P2048 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 P2048 code

P2048 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 P2048 DIAGNOSTIC Get a fair and transparent estimate upfront

P2048 code definition

The P2048 code is a generic powertrain code related to the exhaust system. In this case, it means that the reductant injector circuit located on bank 1 unit 1 of the exhaust has a low circuit.

Codes related to the P2048 include:

What the P2048 code means

A code P2048 will be stored when the engine control module (ECM) finds a fault or malfunction in the reductant injector air pressure sensor circuit. In order to reduce noxious gases expelled from the diesel particulate filter (DPF) in a diesel engine or catalytic converter in a gasoline engine, the reductant injector is used. The bank of the engine that contains the number one cylinder is bank 1, and unit 1 is the pre-diesel particulate filter or upstream catalytic converter sensor.

Most often used on a diesel vehicle, reductant injection systems can be found on all types of vehicle exhaust systems. They utilize water, a chemical agent, or a combination of all three items in order to reduce exhaust emissions through reducing temperature and/or pressure in the DPF or catalytic converter. If a vehicle’s ECM notes an exhaust temperature, pressure, and/or noxious gas concentration higher than allowed preset parameters, the reductant injector will be activated and the reductant compound is sprayed into the DPF or catalytic converter.

As a vehicle’s exhaust gas temperature goes up, the level of resistance in the sensor decreases, which allows a feedback voltage signal to the ECM to also go up. With the engine off, as the exhaust temperature goes back down, circuit resistance increases and the feedback voltage signal to the PCM also goes down.The voltage variations are seen by the ECM as the exhaust gas temperature and it will adjust ignition timing or the air/fuel ratio to needed levels. If the downstream levels fail to display significant reduction, a code will be stored and a service engine soon lamp may be illuminated

What causes the P2048 code?

Several problems may cause a P2048 code including:

  • Damaged, corroded, loose, or defective electrical wiring and related terminals and connectors
  • Damaged or defective exhaust gas temperature sensor
  • Short to ground in exhaust gas temperature sensor
  • Exhaust leak upstream from exhaust gas temperature sensor

What are the symptoms of the P2048 code?

Symptoms of a P2048 code may include:

  • Check engine or warning light may illuminate
  • Vehicle may emit dark smoke when accelerating
  • May be no symptoms aside from a stored P2048 code

How does a mechanic diagnose the P2048 code?

A mechanic may use several methods to diagnose a P2048 trouble code, including:

  • Utilize an OBD-II scanner to check for a stored P2048 trouble code
  • Visually inspect all wiring and related electrical components for signs of wear, corrosion, or damage
  • Visually inspect the exhaust system for signs of leaks
  • Visually inspect the exhaust gas temperature/pressure sensors and circuitry
  • Disconnect exhaust gas temperature sensor connector and sensor
  • Check resistance of exhaust gas temperature/pressure sensor, which should read around 150 ohms
  • Perform a continuity test on sensor wire

Common mistakes when diagnosing the P2048 code

There are times that theoxygen sensor may be identified as the fault, and replaced in error. It is recommended to thoroughly diagnose and repair the exhaust gas temperature/pressure sensor when a code P2048 is stored.

How serious is the P2048 code?

Because a vehicle’s safe and driving operation most likely will be impacted and excessive emissions can be released due to faults that store a P2048 code, this code is considered a potentially serious code. When this code appears, it is recommended to immediately take your vehicle to your local service center or mechanic for repair and diagnosis.

What repairs can fix the P2048 code?

Several repairs can fix a P2048 trouble code and include:

A P2048 code may be stored due to the installation of an aftermarket exhaust system that is causing backpressure on the system. It is recommended to check local, state, and federal laws before updating your vehicle’s exhaust system with aftermarket materials.

Need help with a P2048 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.

trouble codes
P2048
OBD-II

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2048 code.

SCHEDULE P2048 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

5,064

Rating Summary
4,665
194
48
27
130
4,665
194
48
27
130

Mario

8 years of experience
22 reviews
Mario
8 years of experience
Chrysler PT Cruiser - Check Engine Light is on - Los Angeles, California
He was very courteous and knowledgeable. You can tell he knows his trade. Satisfied with his service.

Yoel

8 years of experience
91 reviews
Yoel
8 years of experience
Nissan Versa Note - Check Engine Light is on - Upper Darby, Pennsylvania
Yoel is very competent and provides great customer service. He took the time to explain and show me exactly what was going with my car. I will definitely use him again and recommend him to others.

Jason

31 years of experience
148 reviews
Jason
31 years of experience
Ford Explorer - Check Engine Light is on - Phoenix, Arizona
Jason was on time, friendly, explained everything he was doing and let me know the other services available, so when Jason comes back to install the new part I am having the oil changed too.

DeVaughn

25 years of experience
1 reviews
DeVaughn
25 years of experience
BMW X3 - Check Engine Light is on - Moreno Valley, California
The mechanic arrived on time, completed the work, which was replacement of an oxygen sensor, in a timely and professional manner.


More related articles

P2295 OBD-II Trouble Code: Fuel Pressure Regulator 2 Control Circuit Low
P2295 P2295 code definition Fuel pressure regulator 2 control circuit low What the P2295 code means This trouble code indicates that the powertrain control module has detected a low reference voltage from the fuel pressure regulator circuit. What are the...
P0377 OBD-II Trouble Code: Timing Reference High Resolution Signal B Too Few Pulses
Trouble code P0377 means the PCM has detected an irregularity in the high resolution timing reference signal, due to a faulty crankshaft or camshaft.
P0614 OBD-II Trouble Code: ECM / TCM Incompatible
P0614 code means there has been an error in compatibility between the car’s engine control module and TCM often due too corrosion, or bad PCM.

Related questions

Honda N WGN 660 5cc japanese frequent limp home mode

Hello, thanks for writing in about your Honda N WGN. A likely possibility related to the misfiring may be that the car's computer may have tried to recalibrate the fuel supply as a result of the faulty throttle control relay...

engine wont restart when hot, no spark P0340 has 12v on both connectors, freq from 5-11hz when cranking

Since the crank position sensor gets its timing signal off the damper, I would first replace the damper to be sure timing was correct. The fact that this failure occurs after a "heat soak" cycle, and the P0340 code is...

Random misfire cylinder 123

I'm curious as to what codes are still active. Is it still a misfire code? Several other component failures can cause "misfire" issues - a clogged exhaust gas recirculation valve, a failed diverter valve, even a failed cam phaser. But...

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