P2256Heated oxygen sensor (HO2S) 1, bank 2, negative current control - circuit high
Generic (OBD-II) interpretation in the TuningBot DTC database.
P · PowertrainEmissionsOBD2
What P2256 means
P2256
Heated oxygen sensor (HO2S) 1, bank 2, negative current control - circuit high
Generic · emissions
Data confidence85%
The control module detected that the signal in the Heated oxygen sensor (HO2S) 1, bank 2, negative current control circuit stayed above the expected operating range.
Symptoms
MIL illuminated
Possible increased fuel consumption
Possible unstable idle
Possible causes
Wiring short to positive
H025
Recommended checks
Read live sensor voltage/current and heater status
Inspect wiring and connectors
Check for exhaust leaks near the sensor
Check fuel trim values for upstream mixture faults
Powertrain: engine, transmission and driveline systems.
2
Generic SAE-standard code: same meaning on every make.
256
Specific fault index within the subsystem.
Frequently asked questions about P2256
What does P2256 mean?
Heated oxygen sensor (HO2S) 1, bank 2, negative current control - circuit high. The control module detected that the signal in the Heated oxygen sensor (HO2S) 1, bank 2, negative current control circuit stayed above the expected operating range.
Is P2256 generic or manufacturer-specific?
P2256 is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.
Can TuningBot remove P2256 at file level?
If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry. Checksum correction is not included: it is a separate, optional service. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.
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