blink on
all circuits when connected to ground.
10. Any circuitry, that is suspected as causing the inter-
mittent complaint, should be thoroughly checked for
backed–out terminals, improper mating, broke
locks, improperly formed or damaged terminals,
poor terminal– to–wiring connections or physical
damage to the wiring harness.
12. A test light that remains ON constantly indicates
that the circuit is shorted to voltage.
14. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
16. 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 P0506 – Idle Speed RPM Lower Than Desired Idle Speed
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. Operate the engine to idle speed.
3. Transmission in park or neutral and the parking
brake set.
4. A/C is off.
5. Using scan tool, command the Idle Air Control
(IAC) valve up and down between the specified
value.
Does the rpm change smoothly when he command-
ed by the scan tool?900–1200 rpmGo to Step 3Go to Step 5
31. Turn the ignition OFF.
2. Disconnect the IAC valve connector.
3. Measure the resistance between terminal D
and C of the IAC valve.
4. Measure the resistance between terminal B
and A of the IAC valve.
Is the resistance within the specified value?40–80 WGo to Step 4Go to Step 13
41. Measure the resistance between terminal C
and B of the IAC valve.
2. Measure the resistance between terminal D
and A of the IAC valve.
Is the resistance equal to the specified value?Go to Step 15Go to Step 13

ENGINE CONTROLS 1F – 505
DAEWOO V–121 BL4
S Fuel system too rich or too lean.
S Foreign material in the throttle body bore or in the
air induction system.
S A leaking or restricted intake manifold.
S Excessive engine overloading. Check for seized
pulleys, pumps, or motors on the accessory drive.
S Overweight engine oil.
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. A normally operating IAC system will be able to be
extended and retracted by a scan tool and change
the engine idle rpm. Valve movement is verified by
an engine rpm change.
3. If the scan tool was able to command the IAC valve
smoothly, a malfunction may still exist internally
within the IAC valve. This can be checked by
checking the IAC valves internal resistance.5. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to voltage or open.
6. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to ground or open
8. The IAC circuits are constantly switched between
ground and voltage so the test light should blink on
all circuits when connected to ground.
10. Any circuitry, that is suspected as causing the inter-
mittent complaint, should be thoroughly checked for
backed–out terminals, improper mating, broken
locks, improperly formed or damaged terminals,
poor terminal– to–wiring connections or physical
damage to the wiring harness.
12. A test light that remains ON constantly indicates
that the circuit is shorted to voltage.
14. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
16. 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 for additional checks and information.
DTC P0507 – Idle Speed RPM Higher Than Desired Idle Speed
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. Operate the engine to idle speed.
3. Transmission in park or neutral and the parking
brake set.
4. A/C is Off.
5. Using scan tool, command the Idle Air Control
(IAC) valve up and down between the specified
value.
Does the rpm change smoothly when he command-
ed by the scan tool?900–1200 rpmGo to Step 3Go to Step 5
31. Turn the ignition OFF.
2. Disconnect the IAC valve connector.
3. Measure the resistance between terminal D
and C of the IAC valve.
4. Measure the resistance between terminal B
and A of the IAC valve.
Is the resistance within the specified value?40–80 WGo to Step 4Go to Step 13
41. Measure the resistance between terminal C
and B of the IAC valve.
2. Measure the resistance between terminal D
and A of the IAC valve.
Is the resistance equal to the specified value?–Go to Step 15Go to Step 13

ENGINE CONTROLS 1F – 517
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0601
ECM CHECKSUM ERROR (ENGINE SIDE)
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 uses a value
called a checksum for error detection of the software. The
checksum is a value that is equal to all the numbers in the
software added together. The ECM adds all the values in
the software, and if that value does not equal the check-
sum value, a checksum error is indicated.
Conditions for Setting the DTC
S Program ID is not equal to the value in the soft-
ware.
S Ignition switch is turned to ON.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.S The ECM will attempt to record operating condi-
tions at the time the failure is detected. However,
since this is the internal ECM fault, this information
may be or may not be reliable. 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.
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. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0601 – ECM Checksum Error (Engine Side)
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

1F – 518IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0602
ECM REPROGRAM ERROR
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 uses a value
called a checksum for error detection of the software. The
checksum is a value that is equal to all the numbers in the
software added together. The ECM changes the check-
sum after reprogramming and adds all the values in the
software, and if that value does not equal the checksum
value, a ECM reprogramming error is indicated.
Conditions for Setting the DTCS Calibration ID is not equal to the value in the soft-
ware level.
S S/W major ID not equal to value in S/W.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will attempt to record operating condi-
tions at the time the failure is detected. However,
since this is the internal ECM fault, this information
may be or may not be reliable. 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 P0602 – ECM Reprogram Error
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to ”On–
Board Diagnos-
tic System
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 Applica-
ble DTC TableSystem OK

ENGINE CONTROLS 1F – 519
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0607
LOWER POWER COUNTER ERROR
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 checks op-
eration of Lower Power Counter Integrated Chip (I/C) and
communication between main CPU and Lower Power
Counter I/C.
Conditions for Setting the DTCS Ignition switch is turned to ON.
S Ignition voltage is greater than 11 volts.
S Engine is running more than 10 seconds.
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 P0607 – Lower Power Counter Error
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

1F – 520IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0700
TRANSAXLE CONTROL MODULE MALFUNCTION
Circuit Description
The Transmission Control Module (TCM) and the Engine
Control Module (ECM) are connected through the serial
data link circuit. The TCM sends a Class–II P–code status
message to the ECM every 100 milliseconds to confirm
the transmission is functioning correctly.
If the TCM detects either an A– or B–type malfunction
within the transmission, the TCM will send to the ECM a
P–code status message to turn the Malfunction Indicator
Lamp (MIL) ON and set DTC P0700.
Conditions for Setting the DTC
S Received message from the TCM indicating mal-
function is detected in TCM.
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/or 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
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation.
Check for a poor connection or damaged ECM/TCM har-
ness. Inspect the serial data link circuit for the following
conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wiring connections
S Damaged harness
DTC P0700 – Transaxle Control Module Malfunction
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.
3. Select Transmission Control Module (TCM)
Diagnostic Trouble Code (DTC) with scan tool.
Is a transmission DTC displayed?–Go to Step 3Go to Step 4
31. Repair transmission malfunction. Refer to the
applicable DTC table in the transmission repair
section.
2. Using a scan tool, clear the TCM DTC.
Is the repair complete?–Go to Step 4–

ENGINE CONTROLS 1F – 539
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1133
FRONT HEATED OXYGEN SENSOR (HO2S1) TOO FEW
TRANSITION
Circuit Description
The Engine Control Module (ECM) continuously monitors
the Front Heated Oxygen Sensor (HO2S1) activity for 100
seconds. During the monitor period, the ECM counts the
number of times that the HO2S1 switches from rich to lean
and from lean to rich. With this information, a total for all
switches can be determined. If the number of switches is
too low, a Diagnostic Trouble code (DTC) P1133 will set.
The lean–to–rich and rich–to–lean are less than 15
switches.
Conditions for Setting the DTC
S HO2S1 signal switches from 0.3 to 0.6 volts and
0.6 to 0.3 volts is less than 15 times within 90sec-
onds.
S Closed loop stoichiometry.
S Engine Coolant Temperature (ECT) is greater than
70 °C (158 °F).
S System voltage is greater than 10 volts.
S Engine run time is greater than 60 seconds.
S Purge Duty Cycle (DC) is less than 20%.
S The rpm is between 1600 and 4300.
S Airflow is between 9 and 40 g/sec.S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0134, P0135,
P1167, P0171, P1171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0351,
P0352, P0402, P0404, P0405, P0406, P0506,
P0507, P1404, and P0443 are not set.
S 2 second delay after conditions are met.
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.
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 can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.

1F – 540IENGINE CONTROLS
DAEWOO V–121 BL4
Diagnostic Aids
DTC P1133 is most likely caused by one of the following
items:
S Fuel Pressure – The system will go rich if the fuel
pressure is too high. The ECM can compensate for
some increase. However, if it gets too high, a DTC
P1133 may set. Refer to ”Fuel System Diagnosis”
in this section.
S Leaking injector – A leaking or malfunctioning injec-
tor can cause the system to go rich.
S Manifold Absolute Pressure (MAP) sensor – An
output that causes the ECM to sense a higher than
normal manifold pressure (low vacuum) can cause
the system to go rich. Disconnecting the MAP sen-
sor will allow the ECM to set a fixed value for the
MAP sensor. Substitute a different MAP sensor if
the rich condition is gone while the sensor is dis-
connected.
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 pres-
sure regulator.
S Throttle Position (TP) sensor – An intermittent TP
sensor output can cause the system to go rich due
to a false indication of the engine accelerating.S HO2S1 contamination – Inspect the HO2S1 for sili-
cone contamination from fuel or improper use of
Room Temperature Vulcanizing (RTV) sealant. The
sensor may have a white powdery coating and re-
sult in a high but false voltage signal (rich exhaust
indication). The ECM will then reduce the amount
of fuel delivered to the engine causing a severe
surge or driveability problem.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Chart.
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.
14. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
16. If no malfunctions have been found at this point and
no additional DTCs are set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation.
DTC P1133 – Front Heated Oxygen Sensor (HO2S1) Too Few
Transition
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.
Are any additional Diagnostic Trouble Codes
(DTCs) set?–Go to
applicable DTC
tableGo to Step 3
31. Start the engine and idle at normal operating
temperature.
2. Operate the vehicle within the specified param-
eter under the Conditions For Setting the DTC.
3. Monitor the lean–to–rich transition and rich–to–
lean transition and note the number of
switches.
Does the parameter show fewer transitions than the
specified value within 90 seconds.15Go to Step 4Go to Step 18

ENGINE CONTROLS 1F – 543
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1134
FRONT HEATED OXYGEN SENSOR (HO2S1)
TRANSITION RATIO
Circuit Description
The Engine Control Module (ECM) monitors the Front
Heated Oxygen Sensor (HO2S1) activity for 100 seconds
after closed loop and stoichiometric operation have been
established. During the monitoring period the ECM counts
the number of times that the HO2S1 responds from rich
to lean and adds the amount of time it took to complete all
transitions. With this information, an average time for all
transitions can be determined. The ECM then divides the
–to–lean average by the lean–to–rich average to obtain
the ratio. If the HO2S1 transition time ratio is not within the
range, Diagnostic Trouble Code (DTC) P1134 will be set,
indicating that the HO2S1 is not responding as expected
to changes in exhaust oxygen content.
Conditions for Setting the DTC
S HO2S1 rich–to–lean and lean–to rich transition ratio
is out of specification(between 0.375 and 3.5).
S Closed Loop stoichiometry.
S Engine Coolant Temperature (ECT) is greater than
70°C (158°F).
S System voltage is greater than 10 volts.
S Engine run time is greater than 60 seconds.
S Purge Duty Cycle (DC) is less than 20%.S Engine speed is between 1600 and 4300 rpm.
S Calculated airflow is between 9 and 40 g/sec.
S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0134, P0135,
P1167, P0171, P1171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0351,
P0352, P0402, P0404, P1404, P0405, P0406,
P0506, P0507, and P0443 are not set.
S 2 second delay after conditions are met.
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 vehicle will operate in Open Loop.
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.

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