P1271 INFINITI 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 is P1271 INFINITI Code Repaired?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
When is the Code Detected?
The A/F signal calculated by the ECM from the A/F Sensor 1 signal is constantly around 0V.
Possible Symptoms
- Engine Light On (or Service Engine Soon Warning Light)
- Possible rough engine idle
P1271 INFINITI Meaning
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 heating element in the element.
The sensor is capable of accurately measuring λ=1, but also in the lean and rich ranges. With its control electronics, the sensor emits a clear and continuous signal over a wide λ range (0.7 < λ < air).
The exhaust gas components diffuse through the diffusion gap at the oxygen pump electrode and the Nernst concentration cell, where they are brought to thermodynamic equilibrium.
An electronic circuit controls the pump current through the oxygen pump cell so that the composition of the exhaust gases in the diffusion gap remains constant at =1. Therefore, the A/F sensor is able to indicate the air/fuel ratio by this pumping current. Additionally, a heating element is built into the sensor to ensure the required operating temperature of 700 to 800 C (1,292 to 1,472 F).
