AutoCodes – Generic – P2278

P2278 Code - O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3

Quick Answer

P2278 indicates O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3. Common causes include Faulty O2 Sensor, O2 Sensor harness is open or shorted, O2 Sensor circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P2278 indicates O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3.
Common causes: Common causes include Faulty O2 Sensor, O2 Sensor harness is open or shorted, O2 Sensor circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 8,723

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P2278 Description

OBDII Code P2278 - O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3 - AutoCodes.com — P2278 Code - O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3

What does this mean?

What are the Possible Causes of the DTC P2278?

Faulty O2 Sensor
O2 Sensor harness is open or shorted
O2 Sensor circuit poor electrical connection

How to Fix the DTC P2278?

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 P2278 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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Information for Specific Makes

P2278 Dodge — O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3

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.