DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2)
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DTC P0137 O
2
SENSOR CIRCUIT LOW
VOLTAGE (BANK 1 SENSOR 2)
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Detect the malfunction of oxygen sensor open
or short circuit. Judge NG when the oxygen sensor voltage may be
abnormal from oxygen sensor voltage value with considering the conditions
such as intake air amount, engine coolant temperature, main feedback
control.
(1)
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Atmosphere
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(A)
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Electromotive
force
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(D)
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Lean
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(2)
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Exhaust
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(B)
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Air fuel
ratio
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(E)
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Theoretical
air fuel ratio
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(3)
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Electromotive
force
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(C)
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Rich
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(F)
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Comparative
voltage
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ENABLE
CONDITION (USED ONLY FOR MALFUNCTION JUDGMENT)
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Secondary
Parameters
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Enable
Conditions
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Closed
loop control of oxygen sensor
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In
operation
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Target
output voltage of oxygen sensor
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≥ 0.6
V
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Amount
of intake air
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≥ 10
g/s
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Engine
coolant temperature
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≥ 70°C
(158°F)
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Misfire
detection during 200 engine revs.
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< 5
times
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Compensation
factor for front oxygen (A/F) sensor
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Not
in limit value
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Battery
voltage
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> 10.9
V
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6 seconds
or more fuel shut-off in decel. time
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Experience
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Perform the diagnosis once after starting
the engine.
Abnormality Judgment
Judge NG when the malfunction criteria below
are completed.
Judgment
Value
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Malfunction
Criteria
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Threshold
Value
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Max. output
voltage
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< 550
mV
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Time Needed for Diagnosis:
200
seconds
Malfunction Indicator
Light Illumination:
Illuminates when malfunction occurs in
2 continuous driving cycles.
Normality Judgment
Judge OK when the malfunction criteria below
are completed.
Judgment
Value
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Malfunction
Criteria
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Threshold
Value
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Low
side diagnosis of oxygen sensor voltage
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Incomplete
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Max. output
voltage
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≥ 550
mV
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•
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When the OK idling cycle was completed 40 times
in a row
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•
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When “Clear Memory” was
performed
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MALFUNCTION
INDICATOR LIGHT CLEAR CONDITION
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•
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When the OK driving cycle was completed 3 times
in a row
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•
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When “Clear Memory” was
performed
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Sub feedback control: Not allowed
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ECM OPERATING
AT DTC SETTING
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Memorize the freeze frame data. (For test mode $02)
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Memorize the diagnostic value and malfunction
standard value. (For test mode $06)
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