P2055 OBD-II Trouble Code: Reductant Injector Circuit High Bank 1 Unit 2

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

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2055 code

P2055 is a diagnostic trouble code (DTC) for "Reductant Injector Circuit High Bank 1 Unit 2". 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 for $114.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.0 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 $114.99 $20.0
Toyota $114.99 $20.0
BMW $124.99 $20.0
SCHEDULE P2055 DIAGNOSTIC Get a fair and transparent estimate upfront

P2055 code definition

When the Powertrain Control Module (PCM) detects a variation in the voltage coming from the reductant injector air pressure sensor circuit, a P2055 trouble code is stored. Used most often in diesel engines, the reductant injector air pressure sensor circuit is also found in gasoline and turbocharged engines. A reductant injector system helps cool the exhaust, making it easier for the catalytic converter to reduce the emissions commonly found in the vehicle exhaust. Some other related codes include P2047, P2048, P2049, P2050, P2051, P2052, P2053, P2054, P2056, P2057, and P2058.

What the P2055 code means

A P0255 trouble code means that the reductant injector air pressure sensor has detected a malfunction. This, in turn, causes a code storage on the PCM and the Check Engine Light to come on. Bank 1 is the bank that contains the number one cylinder in the engine, while unit 2 is one of two things – the post diesel particulate filter, also known as the catalytic converter, and the downstream sensor. Keep in mind that multiple drive cycles might be required in some model of vehicles before the Check Engine Light is lit, though a P0255 trouble code is stored upon the initial incident.

What causes the P2055 code?

A P0255 trouble code is most often caused by loose or damaged wiring or connectors. Some other causes include a faulty sensor, a decrease in back pressure, a severe upstream exhaust leak, and the exhaust gas temperature sensor being shorted, either internally or to the ground.

What are the symptoms of the P2055 code?

The only visible sign of a P0255 trouble code is excessive black smoke emanating from the vehicle's tailpipe upon acceleration.

How does a mechanic diagnose the P2055 code?

Diagnosing a P0255 trouble code requires a mechanic to use an infrared thermometer with a laser pointer, a digital volt/ohmmeter, and an OBD-II scanner or code reader. In addition to the proper tools, a mechanic should perform the following steps when diagnosing this code:

  • Inspect all wiring and connectors for looseness and damage. This includes burnt, corroded, or otherwise damaged wiring and connectors.

  • Download any freeze frame data or stored codes by connecting the OBD-II scanner to the diagnostic connector.

  • Visually examine the exhaust gas temperature/pressure sensor and any associated circuitry.

  • Check the resistance of the exhaust gas temperature/pressure sensor using a digital volt/ohmmeter.

  • If the resistance of the exhaust gas temperature/pressure sensor checks out, leave the volt/ohmmeter attached and heat the sensor with a heat gun, observing the resistance level of the sensor as the temperature increases, making sure it decreases smoothly.

  • Use the volt/ohmmeter to check the PCM for continuity.

  • Clear the code and test the system to see if the code returns.

Common mistakes when diagnosing the P2055 code

A common mistake made by a mechanic diagnosing a P0255 trouble code is to mistake the oxygen sensor for the exhaust gas temperature sensor. Also, another misdiagnosis is for the mechanic to mistakenly think the oxygen sensor is somehow integrated into the exhaust gas temperature sensor, so they replace the oxygen sensor. Replacement of the oxygen sensor will not fix the problem in both of these cases, and the a mechanic can expect the code to return.

How serious is the P2055 code?

A fault with the exhaust gas temperature/pressure sensor within the reluctant injection system can lead to higher vehicle emissions.

What repairs can fix the P2055 code?

Repairing a P0255 trouble code can be a multistep process and often requires the mechanic to perform the following:

  • Repair any damaged wiring, connectors, or components.

  • Replace the exhaust gas temperature/pressure sensor if found to be at fault.

  • Replace and reprogram the PCM if faulty.

  • As a last resort, the mechanic can also install an inline resistor, of at least 2.5 ohms between the signal and ground wires of the PCM, and leaving the exhaust gas temperature sensor disconnected.

Additional comments for consideration regarding the P2055 code

Before removing any parts related to a vehicle's emission system, the mechanic should check local, state, and federal laws to make sure they stay within compliance.

Need help with a P2055 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.

Check Engine Light
trouble codes
P2055

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2055 code.

SCHEDULE P2055 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(7400)

Rating Summary
6879
249
58
41
173
6879
249
58
41
173
 at YourMechanic

David

13 years of experience
393 reviews
David
13 years of experience
Chevrolet Malibu L4-2.4L - Check Engine Light is on Inspection - Marietta, Georgia
He explained everything to me in detail on what I needed to know about my car. Definitely recommend him for getting the job done.
 at YourMechanic

Raymond

37 years of experience
402 reviews
Raymond
37 years of experience
Toyota Camry L4-2.2L - Check Engine Light is on - Las Vegas, Nevada
Raymond did a great job however I was charged for two hours labor and he was only here less than 45 minutes. should I expect this on future appointments with your mechanic ?
 at YourMechanic

Shane

17 years of experience
217 reviews
Shane
17 years of experience
Volkswagen EuroVan V6-2.8L - Check Engine Light is on Inspection - Austin, Texas
Arrived on time. Explained the issues he found and how he will fix it. I have parts on order and will schedule an appointment to have Shane install the parts when they arrive.
 at YourMechanic

Kanstantsin

19 years of experience
51 reviews
Kanstantsin
19 years of experience
Ford F-150 V8-4.6L - Check Engine Light is on Inspection - Littleton, Colorado
Kanstantsin arrived early. Was very courteous and professional. Will highly recommend to anyone. Thank you Kanstantsin.


More related articles

P0511 OBD-II Trouble Code: Idle Air Control Circuit
P0511 means that there exists an abnormal condition in the RPMs when the engine is idling due to faulty valves, electrical wiring, or a severe leak.
P0666 OBD-II Trouble Code: PCM/ECM/TCM Internal Temperature Sensor Circuit
P0666 means that a circuit failure has caused a potentially catastrophic overheating condition in a sensor due to defective or shorted control module.
P0819 OBD-II Trouble Code: Up and Down Shift Switch to Transmission Range Correlation
P0819 means there is an issue a voltage or resistance problem with the transmission's up- and down- shift switch, likely due to a manufacturer fault.

Related questions

Car makes sputtering noise
If your car is making grinding noise, and will not turn on then that is a sign that serious engine damage may have occurred. I would recommend having a professional technician, such as one from YourMechanic, listen to the noise...
CEL transmission slipping
Hi there. You definitely appear to have a voltage issue with the vehicle. From what you are can be a bad connection at the battery (https://www.yourmechanic.com/services/battery-replacement), a failing alternator (https://www.yourmechanic.com/services/alternator-replacement), or most commonly a bad ignition switch (https://www.yourmechanic.com/services/ignition-switch-replacement). I usually...
my 2012 ford fusion today the wrench sysbol came on saying throttle control/transmission fault detected why?
Hello Mr. Donald, thank you for writing in. The wrench is another form of a check engine light. When the computer detects there is something wrong (as it is constantly running tests) it will set a "diagnostic troubleshooting code" that...

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