This guide outlines how to disable the “eyebrow” Parking Running Lights (PRLs) on a 2011 Audi A3 8P with factory LED daytime running lights (DRLs) using VCDS (Vag-Com Diagnostic System) and enable the fog lights as DRLs. The goal is to achieve this without triggering any error messages in the Driver Information System (DIS).
Understanding the Challenge
The Audi A3 8P, particularly those equipped with factory LED DRLs, presents a unique challenge when attempting to modify the DRL and PRL behavior. Common methods outlined in online resources often lead to fault codes related to the LED modules, as disabling the PRLs through conventional coding methods can disrupt the expected voltage readings. This article explores a solution to overcome this issue.
VCDS and the Audi A3 8P Central Electrics Module
The key to controlling the lighting functions lies within the Central Electrics module (Module 09) accessible via VCDS. This module manages various vehicle functions, including lighting. Accessing the Long Coding Helper within Module 09 allows for granular control over individual bits controlling specific lights.
Disabling the Eyebrow PRLs – A Cautious Approach
While directly disabling the PRLs via Byte 27, Bit 2 in Module 09’s Long Coding Helper seems like a straightforward solution, it often results in “Supply Voltage” fault codes (02895 and 02897) for the LED modules. This indicates a discrepancy between the expected and actual voltage readings due to the deactivated PRLs.
Alternative Solutions:
- Explore Alternative Coding Options: Consult the official Ross-Tech VCDS documentation and forums for potential alternative coding solutions specific to the Audi A3 8P with LED DRLs. Specific model year variations may have unique coding options.
- LED Resistors: Consider installing LED resistors to mimic the electrical load of the PRLs, potentially preventing the fault codes. This approach requires careful selection of appropriate resistor values to avoid damaging the lighting system. Consult a professional if you are unfamiliar with automotive electrical systems.
Enabling Fog Lights as DRLs
Enabling fog lights as DRLs on the Audi A3 8P is generally achievable through VCDS coding. Specific instructions can be found in the Ross-Tech Wiki for the A3 8P. This modification typically involves adjustments within Module 09. However, remember that local regulations regarding DRLs may restrict the use of fog lights for this purpose. Always ensure compliance with your local traffic laws.
Recommended Steps
- Backup Existing Coding: Before making any changes, always back up your existing coding in Module 09. This allows you to revert to the original settings if any issues arise.
- Consult Ross-Tech Resources: Refer to the official Ross-Tech Wiki and forums for the most up-to-date and accurate information regarding coding changes for the Audi A3 8P, specifically those with factory LED DRLs. Search for “Audi A3 8p Led Vcds” for relevant threads and documentation.
- Proceed with Caution: Understand that modifying vehicle coding can have unintended consequences. Proceed carefully and consult with experienced users or professionals if you are unsure.
- Test Thoroughly: After implementing any coding changes, thoroughly test the lighting system in various conditions to ensure proper functionality and the absence of fault codes.
Conclusion
Disabling the eyebrow PRLs on an Audi A3 8P with LED DRLs requires a cautious approach due to the potential for fault codes. While achieving the desired outcome might involve more advanced techniques beyond simple coding adjustments, leveraging the resources available from Ross-Tech and the VCDS community can provide valuable insights and guidance. Remember to prioritize a thorough understanding of the system and proceed with caution to avoid any unintended consequences. Always prioritize safety and compliance with local traffic regulations.
