What is Freightliner code EEC 61?

When you’re behind the wheel of a Freightliner, seeing the error code EEC 61 is never a good mark.

Driving a truck over long distances requires a lot of work and hours. There is little room for error and little room for profit. For instance, a Freightliner code EEC 61 is an issue that necessitates immediate attention.

EEC 61 code on Freightliner truck on the road


What is the EEC 61 code on Freightliner?

The EEC 61 code represents an error on Freightliner that indicates an after-treatment regulator unit problem. Usually, the code indicates an electrical failure of the injector or a bad solenoid on the injector, but your mechanic should first check and fix the terminal crimp.

The engine utilizes this module as part of the after-treatment system. It will appear that your Check Locomotive light and your Repair light are on at a similar phase. The upkeep warning light seems like a yellow engine and should always be on. A fuel gauge indicator comprised of four green-sided figures indicates that the level of your DEF (Diesel Exhaust Fluid) tank is at its maximum capacity.


If your DEF tank is less than half full, an EEC61 error message will be displayed, but you should strive to keep it at least half full at all times. After a few minutes of driving, the indicator light should turn off after three key presses.

If you don’t put gas in it, the engine will slow down to 25 percent of its average speed; if you keep driving, it will slow down to five miles/ hour. This is only a scrap of information, and I hope the resolution isn’t too bad.

The DEF system will run a purge routine to clear the lines whenever the truck is turned off, and if it doesn’t detect any air stress, it will also set this.

Pulling it off is possible, provided you don’t run into the DEF problem I mentioned earlier. If you carry on to experience the issue, I recommend taking it to your neighborhood retailer. The consumer can determine with relative ease which possible causes are most likely to be at fault. After attempting to move my tandems for several minutes, a low air pressure note most likely rang in my ears; however, I got the leading light, so I’m going with DEF 3/4.

If there is a problem with the low air pressure, will the light go out after three keystrokes? In any event, I am incredibly grateful to you for your assistance.

Of course, the best way to avoid the need for repairs is to take preventative measures. If you have a reasonable maintenance schedule, you can spot complications before they become serious, which will help you avoid breakdowns. The owner’s manual that came with your vehicle provides information on how to perform routine maintenance on your vehicle and identify potential issues.

How to do a proper Freightliner inspection?

Before beginning any journey of significant length, you must perform the following inspections:

  • Make sure you check the amount of oil in your vehicle.
  • It is essential to check both the radiator and the overflow bottle. Always be on the lookout for the possibility of a leak!
  • If you have been parked the truck for a few days, you should inspect the fuel vent;
  • Please make sure the tires have the proper amount of air pressure in them, and
  • Checking the brakes regularly for signs of wear and tear, such as vibrations or squealing sounds, is essential to ensure they are in good working order.

Performing routine maintenance on a vehicle more frequently increases as the vehicle ages. Suppose the FMCSA begins to issue fines for violations of the Compliance, Safety, and Accountability (CSA) Act. In that case, this is a symbol that you should increase the frequency of vehicle maintenance checks.


Robert Aksamit

Robert Aksamit

Robert Aksamit is a mechanical engineer and automotive industry expert. Robert was born in Minnesota and worked in the US automotive industry for 25 years. He is highly regarded for his passion and dedication to continually improving vehicles in response to customer feedback. Robert has a keen eye for sourcing the best vehicle components and materials on the market and is always looking for ways to enhance the user experience. As a writer, Robert covers automotive-related topics. Read more on Robert Aksamit's about page. Contact Robert: robert@promtengine.com

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