How to Activate Mercedes Benz Daytime Running Lights (DRL)

Daytime Running Lights (DRL) serve a crucial role in enhancing road safety. Their primary function is to make vehicles more visible to oncoming traffic, reducing the risk of collisions—especially in low-light conditions such as tunnels, shaded roads, or overcast weather.

Most Mercedes-Benz models manufactured after 2010 come equipped with LED DRLs, which automatically turn on when the engine starts. These include:

• Mercedes-Benz C-Class (W204, S204, C204 Facelift Coupe)
• Mercedes-Benz E-Class (W212, S212, A207, C207)
• Mercedes-Benz S-Class (W221 Facelift)

While DRLs should activate automatically, some vehicles may experience deactivation due to module errors, faulty LED control units, or incorrect software settings. If your DRLs are not functioning correctly, you can manually activate them using Vediamo (for pre-2017 models) or DTS Monaco (for post-2017 models).

Required Tools for Activating Mercedes-Benz DRLs

Before starting the activation process, ensure you have the following tools:

✔ MB STAR C4 or C6 diagnostic tool – Required to connect to the vehicle’s ECU for coding and programming.
✔ Laptop with Vediamo or DTS Monaco installed – Software needed for variant coding.✔ OBD-II connection cable – To connect the diagnostic tool to your Mercedes-Benz.
✔ Stable power supply – To prevent any system interruptions during the coding process.

Please Note:

• Vediamo Software can be used for car models before 2017
• DTS Monaco can be used for car models after 2017

Once you have these tools ready, you can proceed with the activation process.

Signs of Mercedes-Benz DRL Malfunction

If your DRLs are not working as expected, you may notice the following symptoms:

✅ DRLs not turning on when the vehicle is started.
✅ Flickering or intermittent operation of LED DRLs.
✅ DRLs randomly turning on and off while driving.

These issues can be caused by:
🔹 Burned-out bulbs – Requires simple replacement.
🔹 Faulty LED control module – Needs coding or programming.
🔹 Software settings disabled – Requires reactivation using diagnostic software.

How to Activate Mercedes-Benz DRL Using Vediamo (Models Before 2017)

Vediamo is a Mercedes-Benz engineering software used for variant coding and control unit configuration. If your DRLs are deactivated, follow these steps to reactivate them:

Tools Required:

• MB STAR C4 or C6 diagnostic tool
• Vediamo software (installed on a PC or laptop)
• OBD-II connection cable

Activation Steps:

1️⃣ Connect the MB STAR C4/C6 to your Mercedes-Benz OBD-II port and link it to your computer.
2️⃣ Launch Vediamo software and access the ECU control panel.
3️⃣ Navigate to “Variant Coding” under the SAM (Signal Acquisition and Actuation Module) section.
4️⃣ Open “Services:06 Menu Activation” and locate “Lichtschaltung Tagfahrlicht” (Menu_daylight).
5️⃣ Change the setting to “vorhanden” (Available).
6️⃣ Save and exit the settings.

After completing these steps, restart the vehicle to check if the DRLs are now active.

How to Activate Mercedes-Benz DRL Using DTS Monaco (Models After 2017)

For newer Mercedes-Benz models (2017+), DTS Monaco is the preferred software for vehicle coding and programming.

Tools Required:

• MB STAR C4/C6 diagnostic tool
• DTS Monaco software (installed on a PC/laptop)
• OBD-II connection cable

Activation Steps:

1️⃣ Launch DTS Monaco and connect the vehicle using the MB STAR C4/C6 tool.
2️⃣ Select Variant Coding mode.
3️⃣ Choose the ECU: ‘SAMF172’ (Signal Acquisition and Actuation Module – Front).
4️⃣ Locate the Parameter Tagfahrlicht (Daytime Running Light Parameter) section.
5️⃣ Find the setting “PLSM_TFL_POS” and change the value to “ja” (Yes).
6️⃣ Click on “Code Change” and confirm the activation.

After coding is completed, restart the vehicle and check if the DRLs are now functioning correctly.

What If DRLs Are Still Not Working?

If your DRLs are still not activating after following these steps, consider the following:

🔹 Check if the LED control module is faulty – A damaged control module may require replacement.
🔹 Ensure correct coding settings – If the wrong variant is selected, the coding may not work.
🔹 Update ECU software – Some models may require a software update before activating DRLs.
🔹 Check for error codes in ISTA or Xentry – Any existing fault codes could be preventing activation.

Need Professional Assistance?

If you encounter any difficulties during the activation process, AutoExplain provides expert support for Mercedes-Benz DRL coding and programming.

✔️ Remote support available via TeamViewer & UltraViewer.
✔️ Expert coding & diagnostics for Mercedes-Benz, VAG, GM, Ford, Mazda, and BMW.
✔️ 24/7 assistance for DRL activation, ECU programming, and module repair.

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Conclusion

Activating your Mercedes-Benz Daytime Running Lights (DRL) improves road safety and ensures compliance with vehicle lighting regulations. Using Vediamo for older models and DTS Monaco for newer ones, you can efficiently enable DRLs on your vehicle.

For seamless DRL activation and expert diagnostic solutions, AutoExplain is here to help! 🚗💡

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