Air Fuel Ratio Sensor 1 Bank 1 Circuit No Activity Detected


Table of contents

P1271 NISSAN Possible Causes

  • Faulty air fuel ratio (A/F) Sensor 1 Bank 1
  • Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
  • Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection

How do I fix code P1271 NISSAN?

  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’s pins.

Cost of diagnosing the P1271 NISSAN code

  The cost of diagnosing the P1271 NISSAN code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

When is the code detected

  The A/F signal computed by ECM from the A/F sensor 1 signal is constantly approx. 0V.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Possible rough engine idle

P1271 NISSAN Description

  The A/F sensor is a planar dual-cell limit current sensor. The sensor element of the A/F sensor is the combination of a Nernst concentration cell (sensor cell) with an oxygen-pump cell, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement λ= 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide λ range (0.7 < λ < air).
The exhaust gas components diffuse through the diffusion gap at the electrode of the oxygen pump and Nernst concentration cell, where they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-pump cell so that the composition of the exhaust gas in the diffusion gap remains constant at λ = 1. Therefore, the A/F sensor is able to indicate air/fuel ratio by this pumping of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of 700 – 800 C (1,292 – 1,472 F).

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