Skip the auto shop - Our mechanics make house calls

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

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
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...


Related questions

Q: Transmission only has 1st gear

Hello. P0732 is the trouble code for an abnormal gear 2 shift ratio. If the vehicle's transmission computer detects that there is an issue with the gear ratio and timing of second gear, it will set off this code to...

Q: My car won't move when i press the gas pedal i have never had a problem before. I did notice a leak but i thought it was the oil from the transmission.

You should check for any codes that could be stored in the ECM (computer) as the check engine light is on. This will give you a starting place to check for the condition that you are having. Since the vehicle...

Q: I recently had a new stereo installed in my mirage, and now the airbag light is on. How do i reset it or get it to go out.

The Air Bag Light would set a code in the computer and should be checked by the dealer since you are still under factory warranty unless the stereo installer damaged the wiring or something to do with the airbag. I...