How to fix :scr error torque derate ?

Instructions for Fixing Errors SCR Error Torque Derate


The Selective Catalytic Reduction (SCR) system is an essential component of modern diesel engines. It helps to reduce harmful emissions by converting nitrogen oxides (NOx) into harmless nitrogen and water. However, if the SCR system encounters an error, it can cause a torque derate, which can affect the engine’s performance. In this article, we will discuss the instructions for fixing errors SCR error torque derate.

What is an SCR Error Torque Derate?

An SCR error torque derate is a condition where the engine’s power output is reduced due to an error in the SCR system. The engine control module (ECM) detects the error and reduces the engine’s torque output to prevent further damage. The torque derate can be caused by various factors, such as a faulty SCR system, a malfunctioning NOx sensor, or a clogged diesel particulate filter (DPF).

Common Symptoms of an SCR Error Torque Derate

The following are some common symptoms of an SCR error torque derate:

  • Reduced engine power
  • Engine warning light on
  • Reduced fuel efficiency
  • Increased exhaust emissions
  • Engine shutdown

Instructions for Fixing Errors SCR Error Torque Derate

If you encounter an SCR error torque derate, follow these instructions to fix the issue:

Step 1: Check for Error Codes

The first step is to check for error codes using a diagnostic tool. Connect the diagnostic tool to the OBD-II port and read the error codes. The error codes will provide information about the cause of the torque derate. Some common error codes related to the SCR system include P20EE, P207F, and P2201.

Read more :  How to fix :boost system error_code ?

Step 2: Inspect the SCR System

Once you have identified the error codes, inspect the SCR system for any visible damage or defects. Check the SCR catalyst, the NOx sensor, and the DEF injector for any signs of damage or corrosion. If you find any defects, replace the damaged components.

Step 3: Check the DEF Quality

The quality of the Diesel Exhaust Fluid (DEF) can also affect the performance of the SCR system. Check the DEF quality using a DEF refractometer. The DEF should have a concentration of 32.5% urea and 67.5% deionized water. If the DEF quality is low, replace the DEF with a fresh batch.

Step 4: Clean the DPF

A clogged Diesel Particulate Filter (DPF) can also cause an SCR error torque derate. Check the DPF for any signs of clogging. If the DPF is clogged, clean it using a DPF cleaning kit. Follow the instructions provided in the kit to clean the DPF.

Step 5: Reset the ECM

Once you have fixed the issues with the SCR system, reset the ECM to clear the error codes. Use the diagnostic tool to reset the ECM. After resetting the ECM, test drive the vehicle to ensure that the torque derate issue has been resolved.


An SCR error torque derate can affect the performance of your diesel engine. If you encounter this issue, follow the instructions provided in this article to fix the issue. Remember to always check the error codes, inspect the SCR system, check the DEF quality, clean the DPF, and reset the ECM. By following these instructions, you can ensure that your diesel engine runs smoothly and efficiently.

Read more :  how to fix sae j1850 pwm ?

You are looking : scr error torque derate

You can refer more 10 scr error torque derate below

1.Scr error, Torque derate in 25% on an international. Just – JustAnswer

  • Descriptions: More than likely it is an issue with the QLS sensor. This is the sensor that monitors the def quality and will put the unit into derate.
  • Website :

2.What does SCR system fault mean in a truck? – JustAnswer

  • Descriptions: SCR means Selective Cataylst Reduction. This is the system that injects DEF fluid in the exhaust to reduce emissions.
  • Website :


  • Descriptions: HI guys. This is an International 2020 – commins engine – getting these errors : 1. REFILL DEF TORQUE DERATE 2. SCR ERROR – TORQUE DERATE
  • Website :

4.High Performance Diesel Engines – Movin Out Magazine

  • Descriptions: When a EGR or SCR system fault, that is not a UQS or non-circuit error SCR system fault, only torque derate 1 will be enforced. A circuit error such as a …
  • Website :

5.How To Get Out Of 8 KPH Derate Mode SCR System Fault, Mack …

  • Descriptions:
  • Website :

6.International LT derate – YouTube

  • Descriptions:
  • Website :

7.How I fixed my SCR Low Performance problem – YouTube

  • Descriptions:
  • Website :

9.SCR system fault : r/Truckers – Reddit

  • Descriptions:
  • Website :

10.DEF quality derate 25% error – School Bus Fleet Magazine Forums

  • Descriptions: Original DTC was poor DEF quality with engine derate. … If you can get an SCR code to come up check your engine serial number on …
  • Website :

With the above information sharing about scr error torque derate on official and highly reliable information sites will help you get more information.

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *