P2051 OBD-II Trouble Code: Reductant Injector Circuit Low Bank 1 Unit 1

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

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2051 code

P2051 is a diagnostic trouble code (DTC) for "Reductant Injector Circuit Low Bank 1 Unit 1". 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 diagnostic. 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.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P2051 DIAGNOSTIC Get a fair and transparent estimate upfront

P2051 code definition

Reductant injector circuit low bank 1 unit 1

What the P2051 code means

This trouble code indicates that the powertrain control module has noticed a malfunction with the reductant injector air circuit.

What are the causes of the P2051 code?

Some potential causes of this trouble code would include:

  • Damaged wiring connectors that are in the injector air circuit could be damaged.
  • The injector air sensor could be damaged.
  • The powertrain control module could be malfunctioning
  • An exhaust system could have been installed that does not meet the manufacturer’s requirements.
  • A large exhaust leak may exist.

What are the symptoms of the P2051 code?

The symptoms that the driver with this trouble code may experience would be occasional black smoke coming from the tailpipe and the Check Engine Light being illuminated.

How does a mechanic diagnose the P2051 code?

A visual inspection of the exhaust system to check the injector air sensor and its wiring would be a wise place for a mechanic to start. If the issue is not found, the mechanic would then ensure that the vehicle has the correct exhaust system and that no leaks exist.

Once this has been confirmed, if the problem still exists, the powertrain control module would be tested using the manufacturer’s recommended procedure. Any malfunctioning parts that were found during this inspection would be noted and relayed to the customer to make a repair decision.

Common mistakes when diagnosing the P2051 code

A common mistake that could be made during the diagnosis of this issue would be to replace parts without properly testing them. This mistake can apply to any Check Engine Light diagnosis. Most manufacturers offer a diagnostic procedure for all Check Engine Light codes, so it is important to follow these procedures.

How serious is the P2051 code?

Considering that this trouble code does not cause any drivability issues, I would consider this to be low on the seriousness scale. Though, it would be unpleasant to have people behind you getting angry all the time due to the excess emissions from your car. Just like with any Check Engine Light, it is best to resolve the problem as soon as possible.

What repairs can fix the P2051 code?

Repairs that can fix this trouble code would include:

  • Repairing or replacing wiring that is in the exhaust temperature/pressure circuit

  • Replacing the exhaust temperature/pressure sensor

  • Replacing an aftermarket exhaust system with an exhaust system that meets the manufacturer’s specifications

  • Repairing a large exhaust leak upstream of the exhaust temperature/pressure sensor

  • Replacing the powertrain control module

Additional comments regarding the P2051 code

When this trouble code is stored on your vehicle, be sure to run the engine in well ventilated areas as much as possible due to the excess gasses that come out of the tailpipe and pollute the air.

Need help with a P2051 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

P2051
trouble codes
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2051 code.

SCHEDULE P2051 DIAGNOSTIC
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

5,583

Rating Summary
5,159
204
50
34
136
5,159
204
50
34
136

Matt

16 years of experience
35 reviews
Matt
16 years of experience
Jeep Compass - Check Engine Light is on Inspection - Holly Springs, North Carolina
Matt was awesome! Very knowledgeable, thorough. Really knows his stuff. Best part was his level of interaction and being able to ask him questions directly. You just don’t get that at the shops. Will definitely be using this service again and requesting Matt for all future jobs. Thanks again, Matt!

Matthew

32 years of experience
828 reviews
Matthew
32 years of experience
Land Rover LR2 - Check Engine Light is on - Hampton, Virginia
Matt is my go-to mechanic. Always professional and explains in detail what the problem is and how it’s being fixed. Highly recommend.

Richard

16 years of experience
115 reviews
Richard
16 years of experience
Honda Accord - Check Engine Light is on - San Ramon, California
Richard is Polite and skilled in inspecting the issues. I do recommend him for doing diagnostics before giving your car to the garage.

Michael

15 years of experience
565 reviews
Michael
15 years of experience
Chevrolet Avalanche 1500 - Check Engine Light is on - Marietta, Georgia
What professional handled himself well understood what was wrong with the car corrected it immediately and was on time


More related articles

P0440 OBD-II Trouble Code: Evaporative Emission Control System Malfunction
P0440 P0440 code definition Evaporative Emission Control System Malfunction What the P0440 code means P0440 is an OBD-II generic code that the engine control module (ECM) has detected a leak in the fuel tank vapor system or a vapor pressure...
P3449 OBD-II Trouble Code: Cylinder l7 Deactivation/Intake Valve Control Circuit/Open
P3449 means there is an issue with the Engine Control Module via the intake valve due to low oil pressure, or faulty solenoid.
P2510 OBD-II Trouble Code: ECM/PCM Power Relay Sense Circuit Range/Performance
P2510 P2510 trouble code definition ECM/PCM Power Relay Sense Circuit Range/Performance What the P2510 code means P2510 is an OBD-II generic code for the engine control module detecting the ignition relay is open or shorted causing the relay to not...

Related questions

Check engine light not working.

If the check engine light is not coming on, then that is a good sign. If your dashboard before displayed the check engine light before and now it is not coming on, then the dashboard warning light could have burned...

Loud knocking noise and engine is shaking.

Hi there. When passing a vehicle and turning off the overdrive at the same time with the pedal on the floor will be like trying to shift a vehicle without the clutch in a manual transmission driven vehicle. The rpm's...

Stalls when turning or at a stop

Hi there. The first step is to check for any problem codes stored by engine management. This can save a lot of time money when diagnosing drive-ability problems. Most auto parts stores will do this for free. Several problems could...

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