Skip the auto shop - Our mechanics make house calls

P2250 OBD-II Trouble Code: O2 Sensor Ref Voltage Circuit High Bank 2 Sensor 1

Check Engine Light

P2250 code definition

The P2250 trouble code detects an issue with the upstream oxygen sensor voltage circuit in bank 2.

What the P2250 code means

The P2250 code is a generic OBD-II trouble code that suggests a problem with oxygen sensor 1 in bank 2. Bank 2 means that the issue is in the second engine bank, which is the bank that does not house the #1 cylinder. Sensor 1 means that the oxygen sensor is the upstream sensor, which is the one in front of the catalytic converter. The upstream sensor sends voltage information to the powertrain control module (PCM). When the heater circuit voltage varies from the battery voltage by more than 10 percent, or when the resistance level is more than 10 percent off of the standard 8 ohms, then the P2250 trouble code will be triggered.

What causes the P2250 code?

There are many potential causes for the P2250 trouble code, including:

  • Defective upstream oxygen sensor
  • Blow oxygen sensor fuse
  • Engine vacuum leak
  • Drastic exhaust leak
  • Fuel pressure that is very high or very low
  • In rare cases, a defective PCM
  • Malfunctioning or damaged oxygen sensor electrical connectors, wires, and harnesses

What are the symptoms of the P2250 code?

The P2250 trouble code will usually be accompanied by the Check Engine Light, which will illuminate on the instrument cluster. It is also common for the engine to run too lean or too rich, and the fuel efficiency to be lowered. Black smoke emitting from the tailpipe is also common.

How does a mechanic diagnose the P2250 code?

The P2250 code should be diagnosed with a standard OBD-II trouble code scanner. A trustworthy mechanic will use the scanner to view the freeze frame data and analyze the P2250 code. The technician will also look for any other trouble codes that are present. The codes should then be reset, and the vehicle restarted and taken for a short test drive. If the code does not return, then the issue was erroneously detected, or is an intermittent problem.

If the P2250 code returns, the mechanic should visually inspect the upstream oxygen sensor electrical components. All of the harnesses, wires, connectors, and fuses should be inspected, and any that are damaged or malfunctioning should be replaced.

Next, the technician will inspect the upstream oxygen sensor. In many vehicles, the sensor is easily removable, which makes inspection quicker and more thorough. If no issue has been detected after this point, the mechanic will begin a more thorough inspection, to check for exhaust leaks, vacuum leaks, and PCM failures.

Whenever a component is replaced, the trouble codes should be reset and the vehicle restarted to see if the issue has been resolved.

Common mistakes when diagnosing the P2250 code

The most commonly made mistake when diagnosing the P2250 code comes from a failure to properly follow the OBD-II trouble code diagnosis protocol. The protocol should always be followed strictly, to ensure that components are addressed in the right order. This ensures an efficient inspection and repair.

Failure to follow the proper protocol often results in replacing the upstream oxygen sensor when the issue is simple an electrical component.

How serious is the P2250 code?

If the P2250 code has been detected, the vehicle is still drivable. However, the car will likely get decrease fuel efficiency, and the engine may not run as well as it should. Failure to address the issue can result in damage to the engine, so the P2250 code should be handled as soon as possible.

What repairs can fix the P2250 code?

Some repairs for the P2250 trouble code include:

Additional comments for consideration regarding the P2250 code

It is very rare for a defective PCM to be the problem that causes the P2250 code to be detected. All other options should be checked before it is assumed that the PCM is malfunctioning. If the PCM needs to be replaced, it will also need to be reprogrammed.

Need help with a P2250 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...


Related questions

Q: The Check Engine Light came up with the code P2017, what do I need to replace?

If you are getting this code it is due to one of two things. The vast majority of the time it is caused by a failure in the variable charge motion actuator, which is the same part that you mentioned....

Q: Car lost power

Hello. Most of the time when this car suddenly stops like this it is because the timing belt broke. If it has never been replaced then this is very likely. It can also occur if the ASD relay failed or...

Q: What are these codes that appeared on my car?

These codes are related to the engine sensors for mass air flow, idle air control, and the throttle position sensor. It is quite likely, given your mileage, that their sensors have become dirty/clogged, or the sensors have failed. You don't...