ECU 128 Code on Freightliner – Troubleshooting Tips!

ecu 128 code on freightliner

Car makers have added several means to communicate and alert the driver about any issues with a particular component or system as well as be able to find them in order to improve the relationship between the vehicle as well as the person using it. Consequently, what does “ECU 128 Code on Freightliner” mean?

On occasion, we are taken aback by a control panel warning light blinking suddenly. You will receive a quick explanation of what it implies, typical causes, and possible solutions in this post. Learn how to stop it and change the code as well.

What is ECU 128 Code on Freightliner and What does It Indicate?

The electronic control unit (ECU) 128 on the Mercedes-Benz Freightliner Sprinter powertrain is where your trouble code will be located.

Your van’s ECU is its electronic “black box,” therefore whatever is going on there. 128 only directs you to component 128 and says nothing about the underlying problem.

This system’s main job is to ensure that the power unit is operating properly by compiling all the sensor-gathered data, converting it into electricity, and sharing it with the computerized control unit, which then processes and relays the data to the engine’s various motors.

The control unit notifies the user that there is a problem with the engine if it doesn’t get any data from the instruments that keep track of the conditions under which it operates. You may be able to spot the error by paying attention to specific signs.

  • If the module is failing, you can experience engine malfunctions like lagging or spiking.
  • If either too little or too much gasoline is being consumed by your engine.
  • The engine can be stuttering and idling harshly as it seeks to gain speed.
  • You aren’t going to able to turn on your automobile if the ECM is entirely dead.

What are the Common Causes of ECU 128 Code on Freightliner?

On Freightliner vehicles, the trouble code for ECU 128 typically denotes an engine issue. When the vehicle’s engine controls notice a problem or fault with the engine, ECU code 128 could show up on the screen.

Freightliner truck ECU 128 error code reasons might involve a number of things.

Fault with the Oil Level Sensor

An error code of 128 may be generated by the engine control system if the oil pressure sensor is malfunctioning.

Fault with the Engine Coolant Temperature Sensor

The engine’s controls could generate ECU error number 128 if the motor’s coolant sensor for temperature is broken.

Malfunction of the Accelerator Position Detector

ECU signal 128 may be generated by the engine control unit if the sensor that detects the throttle position isn’t working properly.

Faulty Air Pressure Monitor

Your vehicle could show up ECU code 128 if its air detecting pressure is faulty.

Faulty Fuel Injection Device

Error code 128 may be generated by the engine management system if the injector system for fuel isn’t working properly.

An Issue with the Engine’s Electrical Control System

Engine management system error code ECU 128 may be generated if the engine’s computerized control unit is broken.

It is advised that you get in touch with a Freightliner Certified Service Station to evaluate and resolve any issues with an ECU 128 signal on a Freightliner vehicle.

How to Troubleshoot ECU 128 Code on Freightliner?

You might not always need to pay close attention to this code if it just seldom appears. Keep in mind this diagnostic code is a general indication or sign directing to the ECM, wherever the real and correct diagnostic will be found.

It can occasionally happen that certain detectors can be activated while driving via one means or another, and when these are, the ECU128 signal can then show.

You might not have to address the problem immediately away if that’s the situation. You won’t likely discover anything amiss, and if you’re taking the vehicle to a repair or dealership, they’re likewise unlikely to detect anything amiss.

But if an error message keeps coming up, you must investigate it since it can indicate a severe problem with the car.

How to Prevent ECU 128 Code on Freightliner?

You may perform a few steps to lessen the impact on your vehicle and its load if the Freightliner is impacted through the ECU 128 Code.

  • First, confirm that you have the most recent firmware installed.
  • Keep an eye out for warning signs that could be flashing on the vehicle, second. Please don’t be afraid to ask a dealer for help if you notice serious issues.
  • Finally, constantly pay attention to your fuel efficiency. It could be time to get your truck in for service if you notice noticeable drops in efficiency or fuel economy.

In the event that a fault code appears, follow these three steps.

  • Finding out if the fault number that is visible on the instrument panel is active or dormant is the initial step.
  • The next step is to identify the circumstances that led to the occurrence of that active or inert fault number.
  • Having all the right details about the problem code is the third and last stage.

You may fix the error codes accurately the first time by using the proper strategy.

How does ECU 128 Code Affect the Performance of the Freightliner?

In terms of the engine’s efficiency, the ECM is essential. Any flaws with it might have a significant impact on how the automobile operates as a whole.

Engine difficulties are a sign that the ECM may be malfunctioning. Performance can decline if the ECM is malfunctioning since it may alter the motor’s timings and fuel ratios. The vehicle might encounter a decrease in power, velocity, or fuel economy due to a malfunctioning ECM.

An erroneous control unit could be the cause of failing, crashing, or additional performance problems with your engine. The automobile’s fuel economy, power, plus speed might all drastically vary since the ECM is in charge of carrying out modifications to the engine’s configuration.

Onboard diagnostic scanners are frequently used by technicians and auto enthusiasts to find out performance problems with vehicles. The scanner gathers data and controls your car’s operation to warn you of any issues.

How to Reset ECU 128 Code on Freightliner

How to Reset ECU 128 Code on Freightliner?

A complete reset is an easy means of doing this. This calls for disconnecting your car’s battery connections for a minimum of 30 minutes. Reconnect your battery connections, and the issue code should be resolved.

  1. Determine the location of the “ECU Diagnostic” circuit box.
  2. All extra electrical equipment, including the battery cable, should be disconnected.
  3. Every electrical device should be turned off.
  4. The tip of a jumper wire must be attached to the ECU, while the other end must be tied to a reliable, neutral place.
  5. Watch all of the results displayed on the ECU testing screen as soon as your engine is running and let it inactive for no less than five minutes before proceeding.
  6. Take off the cover that protects the wiring connections of the ECU Diagnostic cords.
  7. While concurrently looking for any rules that could have been reset previously, carefully pull out every connector’s cable clip to unplug it one at a time.
  8. After all, codes are successfully eliminated, reconnect every link and restart the vehicle before moving on to the following step.
  9. Replace the safety device.

What is the Cost of Fixing ECU 128 Code on Freightliner?

The brand and model of your car will have a significant impact on the price of a motor control module upgrade. The more a car costs, the more complicated and advanced in technology it is. ECUs for premium automobile brands will be substantially more expensive than those for an average economic car.

Between $400 to $1,400 generally is what you should budget for parts, while between $100 and $200 is what you should budget for labor for setup plus coding. The typical economy-car owner will wind up shelling out almost one thousand dollars for substitute work.

A reconditioned ECU could allow you to make some savings, but there is typically some risk involved. In rare cases, if the combustion control module dies early, a current warranty on the car may cover this cost.

You could occasionally experience an issue with the combustion control unit that is easily fixable. You will undoubtedly avoid the high cost by doing this.

What are the Safety Implications of Driving with ECU 128 Code on Freightliner?

Your vehicle may need some costly repairs if you ignore the ECU 128 error code. The demise of a vehicle entirely might be far worse. As was already indicated, ECU 128 signals a fault with the engine. Therefore, failing to address that issue will certainly cause engine damage.

However, there are some restrictions that one should be aware of. It may not be a significant issue that needs immediate attention if your Freightliner sporadically displays the ECU 128 code. But if you’re consistently or regularly getting the ECU code, it’s essential to act right away. Your car is experiencing some serious problems.


This tutorial will assist you should you require assistance deciphering the ECU 128 signal seen on Freightliner vehicles. It is advised to visit the designated repair facility as soon as this warning appears so that skilled professionals may assist you and help you receive the entire fault code.

Watch this one,

Video Credits – Goldmouthtruckin 870

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