Automotive lighting is designed with various features to help drivers see the road better. Vehicles, like the Seat Leon 5F Pre-Facelift, are equipped with daytime running lights and side lights, which work together to highlight your vehicle in both daytime and nighttime driving conditions. 

However, for one reason or another, these advanced lighting components may fail, triggering a “Check Left Right Daytime Running Light/Side light!” warning message on your dashboard. In this guide, we’ll help you narrow down the reasons behind the warning message and the right solution, starting with a better understanding of your specific vehicle.

About The Seat Leon 5F Pre-Facelift 

The Seat Leon 5F Pre-Facelift (2012 - 2015) is a well-regarded VW Group hatchback that is based on the VW MQB platform. Renowned for its value and tech, the Seat Leon 5F pre-face comes in different types of headlights, including optional full-LED headlamps combined with a full beam assistant. 

This feature is available for the first time in its class and offers numerous advantages, like:

  • Improved illumination
  • Close to daylight colour temperature 
  • Lower energy consumption 
  • Extended service life

Combined with LED headlights, the lighting system also includes LED daytime running lights and side lights with distinct characteristics of their own. However, sometimes these components may stop working, leading to a warning error that appears on your dashboard. 

What Does “Check Left/Right Daytime Running Light/Side Light” Warning Message Mean?

When the warning message appears on the dashboard, it highlights that there’s a malfunction with your daytime running lights (DRL) and side lights. Depending on the faulty side, either the right or left DRLs or side lights may stop working altogether. 

Driving with malfunctioning DRLs or side lights in the UK is considered a huge safety risk and may result in fines for violating technical standards. You must resolve the problem immediately or contact roadside assistance, if needed.

Reason behind “Check Left/Right Daytime Running Light/Side Light” Warning Error 

The warning error on your dashboard directly points to a malfunctioning LED headlight control unit, which is responsible for controlling both daytime running lights and side lights. Replacing the faulty LED headlight control unit with a compatible one can help resolve the error and help eliminate other potential symptoms. 

Other potential reasons for warning error include: 

  • Has reached the end of their average lifespan 
  • External damages, like accidents 

However, in most cases, the reason behind the warning error lies in a faulty LED control module and can lead to symptoms

Potential Symptoms You May See 

When the warning message “Check Left/Right Daytime Running Light/Side Light” comes on your Seat Leon 5F Pre-Facelift, you may notice the following symptoms: 

  • The affected DRL or side light will not work. 
  • Warning messages related to the DRL/side light: 
    • “Check left day. running light/side light!”
    • “Check right day. running light/side light!”
  • Additionally, it could trigger malfunctions for other lights controlled by the same module, such as:
    • Check front-left turn signal
    • Check front-right turn signal
    • Check left headlight
    • Check right headlight
    • Headlight range control error

How To Resolve the Warning Error 

To remove the warning error from your dashboard, the first step is to determine which side is faulty. Start by visually inspecting both sides of the LED headlight module and swap components to check whether the warning error continues to appear. 

Once you have isolated the problem, you can then replace the faulty LED control unit with a new one, like 90028152 5F0941472 LED Steuergerat Module. Factory-fitted to Seat Leon 5F cars with Full LED headlamps, the module is responsible for controlling and powering up low and or high beam LED lights. The best part is that it requires no diagnostic coding, so you can perform the installation yourself. If you run into any problems during the installation, our car specialists are here to help.

Part Number & Compatibility List 

Our module is equipped to meet a broad range of vehicles: 

  • Valeo part numbers:
    • 90028152
  • VAG part numbers:
    • 5F0 941 472
    • 5F0941472
  • Other Valeo part numbers:
    • L90005488
    • L900382783
  • More compatible part numbers
    • 90046417
    • L90005488
    • L900382783
  • Compatible Seat Leon 5F MK3 Pre-Facelift LED headlights
    • 90029771 90112758 5F2941008A 5F2941008
    • 90112684 5F2941008D
    • 90112683 5F2941007D 
    • 90029788 5F1941007B 
    • 90029769 5DF941008B 
    • 90039008 5F2941007A 
    • 90029768 5F1941007B
    • 90029770 5F2941007 
  • Compatible cars: 
    • Seat Leon MK3 III 3 5F Pre-Facelift Hachback
    • 2012 2013 2014 2015 2016 2017
    • 1.2 1.4 1.8 TSI Cupra R
    • 1.5 2.0 EcoTSI Petrol Gasoline
    • 1.6L 1.6 2.0 2.0L TDI FR diesel
    • SE Technology
    • SEAT Toledo 6J 2013 - 
    • Ford Mondeo MK5 V

Please note: this list is not full; the LED module may fit other cars as well.