Engine-Codes - Generic - P2251

P2251 Code - O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1

- Code Popularity: 51,143 Views
- Repair Importance Level: 2/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P2251?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Front Oxygen Sensor Bank 1
  • Front Oxygen Sensor Bank 1 harness is open or shorted
  • Front Oxygen Sensor Bank 1 circuit poor electrical connection
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How to Fix the DTC P2251?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P2251 code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the P2251 Code Mean?

The Front Oxygen Sensor (O2 Sensor 1) is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the Engine Control Module (ECM). The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

P2251 Code - O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1

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Code P2251 Information for Specific Makes

  • P2251 Acura Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage
  • P2251 Dodge O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1
  • P2251 Ford O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1
  • P2251 Honda Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage
  • P2251 Hyundai O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1
  • P2251 Lexus Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage
  • P2251 Lincoln O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1
  • P2251 Mercury O2 Sensor Negative Current Control Circuit Open Bank 1 Sensor 1
  • P2251 Scion Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage
  • P2251 Toyota Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage

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