OBD Guide

P2251

O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1

P2251 is an OBD-II diagnostic trouble code meaning: O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1. Common causes: broken or damaged oxygen sensor wiring, poor contact in the sensor connector. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine light comes on
  • Increased fuel consumption
  • Unstable engine idling
  • Reduced engine power
  • Dips during acceleration

Causes

  • Broken or damaged oxygen sensor wiring
  • Poor contact in the sensor connector
  • Malfunction of the oxygen sensor itself
  • Problems with the engine ECU
  • Short circuit in control circuit

How to Fix

  1. Check the integrity of the wiring and connectors of the sensor
  2. Clean the contacts of the oxygen sensor connector
  3. Check control circuit resistance
  4. Replace the oxygen sensor if necessary
  5. Check the performance of the engine ECU

Related codes

Error P2251 by Vehicle Brand

FAQ

What does the P2251 code mean?

P2251 is an OBD-II diagnostic trouble code that indicates: O2 Sensor Negative Current Control Circuit/Open Bank 1 Sensor 1

What causes a P2251 error code?

The most common causes of P2251 include: Broken or damaged oxygen sensor wiring; Poor contact in the sensor connector; Malfunction of the oxygen sensor itself; Problems with the engine ECU.

How do I fix a P2251 diagnostic trouble code?

To fix P2251: Check the integrity of the wiring and connectors of the sensor. Clean the contacts of the oxygen sensor connector. Check control circuit resistance. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2251?

Yes, but get it checked soon

How much does it cost to fix P2251?

The estimated repair cost for P2251 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

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