Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P0271 OBD-II Trouble Code: Cylinder 4 Injector Circuit High

P0271 OBD-II Trouble Code: Cylinder 4 Injector Circuit High

Check Engine Light

P0271 code definition

Cylinder 4 Injector Circuit High

What the P0271 code means

This diagnostic trouble code (DTC) indicates that a reference voltage from the fuel injector associated with cylinder number 4 has gone higher than the range of acceptance set by the vehicle manufacturer. The powertrain control module (PCM) realizes this and will store a trouble code.

What are the causes of the P0271 code?

  • The fuel injector associated with cylinder number 4 is restricted causing a pressure spike and therefore a higher reference voltage.

  • The wiring or connector associated with the fuel injector on the number 4 cylinder may be damaged in some way.

  • The powertrain control module could be malfunctioning.

What are the symptoms of the P0271 code?

How does a mechanic diagnose the P0271 code?

  • A mechanic may diagnose this trouble code by first checking the fuel injector on the number 4 cylinder for proper function using the manufacturer’s suggested procedure.

  • Next, the mechanic would ensure the integrity of the wiring and connector associated with the fuel injector on cylinder number 4.

If everything checks out during these two tests:

  • The mechanic may run a fuel system cleaning through the engine to try to break any restrictions that may exist down inside the fuel injector.

  • If all else fails, the likelihood of the powertrain control module being faulty is high and it would therefore be tested and replaced as necessary.

Common mistakes when diagnosing the P0271 code

An engine diagram is essential for diagnosing this issue due to the fact that it is easy to test the wrong fuel injector without it. Testing the wrong fuel injector would be a major mistake as it would certainly lead to a misdiagnosis and potentially hours of wasted time.

How serious is the P0271 code?

Any trouble code that can cause a misfire condition would be considered very serious and should be taken care of very soon. Misfires can cause damage to the engine and certain components of the exhaust system. Ensure that all repairs are done by a qualified professional as this repair relates to the fuel system.

What repairs can fix the P0271 code?

  • Repairing or replacing wiring or connectors that are associated with the fuel injector on the number 4 cylinder

  • Replacing the fuel injector that is associated with the number 4 cylinder

  • Running a fuel system cleaning through the engine to release any restriction

  • Replacing the powertrain control module

Additional comments regarding the P0271 code

Using quality fuel in your vehicle can help to prevent the restrictions that can build up inside the fuel injectors. Bad quality fuel can gunk up inside the fuel rail and cause multiple problems such as misfires and even a no start condition. Never use old or contaminated fuel in your vehicle.

Need help with a P0271 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 Vacuum Brake Booster Check Valve Last?
The braking system on your car requires a lot of pressure. The vacuum booster is one of the main sources of this pressure. This booster will take the pressure that...
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...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....


Related questions

Q: Car stalling at random, could be an electrical problem?

Generally, when the car is running consistently and on all cylinders, when stalling it is often times a fuel supply issue (or in some cases indirectly related to electrical - i.e. bad connection or pulse to the fuel injectors). I...

Q: Check Engine code for catalytic converter.

This can be because the catalytic converter is bad or the sensor is defective. A qualified mechanic would have to scan the vehicle and check for broken up or rattling converter signifying its coming apart inside.

Q: My car just shut off while driving nd wont start bsk up dosent even crank over nothing at all turns on

Without additional detail, this would be tough to diagnose, however the fact that it just shut down out of nowhere as you've described suggests that some kind of sensor or relay may have triggered this. I would suggest having an...