Troubleshooting headlight issues on a 2017 Audi A3 often involves using a VCDS (Vag-Com Diagnostic System) to diagnose fault codes and adjust settings. One common problem involves changing the indicator light pattern. This article discusses a specific case where the main beam headlights are not working and explores potential causes and solutions using VCDS.
Diagnosing the Issue with VCDS
A VCDS scan revealed “implausible” Diagnostic Trouble Codes (DTCs) in both Left and Right Control Modules (LCMs – addresses hexD7 and hexD6). These DTCs indicate that the LCMs don’t recognize the type of headlights installed. Additionally, an “Open Circuit” DTC was found in the right LCM, likely due to faulty wiring or a poor connection. The presence of similar implausible DTCs in both LCMs suggests an external cause rather than an issue within the modules themselves.
Potential Causes and Solutions
One possibility is that recently retrofitted headlights are incompatible with the car’s system. The incorrect coding of a related module (hex55 – range control module) could also be contributing to the problem.
To further diagnose the issue, several steps can be taken:
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Wiring Check: Thoroughly inspect the wiring and connections for the right main beam headlight to address the “Open Circuit” DTC. This involves tracing the wiring harness, checking for breaks, loose connections, and proper grounding.
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Module Compatibility: Verify the compatibility of the new headlights with the 2017 Audi A3’s electrical system. Consult the vehicle’s documentation or a qualified Audi technician to ensure the correct headlight assemblies are installed.
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Range Control Module Coding: Investigate the coding of the hex55 range control module. If possible, compare the coding with a known working module or try extracting the long coding string from the original hex55 module (if available) to generate an adaptation map (admap). This comparison can help identify any discrepancies in coding that might be causing the headlight malfunction. Replicating the correct coding in the new module may resolve the issue.
Seeking Expert Advice
While these steps can help pinpoint the problem, consulting with experienced Audi technicians or knowledgeable members of online forums specializing in VCDS diagnostics is highly recommended. They may offer more specific guidance based on the provided DTCs and vehicle information. Expert advice can prove invaluable in resolving complex electrical issues like this.
Conclusion
Resolving headlight problems in a 2017 Audi A3 requires a systematic approach using VCDS to identify and interpret fault codes. By focusing on the identified DTCs, checking wiring, verifying headlight compatibility, and investigating the coding of related modules like the hex55 range control module, a solution can be found. Remember to consult with expert resources for further assistance if needed. A properly functioning headlight system is crucial for safety, ensuring optimal visibility during nighttime driving.
