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TuningBot DTC Database · v4.37.15

P2A08 Heated oxygen sensor (HO2S) 3, bank 1 - circuit negative voltage

Generic (OBD-II) interpretation in the TuningBot DTC database.

P · PowertrainEmissionsOBD2

What P2A08 means

P2A08
Heated oxygen sensor (HO2S) 3, bank 1 - circuit negative voltage Generic · emissions Data confidence 78%

The control module detected a fault associated with the Heated oxygen sensor (HO2S) 3, bank 1 - circuit negative voltage circuit or function; the stored code identifies the affected component rather than a single failure mode.

Symptoms

  • MIL illuminated
  • Possible increased fuel consumption
  • Possible unstable idle

Possible causes

  • Wiring
  • H025
  • ECM

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

Related and nearby codes

How to read P2A08

P

Powertrain: engine, transmission and driveline systems.

2

Generic SAE-standard code: same meaning on every make.

A08

Specific fault index within the subsystem.

Frequently asked questions about P2A08

What does P2A08 mean?

Heated oxygen sensor (HO2S) 3, bank 1 - circuit negative voltage. The control module detected a fault associated with the Heated oxygen sensor (HO2S) 3, bank 1 - circuit negative voltage circuit or function; the stored code identifies the affected component rather than a single failure mode.

Is P2A08 generic or manufacturer-specific?

P2A08 is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.

Can TuningBot remove P2A08 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.

Other file services

ECU tuningDyno-tested results by model and engine See the results →

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