oxygen sensor DAEWOO LACETTI 2004 Service Manual PDF

1F – 484IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST OXYGEN SENSOR LOW EFFICIENCY
Circuit Description
In order to control exhaust emissions of Hydrocarbons
(HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx),
a Three–Way Catalytic Converter (TWC) is used. The cat-
alyst within the converter promotes a chemical reaction
which oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide, it also reduces NOx, converting it into nitrogen.
The catalytic converter also has the ability to store oxygen.
The Engine Control Module (ECM) has the capability to
monitor this process using a Heated
Rear Heated Oxygen Sensor (HO2S2) located in the ex-
haust stream past the TWC. The HO2S2 produces an out-
put signal which indicates the oxygen storage capacity of
the catalyst; this in turn indicates the catalyst’s ability to
convert exhaust emissions effectively. The ECM monitors
the catalyst efficiency by first allowing the catalyst to heat
up, waiting for a stabilization period while the engine is id-
ling, and then adding and removing fuel while monitoring
the reaction of the HO2S2. When the catalyst is function-
ing properly, the HO2S2 response to the extra fuel is slow
compared to the Front Heated Oxygen Sensor (HO2S1).
When the HO2S2 response is close to that of the HO2S1,
the Oxygen storage capability or efficiency of the catalyst
is considered to be bad, and the Malfunction Indicator
Lamp (MIL) will illuminate.
Conditions for Setting the DTC
S Oxygen storage capacity index time is less than 0.3
seconds.
S Before idle test, the vehicle needs to be driven for
at least:
S 15 seconds at airflow is greater than 9.2 g/sec.
for manual transaxle.
S 11 seconds at airflow is greater than 12 g/sec
for automatic transaxle.
S Oxygen Sensor Capacity test condition:
S Closed loop stoichiometry.
S Purge concentration learned.
S Engine is running more than 330 seconds.
S Airflow is between 2.5 and 7.25 g/sec.
S Throttle Position (TP) sensor is less than 1.5%.
S Intake Air Temperature (IAT) is between –7°C
(19.4°F) and 105°C (221°F).
S Barometric pressure (BARO) is greater than 72 kPa
(10.4 psi).
S Catalyst temperature is between 500°C (932°F)
and 850°C (1562°F) for automatic transaxle.
S Catalyst temperature is between 450°C (842°F)
and 850°C (1562°F) for automatic transaxle.
S Closed Loop integrator change is less than 0.03.
S Idle time is less than 1 minute.
S Vehicle speed is less than 3 km/h (1.9 mph).S Block Learn Mode is learned.
S Above condition is stabilized for 5 seconds.
Note : Test is aborted for this idle if:
S Change in engine speed is greater than 80 rpm.
S A/C status changed.
S Cooling fan status changed.
S Insufficient air/fuel shift.
S DTC(s) P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0131, P0132, P0133, P1133,
P0134, P0135, P0137, P0138, P0140, P0141,
P1167, P1171, P0171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0341,
P0342, P0351, P0352, P0402, P0404, P1404,
P0405, P0406, P0443, P0502, P0506, P0507, and
P0562 are not set.
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 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
The catalyst test may abort due to a change in the engine
load. Do not change the engine load (i.e. A/C, coolant fan,
heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the intermittent
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
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.

ENGINE CONTROLS 1F – 485
DAEWOO V–121 BL4
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 any component DTCs are set, diagnose those
DTCs first. A fault in a component can cause the
converter to appear degraded or may have caused
its failure.
3. This step includes checks for conditions that can
cause the three–way catalytic converter to appear
degraded. Repair any problems found before pro-
ceeding with this table.
5. If the three–way catalytic converter needs to be
replaced, make sure that another condition is not
present which would cause the converter to be-
come damaged. These conditions may include thefollowing: misfire, high engine oil or coolant con-
sumption, and/or retarded spark timing or weak
spark. To avoid damaging the replacement convert-
er, correct any possible causes of converter dam-
age before replacing the catalytic converter.
6. Clearing DTCs allows the catalyst test to be run up
to 6 times this ignition cycle. Once the ignition is
cycled, the test will run only once. Driving the ve-
hicle heats the catalyst to a test temperature. The
ECM must see predetermined amount of time at
above idle before allowing the catalyst test to run at
idle. Once at idle, the ECM will allow the system to
stabilize and then test the catalyst in 2 stages.
7. 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 informa-
tion.
DTC P0420 – Catalyst Oxygen Sensor Low Efficiency
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”
2S Install a scan tool to the Data Link Connector
(DLC).
S Turn the ignition ON.
Are any component Diagnostic Trouble Codes
(DTCs) set?–Go to
applicable DTC
tablesGo to Step 3
3Visually/physically check the following:
S Exhaust system for a leak.
S Rear Heated Oxygen Sensor (HO2S2)
Is a problem found?–Go to Step 4Go to Step 5
4Repair the exhaust system as needed.
Is the repair complete?–Go to Step 6–
5Replace the Three Way Catalytic Converter (TWC).
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 – 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 – 541
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
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 9Go to Step 5
5Check the exhaust manifold for a leak near the en-
gine and repair as needed.
Is the repair complete?–Go to Step 3Go to Step 6
61. Turn the ignition OFF.
2. Disconnect the HO2S1 connector.
3. Jumper the HO2S1 low circuit, terminal 3 to
ground.
4. Turn the ignition ON.
Does the scan tool indicate the voltage between the
specified value?400–500 mVGo to Step 7Go to Step 10
7Jumper the HO2S1 signal and low circuit terminal 4
to ground.
Does the scan tool indicate the voltage below the
specified value?200 mVGo to Step 8Go to Step 11
81. Turn the ignition OFF.
2. Replace the HO2S1.
Note : before replacing the sensor, the cause of the
contamination must be determined and corrected in
order to prevent further damage to the sensor.
Check for following:
S Fuel contamination.
S Use of improper Room Temperature Vulcaniz-
ing sealant.
S Engine oil/coolant consumption.
Is the repair complete?–Go to Step 15–
9Repair the condition as needed.
Is the repair complete?–Go to Step 15–
10Repair the HO2S1 signal circuit for a short to ground.
Is the repair complete?–Go to Step 15–
111. Remove the jumper wire.
2. Using voltmeter measure the voltage between
the HO2S1 signal circuit, terminal 4 and
ground.
Does the voltage above the specified value?407 mVGo to Step 12Go to Step 13
121. Turn the ignition OFF.
2. Disconnect the ECM connectors and check the
continuity between terminal 2 of HO2S1 and
the terminal M29 of the ECM.
3. If the circuit measures over the specified value,
repair open or poor connection as needed.
Is the repair complete?5 ΩGo to Step 15Go to Step 14

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

1F – 546IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1167
FRONT HEATED OXYGEN SENSOR (HO2S1) RICH IN
DECEL FUEL CUTOFF (DFCO)
Circuit Description
The Engine Control Module (ECM) supplies a voltage of
about 0.45 volts between terminals M12 and M29 (if mea-
sured with a 10 megohm digital voltmeter, this may read
as low as 0.32 volts). The Front Heated Oxygen Sensor
(HO2S1) varies the voltage within a range of about 1 volt
if the exhaust is rich, down through about 0.10 volts if the
exhaust is lean.
In internal circuitry of the Engine control Module (ECM)
can identify if the vehicle fuel system is capable of cutoff
amount of the fuel supply during deceleration. When a De-
cel Fuel Cutoff (DFCO) mode of operation is requested
during Closed Loop operation, the ECM will cutoff the fuel
supply to the engine. Under these conditions the ECM
should detect a lean condition. If the ECM detect a rich
condition at this time, Diagnostic Trouble Code (DTC)
P1167 will set. Damaged fuel pressure regulator and faulty
injector will be the cause of this DTC.
Conditions for Setting the DTC
S HO2S1 voltage is greater than 0.55 volts in Decel
Fuel Cutoff (DFCO) mode.
S System voltage is greater than 10 volts.S Engine Coolant Temperature (ECT) is greater than
60°C (140°F)
S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0171, P0172, P0201, P0202,
P0203, P0204, P0300, P0336, P0337, P0351,
P0352, P0402, P0404, P0405, P0406, P0506,
P0507, P1404, and P0443 are not set.
S 3 second delay after in DFCO mode.
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.
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.
S DTC can be cleared by using the scan tool.

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