Mitsubishi 3000GT Service Manual page 145

MULTIPORT FUEL INJECTION - Troubleshooting
DTC No.
Oxygen Sensor Heater Circuit Malfunction (Bank 1
Sensor 2)
Background
The engine control module checks whether the heater current is within a specified range when
the heater is energized.
Range of Check, Set Conditions
The oxygen sensor heater current is either lower than several dozen milliamperes or higherthan
several amperes.
DTC No.
Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 1)
Background
When the oxygen sensor begins to deteriorate, the oxygen sensor signal response becomes
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poor.
The engine control module forcibly varies the air-fuel mixture to make it leaner and richer,
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and checks the response speed of oxygen sensor.
In addition, the engine control module also checks for an open circuit in the oxygen sensor
output line.
Range of Check, Set Conditions
The response of the oxygen sensor signal is slow when the amount of fuel injected is increased
or decreased by an override during closed-loop control of the air-fuel ratio.
The oxygen sensor output line is open-circuit.
Oxygen Sensor Heater Circuit Malfunction
(Bank 2 Sensor 1)
Background
The engine control module checks whether the heater current is within a specified range when
the heater is energized.
Range of Check, Set Conditions
The oxygen sensor heater current is either lower than several dozen milliamperes or higher than
several amperes.
DTC No.
PO1 56 Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 2)
Background
The engine control module checks for an open circuit in the heatd oxygen sensor output line.
Range of Check, Set Conditions
The heated oxygen sensor output line is open-circuit.
Oxygen Sensor Heater Circuit Malfunction
PO1 61
(Bank 2 Sensor 2)
Background
The engine control module checks whether the heater current is within a specified range when
the heater is energized.
Range of Check, Set Conditions
The oxygen sensor heater current is either lower than several dozen milliamperes or higherthan
several amperes.
Title
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TSB Revision
Probable causes
Open or shorted oxygen sensor
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heater circuit.
Open circuit in oxygen sensor
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heater.
Engine control module failed.
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Probable causes
Heated oxygen sensor deterio-
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rated.
Open circuit in oxygen sensor
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output line.
Engine control module failed.
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Probable causes
Open or shorted oxygen sensor
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heater circuit.
Open circuit in oxygen sensor
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heater.
Engine control module failed.
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Probable causes
Heated oxygen sensor failed.
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Engine control module failed.
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Open circuit in heated oxygen
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sensor output line.
Probable causes
Open or shorted oxygen sensor
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heater circuit.
Open circuit in oxygen sensor
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heater.
Engine control module failed.
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.