P1289 Code INFINITI Possible Causes
- Faulty Air Fuel Ratio (A/F) Sensor 1, Bank 2
- Air Fuel Ratio (A/F) Sensor 1, Bank 2 Harness is open or shorted
- Air Fuel Ratio (A/F) Sensor 1, Bank 2 Circuit poor electrical connection
- Low fuel pressure
- Faulty fuel injector
- Intake air leaks
- Exhaust gas leaks
- Faulty PCV
- Faulty mass air flow meter
How is INFINITI Code P1289 Repaired?
Start by checking 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.
When is INFINITI Code P1289 Detected?
The response (from RICH to LEAN) of the A/F signal calculated by the ECM from the A/F sensor 1 signal takes longer than the specified time.
What are the Possible Symptoms of INFINITI P1289 Code?
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible rough engine idle
What Does INFINITI Code P1289 Mean?
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 inside the element.
The sensor is capable of precisely measuring λ=1, but also in the lean and rich ranges. With its control electronics, the sensor delivers 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 gas in the diffusion gap remains constant at λ = 1. Therefore, the A/F sensor is able to indicate the air/fuel ratio by this pumping current. In addition, a heater is integrated into the sensor to ensure the required operating temperature of 700 to 800 C (1,292 to 1,472 F).