Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P2240 OBD-II Trouble Code: O2 Sensor Positive Current Control Circuit/Open Bank 2 Sensor 1

P2240 OBD-II Trouble Code: O2 Sensor Positive Current Control Circuit/Open Bank 2 Sensor 1

check engine light logo

P2240 trouble code definition

O2 Sensor Positive Current Control Circuit/Open Bank 2 Sensor 1

What the P2240 code means

P2240 is an OBD-II generic code for the engine control module (ECM) detecting the air-fuel (A/F) ratio sensor signal is shorted or between the A/F positive and negative terminals of the sensor.

What causes the P2240 code?

The engine control module is detecting a signal is shorted or open between the bank 2 A/F sensor 1 signal wires. This can be an issue with the ECM, A/F ratio sensor, or wiring.

What are the symptoms of the P2240 code?

  • The Check Engine Light will be illuminated and the code is set in ECM memory as a fault.

  • The ECM will ignore the sensor and put the engine in failure mode for fuel control. This strategy may be different between manufactures therefore the drive symptoms may be different. You may have surging, bucking or jerking, misfires, low power, pinging, or other symptoms.

How does a mechanic diagnose the P2240 code?

  • Scans and documents the codes in the ECM and looks at the freeze frame data for failure

  • Checks for any problem with the wiring or connector to the sensor

  • Checks the data to see if the sensor is shorted or open

  • Disconnects the sensor to see if the short goes away, indicating a shorted sensor

  • Checks the connector for corrosion that can cause an open in the sensor circuit

Common mistakes when diagnosing the P2240 code

  • Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired

  • Failing to clear the ECM codes after the codes are fixed

  • Failing to check and clean the connector for corrosion before replacing the sensor, the connection may only be okay for a short time before the code returns

How serious is the P2240 code?

Code P2240 is an indication that the ECM is getting a signal from the air-fuel ratio sensor that it may be shorted or open. The ECM cannot control the fuel properly until the signal is fixed. You may have poor fuel mileage and various poor drive symptoms.

What repairs can fix the P2240 code?

Additional comments for consideration regarding the P2240 code

Code P2240 is for one of the A/F sensors and may be accompanied by other engine codes. Some vehicles may have computer software issues pertaining to this code and may need ECM reprogramming. Check for technical bulletins for your application before attempting repairs.

Need help with a P2240 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

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...


Related questions

Q: The Check Engine Light came on, I hooked it up to my scanner and got the code P0308

Hello. A cylinder misfire can be caused by many things. If you are not able to notice any issues with engine performance then the misfire is likely minor or intermittent. A few common causes for a misfire are a faulty...

Q: High idling, check engine light on

The Check Engine Light being on indicates there is a problem and a code will have been set. Have the light checked for codes and then get a professional to thoroughly diagnose the Check Engine Light to see what fixes...

Q: Good morning Patrick, I have a 2007 Pontiac torrent. It refuses to accelerate and when u try to give full acceleration, it starts

Your computer is trying to protest the motor by going into failure mode and limiting the throttle opening. The overheating is the cause of the problem. You need to have the cooling system checked to see if there are any...