P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0291 code

P0291 is a diagnostic trouble code (DTC) for "Cylinder 11 Injector Circuit Low". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light is on diagnostic inspection. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

P0291 code definition

When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector – that doesn’t conform to the predetermined value referenced by the manufacturer.

What the P0291 code means

Inadvertent resistance can lead to voltage variations. If they go above 10% of the amount of voltage referenced by the manufacturer, a P0291 code will be stored and the Check Engine light will generally come on. This code specifically references the fuel injector for cylinder number 11.

During normal conditions, the PCM switches the fuel injectors in your vehicle on and off within the fuel injection system.

What causes the P0291 code?

Oddly enough, the number one cause for this code being stored is actually squirrels. These little critters and other wildlife often find a way up into your hood because they recognize that your engine is warm for a long time after it’s parked. Not content to simply rest and be warm, though, these animals may decide to chew through important wires that leave you with fuel injectors unable to operate as they should.

There are a few other reasons you should know about too:

  • A defective fuel injector
  • Loose electrical wiring
  • Corrosion on the electrical wiring
  • Damaged connector faces

Sometimes, the fuel injector in your vehicle’s PCM may actually be responsible, but this is incredibly rare.

What are the symptoms of the P0291 code?

When a fuel injector isn’t able to function correctly, your ride is going to suffer. This means that you should notice early on when the problem occurs. Your vehicle may all of a sudden have a really tough time accelerating. The [engine could actually misfire) because of just one fuel injector’s problem. Even when you’re sitting at idle, you might find that your vehicle – or at least the ignition – vibrates intermittently.

How does a mechanic diagnose the P0291 code?

First, your mechanic is going to use an OBDII scanner to get a reading on the codes your PCM has stored. For a P0279 issue, they’ll most likely also use an ohmmeter, noid lamp and the vehicle’s user’s manual to figure out how bad the problem is.

Once they confirm there’s an issue, your mechanic will most likely examine all of the associated wires and connectors. If necessary, they may go on to examine your fuses too. All the while, the system should be reset to see if the code comes back or is permanently cleared.

Common mistakes when diagnosing the P0291 code

It’s extremely important that all relevant electrical components get checked before moving onto other possible repairs. It’s usually just a matter of replacing one or two before P0291 clears for good. Unfortunately, if your mechanic doesn’t do this, they may end up blaming the problem on your PCM, which would be a huge, unnecessarily costly mistake.

How serious is the P0291 code?

While this isn’t the type of problem that will necessarily increase your likelihood of getting into an accident, a P0291 code does mean your vehicle is operating at subpar levels. Aside from how frustrating this can be, it might also mean you end up spending a lot more at the pump. Also, if you don’t fix the fuel injector, the problem could have a damaging ripple effect.

What repairs can fix the P0291 code?

Your mechanic will do some combination of the following to get you back on the road:

  • Replace the bad injector
  • Clean out the fuel injector
  • Replace or repair the fuel injector’s electrical connector

That last step is probably going to be all it takes. Electrical connectors can become corroded for all sorts of reasons or get loose and keep working correctly.

Additional comments for consideration regarding the P0291 code

Even if you don’t notice any serious ramifications from this code, get it fixed right away. As we mentioned earlier, fuel injection issues can quickly become much worse.

Need help with a P0291 code?

YourMechanic employs certified mobile mechanics who can drive to your home or place of work to diagnose and repair your vehicle. Receive a quote and book an appointment online or call 1-800-701-6230 to speak with a service advisor about how we can get your vehicle back to working and on the road.

p0291
trouble codes
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0291 code.

Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,736

Rating Summary
5,302
211
50
34
139
5,302
211
50
34
139

Nazareth

26 years of experience
168 reviews
Nazareth
26 years of experience
Mercedes-Benz CLA250 - Check Engine Light is on - Los Angeles, California
Polite and very professional! Nazareth quickly identified my car was suffering from low voltage issues and the battery was the problem. The reader was showing 8 volts hence why my car didn’t receive enough power to start, it needed 12v. My battery was 4 years old and never been changed. Thank you Nazareth!

Cornelius

17 years of experience
78 reviews
Cornelius
17 years of experience
Chevrolet Cobalt - Check Engine Light is on - Peachtree City, Georgia
He was very helpful with explaining what could lead to my check engine light being on. And helping clear my engine light.

Marco

28 years of experience
78 reviews
Marco
28 years of experience
Nissan Maxima - Check Engine Light is on - Highland, California
Marco did a great job of finding the source of the problem and his recommendations were greatly appreciated.

Juan

8 years of experience
128 reviews
Juan
8 years of experience
Chevrolet Tahoe - Check Engine Light is on - Altamonte Springs, Florida
Juan was on time for both appointments. He was knowledgeable and polite and I will most definitely be requesting him for my next steps based on the quote he provided me for other issues I need to address. Excellent customer service and top notch repair work!


More related articles

P0112 OBD-II Trouble Code: IAT Sensor Circuit Low Input Problem
P0112 P0112 code definition Intake Air Temperature (IAT) sensor circuit low input problem What the P0112 code means P0112 is the OBD-II generic code that the engine control module (ECM) has recorded the IAT sensor input below the expected sensor...
P0235 OBD-II Trouble Code: Turbocharger Boost Sensor A Circuit Malfunction
P0235 P0235 code definition Turbocharger Boost Sensor A Circuit Malfunction What the P0235 code means P0235 is an OBD-II generic code that is triggered when the Engine Control Module (ECM) detects intake boost pressure sensor A input malfunction when compared...
P2409 OBD-II Trouble Code: Fuel Cap Sensor/Switch Circuit Range/Performance
P2409 P2409 code definition Fuel Cap Sensor/Switch Circuit Range/Performance What the P2409 code means P2409 is an OBD-II generic code for the Engine Control module (ECM) detecting the fuel cap sensor, switch or circuit is out of range or performance...

Related questions

My car has a check engine light and gave codes P2195, P2251, P0170

Based on these fault codes, it sounds like you have an oxygen sensor that as failed and it will need to be replaced. The trouble codes will also have to be cleared after the sensor is replaced to see if...

I have a 2005 Kia Spectra after I feel it the gas is dropping kind of fast and my check engine lights is on what does that mean?

If your vehicle's check engine light illuminates, there is a malfunction that should be diagnosed and repaired. Malfunctions that cause the check engine warning light to illuminate are very varied as to "cause" (i.e., there are hundreds of possibilities) and...

oil pressure drops,replaced oil pump, ran for a 2 months, and again pressure drops after afew minutes.

Engine oil pressure may go lower after an engine gets warm. You should have the oil pressure checked with a gauge tester to verify the oil pressure is within specification. If it falls to below specification, then you should replace...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com