P1278 INFINITI - Air Fuel Ratio Sensor 1 Bank 1 Circuit Slow Response
P1278 INFINITI Possible Causes
- Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
- Air fuel ratio (A/F) Sensor 1 Bank 1 Harness or connectors is open or shorted
- Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
- Fuel pressure
- Faulty Fuel injector
- Intake air leaks
- Exhaust Gas leaks
- Faulty PVC
- Faulty Air Flow Meter
First diagnose P1278 INFINITI code
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 terminals.
Cost of diagnosing the P1278 INFINITI code
Labor: 1.0The cost of diagnosing the P1278 INFINITI code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
When is the P1278 INFINITI code detected?The response (from RICH to LEAN) of the A/F signal computed by ECM from A/F sensor 1 signal takes more than the specified time.
P1278 INFINITI Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible rough engine idle
P1278 Infiniti DescriptionThe 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).
P1278 INFINITI More InformationNeed more information on how to fix the P1278 INFINITI code?
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