P2278 - OBD Trouble Code

It is the downstream oxygen sensor for engine bank 1 which has delivered a voltage reading which would depict that the signals for engine banks 1 and 2 have been swapped, which would cause the PCM to store this error code and it would also result in the illumination of the service engine soon light. Bank 1 is the engine bank which has the number 1 cylinder. Bank 2 would denote the bank of the engine block that does not have the #1 cylinder. Sensor 3 would inform you that the fault is found in the downstream sensor (aft of the catalytic converter/s) in a three-sensor system.

What causes this problem with the O2 Sensor Signals Swapped Bank 1 Sensor 3/Bank 2 Sensor 3?

• The fuel pressure might be less or more
• Malfunctioning oxygen sensor
• There can be inoperative PCM
• Exhaust might be flawed
• Some issues related to the wiring in the oxygen sensor circuit
• Unusable electrical connector at the oxygen sensor
• There can be vacuum leak on the engine

1. Engine Control Module - Most of the time it is difficult to intercept the ECM faults and thus must be checked for thoroughly. There can be a problem with the circuit or the software might have malfunctioned. Thus repair, replace or reprogram the component as per requirement.
2. Exhaust System Parts - Performance issues are a commonly followed due to an erroneous exhaust system parts. If the parts become damaged or corroded, they can sometimes cause an exhaust leak. A leak or crack can lead to the vehicle to experiencing a significant reduction in power, ability to accelerate, and fuel efficiency due to the loss of back pressure. Tune into Parts Avatar for premium quality car parts.
3. Powertrain Control Module - If the PCM is faulty, it can store wrong OBD codes and can lead to misdiagnosis. This can happen due to misinterpretation of data received from the various sensors and components which also affects the vehicle’s performance. Thus, replace it immediately.
4. Oxygen Sensor - The O2 sensor is mounted in the exhaust manifold to monitor how much unburned oxygen is in the exhaust as the exhaust exits the engine. Monitoring oxygen levels in the exhaust is a way of gauging the fuel mixture. Thus, replace faulty O2 sensor now!
5. Electronic Control Unit - If the ECU is at fault, it will not be able to read the boost converter temperatures correctly leading to underperformance. Thus, replace faulty ECU now!
6. Diagnostic Tool - Choose from our diagnostic tools collection that will come handy to detect and correct the OBD error code.

You might be thinking that how would you diagnose these problems? We at Parts Avatar Canada would help you diagnose the major symptoms easily.

Common Symptoms

• The service engine soon light can start lighting up
• There might be a lean or rich condition in the car engine
• Diminishing fuel efficiency
• Black smoke might start emitting from the tailpipe

The repairs which you will have to do to correct this fault code are simply straightforward; you can surely pinpoint the necessary repairs on the basis of your diagnosis. Have a look at some common fixes:

• Repair or replace the quirky wiring in the oxygen sensor circuit
• The malfunctioning oxygen sensor should be repaired or replaced as per the need
• The PCM should be restored to working order
• Recondition the leakages in the auto exhaust
• Adjust the flawed electrical connector at the oxygen sensor

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of oxygen sensor, powertrain control module, engine control module, fuel injector, air/fuel ratio sensor, exhaust system parts, car muffler, ecu car, pcm car, body control module component and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code:

• The mechanic or the technician will use a diagnostic scanner or code reader like DVOM to visually scan for the error codes in the vehicle.
• After performing a careful inspection, every of the stored codes and freeze frame data are retrieved as it can help down the way for further diagnosis process.
• Most often he has to inspect the solenoid itself to see if they are faulty or damaged. Additional error codes that are stored in the vehicle are also addressed.
• The mechanic performs a continuity test between the PCM and solenoid to check the resistance.
• If the solenoid or the control modules are not faulty, he will then retune the code and test drive the vehicle.
• On test driving, if the P2278 code does not return soon, he will know that an erratic condition exits.
• But if the error returns instantaneously, he will check every components of the control module as well as the circuit like connectors, wires, harness, fuses etc for any possible fault.
• If any component is damaged, he will fix them right away.
• After performing this repair, he will inspect the heated oxygen sensor as well.
• If there are some faults in the heated oxygen sensor circuit, then it needs to be replaced.
• Every time a repair work is carried out, make sure that the mechanic test drives the vehicle after every repair so that the diagnosis is successful. This can eventually help him to know as to where the error occurred.

Common Mistakes When Diagnosing The P2278 Code

• There might be some cases where there are lean or rich engine conditions that are providing wrong readings and because of that the mechanics might by mistake replace the oxygen sensors.
• When there is some fault in the oxygen sensor, then a common mistake of replacing the wrong oxygen sensors is made by a lot of mechanics.