Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P0266 OBD-II Trouble Code: Cylinder 2 Contribution/Balance Fault

P0266 OBD-II Trouble Code: Cylinder 2 Contribution/Balance Fault

Check Engine Light

P0266 code definition

Cylinder 2 Contribution/Balance Fault

What the P0266 code means

This diagnostic trouble code indicates that the powertrain control module has detected that the reference voltage from the fuel injector on cylinder 2 has fallen out of the range of acceptance set by the vehicle manufacturer.

What are the causes of the P0266 code?

  • Damaged wiring or connectors associated with the fuel injector circuit on the number 2 cylinder may be present.

  • A faulty or restricted fuel injector on the number 2 cylinder may exist.

  • The powertrain control module could be malfunctioning.

What are the symptoms of the P0266 code?

Symptoms of this trouble code that the driver may experience would include:

How does a mechanic diagnose the P0266 code?

  • A mechanic may begin diagnosing this trouble code by removing any engine covers that exist to gain access to the fuel injectors.

  • Once the fuel injectors are visible, the mechanic would inspect the wiring and connectors for damages that may have been caused by mice or other small animals that could have nested under the engine cover.

  • Next, the mechanic would test the fuel injector on the number 2 cylinder for proper function using the manufacturer’s suggested procedure.

  • If the cause of the issue has still not been revealed after these two tests have been performed, the mechanic would use a high tech scan tool to test the powertrain control module to ensure that it is working correctly.

After all tests have been performed and the mechanic has come up with a diagnosis, he/she would relay the information over to the customer to make an informed repair decision.

Common mistakes when diagnosing the P0266 code

A common mistake that could be made when diagnosing this trouble code would be to replace the fuel injector on the number 2 cylinder when it is actually the wiring or connector that is faulty. It is very important to check all possible causes of a problem before making a repair decision.

How serious is the P0266 code?

This code would be considered serious because the engine will not run properly with the cylinder 2 injector not functioning as it should. This issue would be worse on 4 cylinder and 6 cylinder engines as opposed to 8 cylinder engines due to the fact that the extra cylinders can make up for the imbalance that the malfunctioning injector on cylinder 2 would cause. A code such as this should be diagnosed and repaired as soon as possible because continuous driving with a misfire condition can cause damage to the engine.

What repairs can fix the P0266 code?

  • Repairing or replacing the wiring or connector that is associated with the fuel injector on the number 2 cylinder

  • Replacing the fuel injector on the number 2 cylinder.

  • Running a good fuel system cleaning through your engine to clear any restrictions the fuel injector on the number 2 cylinder may have.

  • Replacing the powertrain control module

Additional comments regarding the P0266 code

This code will likely be associated with a P0302 code for a cylinder 2 misfire. While the mechanic is inspecting the fuel injector circuitry, it would be a good idea to have him/her check the wiring on the ignition coil or spark plug wire to be sure that the ignition going to the number 2 cylinder is working properly.

Need help with a P0266 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...
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: I have check engine light on and the code is showing p0266 ?

P0266 means that the fuel injector on cylinder number two does not pass the self tests that the Electronic Control Unit performs. It is often accompanied by a code P0302 for an engine misfire. It could be that you have...

Q: Check engine light flashing, sucking fuel, procrastinating when accelerating...

This is a very odd set of symptoms. I would suggest ruling out any fuel-related issues as the poor fuel economy and lack of power could be related to faulty sensors like the throttle body sensor, mass air flow sensor,...

Q: not starting filling tank

Hi! The symptoms you are describing for your 2013 Ford E-250 sound like that of a vacuum leak leaking intake manifold gasket. I suggest that you have the intake manifold tested with the smoke machine. Doing so will test your...