AutoCodes – Infiniti – P1272 Infiniti

P1272 Infiniti Code - Air Fuel Ratio Sensor 1 Bank 1 Circuit No Activity Detected

Quick Answer

The A/F sensor is a planar dual-cell limit current sensor. Common causes include 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. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1272 Infiniti indicates Air Fuel Ratio Sensor 1 Bank 1 Circuit No Activity Detected.
Common causes: Common causes include 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.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 4,577

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 28, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1272 Infiniti 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).

OBDII Code P1272 Infiniti - Air Fuel Ratio Sensor 1 Bank 1 Circuit No Activity Detected - AutoCodes.com — P1272 Infiniti Code - Air Fuel Ratio Sensor 1 Bank 1 Circuit No Activity Detected

What does this mean?

What are the Possible Causes of the DTC P1272 Infiniti?

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 to Fix the DTC P1272 Infiniti?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1272 Infiniti code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.