RS3 Multiple Electrical Failures Linked to Voltage System

Had the same symptoms on a 2014 S3 with 98k km. The unusual electrical failures and starting problems pointed to alternator failure, which was causing voltage spikes across multiple systems. The car ECU kept throwing overvoltage codes, similar to your situation. The voltage regulator inside the alternator was failing, sending inconsistent power to the car battery and electrical systems. This caused cascading issues where various control modules would shut down to protect themselves from damage. The repair required: Complete alternator replacement, New car battery (the old one was damaged from voltage fluctuations), Full diagnostic scan to clear fault codes, Testing electrical system operation This was a serious issue that needed immediate attention to prevent damage to other electrical components. The erratic voltage could have potentially damaged expensive control modules if left unchecked. Key warning signs were: Multiple electrical system failures, Battery warning light, Inconsistent starting, Unusual activation of dash warning lights Would suggest getting it checked soon, as driving with a failing voltage regulator can lead to being stranded when the alternator completely fails.

Thanks for sharing your experience. That definitely sounds like what Im dealing with, especially the unusual failures and warning lights. Relieved to hear you got it sorted. Kind of worried about the extent of damage to my electrical systems from these voltage issues. Did you keep track of the repair costs? Just want to budget properly before taking it in. Also curious if youve had any car electronics problems since the alternator replacement?

Good news, since fixing my car electronics issues, everything has been running perfectly. The overvoltage detected warnings completely disappeared after the repair. My mechanic confirmed the root cause was exactly what I suspected, a failing alternator causing havoc with the electrical system. The total repair came to 290 Euro, which covered replacing the heavily discharged battery that was damaged from the voltage fluctuations. This was actually less than I initially paid, as my first repair attempt elsewhere didn't properly diagnose the circuit protection problems. All electrical components are now working as they should. No more unusual system failures or starting issues. The car battery holds charge perfectly and the voltage stays steady. It's been several months of trouble-free driving since the fix. If your symptoms match what I experienced, getting it addressed quickly is important to prevent further electrical issues from developing. High voltage problems tend to cascade if left unchecked.

Following your repair suggestions, I visited a certified mechanic last week. The diagnosis confirmed your suspicions, my alternator was indeed failing and causing all those circuit protection issues. The car ECU showed the same overvoltage codes you mentioned. The repair bill came to 350 Euro for parts and labor. They replaced the alternator and installed a new car battery since the old one was damaged from the power surges. The high voltage spikes had also fried a small control module that needed replacement. After a week of driving, the car runs perfectly. No more warning lights, all electrical systems work normally, and it starts right up every time. Really glad I caught this before it caused more extensive damage to the electronics. Definitely learned my lesson about addressing electrical issues promptly. The first mechanic I visited missed the root cause completely, which just led to more problems and costs in the long run. Worth every cent to have it properly diagnosed and fixed this time around.