A 2009 Volkswagen Golf MK6 experienced intermittent lighting failures, triggering multiple warning messages upon startup. While the issue seemed to resolve itself after a few hours, the underlying cause remained unknown. This article details troubleshooting steps taken using VCDS Lite on Windows 10 to diagnose the problem on this MK6 Golf.
Initial Symptoms and Troubleshooting
The vehicle initially displayed a series of lighting failure messages, with exterior lights malfunctioning erratically. Hours later, the errors reduced to a single legitimate blown rear indicator bulb. Replacing the bulb temporarily fixed the problem. However, the issue resurfaced later, this time without any faulty bulbs.
Initial troubleshooting included checking the continuity of all fuses in both the cabin and engine bay fuse boxes. All fuses tested fine. The vehicle is well-maintained, garaged, and free from rust or corrosion. Modifications include a genuine VW trailer module, CarPlay head unit, and reversing camera, all installed prior to the onset of the problem.
VCDS Lite Scan Results
A full vehicle scan was performed using VCDS Lite version 23.11.0.0 (x64) on a Windows 10 x64 system. The scan revealed fault codes in several modules:
- 08-Auto HVAC: Malfunction 0010
- 09-Cent. Elect.: Malfunction 0010
- 56-Radio: Malfunction 0010
- 69-Trailer: Malfunction 0010
Further investigation into each module revealed the following specific fault codes:
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Address 08 – Auto HVAC:
- 9472881 – Motor for Fresh Air / Recirculated Air Flap (B108B 71): Actuator Stuck Intermittent. This fault likely unrelated to the lighting issue.
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Address 09 – Cent. Elect.: Numerous fault codes related to various lights, including low beams, tail lights, parking lights, high beams, license plate lights, fog lamps, the 3rd brake light, daytime running lights, brake lights, and backup lights. All faults indicated an open or short to positive connection and were intermittent.
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Address 56 – Radio:
- 00856 – Radio Antenna (011): Open Circuit – Intermittent. This is also likely unrelated to the main lighting issue.
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Address 69 – Trailer:
- 16355 – Control Module – Watchdog Timer (014): Defective. This could potentially be related to the electrical issues, warranting further investigation.
Conclusion and Next Steps
The VCDS Lite scan pointed to a significant number of intermittent electrical faults within the Central Electronics module (Address 09). While a single blown bulb was previously found, the recurring nature of the problem and the widespread fault codes suggest a more complex underlying issue. The “Open or Short to Plus” nature of the faults indicates a potential wiring harness problem, a faulty ground connection, or possibly an issue within the Central Electronics module itself.
The next steps would involve a thorough visual inspection of the wiring harness related to the affected circuits, paying close attention to connectors and areas prone to chafing or damage. Checking ground connections for tightness and corrosion is also crucial. Finally, further diagnostic testing may be required to pinpoint the exact location and cause of the intermittent electrical faults, focusing on the Central Electronics module and the trailer module, considering the watchdog timer error. Addressing the fault codes in a systematic manner, starting with the most prevalent ones, is recommended.
