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

5,010

Rating Summary
4,615
191
48
28
128
4,615
191
48
28
128

Kenneth

19 years of experience
509 reviews
Kenneth
19 years of experience
Toyota Sequoia - Check Engine Light is on - Newport Beach, California
Kenneth did a great job and very knowledgeable. He has a great attitude and I will for sure be using him again.

Richard

11 years of experience
45 reviews
Richard
11 years of experience
Honda Civic - Check Engine Light is on - Tucson, Arizona
Had damage to wires leading to a coil and was unable to drive the car to a service center so I took a chance on having somebody come out to work on the car. It couldn't of worked out any better. Would definitely recommend Richard to anybody needing car service.

Clifton

29 years of experience
207 reviews
Clifton
29 years of experience
Dodge Ram 1500 - Check Engine Light is on - Lake Worth, Florida
Clifton was on time and very professional. I will definitely recommend him to my friends and family.

Walter

45 years of experience
85 reviews
Walter
45 years of experience
Nissan Sentra - Check Engine Light is on - Tulsa, Oklahoma
Very helpful and knowledgeable. Appreciate the friendliness on top of it, would definitely recommend.


More related articles

P2250 OBD-II Trouble Code: O2 Sensor Ref Voltage Circuit High Bank 2 Sensor 1
P2250 means an issue with the upstream oxygen sensor voltage circuit in bank 2 due to a faulty sensor, fuel pressure, or engine or exhaust leaks.
P0178 OBD-II Trouble Code: Fuel Composition Sensor Circuit Low Input
P0178 P0178 code definition Fuel Composition Sensor Circuit Low Input What the P0178 code means P0178 is a generic OBD-II code indicating that the diesel fuel sensor is giving a low input, which could be from an open circuit in...
P2227 OBD-II Trouble Code: Barometric Pressure Circuit Range/Performance
P2227 trouble code definition Either the barometric pressure sensor is providing a reading that does not correspond to the parameters of the...

Related questions

I need help.

IIt looks like you have trouble codes from an import vehicle like an Audi or Mercedes Benz. I cannot decipher these codes without more information like the year make and model of the vehicle. Consider hiring an experienced technician like...

My car has trouble code P0745, do I need to replace the solenoid?

Diagnostic Trouble Code P0745 refers to out of range voltage at a solenoid-operated valve that regulates hydraulic pressure in the transmission based on outputs from the Transmission Control Module (TCM). Code P0745 is set when the TCM sees an out...

I just replaced my brake master cylinder and the brakes still feel soft. What do I need to do after I replace the master cylinder

From what you've described you will have to bleed your brakes. Also, I believe you may have a leak in one of the lines. You may want to use a wrench and tighten the lines a little more. If you're...

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.

1-800-701-6230 · hi@yourmechanic.com