Air Fuel Ratio Sensor 1 Bank 1 Lean Shift Monitoring
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P1273 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
- Fuel pressure
- Faulty Fuel injector
- Faulty Air Flow Meter
How do I fix code P1273 INFINITI?
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.
Tech Notes
- If one or more sensors are replaced the Engine Control Module (ECM) Mixture Ratio Self-Learning clearing procedure must be performed.
- There is a Factory Service Bulletin for the following Infiniti models:
- 2003-2012 Infiniti FX
- 2002 Infiniti G20
- 2003-2006 Infiniti G35 Sedan
- 2003-2007 Infiniti G35 Coupe
- 2006-2012 Infiniti G37 Sedan
- 2008-2012 Infiniti G37 Coupe
- 2002-2004 Infiniti I35
- 2004-2012 Infiniti M
- 2002-2006 Infiniti Q45
- 2002-2003 Infiniti QX4
- 2004-2012 Infiniti QX56
- Infiniti Factory Service Bulletin OBDII Code P1273
Cost of diagnosing the P1273 INFINITI code
The cost of diagnosing the P1273 INFINITI 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 output voltage computed by ECM from the A/F sensor 1 (Bank 1) signal is shifted to the lean side for a specified period.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible rough engine idle
P1273 INFINITI Description
The Air Fuel Ratio (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).