Skip the auto shop - Our mechanics make house calls

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 to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...


Related questions

Q: Check engine light is flashing and reduces the power of the engine.

If the light is flashing then the computer system should have stored codes as to why the problem is happening. I recommend having the computer scanned by a certified technician, such as one from YourMechanic, to retrieve the codes and...

Q: My truck surges at low and idol speeds. Cold or hot. Sometimes quits when put in gear. Very low speed has a miss.

Hello and thank you for contacting YouMechanic. When you unplug the temperature sending unit the problem goes away but the engine light comes on. Check the plug to the sending unit for any corrosion or debris. Look at the pins...

Q: My problem is Check Engine Light on. Cruise control does not work, loses power on hills, as if it does not want to pull hill.

Hi there. From the description you have provided, there is several possibilities for your vehicle's drivability problems. Your vehicle's Check Engine Light may help diagnose the lack of power and inoperative cruise control. Accessing the vehicle's computer for codes stored,...