All codes/P2A3C

P2A3C

O2 Sensor Negative Current Control Circuit Low Bank 1 Sensor 3

Moderate severity

Voltage on the wide-band oxygen sensor negative pump current line of bank 1 sensor 3 is below the expected window. Wire shorted to ground or pump cell short.

Voltage on the wide-band oxygen sensor negative pump current line of bank 1 sensor 3 is below the expected window. Wire shorted to ground or pump cell short.

Common causes

  • Pump current wire shorted to ground

    One of the most commonly reported causes for this code — check this first.

    high

    Typical part cost: $170-770

  • Internal short in pump cell

    A plausible cause — test and verify before replacing parts.

    medium

    Typical part cost: $170-770

  • See all causes + fix costs

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First things to check

  1. 1Confirm the code with a scan tool and check for additional related codes.
  2. 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P2A3C mean?

P2A3C means "O2 Sensor Negative Current Control Circuit Low Bank 1 Sensor 3". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P2A3C?

pump current wire shorted to ground; internal short in pump cell; connector pins corroded - high contact resistance — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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