Will Clearing the Fault Code Reset the ECU?

As technology advances, modern vehicles are equipped with sophisticated systems and components that are controlled by the Engine Control Unit (ECU). The ECU constantly monitors various parameters and generates fault codes when it detects an issue. Many vehicle owners wonder if clearing these fault codes will reset the ECU. In this blog post, we will explore this topic in detail and provide insights into the process.

Understanding the ECU:
The ECU is essentially the brain of a vehicle, responsible for controlling the engine's performance, fuel efficiency, emissions, and various other functions. It collects data from sensors placed throughout the vehicle and uses this information to make adjustments and ensure optimal operation. When a fault is detected, the ECU generates a fault code, which can be retrieved using onboard diagnostic tools.

What happens when a fault code is cleared?
Clearing a fault code essentially means erasing the recorded error from the ECU's memory. However, this does not necessarily reset the ECU itself. The ECU will continue to monitor the system and re-generate the fault code if the underlying issue persists. Clearing the fault code is merely a temporary solution to remove the error message or warning light from the dashboard.

Resetting the ECU:
To truly reset the ECU, a more comprehensive process is required. This involves disconnecting the vehicle's battery for a certain period of time, typically around 15-30 minutes. By doing so, the ECU's memory is completely cleared, and it reverts to its default settings. However, it is important to note that this process may also reset other settings, such as radio presets or trip meters, so be prepared to reconfigure those after reconnecting the battery.

Potential benefits of resetting the ECU:
Resetting the ECU can be beneficial in certain situations. For example, if you have recently repaired a fault and want to ensure that the ECU recognizes the fix, resetting it can help. Additionally, it can also clear any adaptive learning data and allow the ECU to recalibrate itself based on the current condition of the vehicle.

The importance of diagnosing and fixing the underlying issue:
While clearing the fault code or resetting the ECU may temporarily alleviate the symptoms, it is crucial to diagnose and fix the underlying issue to ensure long-term reliability and performance. Ignoring the root cause can lead to recurring fault codes or even more severe problems down the line.


Clearing a fault code will not reset the ECU itself; it merely erases the recorded error from the ECU's memory. To truly reset the ECU, disconnecting the vehicle's battery for a certain period of time is necessary. However, it is important to understand that resetting the ECU is not a cure-all solution and should only be done after identifying and rectifying the underlying issue. If you are unsure about how to proceed, it is always recommended to consult a professional mechanic or use specialized diagnostic tools like Caterpillar ET3 Adapter III, ICOM BMW, John Deere Service Advisor EDL, Heavy Truck Scanner, or Mercedes Star Diagnostic Tool for accurate fault code reading and troubleshooting.