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 rear oxygen sensor
open or short circuit. Judge NG when the rear oxygen sensor voltage
may be abnormal from rear 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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(2)
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Exhaust
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(B)
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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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(D)
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Lean
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(E)
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Theoretical
air fuel ratio
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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 with rear oxygen sensor
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In
operation
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Target
output voltage of rear oxygen sensor
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≥ 0.54
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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≥ 75°C
(167°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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5 seconds
or more fuel shut-off in decel.
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Experienced
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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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< 490
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 rear oxygen sensor voltage
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Incomplete
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Max. output
voltage
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≥ 490
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)
